Welcome to Carbon Brief’s DeBriefed.
An essential guide to the week’s key developments relating to climate change.
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This week
Extreme heat across the globe
SUPERLATIVE EXTREMES: Much of the world is experiencing extreme heat, with temperature records being broken on several continents but little western news coverage. Axios reported that temperatures in Japan are being “broken by rare margins”. The outlet added that Maximiliano Herrera, an independent climatologist who tracks weather records, “has been increasingly struggling to come up with new superlatives to describe” the extreme heat.
AFRICAN HEAT: Late last week, the Nigerian weather agency “predicted a prolonged heatwave across the country”, with temperatures forecast to rise above 40C, according to the Cable. In Kenya, the current “excess heat” could “persist till March”, the Standard reported. And “scorching” temperatures in parts of South Africa led to warnings for residents to stay indoors, the Witness said.
ASIAN EARLY BLOOMER: According to the Weather Channel, Japan’s iconic cherry blossoms are blooming early amid record heat there. The Thaiger reported that Thailand “is bracing for a severe heatwave”, while Cambodia’s meteorological ministry issued several advisories this week that maximum average temperatures could reach 37C, according to the Khmer Times.
AUSTRALIA ‘SWELTERING’: The Sydney Morning Herald wrote that “parts of Western Australia have sweltered through their hottest night on record” this week. “Extreme fire danger” led to school closures in the state, another article said.
Around the world
- US REGULATIONS: US president Joe Biden is reportedly planning to “slow” the roll-out of tailpipe-emissions regulations – one of his administration’s “most ambitious strategies to combat climate change”, according to the New York Times. Meanwhile, US agencies are “scrambl[ing] to finish” environmental regulations “to ensure that a Republican Congress and White House can’t erase them next year”, Politico reported.
- CLIMATE COCKTAIL: A deadly cholera outbreak in southern Africa “was likely triggered by a cocktail of issues”, Al Jazeera wrote, including “more severe flooding linked to climate change”. Heavy rainfall in the Amazon also triggered an alert for oropouche fever in the Brazilian city of Manaus, according to Folha de S. Paolo.
- BACK-BURNER?: European Commission president Ursula von der Leyen is pursuing a second term, Politico reported, with “little appetite for expanding the Green Deal” amid concerns over “competitiveness, migration and defence”. However, a later Politico story quoted the draft manifesto of her party saying: “We want to further develop the Green Deal.” The Financial Times quoted von der Leyen saying: “We must achieve the climate targets…with the people and with the business sector.”
- SOLAR SOARS: “‘World-leading’ electricity production” in China’s north-western deserts is being “fuelled by forces of nature”, with wind and solar making up more than half of the nearly 500 gigawatt capacity, according to the South China Morning Post.
- EXTREMES AND ADAPTATION: Bangladesh was hit by 185 extreme weather events between 2000-19, according to a report covered by DownToEarth, which added that “adaptation policies and local initiatives have saved many lives”.
- HIGH COURT CLAIMS: Three environmental groups are seeking legal action against the UK government over its decision to approve its “carbon budget delivery plan” in March 2023 without fully considering the risks, the Press Association wrote.
$281 billion
The profits of the “big five” oil majors – Shell, BP, Chevron, ExxonMobil and TotalEnergies – since Russia’s invasion of Ukraine, according to the campaign group Global Witness.
Latest climate research
- New research by World Weather Attribution, covered by Carbon Brief, found that climate change had no significant impact on Chile’s recent deadly wildfires.
- Climate change is affecting the feeding and migration patterns of bowhead whales, which could lead to more collisions with ships in the future, according to a new study in Geophysical Research Letters.
- A paper in Environmental Research Letters found that increasing population density could raise the carbon emissions from mangrove forest degradation by 50,000% by the end of the century.
(For more, see Carbon Brief’s in-depth daily summaries of the top climate news stories on Monday, Tuesday, Wednesday, Thursday and Friday.)
Captured
China will need ‘record drop’ in emissions to meet target
Amid rapid growth of electricity demand, China’s energy emissions will now need to fall by a record 4-6% by 2025 in order to meet the government’s “carbon intensity” target – its CO2 emissions per unit of economic output. New analysis for Carbon Brief found that China is “at risk of missing” its other key climate targets for next year, but most of these can still be achieved if the country returns to pre-2020 levels of energy demand growth while maintaining last year’s “acceleration of clean energy deployment”. The analysis was covered by publications including the Straits Times, the South China Morning Post, Reuters, the Guardian and Bloomberg.
