Kareiva: Vanishing Soils, the World’s Dirty Secret

April 10, 2013

Idaho farmer Fred Brossy holds the soil that provides his living. Photo by Jennifer Miller

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 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.

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  1. Although I couldn’t find a primary source, I have read many times that topsoil is the U.S.’s largest export, both by weight & dollar value. I think this is a pretty shocking statistic, and certainly worth a mention in an article about topsoil loss.

  2. The problem is soil erosion is not a secret by any stretch of the imagination. The federal and state governments have spent over a billion dollars in the past century to control erosion rates and restore degraded soils.

    In 1928, Hugh Hammond published the immensely popular “Soil Erosion: A National Menace.” When Congress in 1935 Congress passed Public Law 74-46, declaring that “the wastage of soil and moisture resources on farm, grazing, and forest lands…is a menace to the national welfare” and establishing the Soil Conservation Service, Hammond went on to be its first director.

    Flashing forward, there are now over 3,000 soil conservation districts in the United States; one in virtually every agricultural community.

    You don’t have always “discover” something new, uncover a secret, to look smart. Nor do you have to talk about “new” approaches and the blind spots of other groups to advocate for good work. Most times, in fact, what needs doing is more, better, and bigger versions of what the conservation community has been doing for decades. The hard, humble work of continuing does more for the planet than endless quests for the new.

  3. TNC’s ongoing change of priorities from conserving biodiversity to improving natural resource management for humans has engendered considerable controversy within the Conservancy and without. This is a debate worth having and certainly know one can question that TNC’s corporate-dominated board of directors has the legal right to focus on whatever it wants.

    TNC’s transition to a natural resource conservation group would be less controversial if Dr. Kareiva did not regularly justify it by talking as if TNC invented natural resource management, that natural resource management is new field, and regularly presenting his case in an oppositional manner.

    As Steve notes, concerns about soil depletion and erosion are not in the least bit new, secret, or ignored. Indeed, even prior to the establishment of large federal, state and county bureaucracies devoted soil conservation in the 1930s, the establishment of the National Forest system in the 1880s was directly justified on soil erosion grounds (as well as wood resource depletion). Indeed, early on all grazing was banned for several years in U.S. National Forests to stop erosion. After that, grazing was periodically banned in various watersheds providing important drinking water sources to humans (e.g. Bull Run for Portland, Salt River for Phoenix, Rattlesnake for Missoula).

    Soil conservation is a critically important issue. TNC should be congratulated for joining the very large government and NGO infrastructure working on it. It should not, however, pretend it has discovered anything new or that soil conservation has been and is anything other than an absolutely mainstream, heavily funded conservation agenda. Consider, for example, the number of U.N. reports devoted to soils vs. biodiversity.

    Which brings me to Dr. Kareiva’s odd closing comparison of soil loss (“catastrophic”) with extinction (“sad”). Putting aside his proud declaration of “not being a biodiversity guy” in TNC’s magazine, one has to ask what rhetorical purpose is served by contrasting extinction and soil loss in order to declare the latter more important. Advocating for increased soil conservation does not require such an opposition. It would be rather pointless, if that is where Kareiva is pointing, to divert funding from biodiversity to soils since the former only receives a fraction of the funding of the latter.

    I suspect the reason for the seemingly gratuitousness contrast is to further justify TNC’s move away from biodiversity conservation toward the more traditional, more corporate friendly, much better funded arena of improving management of natural resources for human benefit. In 2011 he argued that “instead of pursuing the protection of biodiversity for biodiversity’s sake, a new conservation should seek to enhance those natural systems that benefit the widest number of people, especially the poor.” Prior to that he argued that conservation biologists should help “tame” the planet for human benefit rather than preserve the existence of other species.

    Shift to human resource management if you wish, but please don’t pretend it is anything but the oldest, most traditional, most highly funded realm of conservation. It always has been and alwasy will be. As our population grows from 7 to 9 or 12 billion, managing natural resources will continue to dominate the conservation agenda of governments, corporations and scientists. Do not imply you are daringly breaking ranks with the “traditional” “institutions” prioritizing biodiversity, wilderness and wildlife habitat. These are much newer, much smaller fields, that have never garnered a fraction of the resources and power of the natural resource managers/developers. TNC is not breaking with tradition, it is merging fully into it.

    This is not necessarily bad. Perhaps it is exactly what the world and TNC needs. But one should be more honest and less divisive about it. There is no need to mischaracterize both traditional and biodiversity-focused conservation in the transition.