In the last of couple of years, everyone is talking about our carbon footprint and its impact on the environment. Carbon dioxide has been the darling of the Climate Change world. However, it is methane gas who is the true villain in the climate change story. Like the character, Darth Vader in the Star Wars Trilogy, methane is ruthless and unforgiving. In fact, “methane gas is about 25 times stronger as a greenhouse gas per metric ton of emission than carbon dioxide,” as stated in a 2008 NASA statement.
NASA has brought to light in 2005 that methane’s effect on climate change may be double of what was previously expected. According to the article, methane emissions account for a “whopping third of the climate warming from well-mixed greenhouse gases between 1750s and today.”
However, the Intergovernmental Panel on Climate Change (IPCC) reports only 1/6th of the greenhouse gases are from methane emissions. Why the difference?
“Drew Shindell, a climatologist at NASA’s Goddard Institute for Space Studies, New York, NY, believes we need to look at the GHGs [sic Greenhouse Gases] when they are emitted at Earth’s surface, instead of looking at the GHGs themselves after they have been mixed into the atmosphere. “The gas molecules undergo chemical changes and once they do, looking at them after they’ve mixed and changed in the atmosphere doesn’t give an accurate picture of their effect,” Shindell said. “For example, the amount of methane in the atmosphere is affected by pollutants that change methane’s chemistry, and it doesn’t reflect the effects of methane on other greenhouse gases,” said Shindell, “so it’s not directly related to emissions, which are what we set policies for.”
Methane gas emissions have a large impact on air pollution. NASA’s Shindell and colleagues found that by categorizing the climate effects by emissions, rather than the IPCC method of calculating the effects of tropospheric ozone increases on climate renders a much higher methane emission effect. For example, smog has been attributed to warming; however, increased methane gas emissions causes increased smog.
What causes methane gas? The chart above from the US Department of Energy Technology Laboratory illustrate the sources of man-made and natural occurrences of methane. According to the EPA, landfills are the largest human-related source of methane in the US, accounting for 34 percent of all methane emissions.
In 2008, Postdoctoral researcher Matthew Rigby and Ronald Prinn, the TEPCO Professor of Atmospheric Chemistry, in MIT’s Department of Earth, Atmospheric and Planetary Science found that Methane gas levels in the atmosphere were on the rise. One of the possible reason was due to the reduction in hydroxyl free radical (OH), often referred to as the atmosphere’s “cleanser.” Rigby and Prinn noted that it was too early to tell whether this was an anomaly or a return to sustained methane growth; however, they stated that careful monitoring of the situation was warranted given the fact that ” pound for pound, methane is 25 times more powerful as a greenhouse gas than carbon dioxide“.
A recent study by Shindell and colleagues, found that “methane emissions have a larger impact than that used in current carbon-trading schemes or in the Kyoto Protocol.” According to Shindell, scientists have failed to account for the interaction of aerosols (fine articles suspended in air) and methane and carbon monoxide.
“What happens is that as you put more methane into the atmosphere, it competes for oxidants such as hydroxyl with sulphur dioxide,” Shindell added.
“More methane means less sulphate, which is reflective and thus has a cooling effect. Calculations of GWP including these gas-aerosol linkages thus substantially increase the value for methane,” as stated in a MercoPress’s article.
Shindell noted in a USA Today article that the total amount of warming has not changed but the balance of which gases which are responsible has. However, curtailing human activity causing methane emissions may be an easier place for policy makers to begin in making climate change agreements.
“Since we already know how to capture methane from animals, landfills, and sewage treatment plants at fairly low cost, targeting methane makes sense,” said Michael MacCracken, chief scientist for the Climate Institute in Washington, D.C.
What can we do?
- Simply reducing what you throw out will reduce methane gas emissions. Practicing the 3 Rs of recycle, reduce, and reuse. Ask yourself before you are ready to pitch something into the trash, can it be reused? Can I recycle it or in the future could I have made a better choice to buy something that could be reused or recycle? Although recycling something is a step in the right direction, realize it still takes energy to transport that item to be recycled and energy to create something new with the product. Again, the power of choice is fundamental. Consider purchasing items that can be reused over and over such a a reusable bottle, cloth napkins, and reusable containers.
- Eat less meat.
- Compost your vegetables and fruits rather than throwing them in the trash or disposal.
- If you can not or don’t want to compost, reduce impulse shopping. Buy only what you need and will use to reduce spoilage. I freeze a lot of my vegetables and reuse them in soup recipes.
Let’s hope that the reality of the impact of methane gases and other non-carbon gases will be become front and center at Copenhagen and not overshadowed by their more famous cousin, carbon dioxide. Instead of waiting for the world to adopt climate change initiatives , do your part as well to reduce your own methane footprint one step at a time.
Readers, how would you reduce your methane footprint?