§ Glacier melt

Glaciers are slow-moving rivers of ice found on almost every continent in the world. They typically advance downhill by a few centimetres every day, driven by their own weight.

The head of a glacier is always found on land – typically at high altitude, where temperatures are low. Here, precipitation and avalanches cause snow to build up on the surface of the glacier. Over time, the snow compacts into ice, adding mass to the glacier. 

Meanwhile, the tail end of the glacier is typically found at lower elevations where the air is warmer. Here, melting ice and evaporating water cause glaciers to lose mass.

As the planet warms, glaciers are melting more rapidly. This often causes the bottom of the glacier – known as the “terminus“, “snout” or “toe” – to recede, reducing the overall length of the glacier. This is known as terminus retreat.

Over 2000-19, glaciers collectively lost around 267bn tonnes (gigatonnes, or Gt) of ice every year. A recent report by the UN warned that many glaciers will “inevitably” disappear entirely over the coming decades.

A separate study estimated that even if the world successfully limits global warming to 1.5C, glaciers could lose a quarter of their total mass by 2100. 

Glaciers can be broadly split into categories based on their location. For example, while “land-terminating” glaciers end on land, “marine-terminating” glaciers flow into the ocean, where they often end in a “floating glacier tongue” that sits on the surface of the water.

When marine-terminating glaciers melt and retreat, new areas of coastline are often revealed. Research shows that marine-terminating glaciers in the northern hemisphere have cumulatively lost 10Gt of mass every year over 2000-20 due to terminus retreat.

The northern hemisphere is home to around 1,500 of the world’s roughly 200,000 glaciers. 

The new study assesses how much new coastline has been exposed due to terminus retreat in marine-terminating glaciers in the northern hemisphere over 2000-20.

§ Satellite monitoring

The authors used a pre-existing dataset to identify all the marine-terminating glaciers in the northern hemisphere. They then manually assessed satellite imagery – mainly from Sentinel-2 – to digitise the new coastline that was exposed as a result of glacier retreat around Greenland, Alaska, the Canadian Arctic, Russian Arctic, Iceland and Svalbard over 2000-20.

Dr Jan Kavan is the lead author of the study and a researcher at the University of South Bohemia’s Centre for Polar Ecology. He tells Carbon Brief that the researchers opted for a manual approach because algorithms trained to identify the position of glaciers “don’t work very well” on coastlines.

This is because Arctic coastlines tend to be highly variable, Kavan explains. For example, glaciers near the coastline may be covered in debris – making it hard for an algorithm to recognise them. 

Dr Simon Cook is a senior lecturer in environmental sciences at the University of Dundee, who wrote a “news and views” piece about the study published in Nature climate change. He praises the study, telling Carbon Brief that manually identifying coastlines is “labour-intensive and slow work, but widely regarded to be robust”. 

The authors inspected 1,704 marine-terminating glaciers in total. They find that 2,466km of new coastline formed between 2000 and 2020 – an average of 123km of new coastline every year. 

The map below shows where the coastline was added (red) and lost (blue) due to changes in glacier terminus positions over 2000-20. The yellow circles the total length of new coastline added in different regions, where larger circles indicate greater additions.

The authors note that the rate of new coastline formation varies highly between regions. Just 101 glaciers were responsible for more than half of the total additional coastline length, they say.

Two-thirds of the new coastline identified in this study were in Greenland, the authors say. The melt of the Zachariae Isstrom glacier in north-east Greenland has resulted in the formation of 81km of new coastline – more than twice as much as any other glacier in the study – according to the paper.

Retreating glaciers also exposed 35 new islands with areas larger than 0.5 square kilometres (km2), according to the study. 

§ Changing coastlines

Rising ocean and air temperatures are the main reason that marine-terminating glaciers are rapidly losing mass, the study says. However, many other factors may affect how quickly new coastline forms due to glacier melt. 

According to the authors, 85% of the glaciers in the study retreated between 2000 and 2020. 

However, not all of these led to the development of new stretches of coastline. 

For example, glaciers that stretch out far into the sea could experience “extensive retreat” without any new coastline forming, according to the paper.

Conversely, glaciers in “deep and narrow fjords” can expose long new areas of coast by losing only a small volume of ice.

The authors note that the most “dramatic” glacier retreats are due to ice shelves or floating tongues breaking off the main glacier and collapsing into the water.

Meanwhile, glacier advances – when glaciers gain mass more quickly then they lose it, or temporarily “surge” forwards – can cause a loss of coastline. (Surges are short-lived periods when the glacier moves faster than its normal rate, often due to meltwater which builds at the base of the glacier and acts as a lubricant.)

The paper finds that more than 50 metres of coastline was lost due to glacier advances. Two-thirds of this gain was in Svalbard due to a “surge” of the Nathorstbreen glacier system, according to the paper.

Lead author Kavan tells Carbon Brief that other studies have assessed coastline gain from “individual glaciers” or “small regions”, but says this is the first paper to quantify coastline gain across the entire northern hemisphere for a uniform time period.

Dr Robert McNabb, a lecturer at Ulster University who was not involved in the study, tells Carbon Brief the study “highlights the importance and immense value of having long-term, freely available satellite archives for research”. 

§ Tsunami risk

Glacier melt is often discussed in the context of water security, as the world’s 200,000 glaciers store around 70% of the Earth’s fresh water. However, Kavan tells Carbon Brief that the impact of retreating glaciers on the bedrock is often “neglected”.

Using a map of rock types across the Arctic, the authors analyse the changing conditions of the new coastlines. They find that most of the new coastline is formed of metamorphic bedrock – a type of rock formed from intense heat and pressure. Meanwhile, softer sedimentary rocks, which are more susceptible to erosion, dominate the newly formed coastlines in eastern Svalbard.

In his news and views piece, Cook – the University of Dundee environmental sciences lecturer – explains that the newly revealed coastlines are known as “paraglacial”. He writes:

“Paraglacial coasts differ from other established areas of Arctic coastline because permafrost will not yet have had time to develop in these freshly revealed areas, meaning that they are more easily eroded by wave action, mass wasting and other processes because of a lack of icy cement. They are, therefore, expected to be highly dynamic.”

Cook says it is “currently unclear” what the implications of the new paraglacial coastlines will be for the people and ecosystems of the Arctic. He suggests that the new coastlines “may become home to important ecosystems that play a hitherto unquantified role in the global carbon cycle”. 

Freshly revealed paraglacial coastlines can be more prone to landslides, which may, in turn, cause “dangerous tsunamis”, the paper notes. As an example, it points to a tsunami on 17 June 2017 in Greenland, which caused “substantial infrastructure damage and loss of life”. 

Dr Anna Irrgang is a coastal geomorphologist at the Alfred Wegner Institute and was not involved in the study. She tells Carbon Brief that the study “may help in detecting potential risk-zones” for such tsunamis. 

She adds that the dataset provided in this study can be used as a “first estimation of the hazard potential”, but adds that “a more in-depth risk analysis needs to be undertaken at the local scale, where communities might be exposed to these arising dangers”. 

Meanwhile, Kavan tells Carbon Brief that marine-terminating glaciers are considered “biodiversity hotspots”. Meltwater from the glacier causes upwellings at the terminus of the glacier, creating “nutrient-rich water” that is vital for many polar species, he says.

As a result, ongoing glacier retreat may result in many of these habitats being lost, putting species like bearded seals and Arctic-dwelling birds at risk, he adds.

§ Global-south sales surge

China’s exports of solar panels to the global south have doubled in the past two years, overtaking global-north sales for the first time since 2018, according to data collated in the Ember export explorer. 

Global-south imports more than doubled from 60 gigawatts (GW) in 2022 to 126GW in 2024. That surpassed global-north imports, which were only 12% more in 2024 than in 2022, as shown on the chart below.

§ Biggest solar importers

The Netherlands was the biggest importer in 2024 and has been every year since 2019, as a result of Rotterdam serving as an import hub for much of continental Europe. The following four places were all global-south countries, the data shows.

