Connect with us

Published

on

Global yields of wheat are around 10% lower now than they would have been without the influence of climate change, according to a new study.

The research, published in the Proceedings of the National Academy of Sciences, looks at data on climate change and growing conditions for wheat and other major crops around the world over the past 50 years.

It comes as heat and drought have this year been putting wheat supplies at risk in key grain-producing regions, including parts of Europe, China and Russia.

The study finds that increasingly hot and dry conditions negatively impacted yields of three of the five key crops examined.

Overall, global grain yields soared during the study period due to technological advancements, improved seeds and access to synthetic fertilisers.

But these yield setbacks have “important ramifications for prices and food security”, the study authors write.

Grain impacts

Most parts of the world have experienced “significant” yield increases in staple crops since the mid-20th century.

The new study notes that, in the past 50 years, yields increased by 69-123% for the five staple crops included in the research – wheat, maize, barley, soya beans and rice.

But crop production is increasingly threatened by climate change and extreme weather. A 2021 study projected “major shifts” in global crop productivity due to climate change within the next two decades.

Earlier this year, Carbon Brief mapped out news stories of crops being destroyed around the world by heat, drought, floods and other weather extremes in 2023-24. Maize and wheat were the crops that appeared most frequently in these reports.

The crops that appeared most frequently in media reports of extreme weather impacts analysed by Carbon Brief, ranked in order of most to least frequent: maize, wheat, rice, potatoes, soya beans, olives, bananas, grapes, sunflowers and coffee. Credit: Carbon Brief.
The crops that appeared most frequently in media reports of extreme weather impacts analysed by Carbon Brief, ranked in order of most to least frequent: maize, wheat, rice, potatoes, soya beans, olives, bananas, grapes, sunflowers and coffee. Credit: Carbon Brief.

Hot and dry weather is currently threatening wheat crops in parts of China, the world’s largest wheat producer, Reuters reported this month.

In the UK, wheat crops are struggling amid the “driest start to spring in England for almost 70 years”, the Times recently reported. Farm groups say some crops are already failing, the Guardian said.

As a result, global wheat supplies are “tight”, according to Bloomberg, with price rises possible depending on weather conditions in parts of Europe, China and Russia.

Food security and prices

The study uses climate datasets, modelling and national crop statistics from the UN Food and Agriculture Organization to assess crop production and climate trends in key grain-producing countries over 1974-2023, including Argentina, Brazil, Canada, China, the EU, Russia and the US.

The researchers assess climate observations and then use crop models to calculate what yields would have been with and without these climate changes.

For example, “if it has warmed 1C over 50 years and the model says that 1C leads to 5% yield loss, we’d calculate that the warming trend caused a loss of 5%”, Prof David Lobell, the lead study author and a professor at Stanford University, tells Carbon Brief.

The study looks at two reanalysis climate datasets that include information on temperature and rainfall over the past 50 years: TerraClimate (TC) and ERA5-Land. (Reanalysis data combines observations with a modern forecasting model.)

The researchers find that yields of three of the five crops are lower than they would have been without warmer temperatures and other climate impacts in the past 50 years.

Yields were lower than they otherwise would have been by 12-14% for barley, 8-12% for wheat and 4% for maize.

The impacts on soya beans were less clear as there were “significant differences” between data sources. But both datasets show a negative impact on yields, ranging from 2% to 8%.

The effects on rice yields were inconclusive, with one dataset showing a positive effect of around 1% while the other showed a negative effect of about 3%.

The chart below shows the estimated yield impacts for each crop based on the calculations from the two climate datasets.

The estimated percentage impact of climate factors on yields of wheat (brown), maize (yellow), rice (blue), soya bean (green) and barley (purple) from 1974-2023, using two different historical climate datasets. Source: Lobell et al. (2025).
The estimated percentage impact of climate factors on yields of wheat (brown), maize (yellow), rice (blue), soya bean (green) and barley (purple) from 1974-2023, using two different historical climate datasets. Source: Lobell et al. (2025).

Given soaring overall crop yields during this time, impacts of 4-13% “may seem trivial”, the researchers write. But, they say, it can have “important ramifications for prices and food security” given growing food demand, noting:

“The overall picture of the past half-century is that climate trends have led to a deterioration of growing conditions for many of the main grain-producing regions of the world.”

