Continuing the theme, NewScientist (2 May 2015) (paywall) discusses yet another factor in climate change – microbes:
THEY’RE collaborating with the enemy. Climate change in the Arctic may be getting a helping hand from microbes, whose effect could thus be underestimated in climate models.
Mette Svenning from the University of Tromsø, Norway, and her team found that microbe communities potentially produce more greenhouse gases than we thought. We knew that higher temperatures speed up the rates at which microbes in the Arctic soil release methane – a greenhouse gas 25 times more potent than carbon dioxide. But the team found it took just a month for entire communities to adapt to rising temperatures and release more methane.
Carl Zimmer, writing for Yale’s environment360, notes:
Even more impressive is the vast amount of carbon that microbes pump around the biosphere. On the surface of the ocean, photosynthetic bacteria suck vast amounts of carbon dioxide dissolved in the water and turn it into organic molecules. The ocean is also rife with bacteria that feed on organic matter and release carbon dioxide as waste. Meanwhile, the microbes that break plant matter into soil release 55 billion tons a year of carbon dioxide. “It’s eight times what humans are putting into the atmosphere through fossil fuel burningand deforestation,” says [Steven Allison, a biologist at the University of California at Irvine].
Exactly how to model the microbes’ contribution is not entirely clear, according to Joe Turner at The Scientist:
An estimated 2,500 billion metric tons of carbon is stored in the soil, so understanding interactions between the soil and the atmosphere is of critical importance to predicting the impacts of climate change. But determining the extent to which carbon dioxide-fixing microbes within the soil can affect the environment—and vice versa—has proved challenging. Two recent studies have highlighted the difficulties of understanding how soil microbes might respond to climate change and question whether climate models should account for these bugs.
In question are the kinds of feedbacks that can be expected from soil microbes in a warmer climate and the resulting effects on the global stocks of soil carbon. Existing climate models do not explicitly consider soil microbial respiration, as it has been considered too complicated, but some researchers argue that considering the soil microbiome is of critical importance. These microbes could help to store or release a lot more carbon and could in turn impact on the levels of atmospheric greenhouse gases—helping to speed up or slow down climate change.
This is a positive feedback loop, typically the bane of engineers – our civilization’s unwanted byproduct is, in essence, heat, and that heat is causing microbes to issue even more heat. The articles may discuss this in terms of difficulties of introducing into models, but the real point is that this is another contributor to our future problem set, and mediating it will become yet another problem. Or, to be fair, another opportunity, if someone can figure out what to do with the gases in question, or that final output – heat. The discussions we hear so much about always seem to center around “how do we stop this?” and then progress to “even if we stop our output of the gases, the temperature increases will continue”. While perhaps it is wrong and/or naive of me, just being a simple programmer, I do like to try to look at problems from other angles – including those where you reclassify your problem as an opportunity. Can we harvest these gases and use them for something else? If not, how about that heat – can we gather that up and use it somehow?
Probably not, but it’s always worth asking those questions.
