Two significant heatwaves resulted in “very strong heat stress” across large swatches of southern and western Europe, including the olive oil-producing countries of France, Portugal and Spain.

Copernicus reported that Portugal, the world’s sixth-largest olive oil producer, experienced “extreme heat stress” in June, with feels-like temperatures reaching 48 ºC. Meanwhile, neighboring Spain, the world’s largest producer, faced its hottest June in 64 years.

“June 2025 saw an exceptional heatwave impact large parts of western Europe, with much of the region experiencing very strong heat stress,” said Samantha Burgess, the strategic lead for climate at the European Center for Medium-Range Weather Forecasts.

“This heatwave was made more intense by record sea surface temperatures in the western Mediterranean,” she added. “In a warming world, heatwaves are likely to become more frequent, more intense and impact more people across Europe.”

According to data from Copernicus, Europe is the fastest-warming continent, with average temperatures rising at twice the global average. 

The service attributed faster warming in Europe to shifting weather patterns that bring more frequent heatwaves, reduced air pollution allowing more solar radiation to reach the surface and its proximity to the rapidly warming Arctic.

The current heatwaves have come at a delicate moment for olive growers in the three countries, which combined to produce an estimated 1.6 million metric tons in the 2024/25 crop year, accounting for 47 percent of total global production.

However, Juan Vilar, the chief executive of the Jaén-based olive oil consultancy Vilcon, said this year’s extreme temperatures have not impacted the olive groves as severely as the intensely hot and dry conditions in 2022 and 2023, which resulted in two historically low harvests.

“To be clear: heat does affect olive trees, but it usually doesn’t have much impact, except when it comes with wind,” Vilar said. “Despite the heat waves, I’ve been out visiting the olive groves, and so far I haven’t seen any serious effects.”

“Also, rainfall has been plentiful and the soil still retains some moisture,” he added. “So, while [the extreme temperatures are] not ideal, it hasn’t had a dramatic effect on the upcoming harvest yet. If this were combined with a series of other negative factors, it could have harmful consequences, but for now, that hasn’t happened.”

While noting that abundant winter rainfall has replenished aquifers and will enable irrigated olive groves — which account for 30 percent of the country’s total — to water as needed, Vilar warned that a prolonged summer of extreme heat could still reduce the harvest.

“After a certain point, the olive tree protects itself. To enter this self-defense mode, it drops the olives,” Vilar said. “This would lead to a lower national olive yield, which would have a negative impact on olive oil production.”

• Copernicus

At the heart of the workshop was a critical issue: how to safeguard the future of the olive tree in a world increasingly defined by drought, heatwaves and pathogens.

According to an IOC note, the three-day event held in Rende, Calabria, marked a significant step forward in the olive sector’s efforts to build resilience against climate change.

More than 25 delegations from olive-growing countries participated in the event, organized in collaboration with Italy’s National Research Center for Olive, Fruit and Citrus Crops (Crea Ofa), and Ciheam Zaragoza, the Mediterranean agronomic institute based in Spain.

According to the IOC, key experts and institutions in olive genetics, plant breeding, and agricultural policy have strengthened their cooperation in defining new mitigation strategies, studying the impacts of climate change, and identifying and producing resilient genotypes.

Participants included IOC deputy executive director Abderraouf Laajimi, scientists from Italy’s National Research Council, olive producers and industry representatives, national and regional officials, and delegates from the United Nations Food and Agriculture Organization (FAO).

Enzo Perri, director of Crea Ofa, said the core objective of the workshop was to connect and coordinate the world’s most crucial olive germplasm collections.

“The idea is to create a network of all major collections recognized by the IOC and national governments,” Perri told Olive Oil Times. “Not just for cataloguing purposes, but to build a true international infrastructure for research and knowledge sharing.”

Germplasm banks are living libraries of genetic diversity. They are essential resources at a time when changing environmental conditions are putting a strain on olive trees that once thrived in the Mediterranean climate.

Rising temperatures, erratic rainfall and declining winter chill hours are becoming common across many Mediterranean regions, threatening flowering and fruit set.

In southern Italy, parts of Greece and Tunisia, among other regions, harvests have declined sharply as key climatic triggers for olive development fail to materialize.

“Drought is only part of the story,” Perri said. “We are also seeing problems caused by insufficient winter chill. Many olive cultivars require a cold dormancy period to flower properly in spring. Without it, productivity collapses.”

Adding to this is the rising threat of pathogens, particularly the bacterium Xylella fastidiosa, which has devastated olive groves in Puglia.

One of Crea Ofa’s most ambitious projects is an open-field experimental site in the heart of the infected area, where more than 250 olive varieties are cultivated side by side to assess their response to the disease.

“It’s a real living laboratory,” Perri said. “And it gives us a chance to test our assumptions under extreme environmental pressure.”

In his remarks, Laajimi stressed the strategic importance of conserving olive genetic resources as a key tool for adapting to climate change and preventing genetic erosion.

Genetic erosion poses a growing threat to the future of olive cultivation. As traditional varieties are lost and replaced by a small number of high-yield cultivars, the genetic diversity crucial for resilience is disappearing.

This loss might undermine the ability to adapt to climate change, fight emerging pests and diseases and secure long-term sustainability.

According to the experts in Rende, preserving this biodiversity is essential for breeding new, climate-resilient cultivars and maintaining the cultural and agricultural heritage of olive farming across the Mediterranean and beyond.

Participants at the Rende workshop also saw the event as a call to rethink how countries collaborate or fail to do so.

“Spain has spent the last 30 years continuously investing in olive breeding programs, developing new varieties for super-intensive systems and disease resistance. Italy, by contrast, has remained largely static since the 1970s. We’ve lost momentum,” Perri said.

One notable exception is the Lecciana cultivar, a hybrid developed by Apulian professor Salvatore Camposeo in collaboration with researchers from Catalonia.

The result of a carefully planned crossing program, Lecciana has demonstrated strong adaptability and resilience, making it suitable for both traditional and intensive cultivation.

“This proves that targeted genetic work can deliver practical results,” Perri said. “But it shouldn’t be the exception, it should be the norm.”

Perri warned that Italy’s research infrastructure needs a renewed and coordinated national strategy. As an example, he noted that there are currently fewer than 30 researchers in the country specializing in olive genetics.

In an era of climate change, Perri argued, the scientifically sound use of resources in the Mediterranean basin is critical. Water and irrigation are central to this effort.

“In traditional narratives, olives are often described as drought-tolerant crops. But that’s only true to a point,” he said.

In increasingly arid regions such as the Ionian coasts of Calabria and Sicily, months may pass without rainfall.

Under such conditions, trees may flower but never set fruit, or olives may form and then fall prematurely. Similar problems are being reported across many Mediterranean regions.

“Emergency irrigation is no longer optional,” Perri warned. “Without it, many growers will have no harvest at all. And that’s not just a local issue, it’s a systemic one.”

Investing in modern, efficient irrigation systems is now crucial, not only in industrialized super-intensive groves but across the board.

“It’s needed to maintain baseline productivity and fruit quality, and therefore the quality of the olive oil,” Perri said.

“Our goal is not just to increase yields or resist disease. It’s to preserve and enhance the nutritional and sensory quality of olive oil,” he added. “That’s what gives our work meaning. Not just surviving the crisis, but producing olive oils that are healthier, tastier and more sustainable.”

Research and collaboration toward sustainable goals are already delivering significant impacts, particularly in the use of olive milling by-products.

“Olive mill wastewater, once seen as an environmental problem, is now being studied for its high content of polyphenols and antioxidants,” Perri said. “We’re realizing that the olive tree fits perfectly into a circular economy model. Nothing has to be wasted.”

Today, olive genetics research spans three main areas. The first involves exploring and conserving lesser-known local varieties that may carry traits functional for future breeding.

Second, the development of new resilient cultivars through controlled hybridization, such as the Lecciana. Third, the long-term potential of biotechnologies, particularly new genomic techniques.

Italy has already sequenced the full genome of the Leccino cultivar, a key step forward. However, applying gene editing remains difficult due to the olive tree’s resistance to in vitro regeneration.

“We’re not ready yet, but we will be,” Perri said. “And when we are, we’ll have new tools to accelerate the species’ improvement.”

According to Perri, the presence of an international institution such as the FAO at the Rende workshop reflects the olive tree’s global relevance as both an economic and nutritional resource for countries in North Africa, Latin America and Asia.

“FAO sees olive oil as part of the solution,” Perri explained. “It’s rich in polyphenols, vitamin E and healthy fats. It fits into sustainable diets and can support smallholder farmers. That’s why FAO strongly supports projects like this.”

For Italy, the stakes are particularly high. Despite soaring prices on international markets, many small and medium growers are struggling.

“They simply don’t have the capital to modernize,” Perri said. “We need targeted public investment in mechanization, water infrastructure and training. Without it, our olive sector will continue to decline.”

The study, conducted in Tunisia under semi-arid conditions, analyzed the Chemlali, Chetoui, Koroneiki, Meski and Picholine cultivars. 

Researchers assessed traits such as branching patterns, density, distribution of inflorescence (a group or cluster of flowers arranged on a plant’s stem, composed of a main branch or a system of branches) and fruit sites, as well as shoot length and shoot dimensions.

They believe that so-called “architectural” analysis can inform key decisions about cultivar selection, orchard layout, pruning and harvest, as well as sustainable olive production when combined with sensor and data technology.

Branching density and shoot length varied significantly among cultivars. Koroneiki had the longest average shoot length (33.5 centimeters), while Chetoui had the shortest (22.2 centimeters).

Chemlali and Koroneiki exhibited high shoot densities with thin, compact branches. These traits may lend themselves to mechanized pruning and harvesting due to their structural uniformity, and are often desirable in dense systems that require high canopy fill. 

Chetoui, with a greater share of long shoots, displayed more vertical, less compact growth. This combination could offer better manual accessibility for traditional or mixed-use groves.

Shoot length also varied by branching order: the hierarchical position of a shoot or branch within the tree’s shoot system, based on its sequence of emergence from previous growth units.

Longer shoots were generally found in secondary branching and became shorter in higher branching orders. Internode numbers followed a similar pattern, with the highest counts in secondary branching and the lowest in senary (pertaining to six) branching.

Basal diameter and apex thickness also decreased with increasing branching order. In addition, thinner shoots were often associated with higher inflorescence and fruit yield in Chemlali and Koroneiki. 

This suggests that lower vegetative vigor may correspond to increased reproductive output, a possible advantage in intensive groves.

