Welcome to Carbon Brief’s Cropped.
We handpick and explain the most important stories at the intersection of climate, land, food and nature over the past fortnight.
This is an online version of Carbon Brief’s fortnightly Cropped email newsletter. Subscribe for free here.
Key developments
Trump chaos
TRUMP TARIFFS: US president Donald Trump’s escalating trade war with the rest of the world sent ripples through global food markets this month. Trump introduced a 10% tariff on goods imported from China, but delayed his planned 25% tariffs on Canada and Mexico after reaching a deal for the two countries to increase border controls, the Associated Press reported. Reuters said that retaliatory tariffs from countries targeted by Trump could significantly harm the US agricultural sector. China, Canada and Mexico are the “top three markets” for US farm products and imported $94bn in agricultural goods from the nation in 2023, according to the newswire. CNN presented three charts illustrating how the tariff war could increase the prices of US groceries, from “fresh avocados to dairy products”.
AID CUTS: The Trump administration also unveiled dramatic reductions to the work of USAid, the country’s main international development arm, the New York Times reported, with leaked plans suggesting staff would be cut from 14,000 to just 294. The move has put around $500m of food aid at risk of spoilage after staff cuts and funding freezes have left the agency in “chaos”, the Guardian reported. Reuters said the dismantling of USAid “is crippling the intricate global system that aims to prevent and respond to famine”. Civil Eats reported that USAid typically purchases $2bn in rice, wheat, lentils and peas from US farmers each year, “prompting questions about how the agency’s shuttering might also impact rural America”. Bloomberg said the Department of Agriculture confirmed that the US will keep buying agricultural commodities to supply food aid in the world’s poorest countries.
NATURE AT RISK: The dismantling of USAid could also have large ramifications for global efforts to tackle nature loss, the Revelator reported, noting that the agency funds efforts to “reduce wildlife poaching and trafficking, tackle deforestation, assist environmental refugees, study animal populations in the wild and protect people in critical habitats”. The New York Times reported that the 150 scientists behind the first US national nature assessment, which was shut down by a Trump executive order, are hoping to find a way to release their findings without government backing. It comes after the assessment’s lead author, Dr Phil Leven, sent an email to his fellow authors saying “this work is too important to die”, according to the publication.
Natural heritage at risk
ECOSYSTEMS THREATENED: Three-quarters of the world’s “natural heritage sites” will face at least one “climate pressure” by the end of the century, under an “intermediate” scenario of climate change, according to new research covered by Carbon Brief. Natural heritage sites are those that are “recognised internationally as the most important ecosystems on Earth”, including sites such as the Galápagos Islands, Serengeti national park and the Great Barrier Reef, according to the article. The research also found that, under the highest emissions scenarios, nearly all such sites will experience extreme heat exposure, with many also facing the compounding impacts of drought or extreme rainfall, by 2100.
BIODIVERSITY LOSS: As part of their study, the authors assessed biodiversity loss inside natural heritage sites to date. They identified 14 natural heritage sites with “vulnerable” levels of biodiversity. These were mainly located in South America, mainland Africa, and on various coasts and islands, including Brazil’s Pantanal conservation complex, Mount Kenya’s national park and Australia’s Ningaloo Coast, according to the research. The researchers added that these vulnerable sites are likely to face the greatest climate risks as the planet warms. Elsewhere, the Guardian reported on efforts to save polar heritage sites on a Canadian Arctic island sinking into the Beaufort Sea.
Spotlight
How global trade harms forest species
This week, Carbon Brief explores a new Nature study which examined how consumption in 24 countries leads to “outsourced” deforestation and biodiversity loss.
Deforestation linked to consumption in major economies, such as the US and China, is harming forest-dwelling animals, according to a new study.
The research found that consumption in many nations led to “outsourced losses of biodiversity” as a result of forest clearance abroad.
