Published

2 years ago

March 15, 2024

Alice Rush

From flooding in New Zealand and wildfires in Canada through to drought in the Middle East and extreme heat across the northern hemisphere, last year provided a powerful demonstration of the impacts of climate change.

With global temperatures over the past decade around 1.2C warmer than pre-industrial levels, the impacts already urgently demand adaptation investments to avoid mounting losses.

However, research suggests that existing limits and barriers to adaptation could take decades to overcome, particularly in vulnerable countries. And while adaptation measures are gradually being put in place, how might they be further affected by continued warming?

In our new study, published in One Earth, we investigate how the effectiveness of well-established adaptation options in relation to water changes as the world warms.

Our findings show that the effectiveness of water-related adaptation declines markedly once warming passes 1.5C above pre-industrial levels – from a central estimate (median) of 90% to 69%, 62% and 46% at 2C, 3C and 4C, respectively.

With the implementation of adaptation already lagging behind what is needed, our findings show that warming beyond 1.5C needs to be avoided for effective adaptation to be possible.

Measuring the effectiveness of adaptation

The latest assessment report from the Intergovernmental Panel on Climate Change (IPCC) shows that current adaptation efforts are insufficient to cope with the increasing severity of warming-related impacts across the world.

This “adaptation gap” – the difference between what is needed to reduce impacts and what has been implemented – is growing, despite increasing adaptation efforts across all world regions.

Where adaptation has been documented, many benefits – such as economic gains, better educational outcomes or infrastructure improvements – have been observed. However, we still have very limited evidence and knowledge about how effective adaptation is in reducing climate risks – arguably the key purpose of adaptation.

This is, of course, an inherently difficult thing to measure, as it is not possible to calculate impacts that have been avoided because of adaptation.

Different ideas of how to measure adaptation effectiveness have been put forward. In a very narrow sense, the IPCC defines adaptation effectiveness as the extent to which an adaptation option is anticipated or observed to reduce climate-related risk, an approach we use in our study. More encompassing definitions of effectiveness include the multiple benefits adaptation can have on a broader set of outcomes, such as human well-being and equality.

A better understanding of the risk reduction potential of adaptation is crucial, as climate impacts will become more severe over the next decades. With limited resources to invest, it is essential that informed decisions can be made.

Adaptation as the world warms

In our study, we look at a set of frequently used adaptation interventions in the water and agricultural sectors, which are central in current modelling approaches of future impacts.

We collated a set of published case studies distributed across all world regions. We grouped these options into nine different types of adaptation interventions – shown in the map below.

For example, adaptation measures under “changes in cropping patterns and crop systems” include approaches such as shifting planting dates or substituting different crops. Measures related to “water and soil moisture conservation” include approaches such as reduced tilling (turning of the soil) or introducing mulching (covering topsoil with plant material).

Map of adaptation intervention types and their distribution. Countries are shaded according to the regional grouping used for the analysis. Source: Lissner, T. K. et al. (2024)

Each case study assesses in detail how a particular option could be implemented according to specific local conditions and provides results on its potential to reduce climate risks.

In many studies, different combinations of measures or different specifications of one measure – for example, shifting planting dates by 10, 20 or 30 days – are tested. Where this leads to different levels of effectiveness, we focus on those specifications that show to be most effective in reducing risk.

Declining effectiveness

To set these case study results into a global context and align them with important levels of warming, as in the IPCC reports, we translate all results into a representation of adaptation effectiveness at 1.5C, 2C, 3C and 4C. To represent effectiveness, we assess the proportion of projected risk that an adaptation option is able to avoid.

Our findings suggest a concerning picture: adaptation options are effective in reducing risks in most assessed settings up to 1.5C of warming, but with increased warming, effectiveness declines across all options and regions.

The central estimate (that is, the median) of adaptation effectiveness across all assessed measures at 1.5C is 90%. However, this declines to a median effectiveness of 69% at 2C and 62% at 3C – a level that current policies could still take warming close to.

At 4C, effectiveness declines even further to a median of 46%, indicating that less than half of projected impacts would be avoided under the adaptation measure.

The decline in effectiveness is most pronounced for adaptation options related to agriculture. For example, changes in cropping patterns and crop systems show high effectiveness at 1.5C, with more than 50% of data points in this category, but the share of highly effective adaptation decreases to 14% at 4C.

