Obama has already used his lame duck status to take a stand on climate change, tweeting with the public and incorporating the issue into commencement speeches. But this afternoon, Obama promises to reveal the "biggest, most important step ever taken to combat climate change".
Carbon dioxide is a greenhouse gas--a gas that can prevent heat from escaping Earth's atmosphere, raising the temperature of the planet. Rising carbon dioxide levels are leading to a changing climate across the globe. Carbon content in the air has already reached dangerously high levels, and continues to rise--as does the global temperature.
Power plants are the largest source of carbon dioxide emissions in the United States, followed extremely closely by transportation. The Clean Power Plan aims to reduce the amount of carbon from electricity generation by 32 percent (from 2005 levels) over the next 15 years. The plan also intends to reduce "pollution that leads to soot and smog" by 25 percent by the year 2030.
In requiring an overall reduction in carbon pollution, the plan relies on an increase in renewable energy source like wind and solar. The plan hopes to increase those energy sources by 30 percent by 2030 as well.
The plan requires each state to submit their own plan for how to reduce the amount of carbon from their power plants. For example, in some sunny states, that might mean an increase in solar power, while windy states might rely on wind turbines, and states that historically rely on coal might turn to carbon capture technologies. There will also be a marketplace available for states to trade emissions. Final plans must be submitted by 2018, and once the plan is approved, they have until 2022 to put their chosen methods in place. Between 2022 and 2029, the states will reduce emissions to the required levels.
The plan is announced in advance of the much-anticipated global climate summit starting in Paris on September 26. There, world leaders will meet to discuss how to tackle climate change around the world.