A new report published Tuesday in the The Proceedings of the National Academy of Sciences shows that the microbes that feed on decaying organic matter release roughly 7.5-9 times more carbon dioxide (CO2) into the atmosphere than man-made emissions worldwide. By a lot. The study, led by Thomas W. Crowther, also showed that soil-dwelling animals such as worms turn around and eat these microbes, which act as a safeguard against the enormous emissions these microbes belch out yearly.
The study’s researchers detail how dirt-loving insects and worms graze on these CO2-emitting microbes, which means less CO2 flowing into the atmosphere. All told, the microbes behind this natural decomposition process release 50–75 Pg (petagram or billion tonnes) carbon annually into the atmosphere, nearly 10 times what humans emit from the burning of fossil fuels. One petagram is equivalent to 1 billion tonnes.
Crowther says that as more carbon dioxide is released by these microbes, the warmer the atmosphere becomes, which “stimulate growth and enzyme production, which aids in the decomposition process.” Add to that the carbon dioxide that comes from man-made emissions, and you have a self-perpetuating feedback loop. He notes that the microbes produce the biggest flow of “carbon into the atmosphere that there is on Earth.”
This microbial carbon dioxide production may cause a 2 to 3 degree Celsius rise in global temperatures over the next 100 years. He also says that, “The failure to incorporate animals and their interactions with microbial communities into global decomposition models has been highlighted as a critical limitation in our understanding of carbon cycling under current and future climate scenarios.”
Crowther believes that improving soil conditions can make a significant difference in combating global warming, though he admits that it’s never really been considered as a way to “mitigate climate change.” And while adding worms and other soil-dwelling insects into the ground may sound like a quick fix, he believes we should take a hands-off approach to our ecosystem and instead cultivate “natural biodiversity,” adding that “natural regeneration is the best way.”
So the next time you go fishing and stick a worm on your hook, you might think twice about setting it free into the vast, earthen wilderness. Or take up fly fishing.