Brazil was in second place again, importing more than 20GW for the second year in a row. However, the imposition of import taxes by the government, the refusal of electricity distributors to connect new solar systems and solar “curtailment” are all causing headwinds in 2025. 

Pakistan and Saudi Arabia jumped to third and fourth, respectively. (The next section charts the rise of these two very different solar giants, from the 12th and 26th biggest importers, respectively, in 2022 into the top five.)

India was in fifth place in 2024. Its module imports remained similar to those in 2023, but its installations rose to a record high, enabled by a step up in new domestic solar panel manufacturing capacity. 

In January 2025, that helped India hit 100GW of solar installed, according to government figures. India is partly relying on Chinese imports, whilst simultaneously scaling up its own manufacturing industry.

The other large global-south markets – identified in the export explorer data – are also spread across the world, as shown in the figure below.

They include the UAE and Oman in the Middle East, Thailand and the Philippines in south-east Asia and then South Africa, Chile, Uzbekistan and Mexico.

§ Pakistan and Saudi Arabia

Pakistan and Saudi Arabia have had almost identical imports of Chinese solar panels for the past two years. They stood at 8GW in 2023 and then more than doubled to 17GW in 2024, placing them as the third and fourth largest importers in the world, the export explorer shows. Their monthly imports from China are shown in the figure below.

However, that is where the similarities end. Pakistan’s growth has come almost entirely from small-scale “distributed” installations, without co-located battery storage and paid for by consumers. Saudi Arabia’s growth has come almost entirely from desert solar farms, complete with some battery storage and paid for by international energy companies.

Pakistan’s solar boom was ignited by spiralling electricity costs and chronic power shortages, which have put energy at the heart of the country’s economic problems. 

The country installed 10-15GW of solar in 2024 alone, according to Bloomberg estimates. Pakistan’s peak electricity demand was just 30GW in 2023, which gives an idea of how big solar has become in the country. 

Large utility-scale solar is minimal – only 0.63GW of such capacity is operational. Instead, almost all of the new solar capacity was installed on rooftops or next to factories or fields, for direct use by consumers.

However, hardly any battery capacity was installed alongside the new solar panels, meaning people and companies still rely on the grid for electricity outside of sunny hours.

The surge in solar capacity has helped drive down electricity generation from fossil fuels, despite fast-growing electricity demand. However, it also “threatens to disrupt” the grid, where demand has created at the same time as becoming more variable.

Turning to Saudi Arabia, solar panels are used mostly in large desert renewable auction tenders. There have been five solar tender rounds in 2017, 2019, 2021, 2023 and 2024. 

The latest tender round contracted 3.7GW of large-scale desert solar parks, achieving the cheapest reported electricity prices in the world of $13 (£10) per megawatt hour. (Note that these reported prices are somewhat artificial and are likely to underestimate the full cost.) 

None of the winning solar parks were contracted with batteries. However, parallel battery tender rounds are now commencing.

There are estimated to be only 3.3GW of solar projects currently operational in Saudi Arabia, but a further 5.4GW are under construction. The solar plant owners are international energy firms including KEPCO, EDF Renewables, Masdar and TotalEnergies, as well as Saudi companies. 

The country plans to move from near-zero renewables in 2020 to 50% of its total electricity generation coming from renewables in 2030. In relative terms, this is one of the most ambitious renewable targets anywhere in the world. 

§ New markets

There were 15 countries that saw a large uptick in imports of Chinese solar panels towards the end of 2024, according to the export explorer data and shown in the figure below.

There were large increases in Nigeria, Algeria and Iraq, where there is clear evidence that demand for panels is growing. 

For example, Nigeria’s growth was driven by blackouts in 2024 and the removal of fuel subsidies, making diesel generators more expensive to run. 

Iraq is currently constructing its first large solar plant, while another 7.5GW of projects were approved by the government in 2024 to meet growing electricity demand.

Meanwhile, Algeria has a plan for 3GW of solar projects, which is now underway. 

For a cluster of a further 12 countries, it is less clear if the recent uptick in solar panel imports is a structural change that will continue into 2025 and beyond.

There are large incentives for China’s solar manufacturing companies to meet year-end targets, so it is possible that containers of solar panels were sold at discounted rates to help meet these goals.

The cluster includes many small African countries – Benin, Burkina Faso, Chad, Djibouti and Guinea – and Latin American countries – Ecuador, El Salvador, Guyana and Nicaragua.

The December 2024 imports are quite large in the context of the small electricity systems of many of these countries. As such, these solar panels would provide a relatively meaningful increase in renewable electricity generation if they go on to be installed.

§ China installs more than exports

China has not just been exporting growing numbers of solar panels. – In 2024, it installed more solar panels than it exported for the second year running, according to Ember analysis.

Indeed, China installed 333GW of solar capacity domestically in 2024, some 38% more than the 242GW of solar panels that it exported, as shown in the figure below.

From 2019 to 2022, China had been exporting more solar panels overseas than it installed domestically. However, that changed when China’s solar panel installations surged from 103GW in 2022 to 260GW in 2023. 

By the end of 2024, China had a total installed solar capacity of 1,064GW, making it the first country to achieve the 1 terawatt (TW) benchmark. 

§ Reducing reliance on China

China’s solar exports grew for the seventh consecutive year in 2024, rising to a record 242GW, Ember’s data shows. 

Exports rose by 10% year-on-year, which was a significant slowdown from the rate of growth seen in recent years. However, solar installations outside of China grew by 30%.

This demonstrates a step-up in ambitions to reduce reliance on Chinese solar panel imports by a number of countries around the world. 

For example, India’s solar panel manufacturing capacity has skyrocketed in recent years. In 2023, it added 23GW and a further 11GW was completed in the first half of 2024. India’s reported module and cell production capacities stood at around 80GW and 7GW, respectively, as of March 2025. 

However, the country still relies on imported Chinese solar cells. The value of shipments to India rose 30% from $970m in 2023 to $1.3bn in 2024, accounting for almost half (48%) of China’s cell exports. 

This reliance is seen as a temporary but essential part of the transition to full India manufacturing capability, as solar cell manufacturing capacity steps up, with the aim that projects contracted through the government solar auctions only use locally-sourced cells from June 2026. 

The EU is on track to meet its 30GW of solar panel manufacturing target in 2025. However, the numbers are relatively small compared to other regions. Europe had 22GW of solar module manufacturing capacity in 2024, with 12GW in the construction pipeline.

The US does not import Chinese panels, but it does rely heavily on imports from other Asian countries. It imported 51GW of solar panels in the first 10 months of 2024, more than 90% of which were from Vietnam, Thailand, Malaysia, India or Cambodia. 

US manufacturing capacity rose from 7GW in 2020 to 50GW in early 2025, with plans announced for a further 56GW, according to trade association the Solar Energy Industries Association. 

§ This week

Raging wildfires

SOUTH KOREAN BLAZE: Wildfires in south-eastern South Korea – the “worst wildfires in its history” – have killed at least 27 people and displaced more than 37,000 from their homes, the Korea Times reported. The Chosun Daily said that the 1,300-year-old Gounsa Temple “was reduced to ashes” and the fire continues to endanger many of the “most prized cultural assets”. A “spate” of recent wildfires in South Korea and Japan have been “linked to climate change”, the Japan Times said.

FUEL TO THE FIRES: Parts of North and South Carolina have been under evacuation orders due to several large, uncontained wildfires, with “millions of downed trees” from September’s Hurricane Helene fuelling the blazes, the Raleigh News & Observer reported. The Guardian added: “Many people in the area are still getting over the hurricane.”

UK climate and energy roundup

DEADLINE DROPPED: The UK’s High Court “agreed to push back the deadline” for the government to modify its “delivery plan” needed to meet its legally binding climate targets, BusinessGreen reported. The plan was published in 2023, but had been “subject to a legal challenge from green groups, which alleged it was not sufficiently detailed”, the outlet added.

‘GREEN SILENCE’: UK chancellor Rachel Reeves made “no mention of green issues” in her spring statement, the Guardian reported, adding that this “silence [came] as a relief” to “green experts”, given cuts announced elsewhere. Meanwhile, the Chinese owner of British Steel “rejected a £500m lifeline offer from the UK government, raising fears about thousands of jobs at the steelmaker”, the Financial Times reported.

