Earlier today it was my privilege to address those attending the United Nations Climate Change Conference in Cancun, Mexico. Climate change is one of the greatest threats facing our planet, and the United States is taking significant action to meet this challenge. Under President Obama’s leadership, the U.S. is advancing policies that address climate change by promoting energy efficiency in our homes, cars and businesses, increasing the domestic production of clean energy – including biofuels – and by investing in renewable energy technology. The United States is also vigorously engaged in international climate negotiations while continuing to work with Congress on domestic climate legislation.