At the other end of the scale, we find that energy related adaptation (85%), flood risk reduction measures (78%) and urban water (78%) are the most likely categories to reduce 80% or more of projected risk across all warming levels.

As models do not account for adaptation limits and barriers, effectiveness in practice is likely to be lower than under idealised model conditions we assess in our study.

In many cases, adaptation in a 1.5C world comes with potential co-benefits, where the adaptation option improves conditions more widely, relative to the baseline of current conditions. For example, shifting from rain-fed agriculture to irrigation systems produces co-benefits in multiple cases.

Our findings for adaptation across Africa show that co-benefits could be substantial in closing existing adaptation gaps: 54% of assessed studies indicate potential co-benefits at 1.5C. However, this potential declines to 12% at 4C.

No-till farming, Arkansa, USA. Credit: Design Pics Inc / Alamy Stock Photo

Similarly, in Asia the potential for co-benefits declines from around 56% at 1.5C to 16% at 4C. In Central and South America, our data also shows a shift towards less effective adaptation outcomes. There is no apparent shift in the level of co-benefits that could be achieved, though it must be noted that much fewer studies were available for this region.

In some situations, adaptation becomes not just ineffective in reducing risk, but it actually aggravates the situation, leading to “maladaptation”.

Africa shows the largest share of maladaptive outcomes at all levels of warming. For example, intensifying the cultivation of maize and sorghum in west Africa or earlier planting of maize in Uganda further decreases yields – in addition to climate impacts – rather than reducing projected risk, even at 1.5C warming.

Models often overestimate the potential for adaptation

Currently, adaptation is not well represented in quantitative models. Integrated assessment models provide information on energy system transition pathways to limit warming, but they do not account for climate impacts or costs and potentials for adaptation.

Climate impact models assess the sectoral effects of warming – for example, on agriculture or the water system. Sectoral climate impact models implement selected adaptation measures, such as irrigation in the agricultural sector, for example, but do not account for limitations such as water availability.

But, even more importantly, models do not account for other constraints and limits to adaptation, which have been documented in practice.

Beside financial barriers, which are a fundamental impediment to effective adaptation, there are also constraints and limits related to governance and institutions, availability of information, awareness, human capacity and socio-cultural constraints. Similarly, adaptive capacity plays an important role in the ability to implement effective adaptation.

Consequently, where models include adaptation, they likely overestimate its potential. This is also true for our own assessment: we assess adaptation in a modelled context, where ideal conditions for implementing the respective option are assumed. If additional adaptation constraints and adaptive capacities were considered, the extent to which adaptation can effectively reduce climate risks may be further reduced.

Climate-resilient development requires limiting warming to 1.5C

Our study focuses on a limited set of adaptation options, which are currently frequently used and have direct entry-points into the modelling space. It can be assumed that progress and learning unlock further innovation for adaptation in the future, increasing the options and approaches available to adapt and reduce risk.

However, we also know that additional limits and constraints are likely to affect effectiveness as compared to a modelling environment that does not consider such aspects.

Our findings show that effective adaptation is only truly possible if it occurs alongside ambitious mitigation action that limits warming to 1.5C. Our study also emphasises that adaptation is not an alternative to mitigation, nor can it be seen as a way to allow for a delay in mitigation efforts.

The post Guest post: Climate adaptation becomes less effective as the world warms appeared first on Carbon Brief.

Guest post: Climate adaptation becomes less effective as the world warms

Climate Change

Whale Entanglements in Fishing Gear Surge Off U.S. West Coast During Marine Heatwaves

Published

7 hours ago

February 25, 2026

Alice Rush

New research finds that rising ocean temperatures are shrinking cool-water feeding grounds, pushing humpbacks into gear-heavy waters near shore. Scientists say ocean forecasting tool could help fisheries reduce the risk.

By Teresa Tomassoni

Each spring, humpback whales start to feed off the coast of California and Oregon on dense schools of anchovies, sardines and krill—prey sustained by cool, nutrient-rich water that seasonal winds draw up from the deep ocean.

Whale Entanglements in Fishing Gear Surge Off U.S. West Coast During Marine Heatwaves

Climate Change

Grasslands and Wetlands Are Being Gobbled Up By Agriculture, Mostly Livestock

Published

7 hours ago

February 25, 2026

Alice Rush

A new study takes a first-of-its kind look at how farming converts non-forested areas and major carbon sinks into cropland and pasture.