§ Around the world

• IT’S ELECTRIC: Chinese automaker BYD “topped $100bn” in sales of electric vehicles and plug-in hybrids, surpassing electric-only manufacturer Tesla, the Financial Times said. Tesla sales have fallen 49% year-on-year in Europe in 2025, ABC News noted, even as EV sales overall grew 28%.
• CARBON MARKET: China released plans to include its steel, cement and aluminium industries in the country’s carbon-trading market, Reuters reported.
• COAL COMMITMENT: Germany’s incoming coalition “stand[s] by” plans to phase out coal power by 2038, according to a leaked draft reported by Euractiv, which noted the outgoing government had “favoured” 2030.
• POWER SURGE: Record temperatures in 2024 meant “global energy demand surged” last year, according to a report from the International Energy Agency covered by the Wall Street Journal. A record 585 gigawatts of new renewables were added last year, Axios reported, citing International Renewable Energy Agency data.
• SHIP-SHAPE: In Climate Home News, Kenya’s special envoy for climate change, Ambassador Ali Mohamed, “unequivocally” endorsed a proposed carbon levy on emissions from ships.

§ 267

The number of days in 2024 – nearly three-quarters of the year – in which the US was experiencing a “major disaster”, according to analysis of US Federal Emergency Management Agency data by the International Institute for Environment and Development and CNN.

§ Latest climate research

• Research in the Journal of Environmental Psychology found that political polarisation around climate change becomes more pronounced as countries become wealthier.
• In China, compound hot-dry and hot-wet events became more frequent, long-lasting and intense from 1985 to 2019, with serious implications for crop losses, a new study in Earth’s Future found.
• A study in Environmental Research Letters detailed a machine learning-driven model capable of accurately forecasting marine heatwaves 10 days in advance. 

(For more, see Carbon Brief’s in-depth daily summaries of the top climate news stories on Monday, Tuesday, Wednesday, Thursday and Friday.)

§ Captured

The US National Snow and Ice Data Center announced that Arctic sea ice reached its annual maximum extent on 21 March. At 14.33m km2, the winter peak is the smallest in the 47-year satellite record. Dr Julienne Stroeve, a senior scientist at the NSIDC, told Carbon Brief that the record low “continue[s] the overall long-term decline in the ice cover”.

§ Spotlight

Warming may turn butterfly hotspots from ‘safe havens to graves’

This week, Carbon Brief covers a new study that mapped and analysed the biodiversity of butterfly species around the world.

Up to a third of butterfly biodiversity “hotspots” will become too warm for the species they host by 2070, according to new research.

The study, which analysed distributional data on more than 12,000 butterfly species, was published this week in Nature Ecology & Evolution. 

It found that two-thirds of butterfly species are mountain-dwellers, with mountains holding 3.5 times more butterfly biodiversity hotspots than lowland ecosystems.

The lead author of the paper told Carbon Brief he hopes that the approach laid out in the study will “broadly boost the representation of insects in global ecology and conservation”.

Mapping hotspots

Butterflies are “uniquely well-documented among insects”, Dr Stefan Pinkert, a researcher at Germany’s University of Marburg, told Carbon Brief. 

But, even so, “much of this information remain[s] fragmented and inaccessible”, said Pinkert, who led the new study.

Pinkert and his colleagues used a country-level database of butterfly occurrences, along with regional range maps and previously published species-distribution models, to model the distribution of 12,119 butterfly species. They then calculated and mapped the “richness” and “range rarity” of butterfly species around the world.

Species richness was calculated as the number of unique species in the database for a given area. “Range rarity” is inversely proportional to the range size of the species in an area.

For both richness and range rarity, the researchers defined a “hotspot” as the 5% of areas around the world with the highest value of each quantity. They found that only 10% of species richness hotspots and 10% of range rarity hotspots overlap. The study said that this underlines the “limited value” of species-richness hotspots for identifying conservation priorities.

Pinkert told Carbon Brief that he was concerned to find that only 40-45% of butterfly biodiversity hotspots overlap with the biodiversity hotspots of land animals. Land-animal biodiversity has historically “served as main surrogates for defining” priorities for global conservation, he added.

Warming warning

The researchers also found that around two-thirds of all butterfly species they studied live in mountain regions, with species richness peaking at around 2,500 metres elevation and range rarity peaking at 3,500 metres. They noted that, while mountains are known for their species richness, the concentration of butterfly biodiversity is “substantially” higher than it is for other types of organisms, such as plants, birds and reptiles.

They then used climate models to project warming over the next 45 years – as well as how those temperature changes will affect butterfly habitat in the future. 

They found that “temperature niche loss” – warming beyond the safe temperature range for species in a given area – would erode up to one-third of species-richness hotspots globally, under a very-high emissions scenario, with some areas losing nearly two-thirds of their hotspot area. Under a moderate emissions scenario, sub-Saharan Africa and south-east Asia would each lose a quarter of their temperature niches.

The loss of safe temperature niches was greater for hotspot areas than non-hotspot areas. The authors concluded that under accelerating warming, mountains might be converted “from safe havens to graves”. 

Pinkert told Carbon Brief:

“Our results underscore the urgent need to prioritise insect conservation amid global change…Business-as-usual in prioritisation and implementation [of conservation actions] will threaten ecosystem integrity – the foundation of our well-being and that of future generations.”

§ Watch, read, listen

TIMELY TREK: Latin America Reports chronicled a journey to visit Colombia’s melting Andean glaciers on the country’s “climate change trail”. 

ENERGY OUTLOOK: Kaare Sandholt of top Chinese thinktank the Energy Research Institute talked about the country’s energy transformation outlook – recently covered by Carbon Brief – on the Environment China podcast.

TRUMP-PROOF TOOLS: The Guardian recreated a climate-risk tool that had been purged from the US Federal Emergency Management Agency’s website under Trump’s anti-climate directives.

§ Coming up

• 2-3 April: 41st UN-Water meeting, Rome
• 7-11 April: Meeting of the Marine Environment Protection Committee of the International Maritime Organization, London

§ Pick of the jobs

• Earthjustice, legislative director, climate and energy | Salary: $164,000-$182,200. Location: Washington DC
• International Maritime Organization, media and communications associate | Salary: £45,347. Location: London
• UN Environment Programme, finance and budget assistant | Salary: Unknown. Location: Nairobi

DeBriefed is edited by Daisy Dunne. Please send any tips or feedback to debriefed@carbonbrief.org.

This is an online version of Carbon Brief’s weekly DeBriefed email newsletter. Subscribe for free here.

§ Record low

Arctic sea ice extent changes throughout the year. It grows during the winter towards its annual maximum extent – often referred to as its “winter peak” – in February or March. It then melts throughout the spring and summer towards its September minimum.

Using satellite data, scientists can track the growth and melt of sea ice, allowing them to determine the size of the ice sheet’s winter maximum extent. This is a key way to monitor the “health” of the Arctic sea ice.

On 22 March 2025, Arctic sea ice reached its smallest-ever winter peak, according to the NSIDC. At 14.33m km2, this was 1.31m km2 below the 1981-2010 average maximum and 800,000km2 below the previous low, which was recorded in 2017.

The chart below shows Arctic sea ice extent over the satellite era (1978 to the present day). Red indicates the 2025 extent, while shades of blue indicate different years over 1978-2024.

NSIDC senior research scientist Dr Walt Meier told the Press Association:

“This new record low is yet another indicator of how Arctic sea ice has fundamentally changed from earlier decades. But, even more importantly than the record low, is that this year adds yet another data point to the continuing long-term loss of Arctic sea ice in all seasons.”

§ Freeze season

The growth season for Arctic sea ice kicked off after reaching its summer minimum extent of 4.28m km2 on 11 September last year. This was the Arctic’s seventh-lowest summer low on record. 

As temperatures cooled, the NSIDC says that Arctic sea ice grew slowly at the start of October. Ice growth then sped up towards the middle of the month and then slowed again towards its end. The average sea ice extent for October was 5.94m km2 – the fourth lowest on record, according to the NSIDC.

