Study: Mankind's Earth footprint growing

SAN FRANCISCO, Dec. 5 (UPI) -- Wisconsin scientists say agriculture dominates more than a third of the Earth's landscape and is a major source of global environmental change.

Navin Ramankutty of the Center for Sustainability and the Global Environment at the University of Wisconsin-Madison, said, "The real question is: How can we continue to produce food from the land while preventing negative environmental consequences such as deforestation, water pollution and soil erosion?"

To better understand that dilemma, Ramankutty and colleagues are mapping changing patterns of agricultural land use around the world, including a look at related factors such as global crop yields and fertilizer use.

"In the act of making these maps we are asking: where is the human footprint on the Earth?" said Amato Evan, a SAGE researcher who merged available census and satellite data to create visuals reflecting the reach of pasture and croplands worldwide. Chad Monfreda, a graduate student at SAGE, is similarly mapping the location, range and yields of more than 150 individual crops reared around the planet.

The scientists will present their early findings during this week's fall meeting of the American Geophysical Union in San Francisco.