Welcome to Carbon Brief’s DeBriefed.
An essential guide to the week’s key developments relating to climate change.
This week
Record heat in 2024
DEADLY DECADE: UN secretary general António Guterres used his new year’s message to declare that “we have just endured a decade of deadly heat”, the Press Association reported. The news outlet said that all of the top 10 hottest years on record took place in this period, with 2024 emerging as the hottest. Meanwhile, China Daily reported that China reached its hottest annual temperature since records began, while ABC News said Australia saw its second-warmest year.
DANGEROUS HEAT: The Associated Press covered research from World Weather Attribution and Climate Central that found people globally experienced “an average of 41 extra days of dangerous heat” last year due to climate change. The analysis also found that climate change intensified 26 of the 29 extreme weather events from last year that the groups studied, according to Euronews.
Turning off Russian gas
GAS BLOCK: Russian gas flowing into several European countries was stopped on New Year’s Day, after Ukraine refused to renegotiate a transit deal “in the hopes of hurting its invader financially”, NBC News reported. Ending the flow of gas via Ukrainian pipelines will cost the Russian state-backed Gazprom around $5bn a year in gas sales, but will also cost Ukraine around $800n a year in transit fees, according to CNN.
EUROPE’S RESPONSE: EU member states prepared for this event by increasing capacity for liquified natural gas (LNG) imports and renewables, according to the Kyiv Independent. LNG from the US and Qatar has also helped the EU move away from Russian gas, Reuters said. However, Euractiv reported on “unease” from negatively affected eastern European countries, with Slovakia “threatening” retaliation against Ukraine, and Moldova – which is not an EU member state – “declaring a state of emergency” amid gas shortages.
Around the world
- FIRE WEATHER: “Out of control” bushfires are blazing in Australia, with elevated fire danger warnings issued for many states amid high temperatures, according to the Guardian.
- FLOOD DAMAGE: Hundreds of people have been evacuated in north-west England due to flooding, BBC News reported. Meanwhile, the Bank of England warned that climate change-driven floods could “devastate the value” of hundreds of thousands of UK homes, according to the Daily Telegraph.
- BANK WITHDRAWAL: Morgan Stanley, Bank of America and Citigroup announced that they were quitting the UN-backed net-zero banking alliance, Bloomberg reported. Financial Times described the departures as “the latest sign corporate America may retreat from climate goals” under incoming president Donald Trump.
- ALL ELECTRIC: Norway is “on the brink” of achieving its target for 100% of new car sales to be electric by 2025, with zero-emission cars making up 88% of new sales last year, the National reported. Meanwhile, the Daily Telegraph said Tesla saw its “first ever drop” in annual electric-vehicle sales, amid pressure from Chinese rivals.
$75 billion
The amount that fossil-fuel companies will be fined over the next 25 years, under a recent New York state law, according to Reuters.
Latest climate research
- The record-long Canadian wildfire season in 2023 was more than five times as likely due to human-caused climate change, according to a new study published in npj Climate and Atmospheric Science.
- New research in Proceedings of the National Academy of Sciences concluded that the rate at which carbon dioxide (CO2) emissions increase could affect the pace at which the Atlantic Meridional Overturning Circulation (AMOC), a current moving water, heat and nutrients around the world, slows down.
- A nationally representative survey of more than 1,000 US adults, published in Environmental Science and Policy, found that only around one-third were aware of the term “climate justice”, but half supported its goals after reading a short description.
(For more, see Carbon Brief’s in-depth daily summaries of the top climate news stories on Thursday and Friday.)
Captured
The UK’s electricity was the cleanest it has ever been in 2024, according to new Carbon Brief analysis that was covered by the Times, the Guardian and other news outlets. CO2 emissions per unit have fallen by 70% over the past decade, as the chart above shows. This trend can be attributed to the UK phasing out coal while expanding its use of renewables, which reached a record 45% of electricity generation last year.
Spotlight
Europe’s forgotten overseas territories and climate change
In the wake of Cyclone Chido, Carbon Brief considers the climate threat facing Europe’s overseas territories.
Cyclone Chido tore through the French island of Mayotte in mid-December, killing at least 39 people and leaving thousands injured or homeless.
The storm, which was made more intense by climate change, was the strongest to hit the tiny Indian Ocean territory in close to a century. Much of the devastation was linked to the lack of sufficient shelter and resources in what has long been France’s poorest region.