Throughout November, air temperatures over the Arctic Ocean were “mixed”, according to the NSIDC. It says that temperatures were above average from coastal Canada to northern Scandinavia, as well as in the area north of Greenland, but below average over the Beaufort, Bering and Laptev Seas.

Arctic sea ice grew at a steady pace for most of November – mainly in the Kara, Beaufort and Chukchi Seas, as well as Baffin Bay and the Canadian Arctic archipelago. However, in the Hudson Bay – where air temperatures were 1-5C above average – “no appreciable sea ice” formed, according to the NSIDC.

The November extent averaged 9.11m km2, ranking the third lowest in the satellite record and 1.59mkm2 below the 1981-2010 average, the NSIDC says.

December saw above-average air temperatures over “essentially all of the Arctic Ocean”, with a particularly “prominent” area of warmth off the Canadian Arctic archipelago and Greenland, the NSIDC says.

Due to delayed ice growth in the Hudson Bay and low extent in the northern Barents Sea, December Arctic sea ice extent was the lowest in the satellite record at 11.43m km2. 

Daily Arctic sea ice extent decreased sharply at the end of January, when the region lost about 0.3m km2 – an area roughly the size of Italy – in less than a week, according to C3S.

It adds that “such a rapid decrease is unusual at this time of year, when sea ice is typically expanding towards its annual maximum”. It points to the “pronounced warm event” over the Greenland Sea and Svalbard region as the reason for the drop.

Dr Rick Thoman – a specialist in the Alaskan climate from the University of Alaska Fairbanks – tells Carbon Brief that the sea ice decrease in late January and early February was partially driven by “separate cyclones producing simultaneous south winds across much of the Barents and Bering Seas”. As winds pushed the ice northwards, “ocean wave action” melted the thin ice at the edge of the ice sheet, he says.

February was marked by slow Arctic sea ice growth, resulting in a record-low February Arctic sea ice extent of 13.75m km2, according to the NSIDC. The organisation adds that daily sea ice growth “stalled” twice in the month, which “helped to contribute to low ice conditions and led to overall ice retreat in the Barents Sea”.

This rapid melt was partially driven by above-average temperatures. Between northern Greenland and the north pole, temperatures reached up to 12C above average, the NSIDC says.

§ Antarctic melt

At the south pole, Antarctic sea ice has been declining during the southern hemisphere summer. It reached its annual minimum of 1.98m km2 on 1 March.

This summer low ties with 2022 and 2024 for the second-smallest Antarctic extent in the 47-year satellite record, the NSIDC says. It adds that the past four years are the only years on record in which Antarctic sea ice has reached a minimum below 2m km2.

The graphic below shows Antarctic sea ice extent over the satellite era. Red indicates the 2025 extent and shades of blue indicate different years over 1978-2023. 

The melt season for Antarctic sea ice began with its winter maximum of 17.2m km2 on 19 September 2024. 

This was 1.6m km2 smaller than the 1981-2010 average maximum and the second-lowest winter peak on record, according to the NSIDC.

As the southern hemisphere warmed, Antarctic sea ice began to melt. Throughout October, Antarctic sea ice extent continued to rank the second lowest on the satellite record following the record-breaking 2023 season, the NSIDC says. 

It adds that “seasonal ice loss was relatively slow during the early part of the month, but the pace picked up substantially during the last week of October, approaching 2023 values”.

By 30 November, Antarctic sea ice was the third lowest on record, tracking higher than the 2023 and 2016 levels for the same date, the NSIDC says.

After a “prolonged period of record to near-record daily lows set in 2023 and 2024”, December 2024 saw Antarctic sea ice loss slow down, with the average rate of decline tracking “well below average”. 

By the end of December 2025, Antarctic sea ice extent was roughly in line with the 1981-2010 average, according to the NSIDC.

As a result, it says that “speculation that the Antarctic had entered a new regime of strongly reduced Antarctic sea ice related to oceanic influences, has, at least temporarily, come to an end”.

It adds that sea ice extent was “above average over the western Weddell and Amundsen Seas and slightly below average in the Ross Sea, with near-average extents in other areas”. 

Throughout February, Antarctic sea ice continued to melt – especially in the eastern Ross Sea and Amunsden sea, where ice concentration is low, according to the NSIDC.

§ Global ‘all-time minimum’

With sea ice at or around record lows in both the Arctic and Antarctic, global sea ice extent dropped to an “all-time minimum” in February this year, according to the Copernicus Climate Change Service (C3S).

Global sea ice hit a new daily low in early February and remained below the previous record from 2023 for the rest of the month, C3S says.

The graphic below shows global sea ice extent over 1978-2025, where red indicates the 2025 extent and shades of blue indicate different years.

C3S deputy director Dr Samantha Burgess noted that the low sea ice came as “February 2025 continues the streak of record or near-record temperatures observed throughout the last two years”. She added: 

“One of the consequences of a warmer world is melting sea ice – and the record or near-record low sea ice cover at both poles has pushed global sea ice cover to an all-time minimum.”

The story was picked up in newspapers around the world, including the Guardian, Hindustan Times and Washington Post.

In response to the news from C3DS, Prof Richard Allan – a professor of climate science at the University of Reading – warned that “the long-term prognosis for Arctic sea ice is grim”. He added: 

“Averaging over all regions the global warming trend is clear, with February 2025 more than 1.5C above pre-industrial conditions, repeating a level of excess warmth experienced in all but one of the past 20 months despite a weak cooling influence of La Niña conditions in the Pacific.”

§ Drying soil

Every year, around 6tn tonnes of water cycles through Earth’s land surface. When rain falls on land it gets held up in soil, wetlands, groundwater, lakes and reservoirs on its journey back to the oceans.

Soil moisture forms a critical part of the Earth’s system, helping to irrigate soil, cycle nutrients and regulate the climate. 

The amount of water contained in the soil is sensitive to a range of factors, including changes in rainfall, evaporation, vegetation and climate – as well as human activity, such as intensive agriculture. 

The research points to a “gradual decline” in soil moisture levels in the 21st century, kickstarted by a period of “sharp depletion” in the three years over 2000-02.

Specifically, the researchers find the depletion of soil moisture resulted in a total loss of 1,614bn tonnes (gigatonnes, or Gt) of water over 2000-02 and then 1,009Gt between 2002 and 2016.

(For context, ice loss in Greenland resulted in 900Gt of water loss over 2002-06.) 

Soil moisture has not recovered as of 2021, according to the research, and is unlikely to pick up under present climate conditions. 

Joint-lead author Prof Dongryeol Ryu, professor of hydrology and remote sensing at the University of Melbourne, explains to Carbon Brief:

“We observed a stepwise decline [in soil moisture] twice in the past two decades, interspersed within a continuously declining trend in soil moisture. We haven’t seen this trend earlier, so that is why this is very concerning.”

Ryu explains the decision to analyse changes to soil moisture on a global scale meant the researchers could confirm trends difficult to see in smaller geographic datasets:

“The unique thing we found through analysing these larger-scale measures is that – even if we have seen widely fluctuating ups and downs in precipitation and increasing temperature – the total water contained in the soil, as soil moisture and groundwater, has been declining gradually from around the beginning of this century.“

The maps below illustrate soil moisture changes in 2003-07 and 2008-12 against a 1995-99 baseline, as estimated by the ERA5-Land reanalysis dataset. The areas marked on the map in brown saw a drop in soil moisture and the areas marked in blue an increase in soil moisture.

The top map shows soil moisture depletion across large regions in eastern and central Asia, central Africa and North and South America over 2003-07. The lower map shows that “replenishment” in the years that followed occurred in relatively small parts of South America, India, Australia and North America.

§ Climate change 

Ryu says the researchers “suspect that increasing temperature played an important role” in the decline in terrestrial water storage and soil moisture in the 21st century. 

The study points to two factors driving gradual depletion of soil moisture over the last quarter century: fluctuations to rainfall patterns and increasing “evaporative demand”.

