Welcome to Carbon Brief’s DeBriefed.
An essential guide to the week’s key developments relating to climate change.
This week
Congress passes Trump’s ‘megabill’
TAX CREDITS CRUSHED: A major budget bill passed by US congress this week is “poised to remake American energy by slashing tax breaks for wind and solar power and electric cars”, reported the New York Times. The legislation, which was “muscled” through by Republicans, “provides a boost to fossil fuels and dismantles many of the biggest actions the federal government has ever taken to fight climate change”, the newspaper said.
‘CRACKDOWN’: The version of the bill approved by the Senate on Tuesday included “compromise language” that gave wind and solar projects one year to begin construction to claim current tax credits, noted Politico. “Hard-line” Republicans in the House of Representatives told the outlet that they backed the bill only after receiving assurances from Donald Trump that he would use executive action to further “constrict” wind and solar.
LAB LIABILITY: The bill, which is expected to be signed by Trump today, also “seeks to defund” multiple climate labs, according to CNN. This includes the Mauno Lao laboratory in Hawaii, where measurements since 1958 have produced the iconic “Keeling Curve” of rising atmospheric CO2, the outlet noted. See below for more on the emissions impact of Trump’s bill.
Record-breaking heatwave ‘grips’ Europe
RED ALERTS: At least eight people died across Europe as a heatwave gripped much of the continent, reported Reuters, “triggering health alerts and forest fires and forcing the closure of a nuclear reactor at a Swiss power plant”. The New York Times quoted UN secretary general António Guterres, who said: “Extreme heat is no longer a rare event – it has become the new normal.”
RECORD-BREAKING: Both Spain and England had their hottest June on record, noted BBC News, with the Spanish weather service saying the average of 23.6C “pulverised records”. The outlet added that France registered its second-hottest June, while the Guardian reported that Portugal hit a provisional record high for June of 46.6C.
FLASH FLOODS: Elsewhere, a record downpour in the central Chinese province of Hubei brought a month’s worth of rain in just 12 hours to the city of Xianfeng, reported Reuters. Authorities moved 18,000 people to safety, the newswire said. Flooding in India’s northern state of Himachal Pradesh left five people dead, reported the Hindustan Times.
Around the world
- ‘WATER[ED] DOWN’: The European Commission’s newly proposed target to cut the EU’s carbon emissions by 90% by 2040 has been criticised for allowing up to 3% of the goal to be met with international carbon credits, reported Carbon Brief.
- BRAZIL OIL BID: Brazil’s COP30 president-designate, André Corrêa do Lago, has “played down concerns” on Brazil’s oil expansion after a new analysis found the nation will drive a surge in new production by 2030, reported the Financial Times.
- ‘REPUTATIONAL RISK’: The nomination of an economist from the Saudi Aramco oil company as a coordinating lead author for an Intergovernmental Panel on Climate Change report has been denounced as “political capture”, reported Politico.
- FLIGHT FEE: A group of countries, including France, Kenya and Barbados, have pledged to tax private jets and premium-class flying in a bid to raise funds for climate action at a summit in Spain, Reuters reported. Climate Home News has all the key climate-finance takeaways from the event.
- ‘MAJOR SETBACK’: A £65m satellite launched last year to detect methane emissions from oil and gas production has been “lost in space”, reported BBC News.
£528m
The amount by which “climate aid” given by the UK government to developing countries was inflated through controversial changes to the way climate finance is now being designated, Carbon Brief analysis showed.
Latest climate research
- Sustained cuts to US military spending could result in annual energy savings by 2032 equivalent to the energy consumption of Slovenia, a study in PLOS Climate found.
- Using satellite data, a study in the Proceedings of the National Academy of Sciences revealed a marked increase in surface salinity across the Southern Ocean since 2015, coinciding with a “dramatic decline” in Antarctic sea ice.
- Research in Nature Cities highlighted the “disproportionate flood exposure” faced by urban slum populations in the global south, with one in three living on a floodplain.
(For more, see Carbon Brief’s in-depth daily summaries of the top climate news stories on Monday, Tuesday, Wednesday, Thursday and Friday.)
Captured
Trump’s dismantling of climate policy means the US will add an extra 7bn tonnes of emissions to the atmosphere from now until 2030, compared to meeting its former climate pledge under the Paris Agreement, according to new Carbon Brief analysis of modelling from Princeton University. The approval of Trump’s megabill repealing clean-energy tax credits, alongside a series of executive orders, means that US emissions are now set to drop to just 3% below current levels by 2030 – effectively flatlining – rather than falling 40% as required to hit the now-defunct target, according to the analysis.
Spotlight
Tipping points that worry scientists the most
This week, delegates at the Global Tipping Points 2025 conference in Exeter tell Carbon Brief which potential tipping “element” in the Earth system they are most worried about.
