Today when you hear about global warming, the first thing that comes to mind is probably carbon dioxide; however, there are many greenhouse gases that may contribute to this phenomenon. Wolfram|Alpha now provides information on the relative global warming effects of about 30 common pollutants in the atmosphere using the global warming potential (GWP) index.
The GWP index estimates how much a certain chemical will add to global warming compared to the same mass of carbon dioxide over a certain time span. The data Wolfram|Alpha uses is from the 2007 report of the Intergovernmental Panel on Climate Change (IPCC).
Let’s take a look at some of this data by asking Wolfram|Alpha about the “gwp of methane”. Here you are able to see three different time horizons for methane: 20 years, 100 years, and 500 years. These different time horizons allow you to see the short-term and long-term contributions that methane will make to global warming in the atmosphere. You may also notice that as the time horizon gets larger, the GWP actually decreases—which seems counterintuitive, but makes sense as soon as you see that methane has an atmospheric lifetime of about 12 years. This is a fairly short lifetime, so methane’s effect on global warming declines as the time horizon increases. A simple click on the “Show comparisons” button pulls up a comparison of methane’s GWP to those of other greenhouse gases. You can also adjust the time horizons to see how methane compares to other greenhouse gases in the short and long term.
GWP values can also be compared for multiple greenhouse gases. For example, an input of “gwp of methane and carbon tetrachloride” provides a comparison of the two gases. The first pod displays the time horizons of both chemicals so you are able to see that carbon tetrachloride contributes much more to global warming than does methane. Moving down to the next pod, it may become more obvious why carbon tetrachloride contributes more: it has an atmospheric lifetime of 26 years, more than twice as long as methane’s.
We are currently working to add a greater variety of climate change and global warming data to Wolfram|Alpha. We encourage you to submit feedback on this feature, as well as any suggestions or ideas you may have.