We handpick and explain the most important stories at the intersection of climate, land, food and nature over the past fortnight.
This is an online version of Carbon Brief’s fortnightly Cropped email newsletter. Subscribe for free here. This is the last edition of Cropped for 2025. The newsletter will return on 14 January 2026.
Key developments
High Seas Treaty enters force
OCEAN BOOST: The High Seas Treaty – formally known as the “biodiversity beyond national jurisdiction”, or “BBNJ” agreement – entered into force on 17 January, following its ratification by 60 states, reported Oceanographic Magazine. The treaty establishes a framework to protect biodiversity in international waters, which make up two-thirds of the ocean, said the publication. For more, see Carbon Brief’s explainer on the treaty, which was agreed in 2023 after two decades of negotiations.
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DEEP-SEA MINING: Meanwhile, the US – which is not a party to the BBNJ’s parent Law of the Sea – is pushing on with an effort to accelerate permitting for companies wanting to hunt for deep-sea minerals in international waters, reported Reuters. The newswire described it as a “move that is likely to face environmental and legal concerns”.
UK biodiversity probe
SECURITY RISKS: The global decline of biodiversity and potential collapse of ecosystems pose serious risks to national security in the UK, a report put together by government intelligence experts has concluded, according to BBC News. The report was due to be published last autumn, but was “suppressed” by the prime minister’s office over fears it was “too negative”, said the Times.
COLLAPSE CONCERNS: Following a freedom-of-information (FOI) request, the government published a 14-page “abridged” version of the report, explained the Times. A fuller version seen by both the Times and Carbon Brief looked in detail at the potential security consequences of ecosystem collapse, including shifting global power dynamics, more migration to the UK and the risk of “protests over falling living standards”.
News and views
- OZ BUSHFIRES: Bushfires continued to blaze in Victoria, Australia, amid record-breaking heat, said the Guardian. A recent rapid attribution analysis found that the “extreme” Australian heat in early January was made around five times more likely by fossil-fuelled climate change.
- MERCO-SOURED: On 17 January, the EU signed its “largest-ever trade accord” with the Mercosur bloc of countries – Argentina, Brazil, Paraguay and Uruguay – after 25 years of negotiations, per Reuters. On 21 January, amid looming new US sanctions, EU lawmakers voted to send the pact to the European Court of Justice, which could delay the deal by almost two years, according to the New York Times.
- SOY IT ISN’T SO: Meanwhile, the Guardian reported that UK and EU supermarkets have “urged” traders who had “abandoned” the Amazon soya moratorium to stick to its core principles: “not to source the grain from Amazon land cleared after 2008”.
- WATER ‘BANKRUPTCY’: A new UN report warned that the world is facing irreversible “water bankruptcy” caused by overextracting water reserves, along with shrinking supplies from lakes, glaciers, rivers and wetlands, Reuters reported. Lead author Prof Kaveh Madani told the Guardian that the situation is “extremely urgent [because] no one knows exactly when the whole system would collapse”.
- KRUGER UNDER WATER: Flood damages to South Africa’s Kruger National Park could “take years to repair” and cost more than $30m, said the country’s environment minister, quoted in Reuters. Rivers running through the park “burst their banks” and submerged bridges, with “hippos seen…among treetops”, it added.
- FORESTS VS COPPER: A Mongabay report examined how “community forests stand on the frontline” of critical-minerals mining in the Democratic Republic of the Congo’s copper-cobalt belt.
Spotlight
Nature’s coast guard, with backup
This week, Cropped speaks to the lead author of a new study that looks at how – and where – mangrove restoration can be best supported across the world.
Along Mumbai’s smoggy shoreline, members of the city’s Indigenous Koli community wade through the mangroves at dawn to catch fish. Behind their boats, giant industrial cranes whir to life, building new stretches of snaking coastal highway that blot out the horizon.
Mumbai’s mangrove cover is possibly the highest for any major city. With their tangled, stilt roots, mangrove species serve as a natural defence for a city that experiences storm surges and urban flooding every year. These events disproportionately affect the city’s poor – particularly its fishing communities.
This mangrove buffer is being increasingly threatened, as the city chooses coastal roads and other large development projects over green cover, despite protests. But can green and grey infrastructure coexist to protect vulnerable communities in a warming world?
A new global-scale assessment published last week tallied the benefits of mangrove restoration for flood risk reduction, factoring in future climate change, development and poverty.
It advanced the idea of “hybrid” coastal defence measures. These combine pairing tropical ecosystems with modern, engineered defences for sea level rise, such as dykes and levees.
