American leadership in the fight against global warming is crucial. America is the world’s largest economy, the second-largest emitter of global warming pollution, and the nation responsible for more of the human-caused carbon dioxide pollution in the atmosphere than any other. Without prompt action by the United States and others to reduce global warming pollution, catastrophic impacts – from coastal flooding to food system disruptions – could become unavoidable.
Fortunately, even in the absence of a comprehensive response from the U.S. Congress, local and state governments and the Obama administration have taken leadership on global warming. State and federal leadership on global warming is already having a significant impact. A set of clean energy policies adopted by states and the federal government and in effect from 2007 to 2012 reduced U.S. carbon dioxide pollution by 162 million metric tons in 2012. That is equal to annual emissions from 34 million vehicles, or all the passenger cars and trucks in Pennsylvania, Michigan, Illinois and Colorado combined. Those emission savings will grow in future years as the policies mature and more ambitious clean energy targets come into effect.
