Since 2007, emissions in the United States have dropped a startling 9%, ending an entire century of rising emissions. And while many will be quick to point to the recession and high gas prices as the main cause for the flagging emissions, other factors, like increased energy efficiency and much more power coming from renewable sources, have played a role as well.
Consider: last year, oil usage fell 5%. Coal usage fell 1% (a relatively big deal, considering more than half the nation gets its power from coal). And overall carbon emissions fell 3%.
H/T EPA-Hugger