Welcome to Carbon Brief’s DeBriefed.
An essential guide to the week’s key developments relating to climate change.
This week
Push for new climate targets
MISSED DEADLINE: During a virtual meeting of 17 world leaders, Brazilian president Luiz Inácio Lula da Silva and UN secretary general António Guterres urged countries to come forward with their overdue climate plans, according to Folha de São Paulo. Diplomats from Brazil, which is hosting COP30, are working with UN officials to encourage countries to launch their new 2035 “nationally determined contributions” (NDCs) by September, Reuters explained. Carbon Brief analysis showed nearly every country missed the original deadline to submit new NDCs in February.
CHINA PLEDGE: Chinese president Xi Jinping announced during the meeting that China will submit its new NDC, covering all economic sectors and all greenhouse gases, ahead of COP30 in November, according to Xinhua. In addition, China Daily reported that Xi told attendees China would not slow down its climate action, “regardless of changes in the international landscape”.
Worst coral bleaching on record
NO END IN SIGHT: Coral bleaching has struck 84% of the world’s reefs in what the International Coral Reef Initiative has described as the worst global bleaching event on record, the Associated Press reported. The ongoing incident, caused by warming oceans, began in 2023 and it is “not clear” when it will end, according to the news outlet.
GLOBAL THREAT: In total, reefs in at least 82 countries and territories “have been exposed to enough heat to turn corals white”, according to the Guardian. Scientists in north and central America “were among the first to raise the alarm” after record ocean temperatures in the summer of 2023 and in recent weeks bleaching has spread to east African reefs, the newspaper added.
Around the world
- CLIMATE-DRIVEN: The early arrival of an April heatwave in north India and Pakistan that saw temperatures reach 49C was “largely driven” by climate change, according to a new analysis by the French organisation ClimaMeter, reported by the Times of India.
- TRADE WAR: The US has announced plans to impose tariffs on solar-panel imports from four southeast Asian countries – with some Cambodian exporters facing duties as high as 3,521% – according to BBC News. Meanwhile, the Trump administration has responded to rumours by stating it has no plans “at this time” to attempt to remove tax exempt status from US climate NGOs, Reuters reported.
- NEW MARKET: Brazil is taking the “initial steps” to launch South America’s first-ever carbon market for major emitters within the country, which is expected to be operating by 2029, according to E&E News.
- AUSTRALIA ELECTION: As Australia’s election looms, right-leaning Coalition leader Peter Dutton has confirmed that he would “scrap a popular tax break” for electric-vehicle drivers, the Guardian reported. Carbon Brief examined where Australia’s major parties stand on climate, energy and biodiversity loss.
- HIGH ENERGY: An energy-security summit hosted in London by the UK government and the International Energy Agency saw prime minister Keir Starmer issue “some of his strongest comments yet” in support of net-zero policies, according to BusinessGreen.
$28 trillion
The scale of the climate-related damage caused by emissions from 111 of the world’s biggest companies, according to a new Nature paper that the Washington Post said could “fuel” global climate litigation.
Latest climate research
- A new study in Nature Climate Change concluded that the urban heat island effect – where cities experience higher temperatures than their surrounding rural areas – increases heat-related deaths, but also currently curbs deaths during cold spells at a higher rate.
- A paper in Nature Reviews Clean Technology, also covered in a Carbon Brief guest post, explored “realistic” roles for hydrogen in the global energy transition, concluding that fuel-cell cars and space heating are “among the least promising applications”.
- Sudden shifts from extreme warm to cold temperatures – and vice-versa – have become more frequent, intense and rapid over the past 60 years, according to new research published in Nature Communications.
(For more, see Carbon Brief’s in-depth daily summaries of the top climate news stories on Tuesday, Wednesday, Thursday and Friday.)
Captured
A Conservative victory over the Liberals in the upcoming Canadian election could lead to nearly 800m extra tonnes of greenhouse gas emissions over the next decade, according to Carbon Brief analysis. Modelling by researchers from Simon Fraser University and University of Victoria shows that if the Conservatives follow through on their pledges to cut various climate policies, Canadian emissions would likely start to creep up in the coming years. However, as the analysis shows, even the Liberals’ policy platform would not put Canada on track to meet any of its climate targets, on the way to net-zero emissions by 2050.
Spotlight
How do the top papal candidates compare on climate?
Following the death of Pope Francis, Carbon Brief explores the various papal contenders’ views on climate issues.
Pope Francis, who died this week, has been praised for making climate action a core part of his work as the spiritual leader of the world’s 1.4 billion Catholics.
His influence extended far beyond the church and included directly lobbying oil companies, engaging in UN climate talks and criticising world leaders’ lack of action.
In 2015, the pope published Laudato Si – the first papal encyclical dedicated to the environment. As Carbon Brief reported at the time, it drew heavily on climate science and even called for fossil fuels to be phased out.
There is much speculation about whether Francis’s successor will continue his relatively progressive agenda, including on climate change.
