Published

5 months ago

March 6, 2026

Alice Rush

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.

Saint Basil's Cathedral, on Red Square, in Moscow, was affected by smog during the fires in Russia in the summer of 2010. — Saint Basil’s Cathedral, on Red Square, in Moscow, was affected by smog during the fires in Russia in the summer of 2010. Credit: ZUMA Press, Inc. / Alamy Stock Photo

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.

Charts showing spatial and temporal occurrences over study period — Spatial and temporal occurrence of compound drought and heatwave events over the study period from 1980 to 2023. The map (top) shows CDHEs around the world, with darker colours indicating higher frequency of occurrence. The chart in the bottom left shows how much land surface was affected by a compound event in a given year, where red accounts for heatwave-led events, and yellow, drought-led events. The chart in the bottom right shows the relative increase of each CDHE type in 2002-23 compared with 1980-2001. Source: Kim et al. (2026)

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

Climate Change

UN chief warns climate crisis “in overdrive” as El Niño threatens to fuel the fire

Published

14 hours ago

July 31, 2026

Alice Rush

The United Nations Secretary-General and foreign ministers from the UK, France and Spain have blamed the deadly wildfires engulfing Europe on climate change, using the disaster to renew calls for faster cuts to greenhouse gas emissions.

António Guterres told journalists on Friday that the “climate crisis is in overdrive”, adding that global heat seen so far is just a “warm up act” as a phenomenon known as El Niño intensifies “adding fuel to a planet already on fire”.

A new World Meteorological Organisation (WMO) report published on Friday predicts that the weather pattern will grow into a “strong event” between now and October, increasing the risk of higher than normal temperatures across much of the world and disrupted rainfalls.

“That risks shattering every seasonal record – and driving even more severe effects worldwide,” Guterres said.

El Niño builds on top of an already warming world, driven primarily by the burning of fossil fuels. A WMO scientist, who did not want to be named, told journalists that all the heatwaves and other climate impacts seen so far this year are “before the effects of El Niño are really kicking in at a global scale”.

Fossil fuellling the fires

Fires have broken out across much of Europe but are threatening the most people in the south-west of France near Bordeaux and in Central Spain near Madrid. Nearly a quarter of a million people have been evacuated in France with hundreds of homes destroyed while in Spain 80,000 people have had to leave their homes and at least 13 died in one village.

A scientific study published on Friday by the World Weather Attribution group found that man-made climate change made deadly fires in France twice as likely and those in Spain twenty times more likely. Smaller fires in the UK were not analysed by the study.

UN Climate Change leader Simon Stiell blamed fossil fuels for the fires, as well as storms in Chile and heatwaves in North America and Japan in recent weeks. “The climate alarm is blaring”, he said on Wednesday.

Guterres criticised new fossil fuel production projects and fossil fuel subsidies for causing hardship across the world. Discussing his speech, a senior UN official – who did not want to be named – said the subsidies amounted to trillions of US dollars a year and criticised pension funds and institutional investors, including insurance companies, for continuing to invest in fossil fuel projects.

The head of the United Nations Antonio Guterres (right) with the head of the UN’s climate arm Simon Stiell (left) at COP30 (Photo: Kiara Worth/UNFCCC)

Asked why world leaders and the public are not prioritising climate action, Guterres said they are distracted by wars in Ukraine, the Middle East, Sudan and elsewhere and sometimes forget “other aspects that are a sometimes even more dangerous threat”.

Also the fossil fuel industry and “some countries” are campaigning to pretend that climate change does not exist, he said, adding that the UN should be more active in “naming the situations as they are and the responsibilties as they are and mobilising the public opinion”.

After meetings in Paris and Madrid earlier in the week, the UK’s new foreign minister Ed Miliband issued joint statements with his French and Spanish counterparts – Jean-Noël Barrot and José Manuel Albares Bueno – calling on the world to reduce its dependence on fossil fuels.

They promised to do more to reduce emissions and protect their people and encouraged other governments to do the same.

The UK-French statement called on governments to publish UN climate plans, known as nationally determined contributions (NDCs), which are aligned with the Paris Agreement’s goal to limit global average temperatures to 1.5C above pre-industrial levels.

According to Climate Action Tracker, only three countries – the UK, Nigeria and Norway – have submitted NDCs with 2035 emissions reduction targets which are compatible with 1.5C. Fifty-two countries – including Egypt, Vietnam and Argentina – have yet to submit an NDC at all.

Defending science

Beyond action on emissions, the ministers also intervened in an ongoing dispute over the timing of the Intergovernmental Panel on Climate Change’s (IPCC)’s next flagship assessment.

Miliband and Barrot’s statement said they “underline the importance” of scientific report feeding into governments’ next global stocktake of progress on climate action in two years’ time, calling it a “critical input” to that process.

The timing of this report has been a contentious issue in government negotiations at the IPCC and at June’s climate talks in Bonn. While a group of nations calling themselves the “friends of science” want the report before the stocktake, others like Saudi Arabia and India have argued that this would make the report of a worse quality and less inclusive of developing countries’ scientists.

