Showing results for "The Present Past" in Earth Sciences

Humans depend on soil for 95 percent of global food production, yet let it erode at unsustainable rates. In the United States, China, and India, vast tracts of farmland will be barren of topsoil within this century. The combination of intensifying erosion caused by climate change and the increasing food needs of a growing world population is creating a desperate need for solutions to this crisis.

The past fifteen thousand years--the entire span of human civilization--have witnessed dramatic sea level changes, which began with rapid global warming at the end of the Ice Age, when sea levels were more than 700 feet below modern levels. Over the next eleven millennia, the oceans climbed in fits and starts. These rapid changes had little effect on those humans who experienced them, partly because there were so few people on earth, and also because they were able to adjust readily to new coastlines.