Final answer:
Between 2007 to 2012, carbon dioxide emissions in the United States decreased by 12% due to successful anti-pollution policies.
Step-by-step explanation:
From the information provided, it is clear that carbon dioxide emissions have seen a notable reduction. Specifically, as highlighted by data from the U.S. Energy Information Administration (EIA), emissions of key air pollutants declined by 12% from the year 2007 to 2012. This decrease demonstrates the effect of anti-pollution policies and shifts in energy use, contributing to efforts to mitigate the impact of greenhouse gases.