CANCÚN, Mexico (December 11, 2010) – As delegates from more than 190 nations at the annual U.N. Framework Convention on Climate Change (UNFCCC) conference here in Cancún wrapped up two weeks of negotiations in the wee hours this morning, there was much to criticize and much to applaud, according to the U.S.-based science advocacy organization, the Union of Concerned Scientists (UCS).

“The outcome in Cancún wasn’t enough to save the climate,” said UCS Director of Strategy and Policy Alden Meyer, “but it did restore the credibility of the United Nations as a forum where progress can be made.”

On a macro level, the conference fell short of what is needed, Meyer said. The collective actions pledged by countries remain insufficient to meet the challenge of climate change. And the declarations by both Japan and Russia that they have no intention of taking on emissions reduction targets when the Kyoto Protocol’s second commitment period starts in 2013 almost derailed the talks—and point to the challenges ahead.

But there were some identifiable successes, he added, most notably on preserving tropical forests and agreeing to create a Green Climate Fund to ramp up support for developing country actions to constrain emissions and cope with the mounting impacts of climate change. Equally important, the skillful and transparent management of the negotiations by Mexico’s foreign minister, Patricia Espinosa Cantellano, and other senior Mexican government officials went a long way to exorcising the “ghost of Copenhagen” that had been hanging over the U.N. negotiating process.

Tropical forest protection was one issue that found some resolution at the conference. Delegates adopted a decision that establishes a three-phase process for tropical countries to reduce deforestation and receive compensation from developed countries, and it includes protections for forest peoples and biodiversity.

“The real bright spot was moving forward with REDD+, the program to eliminate tropical deforestation,” said Doug Boucher, UCS’s director of climate research and analysis. “Historic changes are happening in conference halls and in the Amazon that can end thousands of years of deforestation in our lifetime.”

There was positive movement in other issue areas, Meyer said, including increasing the transparency of both developed and developing country initiatives to constrain their emissions. This measurement, reporting and verification (MRV) issue was a priority for the United States, which wanted greater openness from large developing countries—particularly China—on their progress in meeting their emissions-limitations pledges.

The outcome was mixed on the key issue of setting stronger goals for limiting emissions, Meyer said. While the final Cancún text calls on industrialized countries to do just that, it has no explicit acknowledgement of the significant gap between the current pledged commitments and those needed to meet the goal endorsed by most world leaders at Copenhagen to keep global temperatures from increasing more than 2 degrees Centigrade above pre-industrial levels.

“The Cancún decision creates an opportunity for the world to raise the collective level of emission-reduction targets in the months and years ahead,” said Meyer. “But it doesn’t guarantee success, and there is no more agreement on how much should be done, and by which countries, than there was when negotiators arrived in Cancún.”

After the last stories about the United Nations’ 16^th “Conference of the Parties,” or COP, are filed, the 194 participating nations will be faced with some daunting challenges going into the next COP in December 2011 in Durban, South Africa, Meyer cautioned. The fate of the Kyoto Protocol hangs in the balance, given the statements by Japan and Russia and suspicions that Canada and perhaps other countries would like to join them in getting out of Kyoto’s legally binding framework. Likewise, the creation of the Green Climate Fund in Cancún does not ensure that it will become an effective institution with the substantial resources needed to meet its lofty objectives, given the fiscal and political challenges in the United States and other developed countries.

“World leaders must significantly raise their game if we’re to meet the challenge of climate change,” Meyer said. “Time is running out, and the atmosphere doesn’t negotiate with politicians.”

The Union of Concerned Scientists is the leading U.S. science-based nonprofit organization working for a healthy environment and a safer world. Founded in 1969, UCS is headquartered in Cambridge, Massachusetts, and also has offices in Berkeley, Chicago and Washington, D.C.