A question about climate change?

Question

I was reading a report about climate change and it talks about greenhouse gases and 100 years GWP but it doesn't explain what it means so what is 100 years GWP?

Answer 1

For once, I think this is appropriate:

http://en.wikipedia.org/wiki/Global_warming_potential

Answer 2

GWP is an abbreviation for Global Warming Potential. This is a scale developed to measure how significant a contribution the different greenhouse gases make to global warming.

It's a relative scale and carbon dioxide has a fixed value of one. If a greenhouse gas is described as having a GWP of 50 it means that it's 50 times more effective at contributing to global then carbon dioixide.

But... effectiveness varies over time. The contribution that some greenhouse gases make to global warming begins to deteriorate as soon as they enter the atmosphere, others actually become more effective before 'fading away'.

If a gas is described as having a 100 Year GWP of 296 (as nitrous oxide has) then it means that after 100 years the contribution to global warming will be 296 times that of carbon dioxide.

At the extremes of the scale are water vapour with a GWP of about 0.05 and at the other end are some of the synthetic gases which have GWP's of up to 31,500. These synthetic gases include CFC's and similar gases, these not only contribute to global warming but to ozone depletion and have now been banned.

Answer 3

GWP or global warming potential is way in which gases can be rated by

their share of the greenhouse effect

the amount of time it takes for them to be removed from the atmosphere through natural causes

For example, if you released a certain amount of methane into the atmosphere in 2007, it would have a theoretically measurable greenhouse effect. It would continue to have an effect until all of the gas has left the atmosphere. For your release of methane, that would be a little over 10 years. So if you took a look at your release's 100 year effect on greenhouse warming, you'll see it's quite small because there has been practically zero effect for the last 90 years until 2107.

So, a gas with a high 100 yr GWP usually reflects gases that the environment has a difficult time ridding itself. It would only make sense to try and limit emissions of these more harmful gases. (CO2 has a value of 1)

Answer 4

Global Warming Potentials -GWPs over the next 100 years. Like some CFC's destroy ozone for 90 years, Halons for 120 years. Co2 for 35 years?(I think this is about right). Anyway, you can see that we have already produced problems 50 to 60 years down the road and with out cleaning up the atmosphere we are in for big problems