By Jeff Tollefson

COPENHAGEN--Two lines of evidence nearly brought down the last-minute climate agreement brokered last week in Copenhagen by US President Barack Obama: studies indicating that the impacts of global warming could be more severe than previously thought, and that rich countries could do more to counter the problem without breaking the bank.

Now, negotiators are seeing whether they can strengthen a deal nearly universally acknowledged as weak -- or whether even the mounting scientific evidence on the most dire effects of climate change will be enough to forge a more meaningful deal.

The Copenhagen accord, drawn up as a multilateral political agreement between the United States, China, India, Brazil and South Africa, provides a non-binding framework for capturing national commitments that are already on record. Many environmentalists and a number of developing countries criticized it immediately, saying that current climate commitments would not meet the common goal of limiting the increase in global average temperatures to 1.5-2 °C. Indeed, an analysis by the US modelling consortium Climate Interactive estimated that the commitments would result in a temperature rise of 3.9 °C by the year 2100.

For its part, the European Union elected in Copenhagen not to increase to 30% its conditional offer of a 20% cut in 1990 emissions levels by 2020. The overall goal remains to hammer out a treaty to replace the 1997 Kyoto Protocol on Climate Change while incorporating climate commitments from developing countries and the United States, which has not ratified the Kyoto agreement.

Negotiations will continue over the coming year, and many observers hope for a stronger deal when the parties to the United Nations Framework Convention on Climate Change meet in Mexico in late November 2010.

Obama's announcement on the last day of the Copenhagen talks fractured the G77 group of developing countries. Lumumba Stanislaus Di-Aping, Sudan's fiery chief negotiator and chairman of the G77, claimed that the deal would do nothing less than "destroy" Africa. He was joined by countries including Tuvalu, Bolivia and Venezuela during an all-night debate that included the occasional tirade against capitalism but also focused on how poor nations would be affected disproportionately by climate change (see 'Growing agricultural benefits for climate'), and how rich countries should be paying more.

For instance, scientists at the Copenhagen meeting had enlisted the star power of Al Gore in releasing a pair of reports on the accelerated loss of glaciers and ice sheets in Greenland and Antarctica; melting ice sheets in particular, they concluded, could increase sea level by at least 1 metre by 2100.

Easy targets

Still, an economic analysis by the International Institute for Applied Systems Analysis (IIASA) in Laxenberg, Austria, found that the pre-Copenhagen commitments by industrialized countries would reduce 2020 emissions by 11-22%. Taking into account cost savings due to efficiency and other factors, the cost of achieving that goal would be just 0.15% of gross domestic product, the analysis revealed. Markus Amann, who heads the IIASA's greenhouse-gas initiative, fears that such easy targets will translate into low carbon prices and end up delaying the innovation needed to make deep cuts in decades to come.

Yet most developing countries ultimately defended the Copenhagen accord -- with reservations -- because without it there would have been nothing to show for the largest environmental conference in history. "This is not what we have been seeking, but it is a beginning," said Mohamed Nasheed, president of the Maldives, which is a member of the Alliance of Small Island States that has been pushing for a commitment to limit warming to 1.5 °C. "I beg all nations to please back this document and do not let these talks collapse."

"The most important thing to get done at this moment is to get moving," adds John Holdren, Obama's chief science adviser. "Let's not argue for the next five years what the perfect goal is. Let's get going in the right direction."

For the first time under the new framework, both developing and developed countries -- including the United States, which is gearing up for a legislative battle over climate in the Senate this spring -- will be bound under a single agreement. Rich countries would be required to meet their promised reductions; developing countries would be required to audit and report the activities they undertake to reduce emissions, as well as open their books to international verification for any projects funded with international aid.

In exchange, the agreement offers financing, valued at US$30 billion by 2012, to help developing countries prepare for a warmer world and to push forward with sustainable development goals. Developed countries committed to spending upwards of $100 billion annually by 2020, although the agreement offers no details as to where that money will come from. The World Bank has estimated that developing countries will need about that amount, but developing countries and many scientists say that number could be far too low.

Martin Parry of Imperial College London, a former co-chair of the Intergovernmental Panel on Climate Change (IPCC) working group on impacts, adaptation and vulnerability, has developed a way to portray 'unavoided impacts' in which mitigation fails and there isn't enough money to help people cope with the consequences. Assuming that all countries fulfil their pledges, the agreement in Copenhagen still leaves a gap of 1.5 °C, he says. In other words, funding for adaptation could cover impacts associated with about 1.5 °C of warming, but temperatures are likely to rise by at least 3 °C.

"Even the toughest and most robust measures will not achieve 2 °C," Parry says. "We should hope for 2 °C but realistically expect 3-3.5 °C, and then plan for 4 °C."

The Copenhagen accord includes a goal of limiting temperature rise to 2 °C, but one target that was notably dropped was that for reducing global greenhouse-gas emissions by 2050. Small-island states successfully pushed for language requiring consideration of a target of 1.5 °C during the first review of implementation and commitments in 2015, one year after the IPCC is scheduled to finalize its fifth assessment report. Climate modelling for the next IPCC assessment is under way, and the panel will accept nominations and then appoint lead authors for the various chapters this spring.

Sitting in his office overlooking the main hall of the Bella Center in Copenhagen last week, IPCC chair Rajendra Pachauri said that he was encouraged by the fact that so many world leaders chose to attend, even if a commitment to act falls short.

"There's a certain inertia that will resist it. There are mindsets that will resist it. There are vested interests that will resist it -- let's not minimize their effectiveness," Pachauri says. "This is something that politically one had to anticipate."