Fruit production followed distinct patterns. Chemlali, Chetoui and Picholine produced inflorescences and fruits in the same branching orders, indicating a synchronized reproductive structure. 

Meski and Koroneiki, however, produced fruits in different branching orders from their inflorescences, suggesting a delayed or redistributed fruiting process.

Recognizing where each cultivar focuses reproductive effort can allow for more efficient fruit thinning and targeted pruning. 

Cultivars with mismatched flowering and fruiting zones may need different pruning strategies or support to boost fruit retention, as well as adjusted planting densities. As cultivars with coordinated flowering and fruiting are easier to manage, they may be particularly suited to mechanized harvesting.

Branch insertion angles were found to influence shoot orientation and canopy structure. Shoot angle also affects light interception and pest exposure, both of which are important factors in integrated pest management strategies.

Angles ranged from 30 to 90 degrees, depending on the cultivar and branching order.

Secondary or tertiary branching shoots often formed 90-degree angles, while quinary and senary branching shoots had narrower angles. Chemlali and Koroneiki had a greater number of 90-degree angles, promoting lateral canopy expansion.

Meski, Chetoui and Koroneiki showed similar insertion angle patterns, suggesting inter-cultivar compatibility for shared orchard layouts. This uniformity could simplify pruning and mechanized harvesting.

Generally, similar branching geometries among cultivars support co-planting in mixed groves.

Uniform insertion angles can also simplify mechanical operations and facilitate more consistent light distribution, a conclusion echoed in a recent study using uncrewed aerial vehicles that links canopy shape with light interception and yield.

While acknowledging that the direct applications of their work are still being explored, the researchers believe that their methods and findings can serve as valuable tools in several key fields related to the olive industry. These include genetics and breeding, agronomy, engineering, pathology and entomology.

Although architecture alone does not predict yield, it can inform key decisions in areas such as cultivar selection, orchard layout, pruning and harvest. 

When combined with modern sensing tools, such as uncrewed aerial vehicles-based multispectral imaging, it may prove immensely beneficial to the development of data-driven, sustainable olive production.

The olive oil industry generates a substantial amount of wastewater, with estimates exceeding 30 billion liters per annum worldwide. 

This water is a potent and problematic pollutant, characterized by high salinity and electrical conductivity, as well as high acidity and large quantities of organic and phenolic compounds.

These characteristics make it harmful to soil microbes, aquatic life and long-term soil health. Phenolic compounds, in particular, contribute to the wastewater’s resistance to treatment, inhibiting microbial growth.

The vast majority of olive mill wastewater is currently disposed of in one of two ways. The first is via evaporation ponds, which lead to increased air pollution due to the release of harmful and acidic gases such as methane and hydrogen sulfide, and both soil and groundwater contamination due to leaching.

The second is via its use as an organic fertilizer on agricultural land. However, there is also growing concern about this practice. 

Studies have shown that prolonged and repeated land application leads to the accumulation of phenolic compounds, salts and heavy metals in soils, reduced microbial diversity and activity, widespread impacts on wildlife and the eventual sterilization and desertification of land.

Several microbial organisms have been proposed as candidates for treating olive mill wastewater. Of these, the researchers believe that Yarrowia lipolytica stands out, not only due to its ability to thrive in nutrient-poor, acidic, phenolic-rich environments, but also because of the range of valuable substances it can produce.

Among other compounds, the yeast can synthesize lipases, important in sectors such as food processing, pharmaceuticals and biofuels; citric acid, used in industries as diverse as detergent manufacturing, electroplating and leather tanning; and polyols, including mannitol, erythritol and arabitol, which have applications in products such as low-calorie sweeteners and humectants.

The yeast also synthesizes single-cell oils, rich in oleic and linoleic acids, which are suitable for use as biodiesel or as nutritional supplements. 

By modulating culture conditions such as oxygen levels, pH and carbon source, production can be tailored to different end uses. The resulting lipid profiles can even mimic cocoa butter or serve as precursors for ricinoleic acid derivatives with diverse applications.

The research team emphasizes that these capabilities mean the process of wastewater treatment can contribute to the move towards a circular economy within the olive oil industry, a move supported not only by the scientific community but also by national and supranational government bodies, such as the European Union.

Despite its promise, the widespread deployment of Y. lipolytica for olive mill wastewater treatment and valorization faces several obstacles. 

Wastewater composition is highly variable, influenced by factors such as olive variety, extraction method and seasonal conditions, among others. This variability complicates process standardization and performance.

In addition, compounds, particularly phenolics and salts, can reduce microbial activity or product yields. While some strains tolerate these conditions, others require dilution, pre-treatment or supplementation to maintain efficiency.

Economic factors also pose barriers. Although Y. lipolytica can grow in non-sterile, low-cost media, large-scale operations require systems with high-energy stages, downstream processing and market access for bio-based products.

However, the researchers believe that with sufficient research focused on key areas, the yeast represents an economically viable way to unlock the potential of olive mill wastewater whilst safely removing it from the environment. 

They point to proof-of-concept studies and a considerable body of existing literature to support this view.

• Environmental Science and Pollution Research
• Journal of Analytical Sciences and Applied Biotechnology

With cement production being a major contributor to global carbon dioxide emissions, the research aims to reduce the environmental impacts of the industry.

Published in a special issue of the journal Materials, the study assesses how combining pomace ash affects the physical, mechanical and durability properties of mortar to determine its suitability for large-scale use.

Olive pomace ash is derived from incinerated olive pomace (residual olive skins, pulp and pits). When ground, the resulting powder contains significant amounts of carbon dioxide, silica and lime. 

Compared to ordinary Portland cement, its lighter weight and finer particle size influence mortar characteristics such as density and workability (the ease with which mortar can be mixed, placed and compacted).

Mortar samples were created by substituting Portland cement with pomace ash in ten percent increments up to 50 percent. 

Each mix underwent tests for flowability (the ability of the mix to flow and spread into place when poured), strength, water absorption, and resistance to freeze–thaw cycles over periods of seven, 28, and 90 days.

The researchers found that the workability and flowability of the mortar decreased as pomace ash levels increased. 

At levels of up to ten percent, mortar samples exhibited minimal changes in both wet bulk density and flow time, indicating their suitability for practical applications.

Between ten and 20 percent, the mixtures became harder to work with, but maintained acceptable flow. Beyond 20 percent, flow rates were drastically affected.

Both compressive and flexural strength tests yielded similar results, with pomace levels of up to 20 percent exhibiting reduced strength, but remaining within the acceptable range for structural mortars. 

The researchers noted that strength continued to increase over 90 days, consistent with the activity of pozzolanic reactions—the chemical processes by which certain materials, such as ashes, react with water and cement to form binding compounds that enhance the strength and durability of concrete over time.

Freeze-thaw resistance tests further confirmed the 20 percent limit for pomace ash levels. Beyond this threshold, mixtures exhibited substantial vulnerability.

Water absorption, which can lead to durability-related damage and performance degradation, increased in samples with pomace ash levels above ten percent. 

All samples exhibited a maximum absorption of 6.92 percent, which is well within the ten to 15 percent range deemed acceptable for adequate long-term performance.

Interestingly, the ten percent mixture showed slightly lower absorption than the ordinary Portland cement control mixture. This was attributed to the fine ash particles filling voids and otherwise refining the mixture’s pore structure.

An environmental analysis compared the energy usage and carbon dioxide emissions of pomace ash mortar production to those of the control mix, which is made entirely of ordinary Portland cement. 

Carbon dioxide emissions were calculated based on electricity generation in Algeria, where the study was conducted.

Production of the control mix consumed 1,000 kilowatt-hours per ton (kWh/t) and emitted 500 kilograms of carbon dioxide per ton (kg CO2/ton). 

In contrast, production of the ten percent pomace ash mix consumed 953.5 kWh/t and produced 476.75 kg CO2/t, while that of the 20 percent mix consumed 907 kWh/t and produced 453.5 kg CO2/t.

The authors conclude that the ten and 20 percent mixtures are associated with a meaningful decrease in environmental impact while maintaining acceptable mechanical performance, supporting their candidacy as environmentally friendly construction materials. 

They believe, however, that further study is needed to examine the long-term durability, microstructural behavior and performance in real-world settings. 

They also note that broader adoption would require such materials to be incorporated into updated building codes and specifications.

The International Symposium on Olive Oils of Croatia and the Adriatic Coast is organized by Olive Oil Times in collaboration with the Postira Tourist Board. The patron is the Ministry of Tourism and Sports of the Republic of Croatia. Sponsors of the event include Split-Dalmatia County, the Croatian National Tourist Board, the Split-Dalmatia County Tourist Board, the Municipality of Postira, and Jadran Crikvenica d.d.

The symposium will highlight the region’s unwavering commitment to excellence in olive cultivation and production. It begins on Tuesday, September 16, with a welcome reception hosted by Olive Oil Times editor-in-chief Curtis Cord and Croatia’s Minister of Tourism and Sport, Tonči Glavina. Over the next two days, attendees will engage in a thoughtfully curated program featuring tasting instruction, professional workshops, guided farm visits, expert presentations, and live culinary demonstrations.

Leading instructors and industry experts will explore topics such as premium brand development, sustainable farming practices, and the impact of climate change on olive oil production. Attendees will also enjoy immersive excursions into the olive groves of Brač and gain a firsthand appreciation of the island’s rich agricultural and gastronomic traditions.

The gathering will conclude with a festive closing ceremony honoring producers of excellence and celebrating the Adriatic region’s growing prominence in the world of extra virgin olive oil.

Located on the northern coast of Brač, Postira is a small fishing village with deep agricultural roots and a long-standing connection to olive cultivation. Its surrounding hillsides are lined with centuries-old groves, stone terraces, and traditional architecture that reflect the island’s enduring relationship with the land.

Brač, one of the largest islands in the Adriatic Sea, has long played a central role in Croatia’s olive oil heritage. Its rugged terrain and favorable climate have made it ideal for olive growing, and today the island produces some of the country’s most distinctive extra virgin olive oils.

Fittingly, Postira also hosts the annual World Championship of Olive Picking, a spirited event that honors the region’s traditions and communal ties to the harvest.

By hosting the symposium in Postira, organizers underscore the importance of place in the story of Croatian olive oil — a story shaped by generations of local producers and the unique character of the Dalmatian coast. The symposium will offer a rare opportunity for international collaboration and knowledge sharing in a historic olive-growing region.

Registration is now open at postira.oliveoiltimes.com. Due to limited capacity, early booking is encouraged.

