UN warns world's water cycle becoming ever more erratic

Milton, an extremely dangerous Category 4 hurricane over the Gulf of Mexico, is intensifying at breakneck speed as it churns toward the west coast of Florida. The storm is expected to make landfall Wednesday or early Thursday as a “large and powerful hurricane,” according to the National Hurricane Center. It is predicted to produce a potentially devastating ocean surge over 10 feet in some areas, including perhaps in flood-prone Tampa Bay.

Since Sunday night, the storm’s rate of strengthening has reached extreme levels — its intensity leaping from a Category 1 to a high-end Category 4. The storm’s peak winds late Monday morning were up to 155 mph — just 2 mph from the top tier Category 5 — a 65 mph increase in 12 hours.

The Hurricane Center described the storm’s rate of intensification as “remarkable” — with a 90 mph increase in wind speeds in 24 hours only eclipsed by Hurricane Wilma in 2005 and Felix in 2007. The storm has explosively developed over record-warm waters in the Gulf, with the extreme warmth linked to human-caused climate change.

Milton is the strongest hurricane in the Gulf of Mexico since Michael in 2018 and is poised to become even stronger. It is forecast to reach Category 5 intensity Monday before a very gradual weakening trend commences Tuesday. If it reaches Category 5, it will be the strongest Gulf of Mexico hurricane this late in the calendar year since at least 1966.

Only 48 to 60 hours remain before Milton is set to arrive in Florida. Landfall now looks to be Wednesday afternoon or evening, and the storm — despite some weakening — is anticipated to remain a major hurricane with winds around 120 mph when it strikes the state’s west coast.

Moreover, Milton’s wind field will expand, meaning the storm will more efficiently be able to pile water against the coastline. The National Hurricane Center is warning of a surge of 5 to 10 feet along much of the Gulf Coast of Florida’s peninsula, with locally up to 8 to 12 feet — including in Tampa Bay.

In addition, Milton will bring destructive winds — perhaps gusting over 100 mph at the coastline — as well as flooding rains and the risk of a few tornadoes. Hurricane watches span the southern part of Florida’s Big Bend, ravaged by Helene less than two weeks ago, to just south of Marco Island.

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Widespread power outages are probable in Florida’s interior and even as far away as the state’s east coast, and could affect cities such as Orlando and Daytona Beach — in addition to Tampa, Fort Myers and Sarasota.

On satellite, the storm also exhibited an ominous “enveloped eyewall lightning” signature. Hurricanes only produce lightning when they’re strengthening, usually quickly. The entire eyewall, or innermost ring of ferocious winds, has been sparking hundreds of lightning strikes — a portent of a top-tier storm. The Hurricane Hunters even encountered hail when entering the eyewall from the northwest.

If Milton makes landfall north of Tampa Bay, it could mean another blow for the Big Bend area while also producing some heavy rain and strong winds in southern Georgia and the eastern Carolinas, which were affected by Helene. However, Milton’s effects on Georgia will probably be less severe than Helene’s.

Increasingly intense floods and droughts are a "distress signal" of what is to come as climate change makes the planet's water cycle ever more unpredictable, the United Nations warned Monday.

Last year the world's rivers were their driest for more than 30 years, glaciers suffered their largest loss of ice mass in half a century and there was also a "significant" number of floods, the UN's World Meteorological Organization said in a report.

"Water is the canary in the coal mine of climate change," WMO Secretary-General Celeste Saulo said in a statement accompanying the State of Global Water Resources report.

"We receive distress signals in the form of increasingly extreme rainfall, floods and droughts which wreak a heavy toll on lives, ecosystems and economies," she said.

Saulo said the heating up of the Earth's atmosphere had made the water cycle "more erratic and unpredictable.

Last year was the hottest on record, with high temperatures and widespread dry conditions producing prolonged droughts.

There were also many floods around the world.

These extreme events were influenced in part by naturally-occurring climate conditions including the La Nina and El Nino weather phenomena -- but also and increasingly by human-induced climate change.

"A warmer atmosphere holds more moisture, which is conducive to heavy rainfall. More rapid evaporation and drying of soils worsen drought conditions," Saulo said.

Massive glacier melt

Water is either too abundant or insufficient, plunging many countries into increasingly difficult situations.

Last year, Africa was the most heavily impacted continent in terms of human casualties.

In Libya, two dams collapsed due to a major flood in September 2023, claiming more than 11,000 lives and affecting 22 percent of the population, according to the WMO.

Floods also hit the Greater Horn of Africa, the Democratic Republic of Congo, Rwanda, Mozambique and Malawi.

Currently, 3.6 billion people have insufficient access to fresh water at least once a month per year, according to the UN. That figure is expected to rise to more than five billion by 2050.

For the past three years, more than 50 percent of river catchments have been drier than usual.

Meanwhile the inflow to reservoirs has been below normal in many parts of the world over the past half decade.

Rising temperatures also mean glaciers have melted at unprecedented rates, losing more than 600 billion tonnes of water, the worst in 50 years of observations, according to preliminary data for September 2022 to August 2023.

"Melting ice and glaciers threaten long-term water security for many millions of people. And yet we are not taking the necessary urgent action," Saulo said.

In addition to curbing the man-made greenhouse gas emissions that cause global warming, the WMO wants the world's fresh water resources to be monitored better, so early warning systems can reduce the damage to people and wildlife.

"We cannot manage what we do not measure," Saulo stressed.

Stefan Uhlenbrook, director of the WMO's hydrology, water and cryosphere department, stressed the importance of investing in infrastructure to preserve water and protect people from hazards.

But he also highlighted the need to conserve water, particularly for agriculture, which uses 70 percent of the world's fresh water consumption.

He warned returning to a more regular natural water cycle would be difficult.

"The only thing we can do is to stabilize the climate, which is a generational challenge," he said.