Methane Gas and Global Warming
November 13th, 2009 Posted in Green Living & News
When talking about global warming, carbon always seems to be labeled as the main perpetrator. Well, it looks like carbon has a new sidekick in the global warming phenomenon: methane gas.
The Research
The Goddard Institute for Space Studies at NASA (GISS) is suggesting that non-carbon dioxide gases have a net effect on the atmosphere that might be a greater than carbon dioxide. The study monitored sulfate and nitrate aerosols.
Interestingly, aerosolized sulfates and nitrates don’t directly cause global warming. They actually synthetically cool the earth by scattering incoming sunlight. Also, they are known to cause acid rain and respiratory distress for high risk individuals.
Sulfates and nitrates, when released from places like coal plants, are in the form of sulfur dioxide. Sulfur dioxide is naturally released from volcanoes. When sulfur dioxide is released into the atmosphere it reacts with hydroxyl radicals. The hydroxyl radicals act as a kind of “scrubber,” cleaning the atmosphere of pollutants.
So, wait, you might say. This sounds great! Aerosols that actually help cleanse the atmosphere? Well, not so fast.
These plants also release methane and carbon monoxide. These two gasses also react with hydroxyl radicals, leaving less hydroxyl to react with the sulfates and nitrates. The result? A reduction in the amount of cooling produced by the aerosols, which means more warming.
The Global Effect
Globally, the increase of methane gas emissions has led to a 26% decrease in hydroxyl and an 11% decrease in sulfate particles. The decrease in sulfate particles means that methane gas has 20-40% more warming power.
This study took a much closer look at exactly how human produced methane gas effects the environment. Normally, scientists rely on surface stations and satellites to tell them how the gas has effected the atmosphere. This is called “abundance based” research, and cannot tell you about the exact reactions gases are having with the atmosphere and whether or not these gases are man-made.
Methane does occur naturally. Wetlands, termites, and decomposing matter in bodies of water all release methane gas. But people create methane gas release as well with rice paddies, livestock, landfills, coal mining, and gas production. Scientists at GISS looked at what methane gases are released on the surface of the earth, which gives a much more accurate picture of the quantity of man made methane making its way into the environment.
The good news about methane release is that scientists already know how to capture methane gas emitted by humans, and at a fairly low cost, to boot.
What can we take away from GISS’s research? Global Warming is not all about carbon dioxide. Non-carbon sources might be effecting the atmosphere just as negatively.
