So How Long Have We Got?
450 ppm has beeen set as a target by the European Union for C02 concentration in the atmosphere as the maximum safe level to keep global warming below an increase of 2C. At current rates of emission, how long will it take us to get to 450ppm?
  • Years
  • Days
  • Hours
  • Mins
  • Secs

But this is just calculating the time left using only C02 levels. We know that methane (CH4) is way above pre-industrial levels so we should factor that in, and restart the calculation.

And then there is nitrous oxide, another powerful GHG emitted by agriculture and industry.

And then there are the halocarbons (CFC's, HFC's), which are signifcant in IPCC 2007 for the first time.

The above is based on information in Wikipedia "CO2 Equivalent" and related links, and from data in the IPCC 2007 report. The point being made is that we are out of time to avert serious global warming. The 30% reductions in CO2 emissions from 2005 levels promised in the 2009 Copenhagen accord won't even begin to address the problem. Cancun 2010 also looks like just bromides.

You can see how long it will take to double CO2 levels on an equivalent basis (CO2e); the doubling of pre-industrial CO2 is known as climate sensitivity, and is predicted to cause a temperature rise of around 3C.