Methanogenic organisms can turn carbon dioxide (a gas that makes sparkling water bubble) into methane. Methane is a gas that we can use for heating or to run engines. Most importantly, methane is known as a greenhouse gas, it heats up the planet Earth when there is too much of it in the air. The methanogenic microorganisms are not a big problem because there are organisms that metabolize the methane they produced.
Explanation for children:
Methanogenic organisms can turn carbon dioxide (a gas that makes sparkling water bubble) into methane. Methane is a gas that we can use for heating or to run engines. Most importantly, methane is known as a greenhouse gas; it heats up the planet Earth when there is too much of it in the air. The methanogenic microorganisms are not a big problem because there are other organisms that metabolize the methane they produced.