Welcome to Carbon Brief’s DeBriefed.
An essential guide to the week’s key developments relating to climate change.
This week
1.5C looms
1.5C EXAMINED: The run of record heat last year suggests the world is close to exceeding the Paris Agreement’s target of limiting global temperatures to 1.5C above pre-industrial levels, according to two new studies covered by the Press Association. In 2024, annual average temperatures reached 1.5C for the first time. However, the Paris goal is measured as a 20-year average – meaning breaching 1.5C in a single year does not yet show the target has been crossed, the publication noted.
BREACH IN REACH: The first of the two studies “looked at real-world observations of already reached warming levels…and showed that the first single years exceeding each threshold have consistently fallen with the first 20-year period which averaged the same level of warming”, said the newswire. The findings suggest the Paris goal could be crossed within 10 years – unless there are “stringent” emissions cuts, Agence France-Presse reported. This is in-line with recent estimates from the Intergovernmental Panel on Climate Change and Carbon Brief.
HEAT GOES ON: The second study explored what the run of temperatures above 1.5C from July 2023 to June 2024 could mean for the Paris Agreement, the Independent reported. It continued: “The study shows that having 12 consecutive months above 1.5C means there’s a 76% chance that we’ve already hit that long-term warming threshold under current climate policies. If this trend continues for 18 consecutive months, the research says, the breach of the Paris Agreement threshold will be virtually certain. January 2025 was the 19th month to cross that mark.”
Around the world
- BP SWITCH: According to the Times, BP’s chief executive – under pressure from an activist investor – has pledged to “fundamentally reset” the company’s strategy, which is expected to involve a formal ditching of its target to cut oil and gas output and a further scaling back of its renewables projects.
- 35% RENEWABLE: Under Indonesia’s new electricity plan, the country aims to increase its renewable energy share from 12% to 35% in 2034 by expanding solar, battery, hydro and geothermal capacity, reported Reuters.
- ‘EXISTENTIAL THREAT’: A first-of-its kind German government report found that climate change poses an “existential threat” to the European Union due to its “destabilising and unequal” effects, reported Politico.
- COAL ON A HIGH: As covered by Carbon Brief, China’s construction of coal-fired power plants reached a new 10-year high in 2024, according to a report by the Centre for Research on Energy and Clean Air and Global Energy Monitor.
- ‘100% SUSTAINABLE WOOD’: The UK government agreed a new deal for the Drax power plant – which burns wood pellets to generate electricity – halving its subsidies and requiring all wood to come from “100% sustainable” sources, the Guardian said. Carbon Brief’s Simon Evans had more details.
- INDIA DEALS: Reuters reported that Nigeria is seeking assistance from India with its energy transition plans. Meanwhile, BBC News reported on the US and India agreeing a new deal that will see more American oil and gas imported by Delhi.
57%
The annual increase in second-hand EV sales in the UK from 2023 to 2024, with 188,382 cars changing hands in 2024, reported BusinessGreen.
Latest climate research
- New research in npj Climate Action showed that the more pronounced local climate change effects become, the stronger the relationship between a person’s education level and their level of “climate concern”.
- A new study published in Nature Cities showed that people in more disadvantaged neighbourhoods are more exposed to floods, based on studying nearly 45,000 neighbourhoods in eight Latin American countries between 2000 and 2018.
- Carbon emissions from permafrost “may pose a considerable risk” to climate mitigation efforts, “even if net-zero and negative emissions are achieved”, according to a new study published in Science Advances.
(For more, see Carbon Brief’s in-depth daily summaries of the top climate news stories on Monday, Tuesday, Wednesday, Thursday and Friday.)
Captured
Nearly 95% of countries miss UN climate pledge deadline
Nearly 95% of countries have missed a UN deadline to submit new climate pledges for 2035, Carbon Brief analysis shows. Just 13 of the 195 parties – highlighted on the map above – signed up to the Paris Agreement published their new emissions-cutting plans, known as “nationally determined contributions” (NDCs), by the 10 February deadline. Countries missing the deadline represent 83% of global emissions and nearly 80% of the world’s economy, according to Carbon Brief analysis. The US submitted its NDC under the previous Biden administration and has now announced plans to withdraw from the Paris Agreement.
Spotlight
From faint idea to ‘forest twice the size of London’
This week, Carbon Brief takes you behind the scenes of its recent rapid analysis on UK airport expansion.
At the end of January, Carbon Brief published an analysis showing that a forest “twice the size of London” would be needed to offset the emissions from the UK government’s proposed airport expansion.
It was covered widely in the press, featured on an ITV current affairs show and was cited twice by MPs in UK parliament.
