Explained: Greenhouse gases
When hearing the words “greenhouse gas,” most people think immediately of carbon dioxide. This is indeed the greenhouse gas that is currently producing the greatest impact on the Earth’s rapidly changing climate. But it is far from the only one making its mark, and for mitigating climate change it’s important to be able to compare the effects of the various gases that contribute to warming the planet. But that’s not easy to do. Greenhouse gases vary in not only their sources and the measures needed to control them, but also in how intensely they trap solar heat, how long they last once they’re in the atmosphere, and how they react with other gases and ultimately get flushed out of the air. The differences make it impossible to do the very thing researchers and policymakers want most to do: come up with a simple conversion factor to allow exact comparisons among them. Let’s take...