Harlan Watson, the senior climate negotiator for the U.S. Department of State promised that the United States would contribute to carbon limits that will be set during talks through next year during a media conference in Vienna.

The 1997 Kyoto Protocol set limits for countries of 5 percent below 1990 emission levels by 2012. The European Union was joined by 36 industrialized nations to be bound by these limits. The European Union, a regulatory arm of the E.U., wants developed nations to cut their greenhouse gas emissions by 30 percent below 1990 levels by 2020. Developing nations such as China and India were exempted from the requirements and the U. S. declines to join.

While the U.S. currently emits the highest levels of CO₂, China is expected to soon become the largest emitter as their industries continue to grow.