Below, Carbon Brief examines the climate credentials of the cardinals that have been tipped as most likely to be chosen as the next pope during the church’s secret “conclave” process.
Pietro Parolin
The current favourite to become pope is Pietro Parolin, an Italian cardinal who has served as the Vatican’s secretary of state since 2013. He leads the Holy See’s delegation at UN climate summits.
He has stressed the “unequivocal” evidence and “scientific consensus” behind climate change. Speaking on behalf of Francis at COP28, Parolin described environmental destruction as “an offence against God, a sin that is not only personal, but also structural”.
The Holy See ratified the Paris Agreement in 2022 and has been actively involved in COP negotiations. In 2024, Parolin’s delegation attracted controversy when diplomats accused it of aligning with Saudi Arabia, Iran and Russia to block gender discussions at COP29.
Peter Turkson
Ghanaian cardinal Peter Turkson, chancellor of the Pontifical Academy of Sciences, has been influential in international climate politics.
During his time as president of the Pontifical Council for Justice and Peace, Turkson spent 18 months guiding the drafting of Laudato Si. He was described by the Guardian as “the public face of Pope Francis’s war on global warming”.
The encyclical was launched to influence the nascent Paris Agreement and commentators have pointed to similarities in wording and themes between the documents. Turkson attended the Paris summit with a Vatican delegation and the goal of being a “catalyst” for action.
Luis Antonio Tagle
Another frontrunner, cardinal Luis Antonio Tagle has not had as much high-level involvement in climate politics as other candidates. However, he has often been compared with Francis due to his focus on social justice.
Tagle has been a vocal supporter of Laudato Si and has been involved in climate activism in his native Philippines. He has been active in the response to extreme weather in his country and has made the link between such events and climate change.
Robert Sarah
A conservative cardinal from Guinea, Robert Sarah has been welcomed by multiple right-leaning media outlets and is viewed by some as an “anti-woke” successor to Francis.
However, he has cited Francis’ teachings on the environment and pointed to the role of foreign interests in exploiting African resources. “They pollute the environment and leave the continent in endemic poverty,” he wrote in 2019.
Other contenders
There is huge uncertainty surrounding the conclave voting process to choose the new pope and several other candidates are thought to be in the running.
Among them are the Italian cardinal Matteo Zuppi, another progressive who has called for “bold” action on climate change.
Another is Péter Erdő, a leading conservative candidate from Hungary. While Erdő has not been vocal on climate change, he has close ties with Hungarian prime minister Viktor Orbán, a strong opponent of climate action.
Watch, read, listen
SILENT MAJORITY: Covering Climate Now has launched “the 89% project”, a global media collaboration based on the idea that there is a “silent majority” of people around the world who want climate action.
ATTRIBUTION AND LITIGATION: Dr Friederike Otto and Dr Joyce Kimutai from the World Weather Attribution project at Imperial College London appeared on the New Scientist Weekly podcast to talk about how climate attribution science can be used to achieve climate justice, in part through litigation.
NIMBY NEWSCAST: Tortoise Media’s Slow Newscast investigated the “so-called zealots” who have been taking legal action against everything from road-building to energy projects in the UK, in an episode titled “nimby nation”.
Coming up
- 28 April: Canada federal election
- 28 April: Trinidad and Tobago general election
- 28-30 April: Our Ocean conference, Busan, South Korea
Pick of the jobs
- Delft University of Technology, PhD in water security and climate adaptation in sub-Saharan Africa | Salary: €2,901 per month. Location: The Hague, Netherlands
- World Health Organization, climate and health communications manager | $70,212. Location: Geneva, Switzerland
- UK Department for Energy Security and Net-Zero, climate science advisor | Salary: £34,815-£41,355. Location: London
DeBriefed is edited by Daisy Dunne. Please send any tips or feedback to debriefed@carbonbrief.org.
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The post DeBriefed 25 April 2025: Brazil calls for country emissions plans; Global coral bleaching; Where top pope contenders stand on climate appeared first on Carbon Brief.
American farmers are drowning in health insurance costs, while their German counterparts never worry about medical bills. The difference may help determine which country’s small farms are better prepared for a changing climate.
Samantha Kemnah looked out the foggy window of her home in New Berlin, New York, at the 150-acre dairy farm she and her husband, Chris, bought last year. This winter, an unprecedented cold front brought snowstorms and ice to the region.
On the Farm, the Hidden Climate Cost of the Broken U.S. Health Care System
Climate Change
A Little-Used Maneuver Could Mean More Drilling and Mining in Southern Utah’s Redrock Country
Two Utah Congress members have introduced a resolution that could end protections for Grand Staircase-Escalante National Monument. Conservation groups worry similar maneuvers on other federal lands will follow.
Lawmakers from Utah have commandeered an obscure law to unravel protections for the Grand Staircase-Escalante National Monument, potentially delivering on a Trump administration goal of undoing protections for public conservation lands across the country.
A Little-Used Maneuver Could Mean More Drilling and Mining in Southern Utah’s Redrock Country
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.
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