Evaporative demand refers to the atmosphere’s “thirst” for water, or how much moisture it can take from the land, vegetation and surface water.

Studies have highlighted how global evaporative demand has been increasing over the last two decades globally, impacting water availability, hurting crops and causing drought.

The new study notes that “increasing evaporative demand driven by a warming climate” suggests a “more consistent and widespread trend toward drying as temperatures rise”. 

Ryu says the “very unusual” drop in water moisture observed over 2000-02 could be attributed to low levels of rainfall globally, which coincided with the “period when evaporative demand started increasing”.

Another – less pronounced – period of rapid soil moisture decline seen over 2015-16 can be attributed to droughts triggered by the 2014-16 El Niño event, Ryu notes. 

Ryu says the study findings indicate that soil moisture can no longer bounce back from a dry year, as it has in the past:

“It used to be that when precipitation goes up again, we recover water in the soil. But because of this increasing evaporative demand, once we have strong El Niño years – which lead to much less rainfall for a year or two – it seems that we are not recovering the water fully because of increasing evaporative demand. Because of that – even if we have a wet year following dry years – the water in the soil doesn’t seem to recover.” 

§ Cross-validation

Measuring changes in global soil moisture has historically presented a challenge to scientists, given the lack of comprehensive and direct observations of water in soil.

The researchers attempt to reduce this uncertainty by corroborating the ERA5-Land reanalysis dataset from the European Centre for Medium-Range Weather Forecasts (ECMWF) with three geophysical measurement datasets.

ERA5’s land surface modelling system uses meteorological and other input data to estimate water within the upper few metres of the soil.

These figures were compared with data collected by the Gravity Recovery and Climate Experiment (GRACE) mission – a joint satellite mission between NASA and the German Aerospace Center.

Running since 2002, the GRACE mission tracks changes to the Earth’s gravity by collecting data on groundwater depletion, ice sheet loss and sea level rise. These observations have revealed a persistent loss of water from land to the ocean. 

The scientists also cross-reference the ERA5 reanalysis data with a century-old dataset that measures fluctuations in the rotation of the Earth as the distribution of mass on the planet changes.

(The redistribution of ice and water, such as melting ice sheets and depleting groundwater, causes the planet to wobble as it spins and its axis to shift slightly. This is known as “polar motion”.)

The third set of measurements the scientists use is global mean sea level height, which is collected by satellites. 

To extract soil moisture changes from this set of data, the researchers subtracted other components of sea level rise from the overall total – including Greenland ice melt, Antarctica ice melt, the impact of increasing sea surface temperature (which expands water volume) and the contribution of groundwater. 

This process of elimination left researchers with an estimate of the contribution of soil moisture to global sea level rise. 

The study notes that both the sea surface height and polar motion observations “support the conclusion that the abrupt change in soil moisture is genuine”. 

Ryu says using global average sea level rise and “Earth wobble” to track water redistribution on land is the “main innovation” applied in the paper. 

He adds the value of “reverse engineering” the ERA5 dataset is to understand how to enhance land surface modelling in the future:

“By explaining all the contributing factors to this measurement, you can understand the process. And if you understand the process, you can actually predict what’s going to happen in the future if any of these factors change in a certain manner.”

NASA’s Dr Cook says the “corroborating evidence” supplied by the paper offers a “really strong case that there has been a large-scale decline in soil moisture in recent decades”. 

However, he says the relatively short reference period of the study means that identifying the cause of the decline is less clear cut: 

“Whether [the decline] is permanent or not  is much more uncertain…On these timescales, internal natural variability can be really, really strong. Attributing this decline to something specific – either climate change or internal variability – is much much more difficult.”

§ Sea level rise

A notable finding in the study’s sea level rise analysis is that terrestrial water storage may have been the dominant driver of sea level rise in the early 21st century.

Specifically, the paper notes that the decline in terrestrial water storage over 2000-02 – when soil moisture plummeted – led to global average sea level rise of almost 2mm annually.

The researchers note this rate of sea level rise is “unprecedented” and “significantly higher” than the rate of sea level rise attributed to Greenland ice mass loss, which they note is approximately 0.8mm a year.

Prof Reed Maxwell, a professor at the High Meadows Environmental Institute at Princeton University, who was also not involved in the study, says the researchers’ efforts to compare soil moisture with other global water stores was “novel” and “opens the door to future study of a more holistic global water balance”.

§ ‘Creeping disaster’

The paper notes that land surface and hydrological models require “substantial improvement” to accurately simulate changes in soil moisture in changing climate.

Current models do not factor the impacts of agricultural intensification, nor the ongoing “greening” of semi-arid regions – both of which “may contribute” to a further decline in soil moisture, it states.

Writing in a perspectives article published in Science, Prof Luis Samaniego from the department of computational hydrosystems at the Helmholtz Centre for Environmental Research says that it is “essential” that next-generation models incorporate human-caused influences such as farming, large dams and irrigation systems.

The study posits that the “innovative methods” for estimating changes in global soil moisture presented in the study provide opportunities to “improve the present state of modelling at global and continental scales”. 

More broadly, advances in scientific understanding of changes to soil moisture can help improve the world’s preparedness for drought.

Drought is often described as a “creeping disaster” – because by the time it is identified, it is usually already well under way.

Paper author Ryu explains:

“Unlike a flood and heatwaves, drought comes very very slowly – and has prolonged and delayed consequences. We better be prepared earlier than later, because once drought comes you can expect a long period of consequences.”

Dr Shou Wang, associate professor at the Hydroclimate Extremes Lab and the Hong Kong Polytechnic University, who was not involved in the study, says the research findings are “crucial” for advancing understanding of the “potential drivers and dynamics” of “unprecedented hydrological extremes in a warming climate”. He tells Carbon Brief:

“This is breakthrough work that uncovers the drivers of hydrological regime changes, which are leading to unprecedented hydrological extremes such as compound and consecutive drought-flood events.”

§ Key developments

Forest and biodiversity funds

TRANSFORMING FOREST FINANCE: A Forest Declaration Assessment report revealed that global forest finance is “not only falling short, but actively fuelling deforestation”, said Down to Earth. According to the report, for every dollar allocated to forest protection, six dollars go to activities driving deforestation. In 2023 alone, private financial institutions invested $6.1tn in sectors linked to deforestation, while governments spent $500bn in subsidies harmful to nature. Relatedly, several organisations launched a call to action for forest protection. It listed the priority actions for governments in 2025, which include enhancing ambition in forest goals, promoting deforestation-free trade, scaling up forest finance and securing land rights of forest communities.

NEW CONTRIBUTIONS: Brazil’s planned $125bn “Tropical Forests Forever Facility” is on track to be launched at COP30 this year, the Straits Times reported. The outlet said that several countries, including Germany, France and the United Arab Emirates, have expressed interest in contributing to the fund. Brazilian outlet ((o))eco said that the fund “would pay countries for each hectare of rainforest maintained or restored”. Meanwhile, Ireland announced its first donation, of $16m, to Brazil’s Amazon Fund, according to Reuters. The fund, which is already supported by seven other countries, seeks to halt deforestation and boost sustainable development in the Amazon rainforest.

SHORT SCOPE: The Kunming Biodiversity Fund is only supporting six projects of $1.2m, according to the UN Development Programme, cited by Dialogue Earth. The fund was launched by China at the first part of the COP15 biodiversity summit in 2021. The outlet noted that China’s $207m pledge is the only contribution to the fund so far. The fund approved its first nine projects at COP16 last year, with six of them currently underway. Elsewhere, carbon credit registry Verra suspended the activities of four auditors that “overlooked integrity problems” with methane-cutting rice offset projects in China, Climate Home News reported. 

England’s new national forest  

INTO THE WOODS: BBC News reported that 20m trees will be planted to create England’s first new national forest in three decades. The “Western Forest” will be composed of new and existing woodlands in the south-west of the country, the outlet said. It will be the first of three new national forests to help meet woodland goals, according to the UK government. The 20m trees will be planted over the “coming decades”, the Times noted, and will be spread across farmlands and urban areas. Meanwhile, a new government-led group of major landowners in England met to discuss ways to cooperate on nature restoration goals, Business Green said. 