Spotlight
Guest post: Why climate change matters for the pandemic treaty
In this spotlight, Dr Colin Carlson, a climate epidemiologist at Georgetown University, explains the connections between climate change and the proposed global pandemic treaty, as it enters the final stages of negotiations.
For more than a year, World Health Organization (WHO) member states have been working towards a new treaty that would formalise the lessons learned during the Covid-19 response.
On 19 February, delegates met at the WHO headquarters in Geneva to begin the eighth and penultimate session of negotiations. If countries can agree on final language, the Pandemic Agreement could then be adopted at the World Health Assembly in May.
The climate community has not paid much attention to these negotiations – nor has climate change featured heavily in the negotiations.
In the latest draft of the treaty, climate change is only mentioned once: the WHO and its member states are trying to move towards a “One Health” approach that protects human health, animal health and the environment, including “taking action on climate change”.
Scientists have demanded more of a focus on preventing disease emergence, but for the most part, other drivers – such as wildlife trade and deforestation – have upstaged climate.
But scientists are also starting to see connections between pandemics and climate change.
Animals are on the move, and bringing their viruses to new places. Rising temperatures make another pandemic of Zika virus or another mosquito-borne disease more likely – and next time, the risks to the US and Europe will be far greater. Hotter temperatures also mean more antibiotic resistant bacteria – which will make the next flu or coronavirus pandemic more deadly.
Investment and surveillance
In that light, climate change makes the Pandemic Agreement all the more urgent.
It could mean countries spend more on surveillance, helping scientists spot new diseases as they show up.
Investments in clean water, sanitation and primary healthcare would also reduce the burden of climate-sensitive diseases such as cholera and malaria, while more investments in veterinary workforce would help to protect animal health from emerging diseases such as avian influenza.
Most importantly, the proposed Pathogen Access and Benefit-Sharing (PABS) System would create a new framework for scientists around the world to share pathogen genomic sequence data with each other.
Pharmaceutical companies that access those data to design vaccines and therapeutics would then have to share some percent of their vaccines to the WHO, ensuring that low- and middle-income countries will have access to life-saving medicines – a massive step towards solving vaccine inequity and reducing disease risk in regions that are projected to see the largest increases in exposure because of climate change.
But first, the treaty has to survive the next three months. Since negotiations started, the PABS System has been flagged as a potential deal-breaker for high-income countries.
If the treaty falls through, health could become a much bigger problem for climate policy than it already is – after four million climate change-related deaths and counting.
Watch, read, listen
DEEP-SEA SECRETS: The rediscovery of a 1970s-era deep-sea mining test site may shed light on the method’s lasting environmental impacts, the Post and Courier wrote.
ENERGY EQUITY: On the New Books Network podcast, two researchers discussed equitable clean energy and a just transition in north Africa and the Middle East.
MEKONG’S MANGROVES: The Mekong Eye explored how Vietnam’s mangrove forests have been felled in the name of economic growth – and how they might be saved.
Coming up
- 19 February to 1 March: Sixth UN environment assembly, Nairobi, Kenya
- 25 February: Belarus parliamentary elections
- 26 February: UN Plastics Treaty: Reuse – a climate and plastic solution, Nairobi, Kenya
- 27-28 February: G20 disaster risk reduction working group meeting, Vila Do Conde, Brazil
Pick of the jobs
- Beyond Oil and Gas Alliance, strategic communications lead | Salary: Unknown. Location: remote, anywhere in the world
- Climate Risk Lab at the University of Cape Town, postdoctoral research fellow (four opportunities) | Salary: ZAR 410,000-475,000. Location: Cape Town, South Africa strongly preferred
- Royal Society for the Protection of Birds, country programme manager | Salary: £41,593-£44,651. Location: Monrovia, Liberia
- Stockholm Environment Institute, water programme research associate | Salary: unknown. Location: Bogotá, Colombia
DeBriefed is edited by Daisy Dunne. Please send any tips or feedback to debriefed@carbonbrief.org
The post DeBriefed 23 February 2024: Extreme heat from Asia to Africa; China risks missing 2025 CO2 targets; Why climate change matters for the pandemic treaty 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