When Carbon Brief contacted lead author and climate scientist Dr Timothy Tiggeloven of Vrije Universiteit Amsterdam, he was in Kagoshima in Japan, home to the world’s northernmost mangrove forests. Why combine mangroves and dykes? Tiggeloven explained:
“Mangroves are like active barriers: they reduce incoming energy from waves, but they will not stop the water coming in from storms, because water can flow through the branches. But wave energy can still be overtopped. So if you reduce wave energy via mangroves and have dykes behind this, they very much have a synergy together and we wanted to quantify the benefits for future adaptation.”
According to the study, if mangrove-dyke systems were built along flood-prone coastlines, mangrove restoration could reduce damages by $800m a year, with an overall return-on-investment of up to $125bn.
It could also protect 140,000 people a year from flood risk – and 12 times that number under future climate change and socioeconomic projections, the study said.
According to the study, south-east Asia could reap the “highest absolute benefits” from mangrove restoration under current conditions. Countries that could see the “highest absolute potential risk reduction” – considering future climate damages in 2080 – are Nigeria ($5.6bn), Vietnam ($4.5bn), Indonesia ($4.3 bn), and India ($3.8bn), it estimated.
Maharashtra – which Mumbai serves as the state capital for – is one of two subnational regions globally that could reap the largest benefits of restoration.
Tiggeloven emphasised that the goal of the study was to examine how restoration impacts people, “because if we’re looking only at monetary terms, we’re only looking at large cities with a lot of assets”, he told Carbon Brief.
A pattern that his team found across multiple countries was that people with lower incomes are disproportionately living in flood-prone coastal areas where mangrove restoration is suitable. He elaborated:
“Wealthier areas might have higher absolute damages, but poor communities are more vulnerable, because they lack alternatives to easily relocate or rebuild, so the relative impact on their wellbeing is much greater.”
Poorer rural coastal communities with fewer engineered protections, such as sea walls, could benefit the most from restoration as an adaptive measure, the study found. But as the study’s map showed, there are limits to restoration. Tiggoloven concluded:
“We also should be very careful, because mangroves cannot grow anywhere. We need to think ‘conservation’ – not only ‘restoration’ – so we do not remove existing mangroves and make room for other infrastructure.”
Watch, read, listen
DU-GONE: A feature in the Guardian examined why so many dugongs have gone missing from the shores of Thailand.
WILD LONDON: Sir David Attenborough explored wildlife wonders in his home city of London. The one-off documentary is available in the UK on BBC iPlayer.
GREAT BARRIER: A Vox exclusive photo-feature looked at the “largest collective effort on Earth ever mounted” to protect Australia’s Great Barrier Reef.
‘SURVIVAL OF THE SLOWEST’: A new CBC documentary filmed species – from sloths to seahorses – that “have survived not in spite of their slowness, but because of it”.
New science
- Including carbon emissions from permafrost thaw and fires reduces the remaining carbon budget for limiting warming to 1.5C by 25% | Communications Earth and Environment
- Penguins in Antarctica have radically shifted their breeding seasons in response to rising temperatures | Journal of Animal Ecology
- Increasing per-capita meat consumption by just one kilogram a year is “linked” to a nearly 2% increase in embedded deforestation elsewhere | Environmental Research Letters
In the diary
- 31 January: Deadline for inputs on food systems and climate change for a report by the UN special rapporteur on climate change
- 1 February: Costa Rica elections
- 2-6 February: First session of the plenary of the Intergovernmental Science-Policy Panel on Chemicals, Waste and Pollution | Geneva
- 2-8 February: Twelfth plenary session of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services | Manchester, UK
- 5 February: Future Food Systems Summit | London
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
The post Cropped 28 January 2026: Ocean biodiversity boost; Nature and national security; Mangrove defence appeared first on Carbon Brief.
Cropped 28 January 2026: Ocean biodiversity boost; Nature and national security; Mangrove defence
Drought and heatwaves occurring together – known as “compound” events – have “surged” across the world since the early 2000s, a new study shows.
Compound drought and heat events (CDHEs) can have devastating effects, creating the ideal conditions for intense wildfires, such as Australia’s “Black Summer” of 2019-20 where bushfires burned 24m hectares and killed 33 people.
The research, published in Science Advances, finds that the increase in CDHEs is predominantly being driven by events that start with a heatwave.
The global area affected by such “heatwave-led” compound events has more than doubled between 1980-2001 and 2002-23, the study says.
The rapid increase in these events over the last 23 years cannot be explained solely by global warming, the authors note.
Since the late 1990s, feedbacks between the land and the atmosphere have become stronger, making heatwaves more likely to trigger drought conditions, they explain.