The WMO forecasts that annual average global surface temperatures for each year between 2025 and 2029 may rise between 1.2°C and 1.9°C above the average from 1850 to 1900.

The report further anticipated that there is an 80 percent chance that one of the next five years will surpass 2024 as the hottest year on record, and an 86 percent chance that at least one year will exceed 1.5°C above the pre-industrial level.

Scientists from Copernicus, the Earth observation unit of the European Union’s space program, confirmed in January that average global surface temperatures reached 1.6ºC above pre-industrial levels in 2024.

Climate scientists have warned that multiple tipping points are likely to be triggered by 1.5°C of warming, including the collapse of ice sheets, changes to ocean currents, biodiversity loss, and the melting of permafrost. 

“These very latest predictions suggest we are very close now to having 1.5ºC years commonplace,” said Adam Scaife, the head of long-range forecasting at the Met Office, the United Kingdom’s national weather and climate service.

“We’ve had one in 2024, but they’re increasing in frequency, and we are going to see more of these,” he added. “These are shocking statistics, and there is even a chance now, and it’s the first time we’ve ever seen such an event in our computer predictions, of a 2ºC year, which would be completely unprecedented.”

The WMO warned that every degree of warming fuels heatwaves, torrential rainfall events, intense droughts, the melting of ice and glaciers, ocean heating and rising sea levels.

Heatwaves in the southern Spanish region of Andalusia in May 2022 and 2023 were mostly responsible for back-to-back historically poor harvests in the world’s most prolific olive oil-producing region, contributing to record-high olive oil prices of the previous few years.

The WMO further anticipated that the Arctic, which reached a record-high temperature of 38 ºC in 2020, would warm three and a half times faster than the global average over the next five years, accompanied by significant sea ice melt in adjacent seas. 

A separate report published in April by the Copernicus Climate Change Service found that Europe is warming at a faster rate than the global average. 

“This report highlights that Europe is the fastest-warming continent and is experiencing serious impacts from extreme weather and climate change,” WMO Secretary-General Celeste Saulo said.

The WMO also forecasted increased summer precipitation in some regions, including the Sahel, northern Europe, Alaska and northern Siberia, along with drier conditions in the Amazon basin.

“We have just experienced the ten warmest years on record,” said Ko Barrett, the WMO deputy secretary-general. “Unfortunately, this WMO report provides no sign of respite over the coming years, and this means that there will be a growing negative impact on our economies, our daily lives, our ecosystems and our planet,” 

“Continued climate monitoring and prediction is essential to provide decision-makers with science-based tools and information to help us adapt,” she added.

The study, published in Fermentation, builds on research presented in 2022 at the XVII Argentine Congress of General Microbiology.

The strain in question, Rhodococcus sp. 24CO, efficiently converts various carbon sources to neutral lipids, especially triacylglycerols, accumulating up to 47 percent of its biomass as the dietary lipid. 

Microbial triacylglycerol synthesis has received significant attention recently due to its potential for producing sustainable high-value products from waste materials. Such products include biofuels, detergents, fertilizers, cosmetics and pharmaceutical components.

Rhodococcus sp. 24CO, was isolated from the leaves of Frantoio cultivars on the eastern coast of southern Patagonia. Many Rhodococcus species are known for their capacity for mitigating persistent and dangerous pollution such as pesticides, herbicides and radioactive material, as well as their ability to convert cheap substrate into more valuable compounds.

To assess the strain’s properties and capabilities, the researchers subjected it to various tests.

When cultured, 24CO could grow on four of the 50 carbon sources tested, including fructose, mannitol, sorbitol and arabitol. The first two, naturally present in olive leaves, led to triacylglycerol accumulations of up to 47 percent and 28 percent of cellular dry weight, respectively.

High neutral lipid production from mannitol also occurred in nitrogen, which the authors believe to be previously unreported behavior and industrially relevant since it implies that the strain would produce a high biomass and, simultaneously, high quantities of triacylglycerols.

Chemical analysis of fresh and dewatered leaf extracts of olive pruning waste revealed high carbon-to-nitrogen ratios, indicating its suitability for lipid production. 

Further cultures supported this, yielding more than 20 percent of cell dry weight as neutral lipids with the dewatered infusion and eight percent with the fresh infusion. Triacylglycerols produced with the former resembled those from mannitol cultivation.

In addition, both cultures detected small amounts of polyhydroxybutyrate, a polymer of interest for biodegradable plastic production. Genome analysis of Rhodococcus sp. 24CO confirmed its potential for synthesizing these polymers.

Analysis further revealed significant genetic differences between 24CO and Rhodococcus sp. RHA1, one of the best-studied members of the genus. 24CO lacked several genes linked to redox and nitrogen metabolism present in RHA1, which are typically activated under lipid-producing conditions. The absence of these genes did not appear to hinder 24CO’s lipid accumulation, suggesting alternative regulatory mechanisms.

Although 24CO was found to possess fewer wax ester enzymes than RHA1, its lipid yields were equal to or superior to those of the former. This suggests that the enzymes responsible for triacylglycerol biosynthesis in this strain may be more efficient. Kennedy pathway enzymes were fully present, however, and had high redundancy.

After assessing suitable environmental conditions for the species, the researchers concluded that it could survive and reproduce between 4 °C and 30 °C, with an optimal temperature of 28 °C. 

Salinity and pH experiments showed that it could tolerate up to five percent weight per volume of sodium chloride with a pH value from six to ten, or slightly acidic to basic. 

The authors also note that leaf surfaces in Patagonia represent a harsh environment, subject to high ultraviolet radiation, low nutrient levels and desiccation.

Although many initiatives aimed at reducing and reusing olive waste are underway, most olive pruning waste is still burned. 

In Spain alone, approximately 1.25 million metric tons of leaves are generated from pruning annually. The researchers believe that Rhodococcus sp. 24CO is a viable candidate for transforming this enormous biomass into sustainable and valuable products, primarily via triacylglycerol biosynthesis.

• Conicet
• Microbiology

The USDA Foreign Agriculture Service economists predict that olive oil production will fall to 3.016 million metric tons in 2024/25 from the 3.331 million tons in 2024/25.

The USDA anticipated European Union olive oil production to fall to 1.98 million tons in 2025/26 from 2.079 million tons in the previous crop year. 

Olive oil production in Turkey is also expected to fall to 275,000 tons from the record-high 450,000 tons in 2024/25. 

A separate USDA report published in March forecasted Tunisian olive oil production to sink to 200,000 tons, “reflecting the alternating high fruit bearing cycle which had high production [340,000 tons] in 2024/25.” 

The agriculture department added that production in the rest of the world is also likely to decline. 

The USDA’s production forecasts are based on a combination of market intelligence, cyclical and historical trend data and weather assumptions, which the agency updates in its monthly oilseed markets and trade report.

However, producers in Spain said that conditions have thus far been ideal, leading up to the 2025/26 crop year. Still, the coming months will be critical to determine how well abundant flowering converts into a significant fruit set.

“We are having a year with very good weather,” Álvaro Olavarría, the manager of Andalusian cooperative Oleoestepa, told Agropoular. “We are at a critical stage of flowering, very advanced in some areas, even with fruit set, and therefore, the overall harvest outlook in Spain is very good for the 2025/26 season.”

According to one large bottling company, olive oil production in Spain could reach 1.6 million tons under ideal conditions. Other producers across Spain have told Olive Oil Times that they expect another good harvest in 2025/26.

“We’ve had a rainy winter, and spring is also bringing us very good rain. For now, everything points to the 2025/26 season being better than the 2024/25 season,” said Rosa López, the company director of Aires de Jaén. “Even so, we must wait because we are always exposed to adverse weather conditions.”

“We anticipate a very good harvest in terms of quantity and quality, considering the current condition of the olive trees,” added Luís Rubio, the export manager of Castilla-La Mancha-based Olivapalacios. 

Outside of Spain, Olavarría said current conditions also point to “very good harvest prospects for Tunisia next year,” in contrast to the USDA’s forecast. 

Yahya Chemli, co-founder of Olyfo, which has 300 hectares of olive groves in northern and eastern Tunisia, sees signs that the harvest could be fruitful.

“It’s too early to make predictions, but we’ve had good rainfall recently, and the flowering season is going well,” he said. “It gives us hope for a strong harvest, but we’re watching closely.”

Olavarría added that he expects Portigal to “repeat and slightly improve this year’s production. Greece is also expecting a very good harvest next season.”

Producers in Portugal have told Olive Oil Times that the conditions in the olive groves have been excellent, including mild temperatures and plenty of rain. However, the next few months are critical. 

“The weather forecast shows mild temperatures for the coming weeks, and conditions look ideal for an adequate fruit set,” said Alberto Serralha, the chief executive of Sociedade Agrícola Ouro Vegetal in central Portugal. “Our reservoirs are overflowing, so there won’t be a lack of water for irrigation this year.”

• USDA
• Agropopular

Researchers from the Sapienza University of Rome and the Italian National Agency for New Technologies, Energy and Sustainable Economic Development identified pectin-derived oligogalacturonides with a degree of polymerization between ten and 17 in the olive mill wastewater.

Oligogalacturonides trigger a plant’s immune system via the cell wall, activating defence responses and resistance against some pathogens. The molecules had not previously been separated from olive mill wastewater.

Using transgenic Arabidopsis seedlings, the researchers confirmed that the extracted oligogalacturonides triggered the expected defense responses, including increased calcium ions, which are intracellular messengers critical in plant defense signaling pathways. 

The study is part of researchers’ ongoing efforts to add value to olive oil production byproducts, especially olive mill wastewater. An estimated 30 billion liters of wastewater are produced annually by olive mills in the Mediterranean basin.

While olive pomace byproducts are considered easy to recycle, they are widely used in the food industry, producing olive pomace oil and renewable energy. Olive mill wastewater presents more challenges.

The wastewater is highly acidic with high concentrations of recalcitrant chemical substances, including lignins and tannins, which require significant amounts of oxygen to biodegrade.

Therefore, olive mill wastewater is considered a significant environmental pollutant, with most countries prohibiting it from being dumped without being treated.

“On the other hand, olive mill wastewater contains a wide range of valuable phenolic compounds with proven antimicrobial properties (e.g., flavonoids, hydroxytryrosol, oleuropein) and olive mill wastewater by-products are effective as biopesticides against different microbial pathogens,” the researchers wrote.

“However, the effect of this liquid waste as a plant elicitor of defense responses has not yet been investigated,” they added.

