25.
Global Soil Change
As Serious As Climate Change
Earth’s climate and biodiversity aren’t the only things being dramatically affected by humans—the world’s soils are also shifting beneath our feet.
‘Global soil change’ due to human activities is a major component of what some experts say should be recognized as a new period of geologic time: the human-made age. This new era will be defined by the pervasiveness of human environmental impacts, including changes to Earth’s soils and surface geology.
Daniel Richter of Duke University, in his report published in the December 2007 issue of the journal of Soil Science, warns that Earth’s soils already show a reduced capacity to support biodiversity and agricultural production. As the amount of depleted and damaged soils increases, global cycles of water, carbon, nitrogen, and other materials are also being affected.
In another paper, Jan Zalaseiwicz of the University of Leicester in England and colleagues argue that the fossil and geologic record of our time will leave distinct signatures that will be apparent far into the future.
‘Global soil change’ due to human activities is a major component of what some experts say should be recognized as a new period of geologic time: the human-made age. This new era will be defined by the pervasiveness of human environmental impacts, including changes to Earth’s soils and surface geology.
Daniel Richter of Duke University, in his report published in the December 2007 issue of the journal of Soil Science, warns that Earth’s soils already show a reduced capacity to support biodiversity and agricultural production. As the amount of depleted and damaged soils increases, global cycles of water, carbon, nitrogen, and other materials are also being affected.
In another paper, Jan Zalaseiwicz of the University of Leicester in England and colleagues argue that the fossil and geologic record of our time will leave distinct signatures that will be apparent far into the future.
Overworked Earth
Today about 50 percent of the world’s soils are subject to direct management by humans. Global soil change is also occurring in more remote areas due to the spread of contaminants and alterations in climate. Worldwide, soils are being transformed by human activities in ways that we poorly understand, with possibly dire implications.
The report warns that properties and processes in the soil are more dynamic and susceptible to change than previously thought. Only recently it has been documented that many aspects of soil chemistry and composition are highly responsive to human activities.
Report also warns that severe soil degradation is increasing globally at a rate of 12.4 million to 24.7 million acres (5 million to 10 million hectares) annually.
The report warns that properties and processes in the soil are more dynamic and susceptible to change than previously thought. Only recently it has been documented that many aspects of soil chemistry and composition are highly responsive to human activities.
Report also warns that severe soil degradation is increasing globally at a rate of 12.4 million to 24.7 million acres (5 million to 10 million hectares) annually.
Soil Degradation And Climate Change - A Relationship
Soil degradation plays much a larger role in climate change than was previously suspected. That’s because organic matter in soils store vast amounts of carbon—more than is present in the atmosphere and in all land vegetation combined.
According to the noted geologist Bruce Wilkinson of Syracuse University, heavily cultivated and degraded soils lose their carbon-storing ability as exposed organic matter breaks down.
Over the past half century or so, global soils have lost approximately a hundred billion tons of carbon [in the form of carbon dioxide] to the atmosphere through such exposure. Humans are now the predominant geological force operating on the planet.
Rates of sedimentation and erosion caused by human activities— mainly industrial agriculture—are ten times higher those attributable to natural processes. On agricultural land, soil is being lost ten times faster than it is being replaced. Humans are rapidly consuming the global soil reservoir. In light of the wasting grains to produce meat and biofuels, this is obviously a very serious change.
According to the noted geologist Bruce Wilkinson of Syracuse University, heavily cultivated and degraded soils lose their carbon-storing ability as exposed organic matter breaks down.
Over the past half century or so, global soils have lost approximately a hundred billion tons of carbon [in the form of carbon dioxide] to the atmosphere through such exposure. Humans are now the predominant geological force operating on the planet.
Rates of sedimentation and erosion caused by human activities— mainly industrial agriculture—are ten times higher those attributable to natural processes. On agricultural land, soil is being lost ten times faster than it is being replaced. Humans are rapidly consuming the global soil reservoir. In light of the wasting grains to produce meat and biofuels, this is obviously a very serious change.