Science ‘under attack’ from fossil fuel interests at UN climate talks

The UK-Spanish statement weighed in less explicitly on this issue but said that they “recall the importance of scientific evidence and acknowledge the work of the IPCC in this respect.”

The British and French ministers said they would seek to accelerate reductions of emissions in methane, a particularly potent greenhouse gas, at COP31 in November. They encouraged governments “to work jointly to develop a marketplace for fossil fuels with near-zero methane intensity.”

Methane leaks from oil, gas and coal production are a major contributor to global warming. Over a 20-year period, methane traps around 80 times more heat than carbon dioxide.

Ed Miliband meets José Manuel Albares Bueno in Madrid on 29 July 2026. (Picture by Ed Morris / FCDO)

The UK and Spanish statement emphasised the importance of supporting the Global South and underlined the need to mobilise sustainable financing “at scale with the challenge we face”. The previous UK government, in which Miliband was energy minister, cut climate finance to developing countries to pay for increases in military spending.

The UK government led by new Prime Minister Andy Burnham has yet to outline any major changes to climate finance in its two weeks in power but has announced it will convert some finance from grants to loans in order to free up money to subsidise bus travel in England.

More adaptation needed

Guterres said that “it is time to stop treating each disaster as an isolated tragedy and recognise the systemic risk that is unfolding before our eyes.” A recent study found that three-quarters of UK media reports about the British June heatwave did not mention climate change.

As well as reducing emissions, the UN Secretary-General called for measures to adapt vulnerable people to extreme heat. Specifically, he said that buildings should be built and retrofitted for extreme heat and that every city and country should have heat-health action plans and early warning systems. Over 250 cities have joined the UN’s ‘beat the heat’ initiative, he said.

The Portuguese diplomat called for governments and employers to do more to protect their workers from heat, criticising global fashion brands for not setting heat standards for the factories that supply them. “No one should have to risk their life to earn a living,” he said.

The post UN chief warns climate crisis “in overdrive” as El Niño threatens to fuel the fire appeared first on Climate Home News.

UN chief warns climate crisis “in overdrive” as El Niño threatens to fuel the fire

Climate Change

‘Ride the wave of momentum’: Australia announces once-in-a-decade Marine Parks Network review

Published

1 day ago

July 30, 2026

Alice Rush

In response to the federal government announcing its once-in-a-decade review of Australia’s Marine Parks Network, the following lines can be attributed to Elle Lawless, Senior Campaigner at Greenpeace Australia Pacific:

“Greenpeace Australia Pacific welcomes today’s announcement that the Albanese Government will review Australia’s Commonwealth Marine Parks Network. This is a rare, once-in-a-decade opportunity to strengthen our marine parks and ban industrial fishing in Australia’s marine protected areas.

“Australians would be appalled to know that more than half of Australia’s Marine Parks Network currently allows for extractive industries, like longlining, bottom trawling and oil and gas mining. These so-called ‘protected’ areas were designed to safeguard our beloved ocean wildlife and underwater ecosystems – that is what Australians expect. Damaging industrial industries should not be given a free pass to trawl, fish, drill or extract from our marine parks.”

“With the first Ocean COP just around the corner, and off the back of Australia’s move to ratify the Global Ocean Treaty earlier this year, the Australian government has a unique opportunity to ride the wave of this momentum and solidify itself as a true global ocean leader.

“Greenpeace Australia Pacific is calling for industrial activities to be banned from our protected waters and for at least 30% of Australia’s ocean to be protected as ocean sanctuaries. This review presents a rare opportunity to create more ocean sanctuaries, true blue havens where ocean life can recover, thrive and repopulate the surrounding waters.”

—ENDS—

‘Ride the wave of momentum’: Australia announces once-in-a-decade Marine Parks Network review

Climate Change

Factcheck: No, Europe is not having its ‘quietest’ year for wildfires

Published

1 day ago

July 30, 2026

Alice Rush

In recent days, prominent climate sceptics and rightwing commentators have shared charts on social media incorrectly implying that Europe is having its “quietest” year for wildfires in 2026.

These include Dr Matthew Wielicki, a former University of Alabama geochemist and self-described “professor in exile”, who was recently appointed by the Trump administration to lead the US Global Change Research Program.

However, these charts paint a misleading picture as they are skewed by encompassing the entirety of Russia in the data – including the vast plains of Siberia.

These charts also use data that include fires that are deliberately lit to manage cropland, which is a declining practice across much of Europe.

In this factcheck, Carbon Brief shows that the area burned by wildfires across the European Union in 2026 is second only to 2022 for this time of year.

The latest data from the European Forest Fire Information System (EFFIS) also shows that France has set a new modern record for area burned and Spain’s wildfire season is among the worst on record.

The fires have displaced more than a third of a million people across south-western Europe, while an impending heatwave has also raised fears of the fires worsening in the coming days.

‘Quietest year’

On 27 July, as wildfires raged across multiple European countries, former Conservative peer and climate-sceptic commentator Matt Ridley posted on Twitter that “2026 is the quietest year for wildfires in Europe by some distance”.

