More than two billion people living in the Earth's northern hemisphere may face an impending water crisis as the snow deposits that help provide them with much needed water supply are beginning to decline as a result of climate change.
In a study featured in the journal Environmental Research Letters, scientists from Columbia University have discovered that increasing levels of winter precipitation are falling as rain instead of snow because of warming temperatures.
This in turn severely limits the buildup of snowpacks in mountainous regions, which are relied on by farmers in low-lying areas for water during growing seasons.
"Snow is important because it forms its own reservoir. But the consequences of reduced snowpack are not the same for all places--it is also a function of where and when people demand water," Justin Mankin, a researcher from Columbia's Earth Institute and lead author of the study, said.
"Water managers in a lot of places may need to prepare for a world where the snow reservoir no longer exists."
Mankin and his colleagues found that out of the 421 drainage basins in the northern hemisphere that they examined, 97 of them have at least a two-thirds chance of experiencing declines in snowpacks. The melting snow from these basins provides water for around two billion people living in the region.
Drainage basins that are particularly prone to snowpack declines include the Ebro-Duero basin in Europe, the Atlas basin in northern Africa, the Rio Grande and Colorado River basins, and northern and central California basins.
While the researchers estimate that the current amount of rainfall will continue to provide water supply to meet the demands of human populations for the time being, they believe the reduction of snowpacks could result in more frequent forest fires and the destruction of important ecosystems.
What You Need to Know About the Water Crisis
According to statistics from Water.org, there are around 650 million people living in less developed nations who currently have little to no access to clean water supplies.
These include countries in Africa (332 million); South, West, and Central Asia (155 million); Southeast, East Asia and Oceania (131 million); and Latin America and the Caribbean (32 million).
In developed countries, as much as 13 million people still do not have access to water.
Effects on Populations
The lack of access to usable water is believed to be one of the primary causes of epidemics, particularly in less developed countries. It also compromises the safety and well-being of the people.
The United Nations said as much as 80 percent of diseases are associated with poor water and sanitation conditions in poor nations.
The water crisis also serves to limit the access of poor people to education and economic opportunities, preventing them from reaching their full potential.
The UN's 2006 Human Development Report revealed [pdf] that around 443 million school days are lost annually because of the spread of water-related illnesses in different parts of the world.
Photo: Sara Alaica | Flickr