"Climate deniers like to point to the so-called global warming "hiatus" as evidence that humans aren't changing the climate. But according a new study, exactly the opposite is true: The recent slowdown in global temperature increases is partially the result of one of the few successful international crackdowns on greenhouse gases."

"Back in 1988, more than 40 countries, including the US, signed the Montreal Protocol, an agreement to phase out the use of ozone-depleting gases like chlorofluorocarbons (today the Protocol has nearly 200 signatories). According to the EPA, CFC emissions are down 90 percent since the Protocol, a drop that the agency calls "one of the largest reductions to date in global greenhouse gas emissions." That's a blessing for the ozone layer, but also for the climate. CFCs are a potent heat-trapping gas, and a new analysis published today in Nature Geoscience finds that slashing them has been a major driver of the much-discussed slowdown in global warming.

Without the Protocol, environmental economist Francisco Estrada of the Universidad Nacional Autónoma de México reports, global temperatures today would be about a tenth of a degree Celsius higher than they are. That's roughly an eighth of the total warming documented since 1880."

Tim McDonnell reports for Mother Jones/Climate Desk November 10, 2013. [2]