National Geographic : 2015 Nov
River erosion, intensified by climate change, has destroyed part of Newtok, Alaska. Water may reach the school, the village’s flood shelter, by 2017. Mangrove restoration projects dot the planet: Vietnam, Djibouti, Brazil. These efforts not only protect coastal communities from rising seas and storm surges but also help increase biodiversity and sustain livelihoods. ART: ROMUALDO FAURA. SOURCE: IPCC LAND The dynamic interactions between climate change and freshwater resources on land are critically tied to the availability of good-quality water for human use. Today at least half the world’s population relies on groundwater for safe drinking water. With projected urban growth expected to increase demand by 55 percent by 2050, we’ll have to manage future water use carefully. ICE The freshwater that was once frozen in the Arctic, Greenland, Antarctica, and global alpine regions is melting and spilling into the world’s oceans, streams, and soil. As more ice melts, rivers and watersheds will fill at first. But as the ice dwindles, so will the runoff— and the available freshwater. If conservation doesn’t stem the problem, water-use restrictions loom. Not-so-perma frost When permafrost thaws, land changes. People in the north rethink roads and buildings, relocate cellars that store frozen game, and move from vulnerable areas. Shrinking sea ice As global temperatures rise, Arctic and Antarctic sea ice will continue to shrink and thin. Less ice means less energy reflected, and more absorbed, by the ocean. Low snow Springtime snow cover in the Northern Hemisphere will likely drop 10 to 30 percent by 2100, making comprehensive water management crucial. Dwindling freshwater Water managers will need a flexible mix of strategies. Among them: harvesting rainwater, reusing water, improving storage systems, and diversifying crops. Unfrozen The last ice of Bolivia’s Cha- caltaya Glacier melted away in 2009, leaving mountain villagers no choice but to move to cities, which now must bolster water capture and storage.