The impacts are “substantial, widely distributed and strongly structured by geography and trade linkages”, the study noted. The lead study author, Alex Wiebe, a graduate student at Princeton University, was “surprised” by the magnitude of the findings. He told Carbon Brief:
“The cumulative [biodiversity loss] impacts of the countries we examined were 15 times greater to species outside of their borders than within them. This suggests that the vast majority of a developed country’s impacts on global biodiversity happens outside of its borders.”
The researchers quantified the loss of area in which more than 7,500 forest-dwelling birds, mammals and reptiles lived around the world between 2001 and 2015.
They analysed a dataset attributing land deforested during the study period to the production of goods imported and consumed in 24 countries – including the US, China and UK.
Many of these countries are “effectively moving biodiversity losses overseas”, the study concluded, by “driving land-use change in other countries through their consumption of imported agricultural and forestry products”.
‘Disproportionate harm’ on far-flung species
The findings showed that the US contributed by far the most to international forest species’ range loss, followed by Japan and China.
Dr Janice Lee, an environmental scientist at Nanyang Technological University in Singapore, said the study “advances our understanding and quantification of how international trade affects global biodiversity.”
The “important work” adds to ongoing discussions around the impact of global trade on deforestation and biodiversity, Lee, who was not involved in the research, told Carbon Brief.
Many of the impacts occurred between neighbouring countries, but in some cases nations “inflicted disproportionate harm” on species thousands of miles away, the study said.
Almost half of all of the species range losses recorded far away from the examined countries were in Madagascar, possibly driven by deforestation for vanilla production, the researchers wrote.
Dr Erasmus zu Ermgassen, a scientist at Belgian university UCLouvain, said the study is “interesting”, but “perhaps a bit one-dimensional”.
Zu Ermgassen, who was not involved in the study, noted that biodiversity loss can be driven by “domestic economies and politics within the tropics” as well, rather than solely from consumption abroad. He added that species range impacts do not consider “other wildlife, habitats, nor the humans living in those landscapes”.
The study noted the “limited spatially explicit data on attributable deforestation” and the complications that would occur with broadening the research scope.
The impact countries have on biodiversity in other parts of the world is a topic that deserves more attention, Wiebe told Carbon Brief, noting:
“In the future, understanding how countries impact non-forest species, how the impacts of countries are changing over time, and which products are most closely tied with threats to wildlife in different parts of the world will all be important to investigate.”
News and views
SUSANA QUITS: Colombian politician Susana Muhamad resigned as environment minister, leaving her position as president of the COP16 nature talks in question, El Espectador reported. COP16 will resume in Rome on 25 February after countries failed to find consensus on all negotiating issues in Colombia in 2024. In a public resignation letter, Muhamad appealed to her president, Gustavo Petro, for permission to stay on as head of the talks. In an interview with Colombian TV network Noticias Caracol, Muhamad confirmed it will be down to Petro to decide if she can remain in post.
FOOD CHAIN RISKS: An Arctic geoengineering project will end its operations after identifying environmental concerns and “potential risks” to the region’s food chain, Climate Home News reported. Climate and Indigenous campaigners “welcomed” the shutdown of the experimental project, which aimed to release small silica particles over the ocean to “in theory reflect sunlight from the surface and cool down melting ice”, the outlet said. Panganga Pungowiyi from the Indigenous Environmental Network, told Climate Home News: “Our concerns about the reckless use of harmful materials were dismissed, yet we knew that the health of our ecosystems and the wisdom of our people must not be overlooked.”
CLEARING WAY: Indonesia’s government is eyeing up 2.3m hectares of protected forest – “an area 30 times the size of New York City” – that could be converted to produce food and biofuel crops, according to Mongabay. This formed part of wider plans to convert 20m hectares of forest into “food and energy estates”, which the outlet said could lead to the “largest deforestation project in the country’s history”. The consideration to convert protected land “raised alarms among environmental groups and lawmakers”, the outlet said. The country’s forestry minister, Raja Juli Antoni, said that the plan does not target pristine rainforests, arguing that it could rehabilitate degraded protected forest areas, Mongabay added.
