Monday, September 7, 2009

Humans causing erosion comparable to world’s largest rivers and glaciers

University of British Columbia News: A new study finds that large-scale farming projects can erode the Earth’s surface at rates comparable to those of the world’s largest rivers and glaciers. Published online in the journal Nature Geosciences, the research offers stark evidence of how humans are reshaping the planet. It also finds that – contrary to previous scholarship – rivers are as powerful as glaciers at eroding landscapes.

“Our initial goal was to investigate the scientific claim that rivers are less erosive than glaciers,” says Michele Koppes, a professor of geography at the University of British Columbia (UBC) and lead author of the study. “But while exploring that, we found that many of the areas currently experiencing the highest rates of erosion are being caused by climate change and human activity such as modern agriculture,” says Koppes, who conducted the study with David Montgomery of the University of Washington.

In some cases, the researchers found large-scale farming eroded lowland agricultural fields at rates comparable to glaciers and rivers in the most tectonically active mountain belts. “This study shows that humans are playing a significant role in speeding erosion in low lying areas,” says Koppes. “These low-altitude areas do not have the same rate of tectonic uplift, so the land is being denuded at an unsustainable rate.”…

Erosion near Chimborazo, Ecuador, shot by Patricio Mena Vásconez, who has generously released the image into the public domain via Wikimedia Commons

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