Using tangential-flow membrane filtration, the researchers separated the oligogalacturonides from the olive mill wastewater.

“Tangential-flow membrane filtration is a powerful tool in bioprocessing, allowing the separation and concentration of active biomolecules into specific molecular pools, such as proteins, sugars and secondary metabolites,” the researchers wrote. 

“By using complex mixtures for filtration, tangential-flow membrane filtration effectively removes impurities while retaining the desired molecules,” they added.

The researchers highlighted how the method does not require a chemical solvent and is scalable from a laboratory setting, allowing large-scale olive mills to employ it. They added that the findings could provide a new source of revenue for olive oil producers. 

Oligogalacturonides have been approved in commercial plant protection products recognized by the European Union, which has set a target to reduce synthetic pesticide use by 50 percent by 2030.

According to market research from Industry Research Reports, the global biopesticide market was valued at $6.1 (€5.6) billion in 2023 and is estimated to reach $11.5 (€10.1) billion by 2030. 

“The oligogalacturonide-enriched fraction, described in the present work, is suitable to be employed as a novel bio-pesticide, contributing to enhance both environmental and economic sustainability of the olive oil industry,” the researchers wrote. 

“We pave the way for field experiments with plants of agronomic interest for exploitation of these by-products as sustainable natural phyto-protectants in the control of pathogens causing devastating diseases of economically important crops according to a circular economy perspective in agriculture,” they added.

“In the first 24 hours after the application window opened, we received submissions from more than ten countries, covering over 1,000 hectares and all planting systems,” said Juan Antonio Polo Palomino, head of the IOC’s Olive Oil Technology and Environment Department.

The project aims to assess olive groves as natural carbon sinks.

“The Carbon Balance project is key to showcasing the sustainability of our sector,” added Lhassane Sikaoui, head of the IOC’s Olive Growing, Olive Oil Technology and Environment Unit.

As the initiative progresses, farmers will be able to increase their incomes by selling carbon credits on voluntary markets.

Carbon credits for olive groves are an emerging opportunity in sustainable agriculture.

Olive trees naturally absorb and store carbon dioxide through photosynthesis, and healthy soils—especially those managed using regenerative practices—can amplify this effect.

According to the IOC, olive groves’ carbon dioxide storage capacity is both stable and long-lasting.

“Until recently, agriculture was seen solely as a greenhouse gas emitter,” the IOC said, referencing the latest Intergovernmental Panel on Climate Change report. “However, the 2023 IPCC report recognized its potential to absorb carbon dioxide, creating new financial opportunities for sectors like olive growing.” 

By quantifying the amount of carbon an olive grove removes from the atmosphere, farmers can generate carbon credits that can be sold to companies seeking to offset their emissions.

This system provides an additional income stream and promotes more sustainable land management. However, a clear legal framework supported by robust certification and verification platforms is essential to make this system work.

“During the pilot phase, participants will be able to calculate the carbon balance of their olive grove using a free online tool, receive technical assistance, and provide feedback,” Polo Palomino explained.

“This will help us validate the tool’s usability and make any necessary improvements based on participants’ input,” he added.

Once all registrations are in, the project’s scientific team will design a broad sample to reflect different cultivation areas, olive grove types, management practices, and climate conditions.

To participate, farmers and cooperatives must provide data on their agricultural practices, such as fuel use and fertilizer applications.

“Our goal is to make the tool user-friendly, so we designed a simple interface using data that farmers already manage daily,” Polo Palomino said. “For instance, those who keep a field notebook will already have nearly all the required data.”

Participation in the pilot phase is completely free. This includes the training session and online technical support provided by the IOC.

“Once validated and released, the tool will be freely accessible to any user worldwide,” Polo Palomino said.

The IOC’s carbon balance calculator is based on the IPCC’s 2019 General Guidelines for National Greenhouse Gas Inventories.

“We adapted it to the specific characteristics of olive trees, drawing on the best available scientific knowledge and tested models to ensure maximum robustness,” Polo Palomino said.

“We also built on the IOC’s previous work, including the 2018 report on the global CO2 capture potential of olive groves and the first version of the calculator published in 2012,” he added.

Once the carbon balance is calculated, the Verra VM0042 v2.1 standard is applied to generate carbon credits.

Verra is one of the leading organizations certifying carbon credits, and VM0042 specifically focuses on improved agricultural land management.

Version 2.1 outlines how to measure, monitor, and verify carbon sequestration to ensure scientific and technical validity.

The process complies with European Union Regulation 2024/3012, establishing certification guidelines for carbon removals within the E.U.

The pilot phase includes a technical training session in June. “The session will explain in detail the flow of a voluntary carbon credit project, the criteria used in this methodology, and the tool itself through practical examples,” Polo Palomino said.

“We aim to ensure that participants can begin working with the tool right after the session,” he added.

The next phase is expected to launch in November.

“In November, once the tool is validated and results verified, we plan to release a free and accessible method that allows any olive grower, regardless of size, type, location, or management system, to calculate their carbon balance and generate voluntary carbon credits aligned with current and upcoming standards, especially the E.U.’s CRCF (Carbon Removals and Carbon Farming) framework,” Polo Palomino said.

The IOC’s ambitions go beyond offering a groundbreaking tool to the olive sector.

“Our goal is to ensure society recognizes olive groves as agro-ecosystems that, in addition to producing the best vegetable fat known to humanity, extra virgin olive oil, also provide ecosystem services that benefit human well-being, such as helping combat climate change and contributing to planetary health,” Polo Palomino said.

“In short, everyone should understand that consuming extra virgin olive oil is good for both their health and the planet,” he added.

According to the IOC, this project will make a real contribution to addressing climate change. “We begin from scientific evidence: olive groves, domesticated by agriculture, now cover 11 million hectares, mostly in the Mediterranean region,” Polo Palomino said.

“Through certain agricultural practices, we can optimize their function, improving their net CO2 balance and contributing to the U.N. goal of climate neutrality by 2050.”

Expectations around the market potential of voluntary carbon credits have grown since the latest IPCC report and the introduction of new EU regulations.

Still, the IOC urges cautious optimism. 

“These expectations are still risky, as regulatory processes are ongoing at both the standard and market levels,” Polo Palomino said. “At the IOC, we’re working hard to deliver a scientifically sound system that meets the needs of our sector.”

“The project’s first phase focuses on developing an easy-to-use carbon balance calculator for all olive sector stakeholders,” Sikaoui concluded. “As the pilot phase moves forward, we invite all operators to join in and help strengthen this vital initiative.”

“This success provides a genuine impetus for greater collaboration among our olive growers in their pursuit of exceptional extra virgin olive oils,” said Marko Ivanković, director of the Federal Agro-Mediterranean Institute (FAZ).

The Mostar-based institute has been instrumental in charting the course for modern olive cultivation in Herzegovina. Fifteen years ago, the region possessed a mere 18 hectares of olive groves. Today, that figure has surged to 521 hectares, encompassing 116,000 trees, with new plantings accelerating this growth.

FAZ serves as a hub for expertise, housing a sensory analysis panel and a food health laboratory in Buna. In addition to standard physicochemical analyses, the laboratory conducts crucial polyphenol testing of olive oils.

“Our analysis fees for local olive growers are promotional, equivalent to the price of a single liter of oil,” explains Ivanković. He emphasizes that most Herzegovinian oils boast polyphenol levels exceeding 250 mg/kg, indicating notable health-promoting properties.

A pivotal moment arrived in April 2021 with the establishment of the Herzegovina Association of Olive Growers and Oilers (HUUM). This unifying body brings together olive growers from diverse national (Croats, Serbs, and Bosniaks) and religious (Catholics, Orthodox, and Muslims) backgrounds.

The synergy between HUUM and FAZ yielded two significant achievements last year: the acquisition of a Protected Designation of Origin (PDO) and the registration of the unique “Zlatne kapi Herzegovina” (Golden Drops of Herzegovina) trademark at the Intellectual Property Institute of BiH.

Adding to these milestones, Bosnia and Herzegovina gained membership in Madrid’s International Olive Council (IOC).

These advancements paved the way for individual HUUM members to participate in the prestigious NYIOOC World Olive Oil Competition, the world’s premier olive oil quality contest.

OPG Škegro, owned by renowned winemaker and olive grower Mirko Škegro from Ljubuški (an eight-time Gold Award winnerfor his Krš brand), was joined by several fellow HUUM members. Five of them secured awards for their oils: OPG Murić (Bošnjak brand), the Orthodox Monastery Tvrdoš near Trebinje, and AgroHerc Agriculture (Mostar/Čapljina) (Narentas brand) all received gold medals.

Silvers were awarded to Pax Dol, the olive farm of the Franciscan School Sisters of Christ the King near Mostar, and Uljar Ramljak, owned by Slavko Ramljak from Tasovčić near Čapljina.

“It’s not gold, but silver feels like gold to me,” remarked Sister Dajana Dujmović, director of Pax Dol, one of the region’s northernmost olive groves. Despite a significant hailstorm that halved their expected 33-ton harvest and slightly lowered the oil yield, Sister Dajana remains optimistic: “This year, we hope for a larger harvest and even better oil.”

Podrumi Vukoje 1982 d.o.o. from Trebinje, owned by Radovan Raša Vukoje, also achieved remarkable success, securing two Gold and three Silver Awards for its single-varietal oils. These producers brought home 11 awards for Bosnia and Herzegovina, marking an extraordinary eleven-fold increase from the previous year.

“We anticipate even more awards next year,” predicts Marko Ivanković, emphasizing the unstoppable growth of olive cultivation and oil production in Herzegovina. The strategic vision includes expanding olive groves to 1,000 hectares by 2030 and establishing the “Olive Oil Roads of Herzegovina” to promote local products alongside their prized oils. This approach aligns with EU-recognized territorial development strategies aimed at revitalizing rural communities.

Ivanković stresses the importance of promoting the “Zlatne Kapi Herzegovina” brand, seeking support from local and federal entities. Plans include billboard advertising, social media engagement, and features in prominent publications such as Olive Oil Times and the Croatian magazine Maslina.

Professor Ivanković, a key figure in Herzegovina’s olive oil transformation, concludes that Bosnia and Herzegovina is increasingly solidifying its position as a rising star in the Mediterranean olive oil landscape.

A defender of the poor and marginalized, an advocate for climate action, and a promoter of inter-religious dialogue, hailed by many as a reformer, his passing prompted mourning worldwide. 

On April 26th, numerous world leaders and tens of thousands of people attended his funeral at St. Peter’s Square in the Vatican, followed by the procession to the Basilica of St. Mary Major in Rome, where he was laid to rest.