SHARK ATTACKS: The Times reported that a spate of deadly shark attacks in Australia have coincided with a warning from scientists that warming seas could be drawing the predators closer to popular swimming locations. Prof Culum Brown, a shark expert at Sydney’s Macquarie University, told the publication that the city “needed to prepare for more sharks in popular swimming areas as climate change raises sea temperatures and makes conditions more hospitable for the predators, especially bull sharks”. Australia’s NewsWire reported that a “long-term increase” in shark attacks occurring could be linked to both “an increasing number of people swimming in the ocean and climate change”.
MINING FOR GOLD: Permits for at least 79 “semi-industrial gold mining and exploration projects” were issued in the Sangha region of the Republic of Congo over the past four years – “despite the area being officially designated for a REDD+ project”, a Mongabay investigation found. REDD+ projects are “designed to reduce deforestation”, but “since mining contributes to deforestation, these two activities are fundamentally incompatible”, environmentalist Justin Landry Chekoua told the outlet. Mongabay further detailed the impact of mining in the Sangha region, in which forests have been uprooted and “streams that were once drinkable are now vast, muddy stretches of uninviting water”.
CATTLE CONSPIRACY: Scientists described misinformation about a methane-cutting cattle feed additive as a “wake-up call” to improve communication with farmers and the public, the Guardian reported. Last November, major food company Arla announced plans to pilot using Bovaer, a cattle feed additive, to “reduce the carbon footprint of its products”, the Guardian said. This “quickly became a social media storm about the health effects of the additive, with people videoing themselves throwing away products by the brand and pouring milk down their sinks in protest”, the newspaper said. The UK’s Food Standards Agency (FSA) said that “there are no safety concerns when Bovaer is used at the approved dose”. The FSA’s chief scientific adviser, Prof Robin May, told a press briefing this week: “The more communication and transparency the better.”
Watch, read, listen
GROWING PAINS: An article in Grist explored how climate change is altering the types of crops grown across the world.
DARK DOLPHIN MAGIC: A short documentary by Mongabay investigated the illegal exploitation of endangered pink river dolphins in the Amazon, driven by a myth about their magical properties.
REVEALING REVOLUTION: Through photographs, Undark magazine showed the “downstream effects of India’s green revolution”.
SPOKEN WORD: The Third Pole Podcast from Dialogue Earth explored the impact of climate change on Indigenous languages in Pakistan’s remote mountain communities.
New science
- Climate change could have a variable impact on cocoa yields in west and central Africa, a region responsible for much of the world’s production, according to new research in Agricultural and Forest Meteorology. The study found that wetter conditions could drive yield increases in Nigeria and Cameroon, but decreases in the Ivory Coast and Ghana.
- The widespread deployment of bioenergy with carbon capture and storage (BECCS) to remove CO2 from the atmosphere would violate multiple “planetary boundaries”, according to a new study in Communications Earth and Environment. It noted that widespread BECCS use would have the largest impact on the boundary for land ecosystems.
- A new rice variety showed methane emission reductions of up to 70% in paddy field trials over a three-year period, according to a Molecular Plant study. The findings “offer great possibilities” to mitigate the climate impact of rice, the researchers claim.
In the diary
- 23 February: Germany general election
- 24-28 February: 62nd session of the Intergovernmental Panel on Climate Change | Hangzhou, China
- 25-27 February: Resumed session of the UN biodiversity summit COP16 | Rome
Cropped is researched and written by Dr Giuliana Viglione, Aruna Chandrasekhar, Daisy Dunne, Orla Dwyer and Yanine Quiroz. Please send tips and feedback to cropped@carbonbrief.org
The post Cropped 12 February 2025: Trump chaos; COP16 leadership in question; How global trade harms forest species appeared first on Carbon Brief.
Drought and heatwaves occurring together – known as “compound” events – have “surged” across the world since the early 2000s, a new study shows.
