Topsoil

While thinking about biofuels and how much land is now used with no regard for the safety of human consumption, I also thought about topsoil loss.  So, as I am want to do, I asked the Goo Ghoul what others have written about.  Below are some notes and quotes:

[As an aside: It always amazes me when I see mountains, knowing that it took many millions of years to push up, yet they are eroding so quickly. How is it that they don't erode as fast as they are pushed up? ]

Around the world, soil is being swept and washed away 10 to 40 times faster than it is being replenished,

http://www.news.cornell.edu/stories/2006/03/slow-insidious-soil-erosion-threatens-human-health-and-welfare

A rough calculation of current rates of soil degradation suggests we have about 60 years of topsoil left. Some 40% of soil used for agriculture around the world is classed as either degraded or seriously degraded – the latter means that 70% of the topsoil, the layer allowing plants to grow, is gone. Because of various farming methods that strip the soil of carbon and make it less robust as well as weaker in nutrients, soil is being lost at between 10 and 40 times the rate at which it can be naturally replenished. Even the well-maintained farming land in Europe, which may look idyllic, is being lost at unsustainable rates. 

http://world.time.com/2012/12/14/what-if-the-worlds-soil-runs-out/

Farming takes half the world's available freshwater, much of which is used for irrigation. And all that activity — plus the deforestation and degradation that tends to go hand in hand with farming — helps make agriculture the single biggest source of manmade greenhouse gases, more than industry or transportation or electricity generation. "We are running out of everything," says Foley. "We are running out of planet."

http://content.time.com/time/health/article/0,8599,2115423,00.html

Solutions?

Solutions he [Foley] proposes include, but are by no means limited to: new crop varieties, drip irrigation, greywater recycling, and smarter diets.

http://blogs.worldwatch.org/nourishingtheplanet/john-foleys-ted-talk-calls-agriculture-the-other-inconvenient-truth/

So, no solutions until it gets more serious.