Quantcast
Environmental News for a Healthier Planet and Life

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?

Recycling and general waste plastic wheelie bins awaiting collection for disposal in Newport, Rhode Island. Tim Graham / Getty Images

Reduce. Reuse. Recycle. According to The National Museum of American History, this popular slogan, with its iconic three arrows forming a triangle, embodied a national call to action to save the environment in the 1970s. In that same decade, the first Earth Day happened, the EPA was formed and Congress passed the Resource Conservation and Recovery Act, encouraging recycling and conservation of resources, Enviro Inc. reported.

Read More Show Less
EcoWatch Daily Newsletter
The coal-fired Huaneng Power Plant in Huai 'an City, Jiangsu Province, China on Sept. 13, 2020. Costfoto / Barcroft Media via Getty Images

One of the silver linings of the coronavirus pandemic was the record drop in greenhouse gas emissions following national lockdowns. But that drop is set to all but reverse as economies begin to recover, the International Energy Agency (IEA) warned Tuesday.

Read More Show Less
Trending
A grizzly bear killed an outdoor guide in a rare attack near Yellowstone Park. William Campbell / Corbis / Getty Images

A backcountry guide has died after being mauled by a grizzly bear near Yellowstone National Park.

Read More Show Less
Representative Alexandria Ocasio-Cortez (D-NY) re-introduces the Green New Deal in Washington, D.C. on April 20, 2021. Mandel Ngan / AFP / Getty Images

By Brett Wilkins

In the latest of a flurry of proposed Green New Deal legislation, Reps. Cori Bush and Alexandria Ocasio-Cortez on Monday introduced the Green New Deal for Cities Act of 2021, a $1 trillion plan to "tackle the environmental injustices that are making us and our children sick, costing us our homes, and destroying our planet."

Read More Show Less
Offshore oil and gas drillers have left more than 18,000 miles of pipelines at the bottom of the Gulf of Mexico. Drew Angerer / Getty Images

Offshore oil and gas drillers have discarded and abandoned more than 18,000 miles of pipelines on the floor of the Gulf of Mexico since the 1960s, a report from the Government Accountability Office says.

Read More Show Less