In recent decades a "dimming" of the planet seemed to have slowed the rate of global warming below what had been expected given the rise in greenhouse gasses such as carbon dioxide in the atmosphere. Now the Earth is growing brighter and this is expected to exacerbate global warming. The cause of global dimming is still not clear, and therefore, the cause of global brightening remains unsolved. RealClimate points to several possible candidates. One candidate is air pollution which may have had the effect of reflecting some of the sun's rays. But, our efforts to clean the air for health reasons are now likely letting more sunlight in. But, as RealClimate points out, it would be folly to think we should increase air pollution to fight global warming since we'd have to ultimately make the air thick with haze everywhere at an ever-increasing rate just to keep up with greenhouse emissions. We'd kill ourselves with pollution without tackling the real problem: greenhouse gasses.
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