Compound drought and heat events (CDHEs) can have devastating effects, creating the ideal conditions for intense wildfires, such as Australia’s “Black Summer” of 2019-20 where bushfires burned 24m hectares and killed 33 people.
The research, published in Science Advances, finds that the increase in CDHEs is predominantly being driven by events that start with a heatwave.
The global area affected by such “heatwave-led” compound events has more than doubled between 1980-2001 and 2002-23, the study says.
The rapid increase in these events over the last 23 years cannot be explained solely by global warming, the authors note.
Since the late 1990s, feedbacks between the land and the atmosphere have become stronger, making heatwaves more likely to trigger drought conditions, they explain.
One of the study authors tells Carbon Brief that societies must pay greater attention to compound events, which can “cause severe impacts on ecosystems, agriculture and society”.
Compound events
CDHEs are extreme weather events where drought and heatwave conditions occur simultaneously – or shortly after each other – in the same region.
These events are often triggered by large-scale weather patterns, such as “blocking” highs, which can produce “prolonged” hot and dry conditions, according to the study.
Prof Sang-Wook Yeh is one of the study authors and a professor at the Ewha Womans University in South Korea. He tells Carbon Brief:
“When heatwaves and droughts occur together, the two hazards reinforce each other through land-atmosphere interactions. This amplifies surface heating and soil moisture deficits, making compound events more intense and damaging than single hazards.”
CDHEs can begin with either a heatwave or a drought.
The sequence of these extremes is important, the study says, as they have different drivers and impacts.
For example, in a CDHE where the heatwave was the precursor, increased direct sunshine causes more moisture loss from soils and plants, leading to a drought.
Conversely, in an event where the drought was the precursor, the lack of soil moisture means that less of the sun’s energy goes into evaporation and more goes into warming the Earth’s surface. This produces favourable conditions for heatwaves.
The study shows that the majority of CDHEs globally start out as a drought.
In recent years, there has been increasing focus on these events due to the devastating impact they have on agriculture, ecosystems and public health.
In Russia in the summer of 2010, a compound drought-heatwave event – and the associated wildfires – caused the death of nearly 55,000 people, the study notes.
The record-breaking Pacific north-west “heat dome” in 2021 triggered extreme drought conditions that caused “significant declines” in wheat yields, as well as in barley, canola and fruit production in British Columbia and Alberta, Canada, says the study.
Increasing events
To assess how CDHEs are changing, the researchers use daily reanalysis data to identify droughts and heatwaves events. (Reanalysis data combines past observations with climate models to create a historical climate record.) Then, using an algorithm, they analyse how these events overlap in both time and space.
The study covers the period from 1980 to 2023 and the world’s land surface, excluding polar regions where CDHEs are rare.
The research finds that the area of land affected by CDHEs has “increased substantially” since the early 2000s.
Heatwave-led events have been the main contributor to this increase, the study says, with their spatial extent rising 110% between 1980-2001 and 2002-23, compared to a 59% increase for drought-led events.
The map below shows the global distribution of CDHEs over 1980-2023. The charts show the percentage of the land surface affected by a heatwave-led CDHE (red) or a drought-led CDHE (yellow) in a given year (left) and relative increase in each CDHE type (right).
The study finds that CDHEs have occurred most frequently in northern South America, the southern US, eastern Europe, central Africa and south Asia.
Threshold passed
The authors explain that the increase in heatwave-led CDHEs is related to rising global temperatures, but that this does not tell the whole story.
In the earlier 22-year period of 1980-2001, the study finds that the spatial extent of heatwave-led CDHEs rises by 1.6% per 1C of global temperature rise. For the more-recent period of 2022-23, this increases “nearly eightfold” to 13.1%.
The change suggests that the rapid increase in the heatwave-led CDHEs occurred after the global average temperature “surpasse[d] a certain temperature threshold”, the paper says.
