The Intergovernmental Panel on Climate Change (IPCC) finds global warming is causing glaciers to melt on every continent, and glacial melt is accelerating. It is expected land-based ice-melt could lead to a 3-foot rise in sea levels by the end of this century, a tidal surge, however gradual, that could displace 2-3 billion people living in coastal regions around the world. But the immediate problem examined by NOW in this video is the potential worldwide food crisis resulting from failing river systems, starved of water fed from glacial sources at the top of their watersheds. 

The president of the Earth Policy Institute says the resulting scarcity and price-distortions could become a global security threat. Lester Brown explains that what happens to India's wheat harvest and its agricultural supply chain, including and in large part due to the resulting effect on food prices, will determine the economic status of everyone everywhere, as scarcity and price pressures alter the base economy of every nation around the world. 

Population growth and depletion of water resources are determining the future sustainability of an affordable food supply at high volume. With over 500 million people entirely dependent on the Ganges for drinking water and crop irrigation, even the massive US agricultural export base will not be able to prevent price rises at home. 

The one river feeds more people than live in the entire 27-nation European Union. Glacial melt is so severe and the reduction in river flow already so marked that there is no tap water in some districts even within Delhi. Water-scarcity riots are already commonplace as residents scramble to siphon as much clean water as possible from the government trucks that distribute the slim supplies day after day. 

Disappearing Himalayan glaciers are also causing the thinning of river systems in China. Western China is already experiencing extreme-velocity desertification, in part due to land-use missteps and in part to broader climate phenomena; the depletion of its river systems could be catastrophic. 

The world's two most populous nations face drinking-water and irrigation scarcity from glacial melt, threatening the stability of the global food supply. In the US, Glacier National Park is dying. The glaciers themselves are vanishing; they have already retreated as much as 70% since 1910, and will likely vanish entirely by 2030. 

India's Gangotri Glacier, one of the largest Himalayan glaciers and a major source of fresh water for the Ganges River, is receding at extremely accelerated rates, more than three times the historic average over the last 6 years. Dr. Vandana Shiva says the glacier "looks like a war zone, as more and more of the glacier retreats", leaving behind the scarred mountain terrain underneath. Shiva says the disappearance of the Gangotri is a story of human devastation and the very real ongoing emergence of water-based conflict and economic hardship.