One of the study authors tells Carbon Brief that societies must pay greater attention to compound events, which can “cause severe impacts on ecosystems, agriculture and society”.
Compound events
CDHEs are extreme weather events where drought and heatwave conditions occur simultaneously – or shortly after each other – in the same region.
These events are often triggered by large-scale weather patterns, such as “blocking” highs, which can produce “prolonged” hot and dry conditions, according to the study.
Prof Sang-Wook Yeh is one of the study authors and a professor at the Ewha Womans University in South Korea. He tells Carbon Brief:
“When heatwaves and droughts occur together, the two hazards reinforce each other through land-atmosphere interactions. This amplifies surface heating and soil moisture deficits, making compound events more intense and damaging than single hazards.”
CDHEs can begin with either a heatwave or a drought.
The sequence of these extremes is important, the study says, as they have different drivers and impacts.
For example, in a CDHE where the heatwave was the precursor, increased direct sunshine causes more moisture loss from soils and plants, leading to a drought.
Conversely, in an event where the drought was the precursor, the lack of soil moisture means that less of the sun’s energy goes into evaporation and more goes into warming the Earth’s surface. This produces favourable conditions for heatwaves.
The study shows that the majority of CDHEs globally start out as a drought.
In recent years, there has been increasing focus on these events due to the devastating impact they have on agriculture, ecosystems and public health.
In Russia in the summer of 2010, a compound drought-heatwave event – and the associated wildfires – caused the death of nearly 55,000 people, the study notes.
The record-breaking Pacific north-west “heat dome” in 2021 triggered extreme drought conditions that caused “significant declines” in wheat yields, as well as in barley, canola and fruit production in British Columbia and Alberta, Canada, says the study.
Increasing events
To assess how CDHEs are changing, the researchers use daily reanalysis data to identify droughts and heatwaves events. (Reanalysis data combines past observations with climate models to create a historical climate record.) Then, using an algorithm, they analyse how these events overlap in both time and space.
The study covers the period from 1980 to 2023 and the world’s land surface, excluding polar regions where CDHEs are rare.
The research finds that the area of land affected by CDHEs has “increased substantially” since the early 2000s.
Heatwave-led events have been the main contributor to this increase, the study says, with their spatial extent rising 110% between 1980-2001 and 2002-23, compared to a 59% increase for drought-led events.
The map below shows the global distribution of CDHEs over 1980-2023. The charts show the percentage of the land surface affected by a heatwave-led CDHE (red) or a drought-led CDHE (yellow) in a given year (left) and relative increase in each CDHE type (right).
The study finds that CDHEs have occurred most frequently in northern South America, the southern US, eastern Europe, central Africa and south Asia.
Threshold passed
The authors explain that the increase in heatwave-led CDHEs is related to rising global temperatures, but that this does not tell the whole story.
In the earlier 22-year period of 1980-2001, the study finds that the spatial extent of heatwave-led CDHEs rises by 1.6% per 1C of global temperature rise. For the more-recent period of 2022-23, this increases “nearly eightfold” to 13.1%.
The change suggests that the rapid increase in the heatwave-led CDHEs occurred after the global average temperature “surpasse[d] a certain temperature threshold”, the paper says.
This threshold is an absolute global average temperature of 14.3C, the authors estimate (based on an 11-year average), which the world passed around the year 2000.
Investigating the recent surge in heatwave-leading CDHEs further, the researchers find a “regime shift” in land-atmosphere dynamics “toward a persistently intensified state after the late 1990s”.
In other words, the way that drier soils drive higher surface temperatures, and vice versa, is becoming stronger, resulting in more heatwave-led compound events.
Daily data
The research has some advantages over other previous studies, Yeh says. For instance, the new work uses daily estimations of CDHEs, compared to monthly data used in past research. This is “important for capturing the detailed occurrence” of these events, says Yeh.
He adds that another advantage of their study is that it distinguishes the sequence of droughts and heatwaves, which allows them to “better understand the differences” in the characteristics of CDHEs.
Dr Meryem Tanarhte is a climate scientist at the University Hassan II in Morocco, and Dr Ruth Cerezo Mota is a climatologist and a researcher at the National Autonomous University of Mexico. Both scientists, who were not involved in the study, agree that the daily estimations give a clearer picture of how CDHEs are changing.
Cerezo-Mota adds that another major contribution of the study is its global focus. She tells Carbon Brief that in some regions, such as Mexico and Africa, there is a lack of studies on CDHEs:
“Not because the events do not occur, but perhaps because [these regions] do not have all the data or the expertise to do so.”
However, she notes that the reanalysis data used by the study does have limitations with how it represents rainfall in some parts of the world.