Water stress and heat

The study also assesses the impacts that warming and vapour pressure deficit – a key driver of plant water stress – have on crop yields.

Vapour pressure deficit is the difference between the amount of water vapour in the air and the point at which water vapour in the air becomes saturated. As air becomes warmer, it can hold more water vapour.

A high deficit can reduce plant growth and increase water stress. The models show that these effects may be the main driver of losses in grain yield, with heat having a more “indirect effect”, as higher temperatures drive water stress.

Agricultural irrigation system watering dry soil on a crop field in the US. Credit: Andrii Biletskyi / Alamy Stock Photo. Image ID: 3AKGHEX.
Agricultural irrigation system watering dry soil on a crop field in the US. Credit: Andrii Biletskyi / Alamy Stock Photo.

The study finds that vapour pressure deficit increased in most temperate regions in the past 50 years.

The researchers compare their data to climate modelling simulations covering the past 50 years. They find largely similar results, but notice a “significant underestimation” of vapour pressure deficit increases in temperate regions in most climate models.

Many maize-growing areas in the EU, China, Argentina and much of Africa have vapour deficit trends that “exceed even the highest trend in models”, they write.

The researchers also find that most regions experienced “rapid warming” during the study period, with the average crop-growing season now warmer than more than 80% of growing seasons 50 years ago.

The findings indicate that, in some areas, “even the coolest growing season in the present day is warmer than the warmest season that would have occurred 50 years ago”.

Wheat growing in a field. Credit: Jon Freeman / Alamy Stock Photo. Image ID: EXYNXR.
Wheat growing in a field. Credit: Jon Freeman / Alamy Stock Photo.

An exception to this is in the US and Canada, they find, with most maize and soya bean crop areas in the US experiencing lower levels of warming than other parts of the world and a “slight cooling” in wheat-growing areas of the northern Great Plains and central Canada.

(The central US has experienced a cooling trend in summer daytime temperatures since the middle of the 20th century, according to the National Oceanic and Atmospheric Administration. There are many theories behind this “warming hole”, which has continued despite climate change.)

CO2 greening

Dr Corey Lesk, a postdoctoral researcher at Dartmouth College who studies the impacts of climate on crops, says these findings are in line with other recent estimates. He tells Carbon Brief:

“There are some uncertainties and sensitivity to model specification here – but it’s somewhat likely climate change has already reduced crop yields in the global mean.”

The study’s “main limitation” is that it is “behind” on including certain advances in understanding how soil moisture impacts crops, Lesk adds:

“Moisture changes and CO2 [carbon dioxide] effects are the largest present uncertainties in past and future crop impacts of climate change. This paper is somewhat limited in advancing understanding on those aspects, but it’s illuminating to pause and take stock.”

The research looks at whether the benefits of CO2 increases during the past 50 years exceed the negative effects of higher levels of the greenhouse gas.

Rising CO2 levels can boost plant growth in some areas in a process called “CO2 fertilisation”. However, a 2019 study found that this “global greening” could be stalled by growing water stress.

Yield losses for wheat, maize and barley “likely exceeded” any benefits of CO2 increases in the past 50 years, the study finds.

The opposite is true for soya beans and rice, they find, with a net-positive impact of more than 4% on yields.

Soya beans growing in a field. Credit: Volodymyr Shtun / Alamy Stock Photo. Image ID: 3B84F7G.
Soya beans growing in a field. Credit: Volodymyr Shtun / Alamy Stock Photo.

Climate science has “done a remarkable job of anticipating global impacts on the main grains and we should continue to rely on this science to guide policy decisions”, Lobell, the lead study author, says in a press release.

He adds that there may be “blind spots” on specialised crops, such as coffee, cocoa, oranges and olives, which “don’t have as much modelling” as key commodity crops, noting:

“All these have been seeing supply challenges and price increases. These matter less for food security, but may be more eye-catching for consumers who might not otherwise care about climate change.”

The post Global wheat yields would be ‘10%’ higher without climate change appeared first on Carbon Brief.

Global wheat yields would be ‘10%’ higher without climate change

Continue Reading

Climate Change

Green Climate Fund picks locations for five developing country hubs

Published

on

The UN’s flagship climate fund has selected five locations for its new regional offices, a move aimed at bringing it physically closer to developing countries and making its finance easier to access.

