A recent study discovered that excessive amounts of carbon dioxide in soil causes the creation and release of greenhouse gases such as nitrous oxide and methane.
Researchers from the University of Florida and Northern Arizona University led by Dr. Kees Jan van Groenigen, a research fellow in the botany department at the School of Natural Sciences, Trinity College Dublin, analyzed the results of 49 various experiments from Asia, Europe, and North America which focused on forests, wetland, rice paddies, and agricultural lands. All 40 experiments measured excess amounts of carbon dioxide present in the atmosphere, and the ways the gas can affect soil's release of methane and nitrous oxide.
"This feedback to our changing atmosphere means that nature is not as efficient in slowing global warming as we previously thought," Dr. Kees Jan van Groenigen said in a press release.
Meta-analysis was performed to surface the common trends and patterns among different researchers. The team was able to identify two patterns: first, increased carbon dioxide in the atmosphere also led to an increased release of nitrous oxide, and second, in wetlands and rice paddies, extra amounts of carbon dioxide makes the soil release more methane.
According to the study, this effect is due to microscopic organisms in the soil, which metabolize carbon dioxide as well as the nitrate present in the environment. The microbes are also responsible for producing nitrous oxide and methane, since they do not need oxygen to thrive.
"The higher CO2 concentrations reduce plant water use, making soils wetter, in turn reducing the availability of oxygen in soil, favoring these microorganisms," Van Groenigen explained in a press release.
Microorganisms are more active when carbon dioxide increases because more carbon dioxide makes a plant grow faster. When this happens, the microorganisms are supplied with extra energy, allowing them to metabolize more gases from the atmosphere.
Further details of the study can be read on the April 28 issue of Nature.