Prof Tim Lenton, founding director of the Global Systems Institute and chair in climate change and Earth system science at the University of Exeter:
“The Atlantic Meridional Overturning Circulation, or AMOC, for sure. The consequences of crashing that would be devastating globally – and also for where I live in the UK. By our own calculation, we could have less than half the viable area for growing a couple of major staple crops, wheat and maize, worldwide. We would have a widespread water crisis. We could have collapses of the monsoons in West Africa and India that would displace hundreds of millions of people. It is hard to see that in anything other than a catastrophe.”
Prof Ricarda Winkelmann, founding director of the Max Planck Institute of Geoanthropology and professor of climate system analysis at the University of Potsdam:
“So I am thinking about this from a risk perspective – so both the likelihood as well as the impacts – and I think the answer depends on that. Because when it comes to the likelihood and the particular threshold – and we know about those – I’m mostly concerned about the Greenland and the West Antarctic ice sheets. This is because we know that, even at lower warming levels, they’re already at risk of transgressing tipping points in certain regions.
“But when it comes to the impacts and also the timescales over which those play out, there are other tipping elements that worry me most. In particular, regional tipping elements. So, if we think of the mountain glaciers, for instance, these impacts are already experienced right now and several mountain glaciers are undergoing these accelerated changes.”
Prof Gabi Hegerl, chair in climate system science in the school of geosciences at the University of Edinburgh:
“I am worried about all of them. But, for the immediate future, I am particularly worried about tipping points that involve the biosphere and humans due to breaching thresholds for heat or drought that then ripple into food availability, livelihood and ecosystems. The Earth system tipping points will do that, too, but maybe a little bit later. Examples are coral diebacks triggered by marine heatwaves, forest change and fires, and droughts threatening livelihoods and putting people on the move.
“I did a research project on the US dustbowl and the trigger was drought causing vegetation and crop dieback, then [leading to] extreme heat and dust storms in response – and migration, as memorialised in [the 1939 John Steinbeck novel] The Grapes of Wrath. And, now with warming, all droughts get supercharged.”
Prof Carlos Nobre, Brazilian scientist and meteorologist who spearheaded the multi-disciplinary, multinational large-scale biosphere-atmosphere experiment in the Amazon:
“The Amazon is a very serious tipping point, because [dieback] could release around 250bn tonnes of CO2 by 2100 – which will make it impossible to [limit global warming] at 1.5C. We could also lose the largest [host to] biodiversity on the planet, which would induce a tremendous, large number of epidemics and several pandemics. Also, of course, the Amazon forest controls aspects of the global climate. In South America, the climate is entirely controlled by the Amazon forest.”
Carbon Brief will publish further coverage of the Global Tipping Points conference next week.
Watch, read, listen
‘CLIMATE ACTION IS UNSTOPPABLE’: In a talk at the recent TED Countdown Summit 2025 in Nairobi, former US vice-president Al Gore explained why the narrative of “climate realism” is a “myth”.
PROTESTOR IN PRISON: A BBC Radio 4 Currently documentary followed the story of a “law-abiding Middle England mum”, who received a four-year prison sentence for a Just Stop Oil protest on the M25 motorway.
‘FROM THE GREEN TO THE UNSEEN’: In its L is for Labour YouTube show, the Migration Project asked what a “just transition” to electric vehicles would look like for the traditional automotive industry and its workers in India.
Coming up
- 6-7 July: 17th BRICS summit, Rio de Janeiro, Brazil
- 8-11 July: AI For Good global summit 2025, Geneva, Switzerland
- 7-11 July: 47th Meeting of the Open-ended Working Group of the Parties to the Montreal Protocol, Bangkok, Thailand
Pick of the jobs
- Climate Policy Initiative, senior communications associate, climate finance | Salary: Unknown. Location: Cape Town, South Africa
- Global Action Plan, partnerships manager and campaigner | Salary: £36,000 and £36,000-£45,000, respectively. Location: London
- European Bank for Reconstruction and Development, principal manager, nature & climate finance | Salary: Unknown. Location: London
- Cheltenham Borough Council, climate and decarbonisation manager | Salary: £47,227-52,547. Location: Cheltenham, UK
DeBriefed is edited by Daisy Dunne. Please send any tips or feedback to debriefed@carbonbrief.org.
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The post DeBriefed 4 July 2025: Trump ‘megabill’ guts clean energy; Europe’s record heat; Scientists discuss ‘most worrying’ tipping points 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’ RENEWABLES: Energy analysts said governments should cut their fossil-fuel reliance by investing in renewables, “rather than just seeking non-Gulf oil and gas suppliers”, reported Climate Home News. This message was echoed by UK business secretary Peter Kyle, who said “doubling down on renewables” was “essential” amid “regional instability”, according to the Daily Telegraph.
China’s climate plan
PEAK COAL?: China has set out its next “five-year plan” at the annual “two sessions” meeting of the National People’s Con