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Droughts spanning multiple years have become drier, hotter and more frequent over the past 40 years, according to new research.

The study, published in Science, finds that the global land surface affected by these extreme events has expanded at a rate of nearly 50,000 square kilometres (km2) per year in the past four decades – an area larger than Switzerland each year. 

The authors identify multi-year droughts – which can last from years to decades – that occurred around the world between 1980 and 2018.

They find that multi-year droughts can cause significant declines in vegetation in ecosystems such as grasslands. These impacts can also translate into severe impacts for humans, including water scarcity.

Study author Dr Dirk Karger, a senior researcher at the Swiss Federal Research Institute (WSL), tells Carbon Brief:

“Everybody was talking about droughts, [that they] will be more [frequent] with climate change, but there [was] no clear database where we could look. We finally have a good baseline of what is happening…[and] provide a new way of thinking about the impact the [multi-year droughts have].”

Long-lasting drought

“Multi-year” droughts – those lasting at least two years and for as long as decades – can have dramatic impacts on nature and societies.

These long-lasting events can deplete soil moisture and leave rivers, lakes and reservoirs parched. This, in turn, can result in “devastating impacts”, such as massive crop failures, tree mortality or reduced water supply, according to the study.

(For more on the different ways that droughts can be defined, see Carbon Brief’s guest post.)

In recent years, multi-year droughts have occurred around the world, including Chile, the western US and Australia. For example, a 2015 study found that the so-called “megadrought” that persisted in Chile from 2010 to 2019 led to a “marked decline in water reservoirs and an extended forest fire season”.

The new study maps the distribution of multi-year drought events between 1980 and 2018. It identifies droughts by looking at a “drought index” based on changes in rainfall and potential evapotranspiration, which measures the amount of water that escapes the soil and plants into the atmosphere.

The researchers also rank the drought events by their severity – based on a combination of the extent and duration, along with the magnitude of the drought index. Then, they use the index to estimate the impact of multi-year droughts on global vegetation.

They identify more than 13,000 multi-year drought events during the four-decade study period, spanning every continent except Antarctica.

The map below shows the location and characteristics of the 10 most severe events, with the colours representing each individual drought and its length.

The longest multi-year drought occurred in the eastern Congo basin. It lasted for almost a decade, from 2010 to 2018, and affected an area of almost 1.5m square kilometres (km2).

Occurrence of the 10 most severe multi-year droughts between 1980 and 2018. Each inset map shows one of these events, ranging from 1 (most severe) to 10 (least severe). On the bottom-right corner, the chart displays the number of the event (y-axis), its duration (x-axis) and the period of occurrence (distinguished by colour). Source: Chen et al. (2025)

The study finds that the most affected ecosystems by these extreme events are temperate grasslands.

However, not all multi-year droughts result in significant damage to ecosystems.

In the humid tropics, which are home to rainforests such as the Amazon, the lack of rainfall is not strong enough to diminish vegetation. This suggests that plants in those regions might have a “greater resistance” to drought conditions, the authors write.

Boreal forests in the far-northern hemisphere and tundra ecosystems also had a “minor response” to these events. The authors say this is because their vegetation productivity is more dependent on temperature than on the presence or absence of rainfall.

The drought with the most severe vegetation impacts occurred in Mongolia from 2000 to 2011 and reduced vegetation “greenness” by almost 30%.

For Karger, it is difficult to pinpoint the strongest multi-year drought ever because it depends on what aspect is considered: the drought that had the largest extent or the one that lasted the longest. He continues:

“With our database we can easily answer any of these questions, it’s just a matter of what we sought for, since we provide that open source and open data”.

Drivers of droughts

The research reveals that multi-year droughts have increased in size, temperature, dryness and duration.

The global land area affected by this kind of drought increased at a rate of 49,279km2 per year during that time – equivalent to a size larger than Switzerland per year.

The factors behind the intensification of multi-year droughts are increased potential evapotranspiration, decreased rainfall and rising temperatures, the study says.

