Four formerly developing countries took the reins during climate talks in Copenhagen: China, India, Brazil, and South Africa. It could herald a redistribution of global clout, some experts say.
A Senate bill's target for emission cuts is akin to level US is likely to offer in Copenhagen. Ahead of the global warming talks, other nations have been waiting to see US target.
Differences between major industrialized nations and developing countries are a stumbling block at a US-sponsored forum.
A warming climate would mean less food and more immigration, which could worsen ethnic strife.