Among the many records achieved – including being the first born in the Americas – he was the first pope to choose the name Francis, like the Saint from Assisi who embraced the ideals of poverty, humility and peace.

An excerpt from the last statement he delivered on April 20th, which was read by Archbishop Diego Ravelli before he imparted the Urbi et Orbi blessing for Easter, encompasses the founding values of his pontificate. 

“How much contempt is stirred up at times towards the vulnerable, the marginalized, and migrants,” Pope Francis wrote. “On this day, I would like all of us to hope anew and to revive our trust in others, including those who are different than ourselves, or who come from distant lands, bringing unfamiliar customs, ways of life and ideas. For all of us are children of God. I would like us to renew our hope that peace is possible.”

Francis’s commitment to peace soon became very apparent. On June 9, 2014, the year after his election, he met with Israeli President Shimon Peres and Palestinian President Abu Mazen to plant an olive tree in the gardens of Vatican City and invoke peace in the Holy Land.

The two political leaders were invited during the Pope’s apostolic journey to the Middle East the previous month, when he visited Amman in Jordan, Bethlehem in Palestine and Jerusalem in Israel.

Already on that occasion, after a meeting with priests and worshippers in the Church of All Nations, also known as the Basilica of the Agony, in Jerusalem, Francis planted an olive tree in the Garden of Gethsemane. The olive tree was a cutting taken from one of the eight 1,000-year-old trees in the garden to ensure the continuity of these majestic plants’ genetic heritage.

A few weeks later, the Invocation for Peace in the Holy Land event took place in the Vatican gardens at Francis’s initiative. He welcomed both Peres and President Mazen with a long hug. Then, in front of Pope Francis, the two presidents greeted each other with a hug.

Ecumenical Patriarch Bartholomew of Constantinople was also present at the meeting, which included readings of prayers from Jewish, Catholic, and Islamic traditions. The planting of a young olive tree was the culmination of the event, sending a powerful message of peace.

On June 8, 2024, the pontiff commemorated the historic meeting on its tenth anniversary with a ceremony. In front of that olive tree, which is now grown and thriving, he prayed for peace in Palestine and Israel.

Francis made the last of countless appeals for peace in the Middle East in the aforementioned Easter statement, where he also called for peace, reconciliation, and the restoration of justice across Europe, the Middle East and Africa.

As he considered social justice deeply interconnected with climate justice, Francis was also the first Pope committed to climate action.

His second encyclical letter Laudato si’ (Praise Be to You), named after the Canticle of the Sun, also known as Canticle of the Creatures, composed by Saint Francis in 1224, is the first ever written by a Pope on the subject of the environment.

The pivotal document, subtitled “On care for our common home,” introduces the concept of “integral ecology,” emphasizing “how inseparable the bond is between concern for nature, justice for the poor, commitment to society and inner peace.”

Hence, Francis started the project Borgo Laudato Si’ in his residence at Castel Gandolfo near Rome on February 2, 2023, to promote the principles described in the encyclical.

The Borgo Laudato Si’ estate spans 55 hectares, comprising 35 hectares of gardens and 20 hectares of farmland, greenhouses and service buildings.

Olive trees are one of the seven main tree species chosen as symbols of the project, along with cedar, citron, boxwood, Cypress, holm oak and magnolia.

Based on the three tenets of integral ecology education — a circular and generative economy, and environmental sustainability — Borgo Laudato si’ hosts job training and educational courses, seminars, and cultural events. The estate is also open to visitors.

Its orchards include Pendolino, Frantoio, Rosciola and Vernina trees from which extra virgin olive oil is produced. 

Other olive varieties can be found on the estate, including Pigeon Egg, Taggiasca and a tree from the Gethsemane Garden that was donated to Pope Paul VI by King Hussein of Jordan.

In 2021, the daily newspaper of Vatican City, L’Osservatore Romano dedicated an article to the olive branch that, after celebrating Palm Sunday Mass in the St. Peter’s Basilica, Pope Francis brought with him to Casa Santa Marta (the guest house that he chose as his quarters over the more luxurious Apostolic Palace, which is supposed to be the official papal residence).

In that olive branch, there are the expectations and fears of humanity, writes the daily, “but precisely those infinitely small olive leaves, symbols of true peace, in the hands of the successor of Peter are a sign of a hope that does not die. A sign of the resurrection.”

Father Mattia Ferrari, a chaplain aboard the migrant rescue vessel operated by the civil society platform Mediterranea Saving Humans, was very close to the late pope due to his commitment to migrants and refugees.

“Pope Francis taught us above all to love,” Ferrari told Olive Oil Times. “From love comes the courage to denounce injustices and the commitment to build a human, supportive and fraternal world. We must learn from him to love, and with this love we will be able to continue the path he forged to save each other.”

• Vatican News
• L’Osservatore Romano
• Vatican News

However, U.S.-based farmers and millers have again proven they can produce high-quality extra virgin olive oils that match those from their Old World counterparts.

Farmers and millers from Arizona, California and Oregon combined to win 92 awards at the 2025 NYIOOC World Olive Oil Competition, the third-highest total since the competition began in 2013.

From early frosts in Oregon to unpredictable weather and rising labor costs in California, producers overcame a growing list of familiar challenges to craft well-balanced, flavorful, and defect-free olive oils.

California Olive Ranch (COR), the country’s largest producer, won awards for five 100-percent California products and two of its “Global Blends.” The company also won awards for its Lucini brands, which were produced in Italy.

Mary Mori, COR’s vice president of quality and product, said the COR team was “immensely excited” about the news of the awards. The unprecedented haul motivated the company to continue solidifying its commitment to quality.

“We take pride in the awards and results and always review the feedback shared in the analysis for both winning and non-winning oils,” she said. “We then share this with our team to identify areas for improvement.”

“One difference of NYOOC is its focus on overall quality and good taste rather than individual judge preferences,” Mori added. “This allows us to better control our processes, whether by modifying the oils we purchase or by adjusting our own harvest timing to prioritize fresher, early-harvest oils.”

This year’s awards come after what Mori described as a plentiful harvest compared to previous years. 

According to the United States Department of Agriculture, U.S. olive oil production slightly exceeded the five-year average, reaching 10,000 metric tons in the 2024/25 crop year. The vast majority of this production is located in California.

“While it’s typically an alternate bearing year, we’ve implemented farming changes, focusing on irrigation and precise deficit irrigation techniques, to better stabilize and significantly improve the quality of the olives delivered to the mill,” Mori said.

While many of the country’s largest producers — including Corto Olive, which earned a Silver Award, and Baltimore-based Pompeian, which claimed three Gold Awards — celebrated their NYIOOC successes, small-scale producers also showcased their ability to craft award-winning olive oils.

In the prolific olive oil-producing region of Paso Robles, Marcum Olive Oil earned two Gold Awards for a pair of monovarietals.

“Winning these awards serves as an inspiration to continuing our commitment to quality, freshness and perfecting our olive oil-making craft,” co-owner Lonnie Marcum said.

“California produces the vast majority of the olive oil in the U.S.,” she added. “This recognition brings not only prestige and credibility to California, but also increased visibility among consumers who seek out the very finest extra virgin olive oils in the world.”

The Central California producer overcame unpredictable weather using sustainable growing techniques and organic olive fruit fly management to produce its hand-harvested, award-winning oils.

“2024 was an interesting growing year,” co-owner Grant Marcum said. “One of our varieties, Coratina, produced twice as much as the prior year, while the other trees, the Itrana, produced about half as much.”

About 2.5 hours south on highway U.S. 101, the producers behind Ojai Olive Oil Company marked a fruitful end to the harvest, winning four Silver Awards.

“It’s always very satisfying to win at the NYIOOC,” owner Philip Asquith said. “This year’s wins bring our total to over 20 awards, which is wonderful. We’re quite proud of our medals, and have all the trophies on display in our tasting room.”

Along with his fellow Californians, Asquith touted the role of the NYIOOC in promoting California extra virgin olive oil to local consumers.

“Our customers are surprised and impressed to hear that California olive oils win so many awards,” Asquith said. “They also like knowing that California has very high standards for what can be called ‘extra virgin’ here. People often don’t know how far the industry has come in this region.”

While the 2024/25 crop year produced high-quality olives, Asquith said the quantity was lower than the bumper harvest of 2023/24. As has increasingly become the case, he highlighted hiring workers for the harvest as one of the biggest challenges.

“The biggest challenge we faced this past season was the cost of picking,” Asquith confirmed. “Every other aspect of our operation has been quite consistent year to year, but the harvesting expenses have gone up quite a bit in recent years. It’s manageable for us, but has become the single biggest cost component in making a bottle of olive oil.”

On the opposite end of California, Apollo Olive Oil celebrated winning two Gold Awards at the World Competition for a pair of organic blends.

Winning at the NYIOOC “helps small producers like ourselves to have third-party confirmation that your olive oil is of high quality,” partner Steve McCulley said. “Because of the high standards of NYIOOC, its results are highly regarded in California.”

“The new ranking system shines a light on producers who have consistently earned top marks over the years, making it easier for consumers to find high-quality oils,” said the producer of the world’s second-highest ranked olive oil.

While Apollo Olive Oil faced adverse weather events in 2024, McCulley said the harvest was consistently high quality. The main difference he saw was that it started later than usual. 

However, he added that the main challenges for producing award-winning quality extra virgin olive oil remain constant.

“Organizing harvest to get sufficient pickers to hand pick, scheduling efficient delivery of olives to the mill, and fine-tuning our special mill that greatly reduces oxidation during processing all require careful planning,” McCulley said.

Not far from Apollo Olive Oil, the producers behind Organic Roots also celebrated their World Competition success, winning Gold Awards for organic Arbequina and Koroneiki monovarietals.

“Winning two Golds at the NYIOOC feels incredible,” the Polit family said. “We are a family-owned and operated business, and when it’s olive harvest time, it’s all hands on deck. To win Golds while competing internationally shows how much our hard work pays off.”

The Polits added that the awards also help boost the reputation of California organic extra virgin olive oil on the global stage.

“Winning awards at the NYIOOC not only boosts the reputation of individual producers but also elevates the perception of California extra virgin olive oil as a whole,” the family said. “It serves as a testament to the state’s commitment to quality and innovation in organic olive oil production.”

While Organic Roots enjoyed a harvest rebound in 2024/25 compared to the previous two crop years, unpredictable weather is always the company’s main harvest challenge.