BUDGET WOES: Farming representatives “reacted with fury” after the UK government closed England’s sustainable farming incentive subsidy scheme to new applicants until next year, the Times reported. The newspaper said: “Labour promised £5bn in nature-friendly farming subsidies over this year and the next financial year, but has burnt through the budget already.” The 37,000 existing agreements will still be honoured, the newspaper said. Gavin Lane from the Country Land and Business Association described it as a “disaster for nature recovery”. A “reformed” version of the scheme will be announced this summer, the Department for Environment, Food and Rural Affairs said in a statement. 

PESTICIDE CUTS: Meanwhile, the UK government announced plans to cut pesticide use on farms by 10% by 2030 to help “protect bees and other pollinators”, according to the Guardian. The plan, which the newspaper said had been delayed since 2018, included penalties for irresponsible pesticide use. A spokesperson for Pesticide Collaboration, a group of health and environmental organisations, academics, farmers and others, said they were “thrilled” with the plan. The group told the Guardian that they were pleased that it “takes into account both how much of a pesticide is used and how toxic it is”, but added that they had hoped for a higher target. 

HABITAT CHANGES: Elsewhere, proposed changes to the UK’s planning system “sparked job security fears among thousands of ecologists”, the Financial Times said. The newspaper explained: “The proposed measures will significantly reduce the number of protected species surveys required for development to be approved, as part of a government drive to speed up delivery of big infrastructure projects”. Ecologists who complete these surveys are concerned about the impacts for their work, according to the FT. The proposed reforms survived their “first Commons test” this week, the Independent said, while the Guardian reported that UK nature charities called on ministers to “urgently strengthen environmental protections in new planning laws”.

§ Spotlight

Third of US birds should be prioritised for conservation

This week, Carbon Brief looks at the 2025 US State of the Birds report, which assesses the health of bird populations in the country.

Nearly a third of all bird species in the US face a decline in their populations or other threats, such as habitat loss, a new report concluded.

The 2025 State of the Birds report, published by a coalition of conservation organisations under the North American Bird Conservation Initiative, used bird population data over 1970-2022 to identify the avian species most at risk. 

The “at-risk” species were those with low population numbers or declining populations, as well as those facing external threats.

These species – 229 in all – “should be prioritised in conservation planning to protect existing populations and build toward population recovery”, the report said.

Conservation concerns

Of the birds studied, 112 species are of “high concern” for conservation. 

These species have faced “steep” population losses and have lost at least half of their populations in the last 50 years. They include the whooping crane, chimney swift and California condor. The report termed these species “tipping point species” and called for increased scientific research to determine the drivers of their declines, as well as “immediate help through voluntary and proactive conservation action”.

Another 117 bird species are of “moderate concern”, meaning they have small or declining populations, but have not faced such steep declines as the higher-risk species. This category also includes common birds that have “experienced large losses”, such as sparrows and blackbirds. 

The remaining 489 bird species are of “low concern” for conservation, although the report noted that half of these have also experienced long-term declines in population, but “fall short of the thresholds for priority conservation planning”.

Threatened species

The report also looked at the changes in the population of species from different ecosystems.

The chart below shows the population change, since 1970, for eight types of birds classified in the report.

Notably, grassland birds have seen the largest overall declines, losing around 43% of their total population since 1970 and with several species reaching the “tipping point” described in the report. US grasslands are “in collapse”, the report noted, due to expanding agriculture, drought and invasive alien species.

Aridland birds have also lost more than 40% of their population since 1970, the report said. About a quarter of the 31 aridland species analysed, including the scaled quail and rufous-crowned sparrow, are in the “high concern” category. Shorebirds have the largest number of species listed as high concern. The report noted that the largest declines of these species are registered in migratory staging sites along the Atlantic coastline. 

By contrast, ducks and waterbirds are the best-placed groups, with 24% and 16% increases in their populations, respectively. The abundance of duck populations coincides with policies aimed at conserving their wetland habitats and other conservation programmes. 

Nonetheless, individual species within these groups have also seen declines in population, the report said. Additionally, while their numbers have still improved since 1970, duck populations have dropped steeply over the past decade.

The document also listed various benefits provided by birds. Nearly 100 million people in the US are birdwatchers, a hobby that contributes to the mental well-being of people with depression and reduces symptoms of stress and anxiety. Moreover, birding yields $108bn annually in trips and equipment and generates 1.4m jobs.

The report concluded:

“Restoring bird populations and addressing causes of their declines benefits millions of Americans.”

§ News and views

COP ‘CONTRADICTION’: Earlier this month, BBC News reported on the building of a new highway “to ease traffic to” COP30 host city Belém that would run through “thousands of acres of protected Amazon rainforest”. The Brazilian newspaper O Globo quoted scientists who said the 13km road is a “contradiction in the governor’s environmental discourse”. In response, the Brazilian government clarified that the highway is not “part of the 33 infrastructure projects planned for COP30” and said that the initial framing “misinforms readers by misleadingly suggesting a connection between the construction project and the federal government’s actions” preparing for COP30.

US AG CUTS: The US Department of Agriculture (USDA) cut two programmes that paid farmers $1bn to provide food to schools and food banks for low-income families, the New York Times reported. It added that the agriculture secretary has “broad discretion” to use the funding “for purposes aligned with the administration’s aims”. A smallholder farmer from Missouri told the newspaper that her production had doubled thanks to those programmes, but now she is concerned about how she will make payments on her debts. The Washington Post reported that the USDA also cancelled an additional $500m in deliveries to food banks.

NATURE DEALS: Colombia rejected a number of debt-for-nature swap offers due to “fears” about the impact they could have on the country’s credit rating, Bloomberg reported. Susana Muhamad, who resigned as Colombia’s environment minister in February, told the outlet that these swaps could “send the wrong message to the markets and make our financial situation worse”. This is also the government’s current stance, a spokesperson for the environment ministry told Bloomberg. (See Carbon Brief’s Q&A for more on these financial agreements, where a developing country’s debt is effectively exchanged for investment in conversation.)

PAYOUT PUSHBACK: Context News reported that farmers in India’s most vulnerable districts can pay higher crop insurance premiums, but receive lower payouts, than farmers in less vulnerable areas. The outlet cited a thinktank report saying that this “undermines the purpose” of India’s government-run crop-insurance scheme, which is the world’s largest. The report, from the Centre for Science and Environment, found that farmers living in “climate-vulnerable districts” faced higher premiums, lower levels of insurance cover and smaller payouts than farmers in lower-risk areas, Context News said.

‘FRAGILE’ MOUNTAINS: “Unprecedented changes” to mountains and glaciers threaten fresh water access for more than two billion people, according to a UN report covered by Carbon Brief. Mountains and glaciers are becoming “increasingly vulnerable” to climate change and unsustainable human activities, the report said. This is having a wide range of impacts on agriculture, local ecosystems and other aspects of life. One expert told Carbon Brief that glacier loss is already causing “loss of life, loss of livelihood and, most importantly of all, the loss of a place that many communities have called home for generations”. 

‘METHANE MESS’: Major supermarkets are not reporting on their methane emissions or setting targets to reduce emissions of the potent greenhouse gas, according to a new report. The analysis, published by environmental campaign groups the Changing Markets Foundation and Mighty Earth, said that there is a “disconnect between retailers’ climate promises and action”. The report analysed climate reports and other data from 20 “top-grossing” food retailers in the US and Europe to assess their progress on mitigating methane emissions. It identified a “significant lack of action” to address methane emissions, with US retailers performing “especially badly”. 

§ Watch, read, listen

REN-EWE-ABLE?: Ambrook Research explored whether grazing sheep under solar panels “count[s] as clean energy”.

OFF THE MENU: A Climate Home News comment article by a former Colombian negotiator argued that food systems have been “sidelined” in the agenda for the COP30 climate summit. 

IN DANGER AGAIN: Euractiv covered the increase in wolf hunting in the EU, against a backdrop of “manipulated numbers” and lax regulations.
MARINE LIFE: A “sustainable blue economy” is needed to protect the ocean from “surging” threats, including overfishing and climate change, researchers wrote in Dialogue Earth.

