While earlier reports on global warming focused more on carbon dioxide and CFCs, one of the more important greenhouse gas after carbon dioxide is methane, now increasingly being considered as more dangerous and more potent as a greenhouse gas than carbon dioxide. According to Noam Mohr, the effects of methane of worldwide warming is the same as all the other non-carbon dioxide gases combined. Methane is also 21 times more damaging and has spread faster than than carbon dioxide. Methane is also the cause of almost half of earth’s human-induced warming (Mohr, p. 2).
Moreover, according to the Environmental Protection Agency, methane concentration in the atmosphere has increased by 150% since 1750, while much of the increase in concentration has been seen in recent years (Environmental Protection Agency, online)
Methane may be naturally occuring, with emissions from wetlands, oceans, hydrates and even termites. Man-made emissions, however, account for more than 60% of methane emissions worldwide. Landfills, natural gas systems and animal husbandry are the top three human-related sources of methane, a list that further includes coal mining, waste management, agriculture and rice cultivation, coal mining and petrochemical activities (Environmental Protection Agency, online).
Methane has a global warming potential of 23, compared to the standard, carbon dioxide, with a GWP of 1. That means methane can warm the earth 23 times more than carbon dioxide over a period of 100 years. Global warming potentials are indicators to contrast the potentials of various gases to trap heat (The Pembina Foundation, online). Methane could last for about 12 years in the atmosphere (Environmental Protection Agency, online).
Like all greenhouse gases, methane is capable of absorbing infrared photons, converting it into an “excited” molecule. The vibrating molecule emits radiation, which will in turn be absorbed by other greenhouse gases. This reaction is what is responsible for life on earth, it acts like a blanket that traps heat sufficient to sustain life. However, the same mechanism is responsible for increased global temperatures as more and more greenhouse gases are concentrated in the atmosphere (University Corporation for Atmospheric Research, online).
Studies as recent as 2006 have shown that methane is also increasingly released in the atmosphere, and that this increased methane concentration in turn increases the temperature, which in turn realease more methane (Svoboda, p.1). This cycle has been observed the melting of permafrost. The Associate Press reports that the melted permafrost releases both carbon dioxide and methane, which stays in the atmosphere where it traps more heat, which increases the temperatures needed to melt more permafrost (Borenstein, p. 1).
While releasing both carbon dioxide and methane, thawed permafrosts are responsible for higher concentrations of methane in the atmosphere. Borenstein writes that methane from permafrost is released five times faster than the previously estimated rate. Permafrost also holds a huge deposit of methane underwater (Borenstein, p. 1).
* * *
Methane, as a greenhouse gas, has more power to trap heat in the atmosphere than carbon dioxide, even though it lasts only for a relatively short 12 years (as compared to a centruy for carbon dioxide. If that is not enough, methane has steadily increased in terms of atmospheric concentration over the past decades. What makes methane a more alarming greenhouse gas is a self-perpetuating cycle that results in even more methane in the atmosphere and marked increase in temperatures felt worldwide. Much like, Gremlins doused with water, or a self-replicating amoeba.
Borenstein, Seth. (2006). Study Says Methane a New Climate Threat. Associate Press. Retrieved on 21 May 2008. ;http://www.cbsnews.com/stories/2006/09/06/ap/tech/mainD8JVHMD00.shtml;
Global Warming. The Pembina Foundation. Retrieved on 21 May 2008. ;http://www.greenlearning.ca/climate/science/greenhouse-effect/4?;
Methane: Science. (2006). Environmental Protection Agency. Retrieved on 21 May 2008. ;http://www.epa.gov/methane/scientific.html;
Methane: Sources and Emissions . (2006). Environmental Protection Agency. Retrieved on 21 May 2008. ;http://www.epa.gov/methane/sources.html;
Mohr, Noam. (2005). A New Global Warming Strategy: How Environmentalists are Overlooking Vegetarianism as the Most Effective Tool Against Climate Change in Our Lifetimes. Earthsave International. Retrieved on 21 May 2008. ;http://www.earthsave.org/news/earthsave_global_warming_report.pdf;
Svoboda, Elizabeth. (2006). Global Warming Feedback Loop Caused by Methane, Scientists Say. National Geographic. Retrieved on 21 May 2008. ;http://news.nationalgeographic.com/news/2006/08/060829-methane-warming.html;
The Greenhouse Effect: Background Material. University Corporation for Atmospheric Research. Retrieved on 21 May 2008. ;http://www.ucar.edu/learn/1_3_1.htm;