Final answer:
The EPA's new rules aim to substantially reduce CO2 emissions from coal power plants, which is critical as coal is the worst fossil fuel offender for CO2 emissions. No exact reduction rate is provided, but historical data shows that there have been significant reductions in emissions due to anti-pollution policies.
Step-by-step explanation:
The question addresses recent policies by the Environmental Protection Agency (EPA) aimed at reducing carbon dioxide (CO2 emissions) from coal power plants. While the exact figure for the reduction is not provided in the information, it does indicate significant efforts and policies have contributed to a drop in CO2 levels by 740 million metric tons, or a 12% reduction from 2007 to 2012. Coal has always been a primary contributor to CO2 emissions, and policies that target reducing coal emissions are part of larger efforts to combat the greenhouse effect and global warming.
For example, replacing coal with natural gas has been proposed as a measure to reduce CO2 emissions. Coal burning plants are substantial contributors to not only CO2, but various other pollutants such as sulfur dioxide, nitrous oxide, and mercury emissions. Employing alternative energy sources like nuclear energy, which contribute zero greenhouse gas emissions, is essential for making progress in reducing the greenhouse effect.