Earth Has Lost a Third of Its Farmable Land in Last 40 Years, Researchers Say

http://www.weather.com/science/environment/news/earth-soil-farmable-land-loss-food-production-crisis

By Ada Carr weather.com
Dec. 21, 2015

Over the past 40 years, a third of the world’s farmable land has been wiped out by erosion and pollution, researchers say. This has the potential to become disastrous, as the demand for food soars worldwide.

According to experts from the University of Sheffield’s Grantham Centre for Sustainable Futures, almost 33 percent of the world’s arable land has been lost.

“Soil is lost rapidly but replaced over millennia and this represents one of the greatest global threats for agriculture. This is catastrophic when you think that it takes about 500 years to form 2.5 centimeters of topsoil under normal agricultural conditions,” said University of Sheffield professor of plant and soil biology Duncan Cameron.

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The decline in soil has come at a time when the global demand for food is growing at a rapid rate. It’s estimated that by 2050 the world will need to grow 50 percent more food to feed a projected population of 9 billion, reports The Guardian.

The erosion of soil is largely due to constant disturbance from planting and harvesting crops. If soil is continually turned over it is exposed to oxygen which makes it release carbon into the atmosphere, causing it to fail to effectively bind. This diminishes the soil’s ability to hold water, to buffer flooding and provide a base for plants. These compromised soils are also more likely to be washed away.

Intensive agriculture methods in place requires the heavy use of fertilizers, which need high energy inputs to supply inorganic nitrogen. This process takes up five percent of the natural gas production and two percent of the world’s annual energy supply, experts said.

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tags: human footprint