“​The 2024/25 organic olive oil harvest marked a notable recovery in production and quality compared to the previous two challenging seasons,” the Polits said. “With a combination of timely rains during winter and cooler, steady spring temperatures have supported strong tree development without the extremes that usually hurt organic yields.”

While California dominates U.S. extra virgin olive oil production in quantity, award-winning quality can be found beyond the Golden State.

In neighboring Arizona, Queen Creek Olive Mill earned four Silver Awards.

“Winning four Silver Awards at the 2025 NYIOOC is an incredible honor and a testament to our team’s dedication to crafting exceptional extra virgin olive oil,” president John Rea said.

He added that the awards also serve as a barometer, allowing Arizona’s only commercial olive mill to measure where they stand compared to domestic and international competitors.

“These awards significantly elevate the perception of Arizona extra virgin olive oil, both locally and beyond,” Rea said. “Many people are surprised to learn that high-quality olive oil can be produced in Arizona’s desert environment, and NYIOOC recognition helps dispel skepticism.”

Rea acknowledged that the company’s World Competition success was partly fueled by favorable weather conditions in the previous harvest. He added that the situation is looking good in the olive groves ahead of the coming crop year.

“The primary challenge was timing the harvest in Arizona’s unique desert-continental climate, which differs from other U.S. olive-growing regions,” he said. “We monitor the grove closely from November into December to ensure the olives are harvested at optimal ripeness, balancing quality with weather risks like sudden temperature drops.”

On the other side of California, two producers in Oregon were awarded at the World Competition. Dark Hollow Farm in southern Oregon’s Rogue Valley earned a Gold and Silver Award in its NYIOOC debut.

Further north, Oregonian olive oil pioneer and perennial World Competition winner Durant Olive Mill added four more Gold awards and a Silver Award to its collection.

Owner Paul Durant said that “it feels great” to win at the NYIOOC and know all the oils the company submitted were top-tier, especially its popular Arbequina monovarietal.

“As always, third-party validation is so important for consumers,” Durant said. “We have to source fruit out of Northern California, and people are always interested in how we handle that logistically and if there are any impacts on quality.” 

“We obviously have great quantitative data indicating extra virgin grade, but the awards from NYIOOC hammer home the point that we are able to craft world-class, high-quality olive oil right here in Dayton, Oregon,” he added.

Due to its northern latitude compared to many other olive oil-producing regions, Durant said completing the harvest ahead of the winter frost and snow is always challenging.

“The biggest issue for us is length, weather and logistics,” he said. “We started grape harvest in late August and did not finish milling until December 15th.”

“We had some early-season freezing weather, and if it hadn’t been for our new frost control wind machines, we would have lost a good portion of our estate fruit,” Durant added. “Instead, we were able to get it all harvested at the time of our choosing and did not have our hand forced by the weather.”

Overall, the company processed over 330 U.S. tons of olives this year and had a “fantastic” season in its two-year-old state-of-the-art Pieralisi mill.

“We hit the intersection of amazing quality and fantastic yield.  In an era of rising costs across the board, having such great yield really helped to keep our unit costs down,” Durant said. “We don’t expect to raise any of our prices in 2025.”

Producers were optimistic about the 2025/26 crop year but cautioned that it is still very early in the season and plenty will change throughout the spring and summer.

“We have a great bloom on the trees, and can already tell that it’s going to be a big harvest for 25/26,” Asquith of Ojai Olive Oil Company said. “Even with minimal rain this winter, the trees seem very happy and are packed with blossoms right now.”

“Right now, the trees are looking healthy and the buds are looking good,” Grant Marcum added.

For her part, Mori from COR said that late rain and cool weather in February and March delayed tree growth and blooming, so it remains too early to tell how the harvest will develop.

“The buds we’re observing look promising, but the true picture will emerge in a month or two once the fruit set is established after flowering,” she said. “In previous years with delayed flowering, we anticipated a late harvest; however, summer heat prevented this, so the outcome of this year remains uncertain. Overall, things look good, and we anticipate a fruitful season.”

Meanwhile, Durant said the situation in Oregon looks good so far. “The trees here a just starting to wake up, and we will see how things unfold and hope for the best,” he concluded.

The revelation comes from analyzing pollen released by local vegetation over millions of years. By examining pollen-rich sediment layers, researchers were able to identify olive pollen among many other types.

That also allowed them to determine the point in time when olive pollen became predominant, showing clear signs of olive farming.

The research investigated the contents of sediments in the Pantano Grande area, near Lake Ganzirri—a step away from the mythological turbulent streams of Charybdis and Scylla’s rocky caves in the Strait of Messina.

“It’s a very interesting area, as going through the strait allowed generations of seafarers coming from the West, the East and North Africa to access the Tyrrhenian Italian peninsula,” Jordan Palli, co-author of the study and researcher at the University of Tuscia’s ecological and biological sciences department, told Olive Oil Times.

Adding to that, researchers looked for evidence in that area since it is especially rich in biodiversity and also home to significant historical events.

“As it happens in all large water masses, all that is intercepted because of gravity precipitates and might become sediment,” Palli said. “Among these, there is pollen, which is a microscopic element produced in huge quantities by plants.” 

The sediment column slowly and progressively accumulates material, producing uninterrupted stratification.

“Even more interestingly, it maintains a chronological sequence, as the lower layers are the most ancient. It becomes a natural archive,” Palli said.

Those sediments are rich in materials of many diverse origins, such as leaves, wood, fruits, fungi, or single-cell algae.

In Pantano Grande, wild olives were present, mixed with a wide range of Mediterranean vegetation.

“They have been there for a long time, until the human presence began reshaping most of the coastal areas,” Palli said.

To correctly distinguish wild olive pollen from pollen from olive trees in a human-driven environment, researchers developed two indices.

The first one focused on olive trees growing with the typical Mediterranean seaside vegetation. The second one considered olives sharing forested areas with oaks, such as holm oaks.

The two indices allowed researchers to determine vegetation trends in both settings.

“When the olive pollen predominance emerged in both indices, that was evidence of a significantly broader presence of the plant when compared to all other plants that should have co-existed there,” Palli said.

“This allowed us to interpret such data as the signal of artificial propagation of the plant, as its ecology would not have allowed it to have such predominance,” he added. “That told us that local populations had taken action.”

Such analysis led the researchers to identify three historical periods in which olive farming took place in the area.

While the second (during the Roman Empire) and the third (modern times) are well known and documented, the first identified period came as a surprise.

It stretches from the Middle Bronze Age, in the 18th century BCE, to the 12th century BCE.

Most historians have long agreed that knowledge about olive tree farming originated from the Aegean area, probably brought by Greek colonists to southern Italy around the 8th century BCE.

“We do not know much about the Sicans,” Palli said. “Their settlements are below modern cities, such as Messina. Some investigations showed that there is much to explore down there, but that cannot happen because of what is above it.”

Three thousand years ago, olive growing was already taking place in the Eastern Mediterranean.

The new research evidence shows that knowledge about the olive was probably carried to the Sicilian coasts by merchants coming from the Levant.

“There are archaeological remains of pottery and other objects originating from the Aegean area,” Palli said.

“Thanks to the archaeologists and other researchers who joined our research, we have been able to formulate a scenario of what has probably happened at that time in Pantano Grande,” he added.

In that scenario, trade brought new knowledge through cultural exchange.

“Wild olives were already present in that area, and the local population began appreciating the natural resource,” Palli noted.

In the Levant, where more advanced civilizations thrived, olive oil and the olive tree were already highly significant.

Coming to Sicily from the Levant, merchants and seafarers might have noticed the many olive trees. Sharing knowledge ensued.

“We could say that agronomic know-how developed there, but we should always bear in mind that we are talking of ancient times, so we should not compare that knowledge to modern agronomics in any way,” Palli said.

“Let’s keep in mind that at the time, tools didn’t exist yet, they weren’t widespread,” he added. “There was no plow, none of the equipment we think of today. The possibility of cultivating and breaking the soil in a specific way simply wasn’t there.” 

“When we talk about that very early phase of the Bronze Age, yes, we’re talking about cultivation, but not cultivation as we know it today,” Palli continued.

At that time, farmers could cultivate the olives in areas where they were already present.

“What they might have done was to look for areas where the tree was present or else favored the olive trees over the other plants in specific areas,” Palli said.

A crucial part of the research was the paleoclimate analysis, which allowed scientists to study climate variations over time.

“Times of expansion or regression of specific vegetation might depend on variations happening, for instance, on the relative humidity levels or the amounts of rainfall. Those variations might allow a species to better compete with the others,” Palli said.

By comparing the evidence of paleo-climatic variations as analyzed in previous research, there was no specific correlation with olive predominance.

“That showed us that the increasing volumes of olive pollen were not due to a specific climatic phase. That supported the hypothesis of the human intervention,” Palli said.

The ancient approach to olive farming in the Pantano Grande area lasted for five to six centuries.

“It collapsed in the 12th century BCE,” Palli said. “That does not mean that the knowledge collapsed as well, as populations could have moved to other areas.” 

What researchers know is that around the 12th century, several significant events happened.

“The first impact came from the Ausoni population descending to Sicily from what is today central Italy. Archaeological remains show significant movements of people at the time,” Palli said.

That might have induced the Sicans to leave the area. According to researchers, random pirate-like activity began to occur along the Sicilian coasts at the time, likely carried out by populations who, over time, came to be identified as Saracens.

“Such activities could have easily impacted sea trade and even pushed populations away from the coasts,” Palli said.

Additionally, it is believed that Mount Etna, one of the world’s most active volcanoes, located 100 kilometers from Messina, had an enormous eruption at that time. Traces of this eruption were later found in Albania, approximately 600 kilometers away.

“Ancient Roman authors described it as an unparalleled deep upheaval, a generational event. It is called the Sican Event, as it is believed that it might have pushed Sicans from eastern Sicily to the western part of the island,” Palli said.

Thanks to pollen analysis, researchers verified that after that period, the predominance of olive pollen ceased, with sediment layers showing a return to a more typical condition of mixed plant species.

According to Palli, three years of analysis and two more years to write the research were needed to bring together the work of archaeologists, climatologists, historians, ecologists and paleoecologists.

“Without such collective work, we would not have been able to combine history, pollen, archaeology, sediment analysis, and paleo-climate and produce such evidence,” Palli concluded.

The latest report from the Copernicus Climate Change Service (C3S) also shows that Europe’s surface temperatures are rising faster than the global average.

Copernicus is the Earth observation component of the European Union’s space program.