By Georgina Gustin

Agriculture is widely known to be the biggest driver of forest destruction globally, especially in sprawling, high-profile ecosystems like the Amazon rainforest.

Grasslands and Wetlands Are Being Gobbled Up By Agriculture, Mostly Livestock

Climate Change

Cropped 25 February 2026: Food inflation strikes | El Niño looms | Biodiversity talks stagnate

Published

18 hours ago

February 25, 2026

Alice Rush

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.

Key developments

Food inflation on the rise

DELUGE STRIKES FOOD: Extreme rainfall and flooding across the Mediterranean and north Africa has “battered the winter growing regions that feed Europe…threatening food price rises”, reported the Financial Times. Western France has “endured more than 36 days of continuous rain”, while farmers’ associations in Spain’s Andalusia estimate that “20% of all production has been lost”, it added. Policy expert David Barmes told the paper that the “latest storms were part of a wider pattern of climate shocks feeding into food price inflation”.

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NO BEEF: The UK’s beef farmers, meanwhile, “face a double blow” from climate change as “relentless rain forces them to keep cows indoors”, while last summer’s drought hit hay supplies, said another Financial Times article. At the same time, indoor growers in south England described a 60% increase in electricity standing charges as a “ticking timebomb” that could “force them to raise their prices or stop production, which will further fuel food price inflation”, wrote the Guardian.

‘TINDERBOX’ AND TARIFFS: A study, covered by the Guardian, warned that major extreme weather and other “shocks” could “spark social unrest and even food riots in the UK”. Experts cited “chronic” vulnerabilities, including climate change, low incomes, poor farming policy and “fragile” supply chains that have made the UK’s food system a “tinderbox”. A New York Times explainer noted that while trade could once guard against food supply shocks, barriers such as tariffs and export controls – which are being “increasingly” used by politicians – “can shut off that safety valve”.

El Niño looms

NEW ENSO INDEX: Researchers have developed a new index for calculating El Niño, the large-scale climate pattern that influences global weather and causes “billions in damages by bringing floods to some regions and drought to others”, reported CNN. It added that climate change is making it more difficult for scientists to observe El Niño patterns by warming up the entire ocean. The outlet said that with the new metric, “scientists can now see it earlier and our long-range weather forecasts will be improved for it.”

WARMING WARNING: Meanwhile, the US Climate Prediction Center announced that there is a 60% chance of the current La Niña conditions shifting towards a neutral state over the next few months, with an El Niño likely to follow in late spring, according to Reuters. The Vibes, a Malaysian news outlet, quoted a climate scientist saying: “If the El Niño does materialise, it could possibly push 2026 or 2027 as the warmest year on record, replacing 2024.”

CROP IMPACTS: Reuters noted that neutral conditions lead to “more stable weather and potentially better crop yields”. However, the newswire added, an El Niño state would mean “worsening drought conditions and issues for the next growing season” to Australia. El Niño also “typically brings a poor south-west monsoon to India, including droughts”, reported the Hindu’s Business Line. A 2024 guest post for Carbon Brief explained that El Niño is linked to crop failure in south-eastern Africa and south-east Asia.

News and views

DAM-AG-ES: Several South Korean farmers filed a lawsuit against the country’s state-owned utility company, “seek[ing] financial compensation for climate-related agricultural damages”, reported United Press International. Meanwhile, a national climate change assessment for the Philippines found that the country “lost up to $219bn in agricultural damages from typhoons, floods and droughts” over 2000-10, according to Eco-Business.
SCORCHED GRASS: South Africa’s Western Cape province is experiencing “one of the worst droughts in living memory”, which is “scorching grass and killing livestock”, said Reuters. The newswire wrote: “In 2015, a drought almost dried up the taps in the city; farmers say this one has been even more brutal than a decade ago.”
NOUVELLE VEG: New guidelines published under France’s national food, nutrition and climate strategy “urged” citizens to “limit” their meat consumption, reported Euronews. The delayed strategy comes a month after the US government “upended decades of recommendations by touting consumption of red meat and full-fat dairy”, it noted.
COURTING DISASTER: India’s top green court accepted the findings of a committee that “found no flaws” in greenlighting the Great Nicobar project that “will lead to the felling of a million trees” and translocating corals, reported Mongabay. The court found “no good ground to interfere”, despite “threats to a globally unique biodiversity hotspot” and Indigenous tribes at risk of displacement by the project, wrote Frontline.
FISH FALLING: A new study found that fish biomass is “falling by 7.2% from as little as 0.1C of warming per decade”, noted the Guardian. While experts also pointed to the role of overfishing in marine life loss, marine ecologist and study lead author Dr Shahar Chaikin told the outlet: “Our research proves exactly what that biological cost [of warming] looks like underwater.”
TOO HOT FOR COFFEE: According to new analysis by Climate Central, countries where coffee beans are grown “are becoming too hot to cultivate them”, reported the Guardian. The world’s top five coffee-growing countries faced “57 additional days of coffee-harming heat” annually because of climate change, it added.

