Water world: Something is wrong with the most basic planetary system of all

Everyone remembers the diagram – water evaporates from the ocean, first condensing into clouds, then falling on land as rain, before winding its way back to the sea.

The water cycle, or, more properly, the hydrological cycle, has long been a staple of primary school Geography lessons. For even longer – about 3.8 billion years – it has been sustaining life on Earth.

But hundreds of years of human activity have put immense strain on the system, as well as having a huge sweeping impact on the planet as a whole.

The entire earth’s axis around which the planet spins was shifted by 80 cm between 1993 and 2010 because of the sheer amount of groundwater that humans have pumped from the plant’s interior.

In that same period, humans sucked out 2,150 gigatons of water from natural reservoirs on the earth’s surface. If such an amount was poured into the world’s oceans, its surface would rise by 0.24 inches (six millimetres).

Humankind’s use of water is also compounding the climate crisis. Global temperatures are warming at such a rate that they have warped the earth’s natural cycles, and what was once an easily predictable cycle has now become increasingly erratic, scientists say.

“As a result of rising temperatures, the hydrological cycle has accelerated. It has also become more erratic and unpredictable, and we are facing growing problems of either too much or too little water,” Celeste Saulo, Secretary-General of the World Meteorological Organisation (WMO), warned.

The consequences of this shift have been devastating. On every continent, water is either too plentiful or in desperately short supply, and it’s getting harder to know when and where flooding or drought will strike.

From a violent hurricane season in the Atlantic, to devastating drought in the Amazon and across east Africa, and record flooding on four continents, this year’s extreme weather is a symptom of new volatility in the hydrological cycle, say experts.

Something is wrong with the most basic planetary system of all, but how that disruption makes its mark depends on where you are in the world.

The Atlantic hurricane season

As hurricane Milton bore down on the Florida coastline earlier this month, it was too much for even a veteran meteorologist to bear.

John Morales, a weather man with decades of experience, broke down while reporting on the historic rapid growth of the storm, which whipped up 180-mile-an-hour winds as it barrelled towards the city of Tampa in Florida.

“I apologise,” he said, his voice quavering as he choked up with tears. “This is just horrific.”

Milton rapidly grew from a Category 1 storm into a “catastrophic” Category 5 in a matter of days, making it the most rapidly intensifying hurricane since Wilma in 2005.

“In a span of 10 hours, the barometric pressure at the centre of the hurricane dropped by 50 millibars,” said Mr Morales. “That is an astounding drop.”

Scientists say intense tropical storms are becoming more frequent as the world heats up.

“The fiercest tropical cyclones are becoming more frequent as they tap into more copious energy supplied by hotter oceans,” said Prof Richard Allen, Professor of Climate Science at the University of Reading.

“Greater storm surges that are compounded by rising sea levels and greater volumes of rainfall fuelled by the warmer and more moist atmosphere.”

Dr Shruti Nath, a complex weather and climate expert at the University of Oxford, said it isn’t that there are more tropical cyclones occurring, but that “the likelihood that they intensify is greater.”

Warmer temperatures cause water to evaporate at a faster rate, in turn increasing the frequency and intensity of extreme events, such as heavy rainfall, major storms, hurricanes and droughts, said WMO Secretary-General Celeste Saulo.

“Water is the canary in the coalmine of climate change,” Ms Saulo added. “We receive distress signals in the form of increasingly extreme rainfall, floods, and droughts which wreak a heavy toll on lives, ecosystems, and economies.”

Historic floods

The UN recently warned that increasingly intense floods and droughts are a “distress signal”.

It isn’t just North America that is experiencing such turbocharged weather events. The fallout has rippled across the rest of the globe.

In late September, three other continents were wracked by historic floods as climate change, rising water temperatures and atmospheric circulation patterns collided in a perfect storm.

Super typhoon Yogi erupted across Asia, deadly rain storms Swept West and Central Africa and the worst floods in at least two decades hit Central Europe, wreaking havoc.