§ New science

• A Nature Communications study found that three-quarters of species’ ranges in border areas between countries are not under protection. The findings, based on analysis of the distributional ranges of almost 20,000 land-based species, show the “urgent” need for cross-border cooperation to meet global biodiversity goals, the researchers wrote. 
• Grass-fed beef in the US is generally more carbon-intensive than industrially produced beef, according to a study in Proceedings of the National Academy of Sciences. The research found that the emissions per kilogram of protein in “even the most efficient” grass-fed beef are 10-25% higher than industrial beef – and as much as 40 times higher than plant protein and other animal alternatives. 
• Nearly 30% of forest loss in 15 tropical countries over 2001-20 occurred within one kilometre of a road, a Communications Earth and Environment study found. The researchers used datasets of roads and forest loss to produce high-resolution maps of deforestation, highlighting the “urgent need” to protect and restore forests along tropical roads.

§ In the diary

• 24-28 March: 20th session of the UN FAO commission on genetic resources for food and agriculture | Rome 
• 30 March: International day of zero waste 
• 2-3 April: 41st UN-Water meeting | Rome 

Cropped is researched and written by Dr Giuliana Viglione, Aruna Chandrasekhar, Daisy Dunne, Orla Dwyer and Yanine Quiroz. Please send tips and feedback to cropped@carbonbrief.org

§ How to change behaviour

There is a sizeable evidence base on how to deliver low-carbon and climate-resilient lifestyles and on changing behaviour in professional contexts. 

Using literature searches and a call for evidence, identifying almost 400 sources in total, we examined evidence for what works to change behaviour within eight main areas: 

• diet 
• consumption 
• aviation
• adaptation
• net-zero skills and careers
• business leaders and the transition to sustainability 
• land use and farming 
• policy acceptability

Numerous behavioural theories and models exist to explain and predict climate mitigation and adaptation actions. 

Psychological theories, such as the theory of planned behaviour (TPB) and the value-belief-norm model (VBN) assume action is primarily driven by internal factors, such as attitudes, values and knowledge. 

Specifically, the TPB states that behaviour results from intentions, which, in turn, are the outcome of attitudes, perceptions of social norms and ability.

The VBN sees behaviour as the outcome of a sequence of values, which informs beliefs and perceived responsibility for environmental problems, which shapes the moral obligation to act, leading to action. 

Since the TPB includes perceived ability, acknowledging external social, physical and economic factors can limit or propel action. Research suggests it does better than the VBN at explaining higher-impact environmental behaviours, such as avoiding driving, than lower-impact behaviours that tend to be more within individuals’ control, such as recycling.

In contrast, sociological theories – such as social practice theory – tend to place more emphasis on the contextual drivers of action, such as physical infrastructure and social conventions.

Social practice theory sees practices – such as showering or cooking – as resulting from the interaction of physical and technological factors, social conventions and skills. These also see action as routine or habitual more often than intentional. 

Integrative models also exist that draw on various theories to explain behaviour. One of the most commonly used is the COM-B model, which identifies capabilities, opportunities and motivations as the key drivers of behaviour.

Our review found that, in general, low-carbon and climate-resilient behaviours are driven by both internal and external factors, including: 

1. Individual knowledge, values and emotions.
2. Social factors, such as norms and group identity.
3. Practical factors, such as functionality, ease and price. 

Of these various drivers, individual factors – such as knowledge – tend to be less influential in changing behaviour than wider social or practical factors. 

Consequently, interventions targeting individual decision-making or motivation, such as information provision, tend to be less effective than interventions targeting the context of action. These interventions, such as regulations, incentives and infrastructure changes, typically make behaviour easy, attractive and normal – or even the default.

One review found that informational approaches, such as labelling or in-home displays, were on average only 3% effective. In contrast, “nudges” that adjust choice environments to make sustainable choices easier, but without coercion, were, on average, 25% effective. 

These nudges could include locating recycling bins closer than regular waste bins or putting energy consumers on green tariffs (instead of fossil fuel tariffs) by default. 

Individual-focused interventions, such as information provision (e.g. campaigns), are known as “downstream” measures, while context-focused interventions, such as nudges, economic measures and regulation, are “upstream” measures. 

Despite evidence of its limited efficacy and tendency to exacerbate inequalities, there is a preference amongst policymakers for downstream over upstream interventions. 

This is, in part, because the former is more easily experimentally tested and costed, but it is also due to power structures in government, political ideology and skills gaps.

§ Targeted and timely change

Beyond targeting upstream changes, our review also found that interventions are more effective when they are: 

• Targeted – to the specific needs and abilities of different groups. 
• Combined – that is, they include downstream and upstream approaches, as well as addressing the multiple behavioural drivers and barriers. 
• Timed – to when habits are malleable, such as household renovation or relocation, or when business leaders or farmers are making key investment decisions. (In psychology, this is termed “habit discontinuity”.)

Public engagement is also important for effective behaviour change interventions to both foster acceptance and address contextual factors or constraints to efficacy, our research suggests. 

Interventions to change behaviour that are imposed on people without consultation risk being rejected, as seen with the “Gilets Jaunes” in France and London’s Ultra low emission zone (Ulez) expansion protests. Bringing the public into decision-making from the outset to scope a problem and identify solutions is more likely to lead to fairer and more acceptable outcomes. 

Climate assemblies and juries are examples of how this is increasingly being achieved. Engagement can also help communicate the need for and benefits of climate action and therefore promote policy acceptance.

From our research over the years at the Centre for Climate Change and Social Transformations (CAST), we know that different approaches work better depending on the sector.

For example, adaptation behaviour change requires a stronger focus on information provision than mitigation actions, since there is little public awareness of why or how to adapt to climate risks. 

For transport, congestion charging and reallocating road space from cars to less polluting modes – such as pedestrianisation and low-traffic neighbourhoods – are amongst the most effective ways of cutting car use. Additionally, frequent flyer levies enjoy public support so may be a fair and effective way of curbing aviation growth. 

But, in both cases, there is a need for “carrots” as well as “sticks”. Alternatives to driving and flying must also be convenient, affordable and attractive if people are to switch to these lower-carbon modes, our research found. 

For diet change, communicating the various benefits of low-carbon diets and carbon labelling – for health and the environment – has some effect. However, our research suggests lowering the price of vegetarian options and making them more available – including the default option – is far more effective. 

In one simple, but effective, study, researchers doubled the proportion of vegetarian meals available in canteens – from one-in-four, to two-in-four options. This led to increases in vegetarian meal sales of up to 79%. 

But there are still gaps in the evidence base. Little is known, for example, about how to encourage people to adopt climate-resilient behaviours or to reduce flying. More generally, we found little evaluation of real-world interventions. 

§ Removing barriers

Our review concludes with core recommendations for using behavioural science in climate policy. These include identifying behavioural targets – for example, based on carbon impact and feasibility – engaging with the public and combining, timing and tailoring interventions.

While there are evidence gaps, our research shows that much is already known about how to foster low-carbon, climate-resilient behaviour change. 

Moreover, the public wants to play their part in tackling climate change. Public concern about climate change has not been reduced by Covid-19 or the cost-of-living crisis – and most people in the UK and around the world agree that individual behaviour change is needed. 

We found that the government now needs to use these insights from behavioural science to remove the barriers to behaviour change. This, in turn, will help accelerate the net-zero transition and adapt to climate risks. 

§ This week

Germany’s €100bn climate funding

BILLIONS IN FUNDING: Germany’s parliament on Tuesday voted to create a €500bn defence and infrastructure fund and relax “constitutionally-protected debt rules”, the Guardian reported, with “the last-minute backing of the Greens” in return for “guarantees that €100bn of the funds destined for infrastructure would be allocated for climate and economic transformation investments”. The deal came following “clumsy” initial negotiations from Germany’s chancellor-in-waiting, Friedrich Merz, Bloomberg said. It reported that the Greens “finally came around” after Merz’s negotiators “conceded to their key demands”, which also included adding Germany’s 2045 climate-neutrality target into the constitution. 