This threshold is an absolute global average temperature of 14.3C, the authors estimate (based on an 11-year average), which the world passed around the year 2000.
Investigating the recent surge in heatwave-leading CDHEs further, the researchers find a “regime shift” in land-atmosphere dynamics “toward a persistently intensified state after the late 1990s”.
In other words, the way that drier soils drive higher surface temperatures, and vice versa, is becoming stronger, resulting in more heatwave-led compound events.
Daily data
The research has some advantages over other previous studies, Yeh says. For instance, the new work uses daily estimations of CDHEs, compared to monthly data used in past research. This is “important for capturing the detailed occurrence” of these events, says Yeh.
He adds that another advantage of their study is that it distinguishes the sequence of droughts and heatwaves, which allows them to “better understand the differences” in the characteristics of CDHEs.
Dr Meryem Tanarhte is a climate scientist at the University Hassan II in Morocco, and Dr Ruth Cerezo Mota is a climatologist and a researcher at the National Autonomous University of Mexico. Both scientists, who were not involved in the study, agree that the daily estimations give a clearer picture of how CDHEs are changing.
Cerezo-Mota adds that another major contribution of the study is its global focus. She tells Carbon Brief that in some regions, such as Mexico and Africa, there is a lack of studies on CDHEs:
“Not because the events do not occur, but perhaps because [these regions] do not have all the data or the expertise to do so.”
However, she notes that the reanalysis data used by the study does have limitations with how it represents rainfall in some parts of the world.
Compound impacts
The study notes that if CDHEs continue to intensify – particularly events where heatwaves are the precursors – they could drive declining crop productivity, increased wildfire frequency and severe public health crises.
These impacts could be “much more rapid and severe as global warming continues”, Yeh tells Carbon Brief.
Tanarhte notes that these events can be forecasted up to 10 days ahead in many regions. Furthermore, she says, the strongest impacts can be prevented “through preparedness and adaptation”, including through “water management for agriculture, heatwave mitigation measures and wildfire mitigation”.
The study recommends reassessing current risk management strategies for these compound events. It also suggests incorporating the sequences of drought and heatwaves into compound event analysis frameworks “to enhance climate risk management”.
Cerezo-Mota says that it is clear that the world needs to be prepared for the increased occurrence of these events. She tells Carbon Brief:
“These [risk assessments and strategies] need to be carried out at the local level to understand the complexities of each region.”
The post Heatwaves driving recent ‘surge’ in compound drought and heat extremes appeared first on Carbon Brief.
Heatwaves driving recent ‘surge’ in compound drought and heat extremes
Greenhouse Gases
DeBriefed 6 March 2026: Iran energy crisis | China climate plan | Bristol’s ‘pioneering’ wind turbine
Welcome to Carbon Brief’s DeBriefed.
An essential guide to the week’s key developments relating to climate change.
This week
Energy crisis
ENERGY SPIKE: US-Israeli attacks on Iran and subsequent counterattacks across the Middle East have sent energy prices “soaring”, according to Reuters. The newswire reported that the region “accounts for just under a third of global oil production and almost a fifth of gas”. The Guardian noted that shipping traffic through the strait of Hormuz, which normally ferries 20% of the world’s oil, “all but ground to a halt”. The Financial Times reported that attacks by Iran on Middle East energy facilities – notably in Qatar – triggered the “biggest rise in gas prices since Russia’s full-scale invasion of Ukraine”.
‘RISK’ AND ‘BENEFITS’: Bloomberg reported on increases in diesel prices in Europe and the US, speculating that rising fuel costs could be “a risk for president Donald Trump”. US gas producers are “poised to benefit from the big disruption in global supply”, according to CNBC. Indian government sources told the Economic Times that Russia is prepared to “fulfil India’s energy demands”. China Daily quoted experts who said “China’s energy security remains fundamentally unshaken”, thanks to “emergency stockpiles and a wide array of import channels”.
‘ESSENTIAL