Methane from plants increased by climate change

The debate about climate change has focused on one polarizing gas: carbon dioxide. CO₂ and its portrayal to the general public is controversial because on one hand, it’s essential for all life, since plants need to breathe too.  But on the other hand it’s a greenhouse gas that traps heat in our atmosphere, and in some instances –such as new interpretations of the Clean Air Act–is regulated as a pollutant.

But another, less common gas that doesn’t get as much attention is CO₂‘s cousin, methane, or CH₄. Methane is a major component of natural gas, and recent studies show a considerable amount is also produced (no laughing here) as flatulence from livestock. Thus far, scientists have clashed over whether or not plants produce significant levels of methane.

But a study out today in the journal Physiologica Plantarum suggests that under combined climate change conditions (increased temperature, drought and ultraviolet-B radiation), major crops could show an increase in average methane emitted. Mirwais Qaderi and David Reid of the University of Calgary raised faba beans, sunflowers, peas, canola, barley and wheat in the laboratory and found that this climate change scenario enhanced their methane emissions. This finding is important because, according to the researchers, methane is about 23 times as effective at trapping heat as CO₂. Said Qaderi in a statement:

Our results are of importance in the whole climate warming discussion because methane is such a potent greenhouse warming gas. It points to the possibility of yet another possible feedback phenomena [sic] which could add to global warming.

In some cases, plants can produce methane that they take up from the soil, where it’s made by bacteria. Although this has the same outcome for the climate, it’s important to know whether plants can do it themselves without organic backup in the soil, a biochemical mechanism that–correct me if I’m wrong–has yet to be discovered. Because if they do, all those plant metabolism pathways you learned in high school or Botany 101 might have to be rewritten.

Qaderi, M., & Reid, D. (2009). Methane emissions from six crop species exposed to three components of global climate change: temperature, ultraviolet-B radiation and water stress Physiologia Plantarum DOI: 10.1111/j.1399-3054.2009.01268.x