In its paper, compiled in collaboration with the World Meteorological Organization (WMO), researchers reported that 2024 was Europe’s warmest year on record.

“This report highlights that Europe is the fastest-warming continent and is experiencing serious impacts from extreme weather and climate change,” added WMO Secretary-General Celeste Saulo.

Annual sea surface temperatures across Europe and the Mediterranean Sea reached their highest level ever recorded: 21.5 °C, 1.2 °C above average. European lakes also reached unprecedented temperatures.

The European State of the Climate 2024 report further highlighted widespread global heat stress.

Sixty percent of Europe experienced more days than average with at least intense heat stress, defined by perceived temperatures exceeding 32 °C.

Moreover, annual temperatures reached record highs across nearly half of Europe.

Eastern and southeastern Europe experienced anomalous heat, with the latter region enduring the longest recorded heatwave.

Heat stress significantly affected key olive oil-producing areas in the Mediterranean, including Greece, Turkey and parts of Spain and Italy.

Italy, Croatia, Greece and western Turkey reported a record number of tropical nights, reaching 23. Tropical nights occur when minimum temperatures do not fall below 20 °C.

While less frequent than in recent years, parts of southern Spain and Southern Portugal faced extreme heat stress days, with peak temperatures exceeding 46 °C.

In mid-August, sea temperatures peaked at 28.7 °C, particularly in the Adriatic, Ligurian and Gulf of Lion, bordering northeastern Spain and the South of France. 

This was classified as a severe marine heatwave, coinciding with intense heatwaves on land in critical olive-growing areas of Italy, France and Croatia.

“Heat stress days and tropical nights are increasing in Europe,” the report stated. “2024 saw the second-highest number of heat stress days and tropical nights on record.” 

“Averaged over Europe, this meant nearly a month of at least strong heat stress and around 12 tropical nights, with variations across the continent, particularly in southeastern Europe, which saw record-breaking numbers of both,” the report added.

Conversely, days of unusually cold conditions reached a record low in Europe during 2024.

The area experiencing sub-zero temperatures continued to shrink. According to the report, 2024 recorded the most significant area ever with fewer than 90 days of frost.

All glaciers in Europe continued losing ice, with those in the Alps shrinking by 22 to 93 percent compared to 1970.

Throughout 2024, significant events and alterations were observed in rainfall, river levels, and flooding, with Western Europe experiencing one of its wettest years.

Extreme flooding increased in 2024, notably Storm Boris in central and eastern Europe and the particularly devastating storm Dana in Spain at the end of October.

During this period, Valencia broke rainfall records for one‑, six‑, and 12-hour intervals within a few days.

Storm Boris caused record floods across eight countries, affecting 8,500 kilometers of rivers.

Amid such complex conditions, wildfires significantly impacted areas experiencing prolonged dry weather.

Near Athens, Greece, a fire covering 11,000 hectares evacuated 16,000 residents in August.

In northern and central Portugal, high temperatures combined with dry conditions and strong winds in September caused a record number of wildfires, burning 110,000 hectares in a week.

The devastation in Portugal alone accounted for 32 percent of all burnt land in Europe in 2024.

The European report was published shortly after the United Nations’ Emissions Gap Report, which predicts that global surface temperatures could rise 3.1 °C above pre-industrial levels by the end of the century under current conditions.

The European report also highlights the increasing damage and costs caused by climate change and extreme weather events.

Recent research by the Potsdam Institute for Climate Impact Research projects that global climate-related costs could exceed $38 (€33) trillion by 2049.

“The 2024 report reveals that almost one-third of the river network exceeded high flood thresholds, and heat stress continues to increase in Europe, highlighting the importance of building greater resilience,” said Florence Rabier, director-general at the European Center for Medium-Range Weather Forecasts (ECMWF), a key partner of Copernicus.

Rabier also emphasized how information provided by Copernicus and WMO supports adaptation and mitigation strategies.

“Fifty-one percent of European cities now have a dedicated climate adaptation plan,” Rabier remarked.

Saulo, from the WMO, added that Europe must continue its efforts to prevent further warming.

“Every additional fraction of a degree of temperature rise matters because it accentuates the risks to our lives, economies and planet,” she said. “Adaptation is essential.” 

“WMO and its partners are intensifying efforts to strengthen early warning systems and climate services to help decision-makers and society become more resilient,” Saulo concluded. “We are making progress but must move further, faster and together.”

The study, published in the journal Biology, presents a comprehensive review of the implications of, and possible solutions to, soil salinization, a growing problem globally and one of particular concern in the Mediterranean basin.

The Mediterranean basin is highly susceptible to salinity due primarily to low rainfall, millennia of agricultural irrigation and seawater intrusion.

Agricultural irrigation contributes heavily to soil salinization because irrigation water the plants do not absorb evaporates, leaving behind a progressive salt accumulation. 

An annual irrigation of 1,000 millimeters with water having a salt content as low as 300 milligrams per liter is estimated to add 300 kilograms of salts per hectare. This is further exacerbated by the ions contained in fertilizers.

Seawater intrusion is a complex phenomenon that results from the overexploitation of coastal aquifers for human water consumption and agricultural and livestock uses combined with reduced recharge of these aquifers, which is associated with increased demand for water in river basins.

This phenomenon is compounded by climate change, which leads to rising sea levels and disrupted precipitation patterns. 

Rivers that experience reductions in their basins contribute less water to coastal aquifers, which in turn are subject to a greater inflow of saltwater due to sea level rise and increased storm surges. 

This leads to the salinization of aquifers and, subsequently, of their associated ecosystems and estuaries.

Olive trees are well-known to be salt-tolerant, with saline irrigation frequently employed in olive-growing regions of various Mediterranean countries, such as Spain, Israel and Tunisia, where water shortage is one of the major barriers to sustainable agriculture.

Olive trees display both structural and biochemical strategies to manage salt stress. These include thicker root cell walls, increased production of osmoprotectants, such as proline and mannitol, and enhanced antioxidant systems to combat reactive oxygen species.

The researchers found, however, that the ability of the olive tree to tolerate salinity varies significantly between cultivars.

Cultivars such as Royal de Cazorla and Kalamata were found to exhibit the most consistent salt tolerance, whilst Leccino and Shiraz were among those classed as salt-sensitive and unsuitable for salinized soils unless grafted onto a salt-tolerant rootstock.

Grafting sensitive cultivars onto tolerant rootstocks, often derived from wild olives, can enhance resilience. 

As with other fruit trees, olive tree behavior is affected by the rootstock used, and grafting wild tree rootstocks is a traditional method for producing stronger trees with improved fruit quality. 

Unlike their domesticated relatives, wild olive trees exhibit high genetic variability and are a valuable source of genes resistant to abiotic stresses.

Already a proven technique for reducing the adverse effects of salinity in grapevines, researchers expect that salt-tolerant rootstocks will similarly mitigate salt stress in olives.

Therefore, they recommend using salt-tolerant cultivars or rootstocks in salinized soils in the short and medium term. In contrast, the time-consuming process of breeding salt-tolerant cultivars is carried out.

This technique may be increasingly important as modern cultivation shifts towards high-density, irrigated systems, which demand higher water use and increase salinity risk.

Multi-omics approaches, combining genomics, transcriptomics, proteomics and metabolomics, are proposed as the future of olive stress research. 

Integrating data from these domains with artificial intelligence and machine learning tools could lead to predictive models for cultivar performance under stress. These could be used, for example, to select promising cultivars or rootstocks.

Such approaches could also be used to develop chemical priming strategies. Priming is the mechanism through which plants can perceive a mild stimulus that induces protein post-translational modifications, such as phosphorylation and carbonylation. 

These can regulate stress responses more efficiently than traditional gene expression alone. Identifying suitable post-translational modifications could lead to priming that enhances tolerance to saline stress.

• Plant Stress
• Consejo Superior de Investigaciones Científicas

One hundred thousand branches from the Castel di Guido estate were donated by the municipality of Rome, and another 100,000 by the 46 Città dell’Olio associations of Lazio. In addition, 150 olive branches were gifted to the cardinals.

“We have taken up this challenge with great pride,” said Alfredo D’Antimi, coordinator of the Città dell’Olio in Lazio. “Many olive growers have joined the initiative. Donating their olive branches for such an important day of prayer represents a great emotion for them and a great honor for us.”

Cardinal Leonardo Sandri presided over the Palm Sunday mass, with Pope Francis appearing to greet pilgrims afterwards.

Although palm leaves are now most commonly associated with the holiday, olive branches have played an essential role since ancient times. According to the Bible, “the children of the Hebrews, bearing branches of olive, went out to meet the Lord, crying out and saying: Hosanna in the highest.”

The liturgy contains many references to olive trees and the branches carried by the clergy and worshipers. 

As laid out in the missal, the priest relates the history and symbolism, saying, for example, “on this day the multitude, taught by a heavenly illumination, went forth to meet their Redeemer, and strewed branches of palm and olive at His feet. The branches of palms, therefore, signify His triumphs over the prince of death, and the branches of olive proclaim the coming of a spiritual unction.”

He also calls upon God numerous times to bless the branches, again referring to their symbolism, before they are distributed among the clergy present.

“Let Thy manifold mercy descend upon us, and let these branches of palm or olive trees be blessed… likewise these branches of palm and olive, which Thy servants receive faithfully in honor of Thy name.”

“O God, who, by an olive branch, didst command the dove to proclaim peace to the world: sanctify, we beseech Thee, by a heavenly benediction, these branches of olive and other trees. Bless, we beseech Thee, O Lord, these branches of palm or olive.”

In addition to the branches carried during the Palm Sunday celebrations, large olive trees were placed near the statues of Saint Peter and Saint Paul, at the foot of the tabernacle and the obelisk, where they remain as an integral part of the square’s adornment for the remainder of Holy Week.

As in previous years, the donations are accompanied by statements on the importance of peace and specific prayers for peace in Gaza and Ukraine. 

“The homage of the Città dell’Olio… also brings with it this year the request for a definitive and lasting peace in Gaza and the Ukraine and a message of closeness to the populations who are victims of all the wars in the world,” Città dell’Olio’s national association said in an official release.

“The olive tree teaches us to live in harmony because it is a symbol of peace,” said Michele Sonnessa, the association’s president. “But peace can only be built together. War leaves no escape for anyone; it only sows death and poverty.” 

“On the contrary, civilization sprouts in peace,” he added. “There is no peace without dialogue and mutual recognition, no alliance without the common good. The states of the world must take on this concrete commitment immediately. If they do not do so, history will judge them.”

