Does climate change affect soil?

Q: Does climate change affect soil?

A: Along with changes in temperature, climate change will bring changes in global rainfall amounts and distribution patterns. And since temperature and water are two factors that have a large influence on the processes that take place in soils, climate change will therefore cause changes in the world’s soils.

nitrogen-cycle-2

The nitrogen cycle, showing the place of soils in the cycle. Figure courtesy of NASA. (Click the image to enlarge it.)

In fact, there are several ways that climate change will affect soil. Soils are also part of the global carbon and nitrogen cycles. The carbon-based gases carbon dioxide (CO2) and methane (CH4), and the nitrogen-based gas nitrous oxide (N2O), are important greenhouse gases. So, as carbon dioxide, methane, and nitrous oxide levels change in the atmosphere, there will be corresponding changes in the soil.

The major challenge for soil scientists today is to figure out exactly how climate change will affect soils, because some of the possible effects counteract each other. For example, organic matter is very important in soils. Many scientists expect increased carbon dioxide levels in the atmosphere to increase plant growth, which would mean more organic matter could potentially be added to the soil.

However, higher temperatures also mean increased rates of organic matter decomposition by soil microorganisms. If the microorganisms decompose organic matter more rapidly than it’s replaced, then soil organic matter levels will decline. Working out relationships like this are key to our understanding of the exact effects of climate change on soil and the ramifications for those effects on resources we rely on, like food crops and timber, that depend on soil.

To learn more about the potential effects of climate change on soil, read the article “Soils and Climate Change: Gas Fluxes and Soil Processes” (https://www.soils.org/publications/sh/articles/53/4/12) in the Soil Science Society of America journal, Soil Horizons.

–Answered by Eric Brevik, Dickinson State University

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6 responses to “Does climate change affect soil?

    • The major greenhouse gases produced in soil are carbon dioxide, methane, and nitrous oxide. Carbon dioxide is produced during the aerobic decomposition of organic matter by microorganisms, while methane is produced during anaerobic decomposition of organic matter.

      Nitrous oxide is created when the soil water content approaches what’s called “field capacity” (near but not quite to saturation), and biological reactions in the soil convert nitrate to nitric oxide, nitrous oxide, or nitrogen gas.

      More details can be found in “Soils and Climate Change: Gas Fluxes and Soil Processes” (https://www.soils.org/publications/sh/articles/53/4/12).

      –Eric Brevik

  1. Indeed, it is approximated that about one fourth of the green house gases produced globally come from agricultural activities, with about half of those related to animal production.

  2. My 2013 Umass Biochar presentation, how thermal conversion technologies can integrate and optimize the recycling of valuable nutrients while providing energy and building soil carbon, I believe it brings together both sides of climate beliefs.
    A reconciling of both Gods’ and mans’ controlling hands.

    Agricultural Geo – Engineering; Past, Present & Future
    Across scientific disciplines carbons are finding new utility to solve our most vexing problems
    http://www.trunity.net/files/236901_237000/236919/kinght2013-1.pdf

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