Wednesday, May 5, 2010

Why Air Pollution Control Is Important to Limit Global Warming Under 2 Degrees Celsius

A few people around me realize the importance of non-CO2 greenhouse gases (GHGs; CH4, N2O, CFCs, HCFCs, HFCs, O3) for climate change mitigation.
Fewer people around me realize the importance of non-GHG air pollutants (SO2, NOX (NO+NO2), CO, BC (black carbon), organic carbon) for the same purpose.
An amazingly well-written analysis by scientists from Scripps Institution of Oceanography clarifies how important they are and enlightens the ignorant majority (including me).

In the analysis, the authors show that the atmospheric concentration of carbon dioxide equivalent (CO2e; NOT CO2) greenhouse gases must be stabilized at 441 ppm by 2100 to limit global warming under 2°C above the pre-industrial temperature.
To achieve that goal, they propose three imperatives.

1) Reduce 50% of CO2 emissions by 2050 and 80% by 2100: However, it will NOT reduce the planetary GHG blanket thin enough within the 21st century due to the long lifetime of atmospheric CO2 (100-1000 years).
2) Offset warming from the reduction of aerosol masking: Reduce emissions of two major air pollutants: black carbon (BC) and ozone (and its precursor gases such as NOX, CO, and volatile organics (VOCs)).
3) Thin the GHG blanket: Reduce emissions of short-lived GHGs (methane and halofluorocarbons (HFCs)).

Then can I say that controlling air pollution is as important as reducing CO2 emissions reduction?

Source: Ramanathan, V., & Xu, Y. (2010). The Copenhagen Accord for limiting global warming: Criteria, constraints, and available avenues. Proceedings of the National Academy of Sciences, 107(18), 8055-8062. Retrieved from


  1. can't you put this in a simple way rather then in just a confusing scientific way!!!!!!!!!!