Last week, we saw a significant policy shift on greenhouse gas emissions when President Bush called for a halt in the growth of U.S. emissions by 2025 and urged other major polluting nations to develop national goals to address climate change. On the same day, South Korea’s president started a visit to the U.S. to make a pitch to companies and investors to assist the country’s desire to become an energy producer following the discovery of deposits of gas hydrates — crystalline solids of methane and water molecules — off its coast last year. The country’s aspirations are understandable. They would, however, add to emissions from methane released during extraction. Gas hydrates have also been found in large quantities off the coasts of China, India, and Taiwan, all of which have increasing energy demands.