He supports the cap-and-trade system that was passed in the U.S. House in June. The new cap-and-trade rules would, for the first time, place national limits on the amount of carbon dioxide that companies can release into the atmosphere. The eventual cost to businesses and consumers is at the heart of what has become an intense informational and lobbying campaign on both sides. Environmentalists and some money managers see cap-and-trade as the best way to control carbon emissions while oil refiners warn the House bill could make foreign petroleum products cheaper and lead to even more imports. How the U.S. will proceed on climate change legislation was a major topic at the World Economic Forum in China last week, and it is expected to be discussed in coming days when President Barack Obama speaks at a ministerial meeting of the U.N. General Assembly. Todd Stern, the U.S. State Department's special envoy for climate change, said last week that it's crucial for the Senate to pass a climate bill. Doing so would give the U.S. the "credibility and leverage" needed to convince other countries like China and India to cut their pollution. The hard press right now comes on the eve of the United Nations climate change summit in Denmark, and the world is looking for a "sense of direction from the U.S." said Lord Stern.