The researchers note that during multi-year drought events, the “precipitation deficit” – the difference in the amount of rain compared to a baseline over a certain period and region – has surged over time.

For the 10 most severe multi-year droughts, the precipitation deficit has increased, on average, by 7mm per year over nearly four decades.

Boat stranded on a dry river during a severe drought in the Amazon.
Boat stranded on a dry river during a severe drought in the Amazon. Credit: Paralaxis / Alamy Stock Photo

At the same time, the temperature during these events has increased by 0.26-0.35C per decade.

The study attributes the higher temperatures during multi-year droughts to climate change, noting that the warming “align[s] well” with global changes. It also notes that the years with the largest areas under multi-year drought have followed the El Niño events of 1998, 2010 and 2015.

Dr Maral Habibi, a researcher at the University of Graz, in Austria, and who was not involved in the study, tells Carbon Brief:

“The study clearly illustrates how rising temperatures amplify drought through increased evapotranspiration, precipitation deficits and vicious feedback loops (such as reduced cloud cover exacerbating heat).”

‘More regular’ multi-year droughts

The research says that the most severe multi-year droughts identified in the study “represent valuable case studies to prepare for similar events that may occur more regularly in the 21st century”.

It also says that analysing droughts at a global level, rather than focusing on a single drought event, “paves a more realistic way to develop adequate and fair mitigation strategies”.

Dr Ruth Cerezo-Mota, a researcher at the National Autonomous University of Mexico (UNAM) who was also not involved in the study, tells Carbon Brief that the world needs more data, including high-quality and continuous observations, and more investment in science to “understand these dynamic processes”.

Habibi agrees on the need for “enhanced monitoring tools and predictive climate models”. She adds that “investments in AI-driven drought forecasting and cross-border water resource management are also vital” to “mitigate and adapt to the challenges of a warming, drying world”.

The post ‘Multi-year’ droughts have become more frequent, drier and hotter over past 40 years appeared first on Carbon Brief.

‘Multi-year’ droughts have become more frequent, drier and hotter over past 40 years

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Amid Cuts to the U.S. Fish and Wildlife Service, Species Like the Florida Panther Languish

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Florida conservation groups say they plan to sue after the federal government greenlit another development that threatens the habitat of the panther, the official state animal.

The honey-colored Florida panther inhabits the southwest corner of the state, mostly occupying a remote swath of cypress swamps, sawgrass prairies and other natural and agricultural lands that constitute less than 5 percent of the large feline’s historic range.

Amid Cuts to the U.S. Fish and Wildlife Service, Species Like the Florida Panther Languish

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We must invest in early-warning systems to tackle crises like Kenya’s drought

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Dancliff Mbura is the advocacy and communications manager at Action Against Hunger Kenya. He works to influence policy and resource allocation and is an expert on multisectoral nutrition interventions.

Just four years since the last devastating drought, when five consecutive rainy seasons failed, 3.3 million people in Kenya’s arid and semi-arid counties are facing acute hunger as yet another drought crisis deepens. It is visible everywhere – in the parched riverbeds, weakened animals, and the children, who are too quiet.

Six months ago, the number of people facing acute hunger was 1.8 million. If nothing changes, by August, it will climb to 3.7 million, underscoring the need for urgent aid.

We know the answers. Cash transfers allow families to purchase food in markets that are still functioning. Mobile health and nutrition outreach teams must meet communities where they are, not where facilities happen to be located, which could make them inaccessible. Emergency water provision is essential.

But the resources are not there to address the growing needs. A coalition of humanitarian organisations working across Kenya’s drought-hit regions with the government has estimated the drought response would cost more than 30 billion Kenyan shillings ($232 million). Kenya’s government has released just 6 billion shillings so far.

Reducing the damage

Beyond the immediate response, however, we need to invest in systems that reduce the damage of future drought cycles in this climate-vulnerable region.

Kenya has systems that support the generation of early-warning systems, such as the National Drought Management Authority’s monthly county and national early-warning bulletins with detailed early-warning data. What we need is a means to ensure that information reaches communities in time for them to act on it and make sure they have the resources they need to do that.

