Read here. Western governments have been battling real air pollution for decades with much success. So, when they decided to pour billions into climate research and climate models, they for some reason chose not to focus on the impact of aerosol pollution (e.g. black soot). Per new research out of NASA, that decision was dumb - aerosols chemically react with greenhouse gases causing even more warming but climate models are oblivious to that science fact.
"The IPCC's modeling cronies have just been told that the figures used for greenhouse gas forcings are incorrect, meaning none of the model results from prior IPCC reports can be considered valid. What has caused climate scientists' assumptions to go awry? Short lived aerosol particles in the atmosphere changing how greenhouse gases react in previously unsuspected ways. The result is another devastating blow to the climate catastrophists' computer generated apocalyptic fantasies....This would imply that if aerosols—black carbon in particular—were reduced we should see global cooling. And this is using the IPCC values for CO2 sensitivity. So much for the potency of CO2 as the major driver of climate change."