After fraught discussions during a meeting last week, the board of the Green Climate Fund (GCF) decided in a secret vote on Saturday to open regional offices in Panama City, Amman in Jordan, Suva in Fiji, Nairobi in Kenya and Abidjan in Côte d’Ivoire. The African office will be split across two locations to better serve the continent with the largest number of countries and projects supported by the fund.

The decision marks a significant shift for the fund, which has operated from its headquarters in Songdo, South Korea, since its launch in 2013.

“This is a landmark moment for [the] GCF,” said the fund’s executive director Mafalda Duarte. “It has taken a lot of work, careful negotiation and persistent advocacy for a model that will bring us closer to the countries, to our partners and the communities we were created to serve”.

‘Less delay, more action’

The new offices are expected to act as the GCF’s front line, working more closely with governments, the private sector and civil society to improve access to climate finance and support the delivery of projects aimed at cutting emissions and strengthening resilience to climate impacts.

Welcoming the decision in a LinkedIn post, Fiji’s Permanent Secretary for the environment and climate change Sivendra Michael described it as “a win for the entire Pacific”, citing “long hours” and “tough negotiations” behind the outcome. “Less delay, more action — real support where it matters most,” he added.

    A total of 43 countries applied to host the new offices, with 16 making a final shortlist after the GCF secretariat assessed bids on criteria including cost, connectivity and the ability to attract a “world-class workforce” through quality of life and access to international schools.

    Panama emerged as the top-ranked location overall, according to a document seen by Climate Home News, while some selected hosts, including Amman and Abidjan, scored lower than rival candidates in their regions.

    Establishing the new hubs is expected to cost an initial $6.5 million, but the fund anticipates these upfront expenses will be offset over time through operational savings, including lower staff and travel costs.

    First Palestinian entity approved

    The GCF board also accredited the first organisation in Palestine that will be able to directly apply for and access funding.

    Created by the Palestinian Authority in the West Bank, the Municipal Development and Lending Fund supports local infrastructure projects and services. Working with partners, including the World Bank, it is developing projects to help communities cope with escalating climate risks such as drought and extreme heat.

    In the West Bank, which is occupied by Israel, just under half of the population lives in areas classified as having high to very high climate exposure, according to a recent study.

    The post Green Climate Fund picks locations for five developing country hubs appeared first on Climate Home News.

    Green Climate Fund picks locations for five developing country hubs

    Continue Reading

    Climate Change

    Island nations fight to save cultural heritage from climate change

    Published

    on

    Farmers and fishermen in the Maldives have long relied on an ancient calendar to guide their daily lives.

    The Nakaiy system divides the year into 27 distinct periods, each named after a star or constellation in the night sky.

    Any one period in the calendar tells you about expected weather and tidal patterns, navigational routes, and fishing conditions. The Nakaiy was created through centuries of careful observation and local knowledge, passed down through families as an essential tool for survival.

    But things are now changing. The climate crisis is leading to more extreme weather events across the Indian Ocean island nation and upending the Nakaiy calendar.

    “When you go and speak to communities and ask them what kind of impacts they are facing, a lot of elders will tell you that the weather, it doesn’t follow the calendar anymore,” explained Aishath Reesha Suhail, a programme officer in the Maldives’ Ministry of Tourism and Environment.

    As the effects of climate change worsen, it is a real prospect that the Nakaiy may be abandoned by local people, representing a major cultural loss to the Maldives.

    ‘Systemic and growing threat’

    With extreme weather becoming the norm, communities are observing a domino effect of consequences in their everyday lives. The slow onset of heritage loss is now being seen across continents, but notably among small islands in remote parts of the ocean.

    “Climate change represents a systemic and growing threat to cultural heritage worldwide,” a UNESCO spokesperson told Climate Home, adding that the World Heritage Committee has identified climate change as “one of the most significant long-term risks affecting properties across all regions.”

    UNESCO, the UN body for education, science and culture, defines the loss of cultural heritage as “the erosion of traditional knowledge systems, craftsmanship, social practices and identity, particularly where communities are displaced or livelihoods disrupted”. A clear example is historical sites and even entire islands washed into the ocean as a result of rising sea levels and coastal erosion. 

