From Mother Jones:

One of the most hotly contested issues at Copenhagen is the question of what, if anything, the US and other industrialized countries owe the nations least responsible for the accumulation of planet-warming gases in the atmosphere.

The United States has said that over the next three years it will commit $1.4 billion annually to a $10 billion short-term fund intended to help developing nations cope with the effects of climate change. The European Union volunteered last week to chip in $3 billion.

But that still leaves the question of how much rich nations will pony up over the long haul. The United Nations estimates that poor countries will need as much as $170 billion per year to adapt to climate change—$50 billion more than developed countries spent on aid in 2008. Other development groups have estimated that this task could cost two to three times that much. So far, rich countries have indicated that they're only prepared to offer around $100 billion.

More here.