Modeling methods used by ETH Zurich researchers revealed that global warming is increasing carbon dioxide emissions from soil microbes. Rising carbon dioxide levels in the atmosphere are, in fact, the primary driver of global warming.
One-fifth of the carbon dioxide in the atmosphere is assumed to come from soil sources, according to the study. This is due in part to the action of soil microorganisms like bacteria, fungi, and other microbes. These microorganisms break down organic matter in the soil, such as decaying plant material, by using oxygen. During this process, carbon dioxide is released into the atmosphere. Scientists refer to this as heterotrophic soil respiration.
The findings of the study were published in the peer-reviewed journal Nature Communications. The title of the journal was “Global warming accelerates soil heterotrophic respiration.” Their findings show that CO2 emissions from soil bacteria into the Earth’s atmosphere are not only expected to rise, but also to rise globally by the end of the century. Scientists estimated that carbon dioxide emissions from soil microorganisms will increase by 2100. In the worst-case scenario of climate change, carbon dioxide emissions might rise by up to 40% globally compared to current levels.
The findings do not just validate past research. It does, however, provide a more exact understanding of the mechanics and scale of heterotrophic soil respiration in various climatic zones. According to their calculations, in a worst-case climate scenario, microbial carbon dioxide emissions in polar regions are expected to rise 10% every decade by 2100, more than doubling the global average.
This difference can be related to ideal circumstances for heterotrophic respiration, which occur when the soil is semi-saturated, or neither too dry nor too wet. This situation exists in arctic locations during soil thawing. Soils in other climate zones, which are already relatively dry and susceptible to further drying, exhibit lesser increases in microbial carbon dioxide emissions.
In 2021, the majority of carbon dioxide emissions from soil bacteria came from warm regions of the Earth. Specifically, 67 percent of these emissions originate in the tropics, 23% in the subtropics, 10% in the temperate zone, and barely 0.1 percent in the arctic or polar areas. Significantly, the researchers predict that microbial carbon dioxide emissions will increase significantly in all of these regions compared to levels observed in 2021. Their forecasts show a growth of 119% in the polar areas, 38% in the tropics, 40% in the subtropics, and 48% in the temperate zone by 2100.
Source: national geographic