A study revealed that the decline in accumulation of winter snowpack in the northern hemisphere could lead to water shortage and could affect approximately 2 billion people who rely on snowmelt for water.
Water from snowmelt supports ecosystems, cities and agriculture, but researchers from Columbia University's Earth Institute warned that the snowmelt resource will soon be critically endangered.
Climate scientists said that because the melting of snowpack will occur at different rates than usual, the implication will be complicated. Some regions are likely to see increased rainfall and snow as the climate changes, they said.
In a study issued in the journal Environmental Research Letters, the team of researchers named snow-dependent drainage basins in the northern hemisphere that are at risk of declining in the coming century. Data revealed that water supplies in basins found in California's farmlands to war-torn areas of the Middle East will be imperiled by 2060.
"Water managers in a lot of places may need to prepare for a world where the snow reservoir no longer exists," said researcher Justin Mankin who is also the lead author of the study.
Mankin and his colleagues estimated possible future consequences of reduced snowpack, depending on the number of people relying on snowmelt. They examined 421 drainage basins in the northern hemisphere and found that 97 drainage basins which serve at least 2 billion people are at two-thirds chances of declining.
Researchers said the Shatt al-Arab basin that supports much of the Middle East including Syria and Iraq, the Ebro-Duero basin in Portugal, Spain and southern France, and the basins in northern and central California are included in regions that are most susceptible to climate changes.
Mankin explained that snow is essential because it forms its own reservoir, but he said that the effects of reduced snowpack are different for every region. "It is also a function of where and when people demand water," he said.
Snowmelt is vital as a water source in large mountain chains. When the accumulated snow melts, it acts as a seasonal source of water. Snowmelt flows gradually into the lowlands during spring and summer which is the peak of human demand, but researchers said global warming is disrupting the accumulation of snow in these important areas.
Previous studies revealed that more winter precipitation is falling as rain, not snow. Rain only washes away directly. Winter precipitation that does fall as snow settles at higher elevations and melts earlier.
Meanwhile, Mankin said the news is not entirely bad. Data revealed that rainfall in parts of North America, Russia, Northeast Europe, China and Southeast Asia is expected to meet human demand.
