Microbes and Climate Change

Microbes play a central role in global biogeochemical cycles and can influence the amount of greenhouse gases released or absorbed as environmental conditions change.

Rising global temperatures accelerate microbial metabolism, increasing the decomposition of organic matter.

In oxygen-rich conditions, this decomposition releases carbon dioxide through microbial respiration, contributing to greenhouse gas emissions.

But, in low-oxygen environments, such as wetlands or a ruminant gut, methanogenic archaea can generate methane, a more potent greenhouse gas than carbon dioxide.

In addition, soil microbes can produce nitrous oxide during both nitrification and denitrification, adding another greenhouse gas to the atmosphere.

Some microbes help balance these effects.

For instance, denitrifying bacteria like Paracoccus denitrificans convert nitrous oxide into harmless nitrogen gas, lowering greenhouse gas levels.

Marine photosynthetic microbes absorb carbon dioxide to grow, introducing it into the food web. Some of this carbon then sinks as cells, waste, and dead material into deeper water.