• Vatican News
• Città dell’Olio

The study, published by the International Journal of Climatology, focused on Italy to understand the factors triggering multi-year drought phenomena.

“Even if these phenomena can be considered cyclical and typical in the region, they now tend to last longer, their intensity is increasing and their impacts are broader,” Salvatore Pascale, a researcher at the University of Bologna’s department of physics and astronomy, told Olive Oil Times.

The scientists defined a widespread multi-year drought as an event lasting more than 12 months, often extending over two or three years.

To measure these conditions, the authors relied on the standardized precipitation evapotranspiration index (SPEI), which considers precipitation and moisture loss due to evapotranspiration. Evapotranspiration occurs when water evaporates from water bodies and soil and is transpired by plants.

A widespread multi-year drought begins when it affects at least 30 percent of Italian territory (SPEI +1) and ends when more than 70 percent returns to near-normal conditions (SPEI ‑1).

The study focused on events over the last 123 years in Italy.

“We found that such events frequently impact more than 30 percent of the territory,” Pascale said. “In most cases, these droughts affected nearly the entire country, reaching about 60 to 70 percent of Italy during their peak.” 

Even the most recent intense widespread multi-year drought involved large areas of Italy. “One might assume the warmer south is most affected, but that’s not the case,” Pascale said.

When droughts persist, they worsen conditions in areas already impacted by accelerating evapotranspiration.

“Temperature is the primary factor influencing this process,” Pascale said. “Other factors like wind also matter, but temperature is dominant. Surface temperatures are rising due to global warming, causing a decline in available surface water and soil moisture.”

The loss of soil moisture directly impacts agriculture and soil fertility.

“Considering soil moisture loss alone, droughts are clearly becoming more severe, with longer-lasting consequences,” Pascale said.

The researchers emphasized how temperature has become as critical as rainfall in shaping drought dynamics. While rainfall volumes have not decreased, the capacity of soil and vegetation to retain water has significantly declined due to rising evaporative demand.

Currently, rainfall volumes have a limited impact in a rapidly changing scenario.

“We observe worsening extreme events becoming more intense and frequent,” said Pascale, specifying that overall rainfall volumes remain relatively stable.

“Instead, temperatures continue rising, accelerating the depletion of surface water,” he added.

In Italy, higher temperatures also shorten the snow season. Alpine snow accumulation is reduced and melts earlier than in the past.

“The mountain water we historically relied upon in summer is increasingly unavailable. The buffering role of snow and water storage historically played by Italy’s mountains is diminishing,” Pascale said.

Reduced snow also means critical rivers for agriculture, such as the Po River, may no longer provide sufficient water to regions heavily dependent on farming.

“The aggressiveness of the widespread multi-year drought event from 2021 to 2023 was astonishing. The Po River reached levels never recorded in the last 200 years,” Pascale said.

The study highlights that recent drought severity results from persistent weather patterns maintaining high-pressure systems over Europe, blocking precipitation.

Widespread multi-year drought events in Italy originate from specific atmospheric circulation patterns, such as the North Atlantic Oscillation (NAO).

“The persistence of the positive phase of the NAO results in less rainfall over the Mediterranean, as Atlantic storm systems are pushed toward the northeast, toward Scotland and Scandinavia.”

“Some of these conditions persist over Europe for extended periods, sometimes recurring multiple times within two or three years,” he added.

In such scenarios, widespread multi-year droughts occur predominantly under anticyclonic conditions, characterized by higher-than-average temperatures and reduced rainfall.

“These phenomena reflect normal atmospheric variability and are not driven by global warming,” Pascale said. “Understanding if and how global warming influences atmospheric circulation dynamics is very challenging; climate models on this topic remain unreliable.”

“Global warming means the climate retains more energy, causing temperatures to rise, a thermodynamic reality,” Pascale added. 

“Rainfall, however, depends not only on thermodynamics but also on dynamics such as wind patterns,” he continued. “Rainfall forms when winds converge, accumulating humidity. That accumulated water must then be released as precipitation.” 

According to the researcher, volumes dependent on wind and circulation dynamics are more complex than temperature-driven changes.

“That means we need significantly more time and further warming to observe clear trends,” Pascale said.

The authors cross-checked data from two distinct climate datasets to strengthen their findings and utilized precipitation-only and combined indices.

This approach helps address regional data discrepancies and enhances confidence in the study’s conclusions.

What researchers do know for sure, however, is that droughts will become more severe, with increasingly harsh impacts on affected areas.

“This means wise, innovative and dynamic management of water resources becomes crucial. Not only for populations and agriculture but also for industry, which consumes approximately 30 percent of potable water,” Pascale said.

Climatologists are not yet capable of reliably predicting widespread multi-year drought events. However, extensive research is underway to develop trustworthy seasonal forecast models.

“We foresee a future where seasonal forecasts become reliable enough to predict when widespread multi-year droughts will start,” Pascale said. “We have short-term forecasts, which we use daily, and long-term climate projections spanning decades or even centuries.” 

“In between are seasonal forecasts, such as projections made in April for the upcoming summer,” he added. “These forecasts account for predictable and slowly evolving climate factors, like El Niño events, triggered by warming Pacific Ocean waters.”

The goal is forecasting weather three to six months in advance.

“However, these models are not yet reliable, with high levels of uncertainty. The good news is that extensive research is underway, highlighting their potential importance in our rapidly changing climate,” Pascale said.

Predicting widespread multi-year drought would enhance the ability of countries to adapt.

“Adaptation is essential because we are already experiencing climate change. In many sectors, adaptation is our only viable response, necessitating measures to mitigate drought impacts,” Pascale said.

“But adaptation doesn’t solve the root problem. True mitigation of global warming requires dramatically reducing or even eliminating greenhouse gas emissions,” he added.

“Should humanity ever achieve this goal, it will still take considerable time. Meanwhile, adaptation, alongside developing more reliable seasonal forecasts, remains our best strategy,” Pascale concluded.

“Despite a strong harvest in 2023/24, the expected biennial production alternation was less pronounced this year, allowing for a higher-than-anticipated olive yield,” said Alexandra Paris, the director of the producer association France Olive’s communications and economics department.

“However, oil yield was two to three points lower than usual averages,” she added. “This decrease significantly impacted overall olive oil production, which is estimated to be between 5,000 and 5,200 metric tons for 2024/25, compared to 6,667 tons in 2023/24.”

According to data from the International Olive Council and France Olive, the country has produced an average of 4,773 tons of olive oil annually over the past half-decade.

The mountainous topography of southern France and its proximity to the Mediterranean Sea create many microclimates, frequently leading to disparate harvest results across the country. The harvest usually runs from October to December, varying by region and variety. 

“As in previous years, production varied across regions,” Paris confirmed. “Drought particularly affected certain areas, notably in Occitanie.”

Olive farmers in Gard, a department of Occitanie, experienced lower yields than the previous year due to summer drought and high autumn humidity. These conditions caused the olives to absorb water, leading to lower oil accumulation. 

“Additionally, in departments such as Drôme, where production had been exceptional in 2023/24, the alternation effect was more pronounced this year, leading to a natural decline in harvest volumes,” Paris said. 

Producers across Provence and Languedoc, in Occitaine, confirmed they faced difficult climatic conditions, including unpredictable weather, heat waves and rain episodes during the flowering. Some farmers reported declines of up to 50 percent.

“Some regions experienced a strong season, particularly the Alpes-Maritimes and Bouches-du-Rhône, where conditions were more favorable,” Paris said.

In Grasse, a subprefecture in Alpes-Maritimes, a local cooperative reported “an exceptional campaign,” according to its president, Jean-Pierre Franchi.

After purchasing new equipment, the 97-member cooperative produced 63,600 liters of olive oil, the highest total since 1954.

About 100 kilometers to the west in the Vallée des Baux-de-Provence, Château d’Estoublon also experienced a production increase compared to the 2023/24 crop year.

“The olive harvest started in the second week of October and finished in the second week of December, with Salonenque being harvested first and Picholine last,” technical director Victor Joyeux said.

“We saw a significant increase in tonnage this year, with 32 percent more olives harvested compared to 2023, thanks to the meticulous pruning work on our trees in previous years,” he added.

Joyeux said the award-winning producer’s ​​season had gone smoothly, benefiting from a wet year. “We narrowly avoided a late frost event in November, and our Picholine parcels were untouched,” he added.

Joyeux cited timing as the most significant challenge the company faced. The harvest team carefully picked the olives of each variety at optimal ripeness.

“We are also fortunate to have our mill on the estate, which enables us to press the olives at the ideal time, ensuring the highest quality oils,” he added.

In the neighboring Donce Valley, Domaine Clos des Faucons also completed its harvest in December. Despite harvesting more olives, the olive oil yield was lower than the previous harvest.

“The atypical weather conditions at the end of the summer made this campaign particularly demanding, with hazards that are difficult to predict,” the company wrote on LinkedIn. “This reflects the challenges faced this season by our estate, but also by many fellow olive growers.”

Meanwhile, fellow Provençal producer Domaine de Gerbaud had a modest olive yield compared to their abundant 2023/24 harvest, but the quality remained high. 

Despite 700 millimeters of rainfall, the farm’s elevation on the lower slopes of the Luberon massif helped mitigate humidity issues. 

Co-owner Louisa Sherman described the harvesting period as exciting and demanding, requiring a final effort to create high-quality olive oil.

“It’s always a hectic time,” she told Olive Oil Times. “Tractors, pickers, nets and equipment arrive at the property, creating so much noise despite our use of battery-operated rakes. Large containers for olives are positioned beneath the olive trees.”

“We harvest olives at different times based on variety to produce high-quality oils with fresh aromas and balanced bitterness and pungency,” she added.

Indeed, harvesting olives at the right time for each variety is crucial for producing high-quality olive oils with desirable flavors and aromas. 

“When the harvesting campaign began, the olives had a very high water content, resulting in low oil yields,” Sherman said. “Their advanced aromatic maturity compared to lipogenesis worsened the situation.”

“The wind exposure ensured that our groves dried off well, limiting cryptogamic disease development, ” she added. “We also did not suffer severely from olive fruit fly damage. Healthy olives produce good quality olive oil!”

Domaine de Gerbaud blends Aglandau, Salonenque, Verdale and Gossane olives to create a ‘green, fruity oil,” which earned a Silver Award at the 2025 NYIOOC World Olive Oil Competition.

Daniel Dawson contributed to this report.

• Nice Martin