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.
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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