Spotlight

Nature talks inch forward

This week, Carbon Brief covers the latest round of negotiations under the UN Convention on Biological Diversity (CBD), which occurred in Rome over 16-19 February.

The penultimate set of biodiversity negotiations before October’s Conference of the Parties ended in Rome last week, leaving plenty of unfinished business.

The CBD’s subsidiary body on implementation (SBI) met in the Italian capital for four days to discuss a range of issues, including biodiversity finance and reviewing progress towards the nature targets agreed under the Kunming-Montreal Global Biodiversity Framework (GBF).

However, many of the major sticking points – particularly around finance – will have to wait until later this summer, leaving some observers worried about the capacity for delegates to get through a packed agenda at COP17.

The SBI, along with the subsidiary body on scientific, technical and technological advice (SBSTTA) will both meet in Nairobi, Kenya, later this summer for a final round of talks before COP17 kicks off in Yerevan, Armenia, on 19 October.

Money talks

Finance for nature has long been a sticking point at negotiations under the CBD.

Discussions on a new fund for biodiversity derailed biodiversity talks in Cali, Colombia, in autumn 2024, requiring resumed talks a few months later.

Despite this, finance was barely on the agenda at the SBI meetings in Rome. Delegates discussed three studies on the relationship between debt sustainability and implementation of nature plans, but the more substantive talks are set to take place at the next SBI meeting in Nairobi.

Several parties “highlighted concerns with the imbalance of work” on finance between these SBI talks and the next ones, reported Earth Negotiations Bulletin (ENB).

Lim Li Ching, senior researcher at Third World Network, noted that tensions around finance permeated every aspect of the talks. She told Carbon Brief:

“If you’re talking about the gender plan of action – if there’s little or no financial resources provided to actually put it into practice and implement it, then it’s [just] paper, right? Same with the reporting requirements and obligations.”

Monitoring and reporting

Closely linked to the issue of finance is the obligations of parties to report on their progress towards the goals and targets of the GBF.

Parties do so through the submission of national reports.

Several parties at the talks pointed to a lack of timely funding for driving delays in their reporting, according to ENB.

A note released by the CBD Secretariat in December said that no parties had submitted their national reports yet; by the time of the SBI meetings, only the EU had. It further noted that just 58 parties had submitted their national biodiversity plans, which were initially meant to be published by COP16, in October 2024.

Linda Krueger, director of biodiversity and infrastructure policy at the environmental not-for-profit Nature Conservancy, told Carbon Brief that despite the sparse submissions, parties are “very focused on the national report preparation”. She added:

“Everybody wants to be able to show that we’re on the path and that there still is a pathway to getting to 2030 that’s positive and largely in the right direction.”

Watch, read, listen

NET LOSS: Nigeria’s marine life is being “threatened” by “ghost gear” – nets and other fishing equipment discarded in the ocean – said Dialogue Earth.

COMEBACK CAUSALITY: A Vox long-read looked at whether Costa Rica’s “payments for ecosystem services” programme helped the country turn a corner on deforestation.

HOMEGROWN GOALS: A Straits Times podcast discussed whether import-dependent Singapore can afford to shelve its goal to produce 30% of its food locally by 2030.

‘RUSTING’ RIVERS: The Financial Times took a closer look at a “strange new force blighting the [Arctic] landscape”: rivers turning rust-orange due to global warming.

New science

Lakes in the Congo Basin’s peatlands are releasing carbon that is thousands of years old | Nature Geoscience
Natural non-forest ecosystems – such as grasslands and marshlands – were converted for agriculture at four times the rate of land with tree cover between 2005 and 2020 | Proceedings of the National Academy of Sciences
Around one-quarter of global tree-cover loss over 2001-22 was driven by cropland expansion, pastures and forest plantations for commodity production | Nature Food