Intensive groundwater pumping, evaporation and melting due to rising global temperatures have shifted a growing amount of freshwater from the continents to the oceans. This threatens water availability for most of the world’s population and adds to sea level rise.

at Arizona State University and his colleagues used gravity measurements from satellites to estimate changes in the total amount of water mass stored on the continents. That includes all forms of freshwater, from rivers and underground aquifers to glaciers and ice sheets.

These measurements show there have been alarming declines in freshwater in many parts of the world between 2002 and 2024. The researchers found dry regions aren’t just getting drier – a trend expected with climate change – they are also expanding by more than 800,000 square kilometres per year, an area about the size of the UK and France combined.

The team identified four “mega-drying” regions where separate areas of freshwater loss have now connected to create a swathe of drying. Those include northern Canada and Russia, where loss is driven by melting glaciers, permafrost and reduced snow.

In the other two regions, water loss is dominated by groundwater depletion, mainly from pumping for irrigation. Those are the US Southwest, much of Central America and a region stretching from western Europe and North Africa to northern India and China. They found groundwater depletion, which can be exacerbated by heat and drought prompting people to pump more, makes up 68 per cent of the decline in overall water storage.

This transfer of mass is so large it has become a major contributor to sea level rise. They found since 2015, water loss from the continents has caused more sea level rise than meltwater from the Antarctic or Greenland ice sheets, raising the oceans by just under a millimetre per year.

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These trends together “send perhaps the direst message on the impact of climate change to date”, the researchers write in their report. “The continents are drying, freshwater availability is shrinking, and sea level rise is accelerating.”

We already knew about these drying trends in many individual regions, says at the Virginia Polytechnic Institute and State University. But he says the power of this research comes from its global view of the problem. “We are not producing water or destroying water. We are just redistributing water. But redistribution is not going in the right direction,” he says.

“The next step is really to do the detailed diagnosis to actually separate out what’s driving the groundwater depletion,” says at Columbia University in New York. “It would take a little more detail to separate the climate change story from the groundwater depletion story.”

A weak La Niña climate pattern has emerged in the Pacific Ocean, months later than was initially forecast. This will raise the risk of drought and heavy rain in parts of the world, even as it lowers global average temperatures.

The eastern tropical Pacific Ocean shifts from hot to cold and back in a temperature cycle known as the El Niño Southern Oscillation (ENSO), and La Niña is the cool phase of the cycle. It normally occurs about every three to five years when trade winds strengthen, which pushes colder water upwelling off the coast of South America to the west.

Sea surface temperatures in that part of the Pacific have been cooler than average for months, but they didn’t fall below the threshold needed to declare a La Niña event , according to the US National Oceanic and Atmospheric Administration (NOAA). Wind patterns also now reflect La Niña conditions.

The agency forecasts the La Niña will continue through April 2025 before temperatures return to neutral conditions.

Even though it is a weak event, the cooler-than-average sea surface temperatures are expected to have their characteristic influence on global weather patterns, increasing the risks of drought in parts of North and South America and intense rainfall in Australia and South-East Asia.

La Niña also tends to lower global average temperatures, although this cooling effect is proportional to the strength of the event, says at the University of Colorado Boulder. Temperatures have cooled as the warm El Niño gave way to neutral and now La Niña conditions, but remain above average in much of the world, says DiNezio.

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That’s also true of the oceans. The shift to La Niña means temperatures in the eastern tropical Pacific are colder than average. But global sea surface temperatures remain above average.

“The oceans in particular were slow to cool from the record warmth that developed in mid to late 2023,” said at NOAA during a press call in December before La Niña had officially emerged.

It is not unusual for La Niña to emerge so late, even following a strong El Niño event. But the shift comes months later than forecasters predicted. It remains unclear exactly why forecasts were so far off, and whether human-caused climate change played a role in the delay.