    The Maldives is dealing with such a situation now. The Koagannu Cemetery is a 900-year-old resting place, located on the country’s southernmost atoll, a mere 50 metres from the shoreline. The monument’s intricate coral gravestones are being actively threatened by the encroaching Indian Ocean. 

    The government and local community have responded to this challenge with emergency protection measures. Sandbags and concrete structures have been installed along the coastline, complemented by large numbers of palm trees to create a seawall. A wider solution is ‘beach nourishment’, a common practice in the Maldives where sand from elsewhere is brought in to replace what has been lost through erosion. Taken together, these solutions have so far protected the cemetery.

    Pacific islands push back against growing climate threats

    Among the many issues climate change creates, cultural heritage is not always front of mind. In the Maldives, one of the main barriers people face is awareness. “Most of what we are dealing with relates to the erosion of our islands along with areas such as fisheries… but we are quite limited in our capacity to do something about it,“ Suhail said.

    “We don’t understand the full breadth of the issue at present because we haven’t been able to do extensive research on the matter,” she added. However, assessing the extent of the damage – and how to respond effectively – is a key priority for the government, outlined in its latest climate plan, known as a Nationally Determined Contribution, and as part of its National Adaptation Plan process.

    Fishing is at the core of the country’s culture and identity, employing thousands of people. Most dishes include fish – “we have it for breakfast, lunch and dinner,” Suhail noted – but the climate crisis and overfishing are shifting how and when communities can fish. Tuna makes up 98% of all fish caught in the Maldives, but warmer ocean temperatures are changing migratory patterns, pushing the species into deeper, colder waters.

    As a critical economic and cultural resource, the government has outlined a range of solutions to protect the fisheries sector in its first Biennial Transparency Report to the UN. These include using real-time tracking data to improve the efficiency of fishing operations; investing in canneries to increase fish storage; and diversifying away from tuna through marine farming.

    Koagannu Cemetery, a 900-year-old resting place in the Maldives, is threatened by rising sea levels in the Indian Ocean. (Image: Ashwa Faheem) 

    Koagannu Cemetery, a 900-year-old resting place in the Maldives, is threatened by rising sea levels in the Indian Ocean. (Image: Ashwa Faheem) 

    Culture and nature go hand-in-hand

    The same pattern is playing out elsewhere.

    Palau and the Maldives are not close to one another. The two states are separated by around 4,000 miles and sit in different corners of the ocean. But both are experiencing very similar climate challenges, based on their position as a set of scattered, low-lying islands surrounded by an imposing body of blue water.

    In the same way as the Maldives, Palau’s cultural heritage is closely tied to “land, coastlines and traditional food systems,” according to Toni Soalabla, at the Palau Office of Climate Change.

    “Many of the places that hold stories, history and identity of our communities are located along the coast and are increasingly exposed to erosion and sea level rise,” she said.

    One of these places is Ngerutechei village, reportedly the oldest in Palau, and home to ancient stone paths and carvings. The village provides a glimpse into the past social values and culture of the people in this western Pacific nation.

    How Vanuatu is facing up to rising climate risks

    As part of the development of Palau’s National Adaptation Plan, the government has worked with local leaders to identify similar sites of cultural significance. The plan encourages communities to use their own knowledge to create protective measures for these sites.

    Climate change is also prompting communities to take up traditional land and food practices again. These include cultivating taro, a stable food source that has historically supported water, soil and food security on the islands. 

    “These systems developed over generations in response to local environmental conditions, so strengthening them today is both a climate adaptation measure and a way of maintaining cultural knowledge that might otherwise fade,” said Soalabla.

    Cultural practices in Palau have developed alongside the natural ecosystems that people rely on to survive. It is within this context that researchers believe adaptation policies should be created. Recognising this relationship “can strengthen both community identity and environmental resilience at the same time”, according to Soalabla.

    Taro farming is making a return to Palau as a traditional source of food security. (Image: Kiara Worth / IISD / Palau Office of Climate Change)

    Taro farming is making a return to Palau as a traditional source of food security. (Image: Kiara Worth / IISD / Palau Office of Climate Change)

    An ancient monolith in Ngerutechei village is being protected against coastal erosion. (Image: Kiara Worth / IISD / Palau Office of Climate Change).