One approach could be the establishment of village-level climate change and disaster hubs. These hubs would provide communities with simplified, actionable information, sometimes via dashboards on weather patterns and forecasts, and support them in generating locally relevant, cost-effective early actions.

By engaging communities in this process, the government and development partners can complement these efforts with additional resources where needed. This approach fosters community ownership while simultaneously enhancing resilience to climate-related risks.

    With better technology, including AI-assisted climate modeling, we can generate precise early-warning information. When shared in a timely manner with communities and accompanied by support for early or anticipatory actions, this can help build resilience to frequent droughts and other crises.

    For example, with access to early-warning information, vulnerable communities could store water ahead of droughts, switch to short-maturity crops when reduced rainfall is forecast, and move livestock and food stocks to higher ground before floods hit. They could also apply preventative treatments to protect crops and animals from pest or disease outbreaks, and make smarter market decisions, such as selling livestock early before prices drop, to safeguard their income.

    Different in scale

    I have spent 15 years working on humanitarian response in Kenya. I have seen drought cycles come and go. But what is happening right now across our arid and semi-arid lands – the ASAL counties that cover nearly 80% of the country – is different in scale and in the depth of suffering it is causing.

    The October-December 2025 short rains delivered only 30 to 60% of the long-term average, making it one of the driest seasons since 1981. In some areas, rainfall failed almost entirely. More than 90% of open water sources have dried up in most parts of ASAL counties. Families are walking up to 20 km (12 miles) or more just to find water.

    A woman carries her tomato harvest from an Action Against Hunger climate-smart farming initiative that supports food security during drought. Photo credit: Action Against Hunger

    A woman carries her tomato harvest from an Action Against Hunger climate-smart farming initiative that supports food security during drought. Photo credit: Action Against Hunger

    Now, as we approach Kenya’s more reliable rainy season from March to May, projections are well below average across the hardest-hit northern counties, and we may be heading into a fourth consecutive poor season. For communities who have already exhausted every coping mechanism they have, another failed season could be catastrophic.

    More than 810,000 children between the ages of six months and five years are acutely malnourished. Nearly 117,000 pregnant and breastfeeding mothers are also acutely malnourished. The cycle of nutrition that healthy communities depend on is breaking down.

    And yet approximately half of severe acute malnutrition cases are going untreated. Only 24% of the nutrition and health outreach sites mapped across the arid and semi-arid counties are currently functioning.

    Impossible choices

    The economic devastation compounds everything. Livestock is the backbone of life in these pastoral lands. But in Marsabit county alone, more than 50,000 sheep and goats have died. Mandera has lost nearly 30,000 animals. Milk production has plummeted by 55%. As animals grow weaker, families receive less and less when they sell them. Livelihoods are collapsing in slow motion, and families are running out of options.

    That can lead to desperate decisions: more daughters are married off early in exchange for dowry like livestock, a practice that rises sharply in times of crisis. Girls are subjected to female genital mutilation so they can be considered ready for marriage. Children drop out of school as families are forced to move in search of better land.

    Every week that passes without a scaled-up response is a week in which children go hungry, animals die, and families make impossible choices. We are at a point where, if we do not act, lives will be lost – preventably.

    Not because we lacked the knowledge, not because we lacked the warning, but because we were not able to move fast enough.

    The post We must invest in early-warning systems to tackle crises like Kenya’s drought appeared first on Climate Home News.

    https://www.climatechangenews.com/2026/03/10/we-must-invest-in-early-warning-systems-to-tackle-crises-like-kenyas-drought/

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    A Warmer Climate Means Bigger Hail

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    New attribution research shows how extra heat in the atmosphere can turn thunderstorms into factories for dangerous, softball-size hail.

    Regions that are often pummeled by severe storms—like the Midwestern United States under last weekend’s powerful thunderstorms and deadly tornadoes—could also face the threat of more extreme hail.

    A Warmer Climate Means Bigger Hail

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