A temporary plan to save the Colorado river is shaping up after months of heated debate. The plan represents a breakthrough in negotiations over how to use less water from the overdrawn river, but is still a far cry from solving the water crisis facing the western US.

The proposed plan would see California, Arizona and Nevada – states that rely on the river’s lower basin – reduce the amount of water they take by at least 3 million acre-feet between now and 2026. Half of that would be conserved by the end of 2024, according to a to the US Department of the Interior on 22 May. An acre-foot is the amount of water needed to cover an acre of land at a depth of 1 foot.

The Colorado river supplies water for more than 40 million people. The majority of these new cuts – 2.3 million acre-feet – would come from reductions in water use in cities, Native American tribes and irrigation districts. The total cuts are equivalent to around 13 per cent of all water use in the lower basin states, and would be compensated by $1.2 billion from the Inflation Reduction Act, .

California, Arizona and Nevada would be responsible for finding places to cut the remaining 700,000 acre-feet themselves. The four states that rely on the river’s upper basin – Colorado, New Mexico, Utah and Wyoming – have the consideration of the proposal by the US federal government, but have not endorsed the plan.

After decades of megadrought and overuse, Lake Powell and Lake Mead, the two major reservoirs on the river, faced record-low levels. Water officials warned that without cuts the reservoirs could get so low that water wouldn’t be able to flow past the dams and produce energy.

In June 2022, US officials said states would have to come up with a plan to cut between 2 million and 4 million-acre feet or face mandated cuts, setting off months of intense negotiations and two missed deadlines to propose a plan.

The new proposal was aided by what has turned out to be an extremely wet year in the western US, which has made reductions in water use easier to stomach, says at Arizona State University.

While the proposal represents a breakthrough in negotiations, it would still have to be agreed to by the US government and other states. And the plan says nothing about what might happen after 2026, when the rules that divvy up water on the river are set for a major renegotiation. “This is an attempt to keep the system functional,” says Porter.

The seven states that rely on the river to irrigate farms and provide drinking water for millions of people recognised as much in their letter to the federal government: “One good winter does not solve the systemic challenges facing the Colorado River”.

Forest fires burning in central and southern Chile have led to at least 26 deaths and nearly 2000 injuries in what is among the deadliest wildfires on record in the country.

The fires have burned across more than 2700 square kilometres as of 7 February, according to a from the European Union’s Copernicus Atmosphere Monitoring Service. More than 1000 homes have been destroyed and 280 as of 6 February, according to Chile’s disaster response agency SENAPRED.

Already, that makes this the country’s second-most destructive fire season on record after 2017, which saw thousands of fires burn more than 5700 square kilometres and led to Most in Chile burn in January and February at the height of the southern hemisphere’s summer.

More than 6000 Chilean firefighters have participated in battling the blazes. Brigades from Spain, Mexico and Argentina are also the fires, along with more than 70 planes and helicopters.

Extreme temperatures and years of drought have contributed to the scale and intensity of the fires.

Weather stations in Chile’s Central valley reported record or near record temperatures above 40°C (104°F) over the weekend, says at the University of Chile in Santiago. High temperatures and strong winds are forecast for the coming days. “Meteorology plays against us,” he says.

Garreaud says the extremely high temperatures are driven by warm, naturally recurring “Puelche winds” blowing from the east, superimposed on a warmer climate. The past decade has been the warmest on record in Chile, says Garreaud. Megadrought in the region – the past 10 years were the driest on record in Chile – has also contributed to fires, he says.

The fires have mainly affected the regions of Maule, Ñuble, Bío-Bío and Araucanía, which together contain most of Chile’s forest plantations. Along with heat and drought, the added fuel load from the plantation trees have also of fire.

at the Copernicus Atmosphere Monitoring Services said the fire’s intensity is reflected by the huge plumes of smoke sent billowing over the Pacific Ocean. The service estimates the fires have so far released 4 million tonnes of carbon into the atmosphere, leading to the highest emissions from some regions in the past 20 years.