OPINION: Greenhouse gases, ill effects on our oceans & coastal cities
The notion that greenhouse gases are warming the Earth is nothing new, as is the notion that methane — while having 23 times the heat retention capabilities of carbon dioxide — is rarer and breaks down relatively quickly. Many efforts to curb climate change, therefore, tend to focus on CO2, which can linger in the atmosphere for centuries, rather than methane, which is generally expected to be absorbed into soil or broken down in the atmosphere after about 12 years.
But a new study indicates that the negative effects of short-lived gases such as methane might last longer than previously thought, at least as far as the ocean is concerned.
According to researchers, methane and other rarer greenhouse gases contribute a lot of extra heat to water, which is much harder to cool down once it has been warmed up. If the new study is accurate, eliminating greenhouse gases within a relatively short span of time will not be able to cool down the oceans sufficiently to avoid further ice melt at the poles. As a result, ocean levels could continue to rise for centuries, even after greenhouse gas emissions are finally reduced to zero.
“As the heat goes into the ocean, it goes deeper and deeper, giving you continued thermal expansion,” Susan Solomon, professor of atmospheric science at the Massachusetts Institute of Technology and study co-author said in a statement. “Then it has to get transferred back to the atmosphere and emitted back into space to cool off, and that’s a very slow process of hundreds of years.”