Quantcast
Environmental News for a Healthier Planet and Life

Help Support EcoWatch

2 Billion People to Face Water Shortages as Snowpack Declines

Climate
2 Billion People to Face Water Shortages as Snowpack Declines

Up to 2 billion people who depend on winter snow to deliver their summer water could see shortages by 2060 as upland and mountain snowpacks continue to dwindle.

An estimated 300 million people could find, 45 years on, that they simply won’t have enough water for all their needs, according to new research.

Melting snowpack in Turkey’s Lesser Caucasus mountains. Photo credit: Dario Martin-Benito

Climate change driven by rising atmospheric levels of carbon dioxide—in turn, fed by human combustion of fossil fuels—may already be affecting global precipitation. Researchers have consistently found that much of the world’s drylands will increase as global average temperatures rise.

But warmer temperatures increasingly also mean the water that once fell as snow, to be preserved until the summer, now falls as winter rain and runs off directly. The snow that does fall is settling at ever higher altitudes and melting ever earlier.

Reliable Flow

This is bad news for agricultural communities that depend on a reliable flow of meltwater every summer.

California is already in the grip of a sustained drought, made worse by lower falls of snow. Great tracts of Asia depend on summer meltwater from the Himalayan massif and the Tibetan plateau.

Justin Mankin, an environmental scientist at Columbia University’s Earth Institute in the U.S. and colleagues report in Environmental Research Letters journal that they studied 421 drainage basins across the northern hemisphere.

They took account of the water used now and the patterns of population growth and tested the impact of global warming, using computer simulations of a range of possible future patterns.

From this larger picture, they isolated 97 drainage basins that deliver water to 2 billion people who are reliant on snow on the high ground as a reservoir of summer water.

All of these face at least a 67 percent risk of a decline in stored snow, given the demand for water now. But in 32 of those basins, home to 1.45 billion people, snowmelt is already needed to meet a substantial proportion of demand.

These include northern and central California, the basins of the Colorado River and the Rio Grande in the U.S. West and northern Mexico, the Atlas basin of Morocco, the Ebro-Douro basin that waters Portugal and Spain and a series of basins in eastern Italy, the southern Balkans, the Caucasus nations and northern Turkey.

It also includes the Shatt al-Arab basin that brings meltwater from the Zagros mountains to Iraq, Syria, eastern Turkey, northern Saudi Arabia and eastern Iran. Research has linked civil conflict in the region and in other parts of the world with climate change.

Areas most at risk of reduced water supply (red = highest risk; yellow = lowest). Photo credit: Justin Mankin / Environmental Research Letters 2015

But although snowpack will continue to decline, the researchers think rainfall will continue to meet demand across most of North America, northern Europe, Russia, China and southeast Asia. There may be no real change for India’s Indus and Ganges basins, which are home upwards of a billion people.

And accelerated melting of the glaciers could actually increase water supplies for some central Asian nations, including Uzbekistan and Kazakhstan.

Planning for Change

The message of the research is that national, regional and civic authorities must start planning for change.

“Managers need to be prepared for the possibility of multi-decadal decreases in snow water supply,” Dr. Mankin says. “But at the same time, they could have large multi-decadal increases. Both these outcomes are entirely consistent with global warming.”

The authors warn that their projections do not consider the water demands of forests and wild things, as they had been focusing on human needs. Nor had they taken into consideration future population growth or migration.

“Total human population—and thereby total water demand—will almost certainly increase in the future,” the researchers write. “However, we do not predict changes in total population or the geographic distribution of people, nor the changes in consumption patterns that are likely to accompany future socio-economic changes."

“To do so would introduce additional sources of uncertainty, whereas our aim is to isolate the uncertainty from climate change.”

YOU MIGHT ALSO LIKE

World Bank Climate Envoy Delivers Powerful Message on Coming Low-Carbon Revolution

John Kerry: ‘Climate Change Is Not Just About Bambi,’ It Threatens All of Humanity

Climate Change Poised to Push 100 Million Into ‘Extreme Poverty’ by 2030

What’s Going on in Antarctica? Is the Ice Melting or Growing?

EcoWatch Daily Newsletter

Atlantic puffins courting at Maine Coastal Island National Wildlife Refuge in 2009. USFWS / Flickr

When Europeans first arrived in North America, Atlantic puffins were common on islands in the Gulf of Maine. But hunters killed many of the birds for food or for feathers to adorn ladies' hats. By the 1800s, the population in Maine had plummeted.

Read More Show Less
Rescue workers dig through the rubble following a gas explosion in Baltimore, Maryland on Aug. 10, 2020. J. Countess / Getty Images

A "major" natural gas explosion killed two people and seriously injured at least seven in Baltimore, Maryland Monday morning.

Read More Show Less
The recalled list includes red, yellow, white and sweet yellow onions, which may be tainted with salmonella. Pxhere

Nearly 900 people across the U.S. and Canada have been sickened by salmonella linked to onions distributed by Thomson International, the The New York Times reported.

Read More Show Less
Methane flares at a fracking site near a home in Colorado on Oct. 25, 2014. WildEarth Guardians / Flickr

In the coming days, the U.S. Environmental Protection Agency (EPA) is expected to use its power to roll back yet another Obama-era environmental protection meant to curb air pollution and slow the climate crisis.

Read More Show Less
Researchers on the ICESCAPE mission, funded by NASA, examine melt ponds and their surrounding ice in 2011 to see how changing conditions in the Arctic affect the biological and chemical makeup of the ocean. NASA / Flickr

By Alex Kirby

The temperature of the Arctic matters to the entire world: it helps to keep the global climate fairly cool. Scientists now say that by 2035 there could be an end to Arctic sea ice.

Read More Show Less
President Vladimir Putin is seen enjoying the Opening Ceremony of the Sochi 2014 Winter Olympics in Sochi, Russia. Pascal Le Segretain / Getty Images

Russia's Health Ministry has given regulatory approval for the world's first COVID-19 vaccine after less than two months of human testing, President Vladimir Putin said on Tuesday.

Read More Show Less

Trending

A John Deere agricultural tractor sits under a collapsed building following a derecho storm on Aug. 10, 2020 near Franklin Grove, Illinois. Daniel Acker / Getty Images

A powerful series of thunderstorms roared across the Midwest on Monday, downing trees, damaging structures and knocking out power to more than a million people.

Read More Show Less