Methane - a mysterious but powerful greenhouse gas

I’m colourless, odourless and tasteless. I am the simplest existing alkane, but don't underestimate me - it's known more and more that I can change the global temperature tremendously. What am I?

Yes, that’s right. I am methane. 

Methane is one of the most potent greenhouse gasses. According to the IPCC Fifth Assessment report, one molecule of methane traps 28 times more heat in the atmosphere than one molecule of carbon dioxide over a period of 100 years. Although the concentration of methane in the atmosphere is much lower than the carbon dioxide concentration (fig. 1), emissions are growing fast.

Figure 1 | The concentrations of atmospheric greenhouse gasses, measured from ice cores. (IPCC, 2014)

What worries me about methane is that there is still much unknown about the cycle of this greenhouse gas. Sources and sinks are mostly known, but what are their relative contributions to methane emissions? How much methane is locked up in the permafrost and can global warming lead to a tipping point at which all this methane will be released? Why did the global concentrations of methane level off from the 1980s and what explains the increase again after 2007?

I am Laura van der Marel and I am a student of the master programme Climate Change at UCL. For the module Global Environmental Change I am writing a 14-week blog on the topic methane. The aim is to inform you and myself about the methane: to explore the mysteries about the compound, get to grips with the sinks and sources and understand the ways in which past methane levels can be measured. Then I want to take you back in time and see how atmospheric methane concentrations have developed.

Come along on this journey and follow my blog!