In Nigeria, heavy rains ravaged the northeastern Borno state, causing the worst flooding felt for 30 years. At least 239,000 people were affected, according to Save the Children.

“Many people had to be rescued from trees … almost all major services have shut down. Major hospitals and clinics are closed, because they are inaccessible,” Chi Lael, head of communications in Nigeria for the World Food Programme (WFP), told The Telegraph.

The World Weather Attribution (WWA) service said the recent flash floods in central Europe in September, saw the rainiest four-day period ever recorded in the region – a magnitude made twice as likely by climate change.

“This is definitely what we will see much more of in the future,” said Friederike Otto, senior lecturer in climate science at Imperial College London and co-author of the WWA study.

”[It] is the absolute fingerprint signature of climate change … that records are broken by such a large margin.”

Droughts

Conversely, soaring temperatures have also fuelled prolonged droughts across the globe.

Last year was the world’s hottest year documented by a clear margin, with the global average near-surface temperature at 1.45 celsius above the pre-industrial baseline.

On an average day, nearly one third of the global ocean was gripped by a marine heatwave, harming vital ecosystems and food systems, according to the WMO.

“Sirens are blaring across all major indicators ... Some records aren’t just chart-topping, they’re chart-busting. And changes are speeding-up,” said United Nations Secretary-General António Guterres.

A new report found that demand for fresh water will outpace supply by 40 per cent by the end of the decade, because the world’s water systems are being put under “unprecedented stress”, according to the Global Commission on the Economics of Water.

Now, about two out of three people globally, or 61 per cent, live in areas where total water storage is declining, the report found.

More than a third, or 38 per cent, live where it is diminishing at extreme rates. Densely populated areas, including northwestern India and south and eastern Europe, are particularly vulnerable.

The double pronged effects of climate change and food insecurity have torn through Africa. In 2023, the Horn of Africa was struck by its worst drought in 40 years, with Ethiopia, Kenya and Somalia hit the hardest.

Five consecutive failed rainfall seasons have wreaked havoc over large parts of East Africa, creating a wave of reduced agricultural productivity, food insecurity and high food prices.

Consequently, the number of people who are acutely food insecure worldwide has more than doubled, from 149 million people before the Covid-19 pandemic to 333 million people in 2023, according to the World Food Programme.

La Niña is approaching

Things could be about to get worse.

Extreme events are fuelled in part by the natural-occurring climate pattern caused by fluctuating surface water temperatures in the Pacific Ocean – the El Niño and La Niña weather phenomena.

“El Niño and La Niña are part of the natural vulnerability,” said Dr Joel Hirschi, Associate Head of Marine Systems Modelling at the National Oceanography Centre.

“They have always been there, or have been there for probably millions of years. So they just come on top of what is happening,” he told The Telegraph.

We are currently in a “neutral” phase, he added. El Niño came to an end in July and the pendulum is still swinging before its counterpart, La Niña, will officially begin.

“It’s not El Niño anymore, but it’s not La Niña yet … forecasts are still saying that it will happen later this year, but it’s not there yet,” he added.

This year’s Atlantic hurricane season – spanning from the Caribbean to the United States – is predicted to last until 30 November, according to the National Oceanic and Atmospheric Administration (NOAA).

Dr Hirschi warned that the hurricane season could be extended due to high temperatures.

“La Niña favours atmospheric conditions over the North Atlantic that are conducive to making storms more likely to occur,” he said.

“Given that the temperatures are so warm, they are going to remain over the threshold needed for hurricanes later in the year than usual.”

The effects of La Nina can be crippling. But the reach of its impact is typically confined to tropical regions.

In central Europe, where the worst floods in at least two decades killed 24 people, it is climate change that is thought to be to blame for the destruction incurred.

“Climate change is the primary factor for what [happened] in Central Europe,”  said Dr Neven Fučkar, climate scientist at the University of Oxford.

“La Nina and El Nino play a very small role in European climate, it’s more in the tropics…you have to be really precise about what region you’re talking about.”

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