Early Agricultural Methods May Have Altered Global Climate, Study Suggests

William Ruddiman and Erle Ellis of the University of Virginia and University of Maryland-Baltimore hypothesized five years ago that humans began altering global climate thousands of years ago, by cultivating large expanse of land to support the food demand of the population. A study using findings of several studies by anthropologists, archaeologists and paleoecologists was conducted and results indicate that early civilizations used a great amount of land to grow relatively small amounts of food. Early populations would have resorted to slash and burn agriculture where forests are continuously cleared to allow farmers to plant crops.

"It was only as our populations grew larger over thousands of years, and needed more food, that we improved farming technologies enough to begin using less land for more yield," Ruddiman said. He also noted that with the highly efficient and intensive farming of today, growing populations are using less land per capita for agriculture. Forests are returning in many parts of the world, but the increased industrialization resulted to climate change.

The authors suggested that "climate modelers might consider how land use has changed over time, and how this may have affected the climate."

For details, see the press release at: http://www.virginia.edu/uvatoday/newsRelease.php?id=9443