John McCain
Introduced the Climate Stewardship and Innovation Act of 2007 with Sen. Joseph Lieberman (I-CT). The legislation is designed to significantly reduce the nation's greenhouse gases, accomplished through a combination of trading markets and the deployment of advanced technologies. Would propose use of alternative energy sources, including nuclear.
 Watch McCain speak about the environment

Barack Obama
Would implement an economy-wide cap-and-trade program to reduce greenhouse gas emissions to the level recommended by top scientists. Would make the United States a leader in the global effort to combat climate change by leading anew international global warming partnership. Would establish a National Low Carbon Fuel Standard (LCFS) to speed the introduction of low-carbon non-petroleum fuels. Would create a Technology Transfer program within the Department of Energy dedicated to exporting climate-friendly technologies to developing countries. Would offer incentives to maintain forests globally and manage them sustainably. Would develop domestic incentives that reward forest owners, farmers and ranchers when they plant trees, restore grasslands or undertake farming practices that capture carbon dioxide from the atmosphere.
 Watch Obama speak about the environment