Compound impacts
The study notes that if CDHEs continue to intensify – particularly events where heatwaves are the precursors – they could drive declining crop productivity, increased wildfire frequency and severe public health crises.
These impacts could be “much more rapid and severe as global warming continues”, Yeh tells Carbon Brief.
Tanarhte notes that these events can be forecasted up to 10 days ahead in many regions. Furthermore, she says, the strongest impacts can be prevented “through preparedness and adaptation”, including through “water management for agriculture, heatwave mitigation measures and wildfire mitigation”.
The study recommends reassessing current risk management strategies for these compound events. It also suggests incorporating the sequences of drought and heatwaves into compound event analysis frameworks “to enhance climate risk management”.
Cerezo-Mota says that it is clear that the world needs to be prepared for the increased occurrence of these events. She tells Carbon Brief:
“These [risk assessments and strategies] need to be carried out at the local level to understand the complexities of each region.”
The post Heatwaves driving recent ‘surge’ in compound drought and heat extremes appeared first on Carbon Brief.
Heatwaves driving recent ‘surge’ in compound drought and heat extremes
Greenhouse Gases
DeBriefed 6 March 2026: Iran energy crisis | China climate plan | Bristol’s ‘pioneering’ wind turbine
Welcome to Carbon Brief’s DeBriefed.
An essential guide to the week’s key developments relating to climate change.
This week
Energy crisis
ENERGY SPIKE: US-Israeli attacks on Iran and subsequent counterattacks across the Middle East have sent energy prices “soaring”, according to Reuters. The newswire reported that the region “accounts for just under a third of global oil production and almost a fifth of gas”. The Guardian noted that shipping traffic through the strait of Hormuz, which normally ferries 20% of the world’s oil, “all but ground to a halt”. The Financial Times reported that attacks by Iran on Middle East energy facilities – notably in Qatar – triggered the “biggest rise in gas prices since Russia’s full-scale invasion of Ukraine”.
‘RISK’ AND ‘BENEFITS’: Bloomberg reported on increases in diesel prices in Europe and the US, speculating that rising fuel costs could be “a risk for president Donald Trump”. US gas producers are “poised to benefit from the big disruption in global supply”, according to CNBC. Indian government sources told the Economic Times that Russia is prepared to “fulfil India’s energy demands”. China Daily quoted experts who said “China’s energy security remains fundamentally unshaken”, thanks to “emergency stockpiles and a wide array of import channels”.
‘ESSENTIAL’ RENEWABLES: Energy analysts said governments should cut their fossil-fuel reliance by investing in renewables, “rather than just seeking non-Gulf oil and gas suppliers”, reported Climate Home News. This message was echoed by UK business secretary Peter Kyle, who said “doubling down on renewables” was “essential” amid “regional instability”, according to the Daily Telegraph.
China’s climate plan
PEAK COAL?: China has set out its next “five-year plan” at the annual “two sessions” meeting of the National People’s Congress, including its climate strategy out to 2030, according to the Hong Kong-based South China Morning Post. The plan called for China to cut its carbon emissions per unit of gross domestic product (GDP) by 17% from 2026 to 2030, which “may allow for continued increase in emissions given the rate of GDP growth”, reported Reuters. The newswire added that the plan also had targets to reach peak coal in the next five years and replace 30m tonnes per year of coal with renewables.
ACTIVE YET PRUDENT: Bloomberg described the new plan as “cautious”, stating that it “frustrat[es] hopes for tighter policy that would drive the nation to peak carbon emissions well before president Xi Jinping’s 2030 deadline”. Carbon Brief has just published an in-depth analysis of the plan. China Daily reported that the strategy “highlights measures to promote the climate targets of peaking carbon dioxide emissions before 2030”, which China said it would work towards “actively yet prudently”.
Around the world
- EU RULES: The European Commission has proposed new “made in Europe” rules to support domestic low-carbon industries, “against fierce competition from China”, reported Agence France-Presse. Carbon Brief examined what it means for climate efforts.
- RECORD HEAT: The US National Oceanic and Atmospheric Administration has said there is a 50-60% chance that the El Niño weather pattern could return this year, amplifying the effect of global warming and potentially driving temperatures to “record highs”, according to Euronews.
- FLAGSHIP FUND: The African Development Bank’s “flagship clean energy fund” plans to more than double its financing to $2.5bn for African renewables over the next two years, reported the Associated Press.
- NO WITHDRAWAL: Vanuatu has defied US efforts to force the Pacific-island nation to drop a UN draft resolution calling on the world to implement a landmark International Court of Justice (ICJ)