Chido marks the latest extreme weather event to hit one of Europe’s “overseas territories” – colonial remnants that are largely dotted around the tropics, from the Caribbean to the Pacific.
‘Urgent action’ required
Most of the 34 European overseas territories are part of France, the UK and the Netherlands, due to their histories operating slave plantations on tropical islands.
These territories vary significantly in governance, wealth and independence. However, they have a shared vulnerability to climate-related threats, such as cyclones and sea level rise.
The EU’s first climate risk assessment report, published last year, called for “urgent action” to protect member states’ overseas territories from climate change, highlighting their “remote locations, weaker infrastructure and economic vulnerability”. UK territories, particularly those in the Caribbean, face similar challenges.
“Technically, politically, institutionally, they’re in the global north, but their realities are akin to any other country in the global south,” Dr Vanessa Deane, an urban planning researcher at New York University, told Carbon Brief.
Carbon Brief analysis of the Emergency Events Database (EM-DAT), run by the Centre for Research on the Epidemiology of Disasters (CRED) in Belgium, shows that at least 197 people in European overseas territories were killed by extreme weather events over 1990-2024. (EM-DAT is the most comprehensive disaster database, but lacks complete data for poorer countries, meaning this figure is likely to be an underestimate.)
At least another 39 have been killed by Chido in Mayotte, making it the deadliest single event over this period in an overseas territory, according to EM-DAT data. The final death toll may be far higher.
Another quarter of a million people in these territories have lost their homes, been injured or otherwise affected over this period, mainly due to cyclones, according to EM-DAT.
‘Lagging behind’
Dr Virginie Duvat, a small islands researcher at the University of La Rochelle in France, said territories such as Mayotte are simply not treated the same as their mainland counterparts by French policymakers:
“Climate adaptation policies are lagging behind. This is paradoxical because these territories are more exposed and more vulnerable to climate change.”
Elise Naccarato, a climate justice advocate at Oxfam France, pointed to the “almost total absence of the overseas territories” in France’s upcoming climate adaptation plan.
Overseas territories generally lack the financial and technical capacity to implement climate adaptation programmes, or recover from climate-related disasters. Yet they also often cannot access climate-related aid.
Instead, the territories tend to rely on specialised funds set up by the EU and central governments to support climate-related activities, but these have been described as “insufficient” and “uncertain”.
As an example, Dr Daphina Misiedjan, a legal researcher at Erasmus University in the Netherlands, pointed to the “roundabout way” that the Dutch government provided relief to the territory of Sint Maarten, in the wake of Hurricane Irma. Rather than providing money directly, the government handed control to the World Bank, and funds took years to reach people.
Last year, residents of the Dutch Caribbean island of Bonaire, alongside Greenpeace Netherlands, launched a lawsuit against the Netherlands, claiming the state had not protected them sufficiently from climate change.
“[European countries] really profited from the colonial times, but now they have extra responsibility to make sure these islands are safe during the climate crisis,” Greenpeace climate campaigner Maarten de Zeeuw told Carbon Brief.
Watch, read, listen
THE YEAR IN CLIMATE: After a year of key elections and many extreme weather events, BBC podcast the Climate Question presented a review of the top climate stories from 2024, hosted by an expert panel.
WINE LIST: A “big read” article in the Financial Times, which includes interactive graphics, looked at how the changing climate is pushing wine making into northern regions and “redrawing of Europe’s wine map”.
BEST BOOKS: Mongabay has published a list of 10 “notable” environment-themed books published in 2024. Topics covered range from Indigenous land rights to coral bleaching.
Coming up
- 6-11 January: First Global Heat Health Information Network Southeast Asia Heat Health Forum, Singapore
- 9-10 January: Attribution Science and Climate Law Conference, New York City
- 9-11 January: Extraordinary Summit on the Post Malabo Comprehensive Africa Agriculture Development Programme, Kampala, Uganda
Pick of the jobs
- UK Climate Change Committee, chair | Salary: £1,000 per day. Location: London
- Wiley, deputy editor – environment | Salary: $59,900-$87,767. Location: Remote or hybrid, US, UK or Brazil
- Smith School, University of Oxford, data lead – state of carbon dioxide removal | Salary: £48,235-£57,255. Location: Oxford, UK
DeBriefed is edited by Daisy Dunne. Please send any tips or feedback to debriefed@carbonbrief.org.
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The post DeBriefed 3 January 2025: ‘Decade of deadly heat’; Russian gas cut off; Europe’s forgotten overseas territories and climate change 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
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