The analysis – by myself, Carbon Brief’s data scientist, and policy correspondent Josh Gabbatiss – came together in just a few days. Below, I explain how we undertook the rapid analysis.
Heathrow third runway
In January, UK chancellor Rachel Reeves signalled that the UK government was planning to back a third runway at Heathrow airport, along with the expansion of two other London airports, Luton and Gatwick.
We decided to examine what the “climate cost” of such an expansion would be. The UK has so far done little to align its aviation sector with its net-zero target and this seemed like it could make that target even harder to reach.
The question was how should we go about this? Carbon Brief has previously published a guest post showing that airport expansion was not net-zero compatible and others had published more recent emissions analysis. What more could we add?
For a new angle, we wanted to focus on the extra emissions that would result specifically from the expansion of the three airports.
Calculating airport emissions
We noted that Carbon Brief’s guest post had used estimates for the average emissions per passenger to calculate the extra emissions in the year 2050 from the Climate Change Committee (CCC), the UK’s official climate advisers.
But calculating the extra emissions for a single year more than two decades in the future did not feel sufficient because the expansions would be operational years before 2050 – and it is the cumulative that matters for global temperatures.
However, calculating cumulative emissions would require modelling based on airport expansion dates.
Assuming the expansions are fully operational by 2040 and using CCC modelling, I produced the first rough chart (below) using pandas, a data analysis tool designed for the Python coding language.
This showed that the expansion of Heathrow, Luton and Gatwick would produce an extra 81m tonnes of carbon dioxide equivalent (CO2e) by 2050 (in orange on the chart below).
Forest figures
After calculating the extra emissions from the UK’s planned airport expansion, we decided that we needed to come up with a way of contextualising the number for our readers.
This is a common issue for us at Carbon Brief – how to communicate the scale of emissions. The average person does not necessarily know how to interpret 81m tonnes.
It can help to compare it to something more grounded and visible. In this case, we decided to work out how many trees would be needed to absorb all the extra emissions.
First, I redid the analysis with more accurate information on airport-expansion timelines from the Aviation Environment Federation, an NGO focused on the climate impacts of flying, which updated the total to 92m tonnes.
For converting this to trees, I drew on the methods of a previous analysis to get the emissions absorbed per hectare of forest planted over its lifetime.
From this, and assuming that the new forest is planted in 2028, I could calculate the forest area that would need to be planted so that by 2050 it has offset the extra aviation emissions from 2028 to 2050.
Using this, we got a forest “twice the size of Greater London”.
For more context, I added the historical emissions from the aviation sector and separated out each airport’s contribution in the updated chart (below).
Visualising the headline
The last step of the analysis was to present it in Carbon Brief style. I sent the data to our multimedia team and asked them to add two London-shaped forests to the chart.
Armed with the headline and caption text, the multimedia team turned the data into something visually captivating that could tell the story on its own.
If such work interests you, consider applying for our data-analyst vacancy. Deadline: 9am GMT 17 February
Watch, read, listen
CLIMATE BOWL: Super Bowl viewers in Los Angeles were shown the first-ever climate advert from a nonprofit group, showing the progress of climate change through the timeline of a young girl.
BIG SIX WASHING: A DeSmog investigation outlined how the six largest communication companies present themselves as climate friendly while helping to promote fossil fuels.
‘TOTAL WIPEOUT’: A France24 video report highlighted how some lower altitude ski towns are adapting to their new snow-scarce reality in the face of climate change.
Coming up
- 15-16 February: 38th African Union Summit: assembly of the heads of state, Addis Adaba, Ethiopia
- 17-19 February: UN Environment Programme UrbanShift Africa Forum, Nairobi, Kenya
- 17-21 February: 18th session of the Intersessional Working Group on reduction of greenhouse gas emissions from ships, London
Pick of the jobs
- World Resources Institute, programme lead, Latin America Clean Energy Coalition | Salary: Unknown. Location: Brazil, Mexico or Colombia
- Potsdam Institute for Climate Impact Research, postdoctoral researcher AMOC | Salary: €4,630 per month. Location: Potsdam, Germany
- Action for the Climate Emergency, director of renewables, UK, | Salary: £80,000-£90,000. Location: Remote, UK
- InfluenceMap, analyst, climate change (India-focused), UK-based | Salary: £29,000. Location: London (hybrid)
DeBriefed is edited by Daisy Dunne. Please send any tips or feedback to debriefed@carbonbrief.org.
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The post DeBriefed 14 February 2025: Nearly 95% of countries miss UN climate deadline; 1.5C on horizon; Behind-the-scenes of CB analysis 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