Ridley, who sits on the academic advisory council of the Global Warming Policy Foundation (GWPF), a UK-based climate-sceptic lobby group that refuses to reveal the sources of its funding, was responding to an article by Daily Telegraph columnist Tim Stanley.

Stanley’s column, headlined: “Climate change is real – and the right needs to get serious about it”, warned:

“This is no longer a matter of speculation: the wildfires of Europe, pitiless and persistent, are the way we live now.”

Ridley included a chart from Our World In Data, showing the cumulative area burned by wildfires by week for Europe. The chart puts 2026 as having the smallest area for this time of year in a dataset going back to 2012.

Ridley’s post was widely shared by prominent rightwing figures – including Richard Tice, deputy leader of the hard-right, climate-sceptic Reform UK party, former Conservative cabinet minister Jacob Rees-Mogg and multiple commentators.

Separately, Wielicki also shared a chart on Twitter to imply that wildfires in Europe are declining. Wielicki has previously claimed that the “science is not settled on climate change”.

The charts posted by Ridley and Wielicki both use data from the Global Wildfire Information System (GWIS). The GWIS category for “Europe” encompasses all the countries on the continent and includes the whole of Russia.

As a result, Russia accounts for about 74% of the area included in the GWIS definition of “Europe”.

Wildfires in Russia typically account for 80-90% of the burned area in the GWIS Europe dataset. In 2026, fires in Russia are substantially below average. Therefore, including Russia in this comparison creates the false impression that wildfire activity across Europe is unusually low.

Dr Calum Cunningham, a research fellow at the University of Tasmania’s Fire Centre, says that such claims are “highly misleading”, noting that “they rely on aggregating fire activity across an enormous and climatically diverse region”. He tells Carbon Brief:

“A relatively quiet season in Russia can easily mask an exceptionally active season in France or Spain. If the analysis is focused on the regions actually experiencing the current fires, the picture is very different.

“The reality is that western Europe has experienced an extraordinary sequence of climate conditions this year.”

In contrast, the EFFIS provides a subset of wildfire data specifically for the area covered by the 27 nations of the EU, which, therefore, excludes Russia.

Another difference between the two datasets is that GWIS monitors all fires – including those on agricultural land that are intentionally set alight. The burned area as measured by GWIS contains significant cropland area.

By contrast, EFFIS uses land-cover data and other information to filter specifically for forest fires.

Looking at the EU-only data from EFFIS reveals that Europe is far from having its “quietest” year. The bloc’s burned area, as of 29 July, is almost 435,000 hectares (ha) – second only to 2022 for this time of year.

The area burned by wildfires in the EU in 2026 by end of July is second only to 2022. Weekly cumulative burned area (hectares). Line graph shows 2026 burned area reaching over 400,000 hectares by late July, far exceeding the 2006-2025 average. Source: EFFIS - (alt text generated by Google Gemini)

Notably, Wielicki has actually continued to post charts based on GWIS data, even after acknowledging that “includ[ing] all of Russia, including vast areas of Siberia…isn’t a good proxy for Europe”.

French fires

Even looking at EU-wide data misses the scale of this year’s wildfires for some individual countries.

The chart below shows the surge in burned area in France since mid-July.

For much of the first half of the year, the country was having a wildfire season that was only slightly above average in terms of total burned area. However, a notable uptick began in the first week of July.

The third week of the month saw France break its previous cumulative annual record by more than 19,000ha. That gap has widened as the fires continue to burn; as of 29 July, the cumulative burned area in France during 2026 was nearly 24,700ha above the previous record.

France's wildfires in 2026 are the most widespread in modern records. Weekly cumulative burned area (hectares). A line chart shows 2026 burned area sharply rising by August to over 90,000 hectares, well above the 2006-2025 range maximum of around 65,000 and average of 15,000. Source: EFFIS - (alt text generated by Google Gemini)

The fires in France follow a record-breaking June heatwave that “dried out vegetation across the region, allowing fires to spread quickly”, wrote the New York Times.

On 27 July, French president Emmanuel Macron called a “crisis cabinet meeting” in order to address the fires “ravaging several areas of south-west France”, said France 24.

More than 220,000 people have been evacuated due to the Gironde fire, west of Bordeaux, in “what may be France’s largest peacetime evacuation”, reported the Associated Press.

In the Conversation, Cunningham and two other University of Tasmania researchers write that evacuation orders “protec[t] human lives, but makes it more likely houses and other structures will burn if there’s no one to defend them”. They add:

“There is little doubt climate change has made France and Spain’s wildfires worse. They represent yet another reason to redouble our efforts to tackle climate change and stabilise our climate.”

Central Spain scorched

While Spain’s fire season has not broken records in the same way that France’s has, it is on track to be among the worst since EFFIS began reporting data in 2006.

The chart below shows the rapid increase in burned area in Spain since 8 July. The latest data from EFFIS reveal that, as of 29 July, Spain has almost matched its previous record at this point in the year. It is also nearly five times the average area burned for this time of year.