Money on the table _ perhaps $10 billion a year or more _ could help close a deal in Denmark next month and keep climate talks moving toward a new global treaty in 2010. But if poorer nations see too little offered up front, the U.N. conference could end in discord.
The money would help developing countries cope with ocean flooding, drought and other effects of climate change, while also helping them cut down on emissions of global-warming gases. The funds might eventually come from new sources, such as a tax on airline flights, but negotiators for now are seeking quicker infusions.
"Rich countries must put at least $10 billion a year on the table to kick-start immediate action up to 2012," the U.N. climate chief, Yvo de Boer, told reporters last week in a preview of the two-week conference opening next Monday in Copenhagen.
His goal gathered backing in recent days, including from French President Nicolas Sarkozy and Britain's Prime Minister Gordon Brown, who said his nation would contribute $1.3 billion over three years.
"The rest of Europe will do so," Brown told a Commonwealth summit in Trinidad on Friday. "And I believe America will do so as well."
U.S. President Barack Obama and the Chinese leadership energized lagging climate talks last week by announcing modest targets for controlling their countries' emissions of carbon dioxide and other gases blamed for warming the atmosphere.
Although talks will now be extended, Copenhagen was originally meant to culminate years of negotiation centered on two pillars: emissions reductions and financial aid for developing countries to adapt to climate change.
The proposed emissions targets by industrialized nations for 2020 _ and China's plan to slow emissions growth _ fall short of what scientists say is needed to head off damaging climate change. But if developing nations accept the quick-start financing, a deal might be reached at Copenhagen on a framework for putting all elements in a binding agreement next year, with an eye toward deeper emissions cuts and heftier financing beyond that.
"Short-term finance would be used as an opportunity to get a political buy-in for the other elements of an agreement," said Athena Ballesteros, a climate-finance expert at the Washington think tank World Resources Institute.
The needs are becoming increasingly clear.
An international scientific update last week said changes are happening faster than anticipated. Global temperatures are rising by 0.19 degrees C (0.34 degrees F) per decade, pushing the world into a time of climate disruption, species die-off and expanding seas. Oceans are rising by 3.4 millimeters (0.13 inches) per year, faster than predicted.
"It threatens to submerge the Maldives. My country would not survive," Mohamed Nasheed, president of that low-lying Indian Ocean island nation, told a conference of vulnerable nations earlier this month.
Offers of assistance thus far have been "so low, it is like arriving at an earthquake zone with a dustpan and brush," Nasheed said.
In scores of nations, money will be needed to build coastal protection, modify or shift crops threatened by drought, build water supply and irrigation systems, preserve forests, improve health care to deal with diseases spread by warming, and move from fossil-fuel to low-carbon energy systems, such as solar and wind power.
The World Bank estimates adaptation costs alone will total $75 billion to $100 billion a year over the next 40 years. The cost of mitigation _ reducing carbon emissions in poorer nations _ will add tens of billions to that. China and other developing countries say the target should be even higher, in the range of $350 billion.
De Boer's $10 billion a year to 2012 is barely a start. But "kick-start finance is so important because such finance will allow developing countries to plan," he told The Associated Press.
In fact, much of the funding would go to "capacity building" _ training, planning, getting a fix on needs, local emissions and related concerns.
Upfront money would also help rebuild trust between the rich north and poor south, eroded by years of relative inaction on climate, particularly by the United States.
Climate conference observers expect the European Union to offer most at Copenhagen, perhaps $5 billion a year or more. Japan might contribute $1 billion or more, as would the United States. Appropriations for 2010 totaling some $1 billion to $1.3 billion related to international climate aid are making their way through Congress.
"Quite simply it's the bottom line for getting a deal," New Zealand's Prime Minister John Key said of the financing package, as he pledged up to $50 million on Sunday at a Commonwealth summit in Trinidad.
Obama might use his Dec. 9 drop-by at the Copenhagen conference _ on his way to receive the Nobel Peace Prize in Oslo, Norway _ to announce a U.S. offer on financing. Some 80 other presidents and premiers are expected to attend the final days of the conference Dec. 17-18.
Finance expert Ballesteros expects Copenhagen to narrow the focus of talks next year on sources for longer-term, richer adaptation funding, such as a levy on international air transport, sharing in proceeds from the growing trade in carbon emission allowances, or even a global levy on carbon emissions.
Most important is that such revenue be "stable and predictable," not dependent on vagaries of budget-writing in national capitals, she said.
Emissions reductions, adaptation finance and other elements would be part of a hoped-for treaty or set of internationally binding agreements next year to succeed the 1997 Kyoto Protocol. Its limited emissions reductions expire in 2012. The U.S. was the only industrial nation not to accept Kyoto.