By Peter Kareiva, chief scientist, The Nature Conservancy
We talk a lot about the biodiversity crisis, the energy crisis, the water crisis, the climate crisis, the food crisis, deforestation and so on. But what about the soil crisis?
Today, around the world the mean rate of soil loss is roughly ten times the rate at which soil is replenished. In some countries such as China, the rate of soil loss can be as high as 50 times greater than replenishment.
It is hard to imagine a better indicator of our failure to achieve sustainability. What could be more fundamental than the soil that grows the plants from which 99% of humankind’s calorie intake is derived?
From a biodiversity and conservation perspective, this soil loss also impinges on many of our more traditional concerns. It represents nutrient and sediment flow into our rivers and estuaries, to the detriment of fisheries.
Conservation has many narratives of profligate humanity soiling their nest and creating some sort of eco-catastrophe. Often those narratives are overstated and excessive.
But in the case of soil, the doom-and-gloom has some merit. Some historians have examined the arc of human history as a series of civilizations bankrupting their soils.
And it is not just data and science. If you have gardened and felt the comfort and seduction of warm, fertile soil in your hands, you know how primal is the link between people and soil. When someone back in the recesses of time coined the term “Mother Earth,” I have to believe she or he was thinking of warm soil.
The soil crisis also intersects our attention to the hundreds, maybe thousands, of newly emerging cities.
In much of the world we have built our cities on the most fertile soils, thereby squandering a valuable resource when buildings and settlements could be much more wisely placed on unproductive soils. It is now routine to inform plans for infrastructure or development with maps of where biodiversity is concentrated and especially valuable. We need to adopt a similar approach for our world’s soils.
Unless we fundamentally change our agriculture practices, current rates of soil loss and erosion will pose severe challenges for agricultural productivity, as well as the need for massive clearing of lands as yet undisturbed.
The United Nations Environment Programme (UNEP), the Food and Agriculture Organization (FAO), and the World Bank have all recognized how crucial soil is to their mission of sustainable development. And in 2009, the globalsoilmap.net project was initiated with support from the Bill and Melinda Gates Foundation.
But we still lack global- and national-level soil monitoring. We lack clear site specific indicators that can give us an early warning signal that we might be on the brink of irreversible soil loss.
And we have not developed policy incentives to reward landowners, farmers or local communities who treat their soils well.
The loss of any species is tragic and sad. But the loss of one’s fertile soil is catastrophic. The conservation community, the environmental community, the agricultural community, and the development community need to unite around the issue of protecting and restoring our soils.
McNeill, J. and V. Winiwarter. 2004. Breaking the sod: humankind, history, and soil. Science 304: 1627-1629.
Montgomery, D. 2007. Soil erosion and agricultural sustainability. Proceedings of the National Academy of Science. 104: 13268-13272.
Nizeyimana, E.L., G.W. Petersen, M.L. Imhoff, H.R. Sinclair, S.W. Waltman, D.S. Reed-Margetan, E.R. Levine and J.M. Russo. 2001. Assessing the impact of land conversion to urban use on soils of different productivity levels in the USA. Soil Science Society of America Journal 65: 391-402.
Opinions expressed on Cool Green Science and in any corresponding comments are the personal opinions of the original authors and do not necessarily reflect the views of The Nature Conservancy.