Agence France-Presse: Cleaning up skies choked with smog and soot would sharply curtail the capacity of plants to absorb carbon dioxide and blunt global warming, according to a study released on Wednesday. Plant life — especially tropical forests — soak up a quarter of all the CO2 humans spew into the atmosphere, and thus plays a critical role in keeping climate change in check. Through photosynthesis, vegetation transforms sunlight, CO2 and water into sugar nutrients. Common sense would …