TAKING CLIMATE ‘SERIOUSLY’: The Greens said in a statement on social media that the agreement “finally takes the challenges of the future seriously”, according to the New York Times. Paula Piechotta, a member of the Greens in the German Bundestag, told the German newspaper Tagesspiegel that the deal was a “great success for democracy in our country, for sustainability and intergenerational justice”. The newspaper added that the far-right Alternative for Germany (AfD) and the Left party, “unsurprisingly”, criticised the agreement.

UK opposition breaks cross-party climate consensus

BREAKING AWAY: In a speech, Kemi Badenoch, leader of the UK opposition Conservative party, said it was “impossible” for the UK to meet its net-zero target by 2050, marking a “sharp break from years of political consensus”, BBC News reported. She did not offer an alternative target for the goal, the broadcaster said, quoting her telling reporters that if the Conservatives “do find a target is necessary, then yes we will have one”. Badenoch “failed to cite any evidence in support” of her arguments, according to a factcheck published by Carbon Brief, which concluded that much of the existing evidence “contradicts” her claims.

TORY BACKLASH: In response, Conservative former prime minister Theresa May, who was responsible for passing the 2050 target into law, warned the move “will hurt future generations and cost Britons”, the Times reported. The Confederation of British Industry (CBI) also criticised the speech, warning that “now is not the time to step back from the opportunities of the green economy”, according to the i newspaper. In the Daily Telegraph, Ambrose Evans-Pritchard said Badenoch’s “rant comes close to political tragedy”.

§ Around the world

• CARNEY CUTS: New Canadian prime minister Mark Carney removed the country’s “consumer carbon tax”, CBC News reported, adding that the policy had been a “potent point of attack” for his political opponents.
• GREENPEACE BILL: Greenpeace has been ordered to pay $660m in damages over its protests against the Dakota Access pipeline in 2016, which could “bankrupt its US operations” if upheld, the Financial Times said.
• UK-CHINA FORUM: The UK and China agreed to establish an “annual climate dialogue”, with the first meeting to be held in London later this year, the Times reported. 
• CHEQUES AND BALANCES: A US judge has “temporarily barred” attempts by the Trump administration to recoup at least $14bn in “grants issued by the Biden administration for climate and clean-energy projects”, the Washington Post said.
• EXTREME HEAT: “Severe heatwave conditions” have begun affecting several areas across India “unusually early in the season”, the Hindustan Times reported.
• SOUTH AFRICAN SUPPORT: The EU will fill a “$1bn hole” in South Africa’s “just energy transition partnership” left by the US, the Financial Times reported. The US is also “stalling” $2.6bn of climate finance for South Africa, Bloomberg said.

§ 152

The number of “unprecedented” extreme weather events that occurred in 2024, according to the World Meteorological Organization’s State of the Climate 2024 report. Heatwaves were the most common type of unprecedented events – defined as events “worse than any ever recorded in the region” – followed by “rain or wet spells” and floods.

§ Latest climate research

• New research in Climate and Development explored how environmental justice featured in the climate action plans of rust-belt cities in the US, finding that few “provided enough details” to determine if it was a priority.
• A new Science Advances study identified “increasing storminess” in the south-western Caribbean, which was attributed to “industrial-age warming”.
• Marine heatwaves are now 5.1 times more frequent and 4.7 times more intense since records began, new research in Communications Earth & Environment found.

(For more, see Carbon Brief’s in-depth daily summaries of the top climate news stories on Monday, Tuesday, Wednesday, Thursday and Friday.)

§ Captured

The UK’s high electricity prices are primarily driven by gas prices, according to an analysis published by Carbon Brief, with the UK typically seeing gas set electricity prices 98% of the time – compared to an average in the EU of 40%.

§ Spotlight

Chatham House talks climate and resilience

Carbon Brief outlines key takeaways from Chatham House’s climate and energy summit.

Chatham House, the UK’s leading international affairs thinktank, held its annual summit on climate and energy on 18-19 March. This year’s theme was: “Securing a resilient future.”

Carbon Brief attended the conference, where speakers including COP30 CEO Ana Toni, UK climate envoy Rachel Kyte and Moroccan minister for energy transition and sustainable development Leila Benali shared their thoughts on encouraging and enacting climate action.

Climate backlash

A sense of urgency permeated discussions at the summit, underpinned by concerns over growing anti-climate narratives.

Toni argued climate scepticism proves climate action is on the right track. 

She said: “First people ignore you, then they laugh at you, then they fight you – and this is where we are – then we win.”

Other speakers said that increasing support for climate action by building new norms and creating overlapping interests could also be effective strategies. 

Former US climate envoy Todd Stern pointed to increasing adoption of electric vehicles, while ClientEarth CEO Laura Clarke raised the example of community-owned renewable power. 

Fretting over finance

Clean Earth Gambia founder Fatou Jeng warned that climate finance, as ever likely to be an important issue at COP30, has “not progressed much”.

“Blended finance” – using public money to leverage private funds – was heavily criticised in several panels. Ben Parsons, a partner at consultancy firm Oaklin, noted that only 72 such deals were agreed in 2024.

Speakers agreed that innovative mechanisms to derisk climate finance were needed, with Morocco’s Benali critiquing “exclusive” and inflexible private financing options.

Ndongo Samba Sylla, head of research and policy at International Development Economics Associates, argued that using local currencies would significantly boost climate finance. 

Resilience through renewables

A key benefit of the UK’s “climate leadership”, Kyte argued, is that the energy transition will “make British people more secure”.

Parsons said the argument – recently deployed by Conservative leader Badenoch – that the energy transition replaced reliance on Russian fossil fuels with reliance on Chinese technology was incorrect. 

“Fossil fuels are fuel – they require constant replenishment. Renewables are infrastructure,” he said, adding that arguably the UK should be accelerating its deployment of clean-energy technology.

On cybersecurity challenges in renewable power systems, Alex Schoch, vice president and group director of flexibility and electrification at Octopus Energy, argued that the key issue is how renewable energy “hardware” is managed, rather than where it is sourced from.

Parsons agreed, noting that the UK’s current power system has “plenty of cybersecurity vulnerabilities in it today”. 

He said: “We have to make sure we’re putting [cybersecurity strategies] in place…But I don’t think that goes hand in hand with thinking we should avoid buying renewables from certain parts of the world.”

In a session on energy security in war-time Ukraine, held under the Chatham House rule, participants noted that the country was a case study for the importance of energy security.

Speakers said that since Russia’s invasion of Ukraine, attacks on thermal power plants have seen growing use of low-carbon energy – particularly distributed solar.

§ Watch, read, listen

ELEPHANT IN THE ROOM: The Columbia Energy Exchange podcast explored how the new Trump government underpinned discussions at the energy industry event CERAWeek.

‘CONFLICT BLINDSPOT’: A new report by ODI found that “less than 10% of international climate finance” in 2022 went to fragile and conflict-affected countries.

METHANE INACTION: Leading supermarkets in the global north are “failing to address the methane pollution in their supply chains”, according to a study covered by Desmog.

§ Coming up

• 24-26 March: 16th Petersberg Climate Dialogue, Berlin, Germany
• 24-26 March: IPCC lead author meeting for methodology report on inventories for short-lived climate forcers, Bilbao, Spain
• 24-28 March: 20th session of the UN FAO commission on genetic resources for food and agriculture, Rome, Italy
• 25 – 28 March: First G20 climate and environment sustainability working group meeting, online

§ Pick of the jobs

• ClientEarth, lawyer or legal consultant, energy systems, Asia | Salary: 455m-585m Indonesian rupiah. Location: Jakarta
• European External Action Service, policy officer for green diplomacy | Salary: Unknown. Location: Brussels
• Bloomberg, climate reporter | Salary: Unknown. Location: Hong Kong
• The Grantham Research Institute on Climate Change and the Environment, project manager | Salary: £42,679-£51,000. Location: London

DeBriefed is edited by Daisy Dunne. Please send any tips or feedback to debriefed@carbonbrief.org.

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