    An ancient monolith in Ngerutechei village is being protected against coastal erosion. (Image: Kiara Worth / IISD / Palau Office of Climate Change).

    Heritage on the global stage

    The issue of cultural loss has not gone unnoticed in international climate negotiations. 

    Small island states such as the Maldives have used their role at the UN to push for greater awareness and action, with some key successes.

    In 2015, the Paris Agreement established a Global Goal on Adaptation (GGA) which recognised that countries needed to do something about climate change now and not later. However, it took six years before a framework and a set of adaptation targets were agreed at the UN climate summit in Glasgow to pursue this goal. 

    From this came the establishment of seven overall themes – from poverty eradication to access to health – to guide adaptation action and a set of around 60 indicators to measure progress against the targets.

    World leaders invited to see Pacific climate destruction before COP31

    Emilie Beauchamp, an adaptation specialist at the International Institute for Sustainable Development (IISD), said that “cultural heritage was highlighted as one of the global priorities [of the GGA Framework] and is one of the seven themes, so it is considered very important by the international community.”

    The much-debated set of indicators, only finalised in Belém at last year’s COP30, include five related to cultural heritage with a focus on preserving cultural practices and important sites that are “guided by traditional knowledge, Indigenous Peoples’ knowledge and local knowledge systems”. A spokesperson for UNESCO said the inclusion of heritage indicators “marks an important recognition that climate impacts extend beyond economic losses”. 

    While critics said the set of final indicators was rushed through by the Brazilian presidency, they now serve as guidance for national governments that wish to implement plans to protect their common heritage. The missing piece of the puzzle remains how to finance these plans – something notably absent from the Belém text, which made clear that the adaptation indicators “do not create new financial obligations or commitments, nor liability or compensation”.

    The lack of financial commitments proved disappointing for many small states grappling with how to prevent their cultural history from being entirely forgotten, especially at a time when adaptation finance remains below requirements. A recent UNEP report found that developing nations would need an estimated US$310 billion per year in 2035 to adapt to climate change, while current public financing was around $26 billion.

    At these low levels “only a small percentage of what the framework outlines could be implemented,” according to Beauchamp.

    Recent research from WRI and UNESCO found 73% of non-marine World Heritage Sites are threatened by at least one severe water risk.

    Recent research from WRI and UNESCO found 73% of non-marine World Heritage Sites are threatened by at least one severe water risk.

    The challenge of cultural heritage

    When looking at low-lying islands on a map, they can appear as specks of land amid a vast ocean. Many of the stories from these remote places go unnoticed. But the specks represent millennia of human culture that is slowly being lost to the ocean.

    While the international community has now recognised the problem and solutions exist, the recurring issue of scarce finance may prevent governments from taking sustained action. Island communities have already been forced to move home as sea levels rise, leaving behind their cultural connections to a place.

    The value of any cultural asset, or of human heritage, can be judged by how it is engaged with over generations. Without human intervention, many historical sites, language, cuisine and other local customs would become a forgotten part of history. The rapid onset of climate change brings the role of cultural heritage into sharp relief, challenging communities to decide in real time what they value, what deserves saving, and how to achieve that.

    Stories of cultural loss are not confined to small islands but it is here where the challenge is presenting most acutely. The experiences of these vulnerable nations in protecting their heritage will provide the litmus test for effective adaptation responses elsewhere.

    Adam Wentworth is a freelance writer based in Brighton, UK.

    (Main image: The Isdhoo Havitha is an ancient Buddhist monastery in the Maldives, located moments from the shoreline. Photo: Ashwa Faheem) 

    The post Island nations fight to save cultural heritage from climate change appeared first on Climate Home News.

    Island nations fight to save cultural heritage from climate change

    Continue Reading

    Climate Change

    The Wabanaki Basketmakers’ Plans to Save Maine’s Ash Trees

    Published

    on

    The invasive emerald ash borer, native to northeast Asia, has spread to 37 states over the past quarter century, killing nearly all of the ash trees it infests. But in Maine, a coalition of basketmakers, scientists and government officials are plotting a future for their trees.

    Each strip of wood in Richard Silliboy’s hands started as a year of an ash tree’s life.

    The Wabanaki Basketmakers’ Plans to Save Maine’s Ash Trees

    Continue Reading

    Trending

    Copyright © 2022 BreakingClimateChange.com