But tougher work of cutting greenhouse gases under Kyoto Protocol remains.
After seven years of bruising negotiations, repudiation by one of its early architects, and repeated pronouncements of its imminent demise, a 1997 pact to curb the growth of greenhouse gases tied to global warming is limping toward ratification.
Now comes the hard part: putting its complex rules into effect, and planning for what will follow once the agreement's first - and so far, only - formal commitment period ends after 2012.
"This is the most complicated, sophisticated effort at directed change" in international environmental policy ever attempted, notes Elliot Diringer, director of international strategies for the Pew Center on Global Climate Change. "Is it possible? We'll find out."
The pact in question, the 1997 Kyoto Protocol, requires countries signing the agreement to reduce global carbon-dioxide emissions by an average of 5 percent below 1990 levels by 2012.
Many atmospheric scientists agree that these emissions are at least partly responsible for an increase in average global temperatures. Those temperatures are expected to rise for the foreseeable future, with disruptive consequences worldwide.
Already, 126 nations have ratified the agreement - more than double the 55 needed. But the ratifying industrial countries only accounted for 44.2 percent of industrial-country emissions (55 percent are needed).
Last week, the final piece in that ratification puzzle appeared to fall into place when the Russian cabinet voted to ratify the accord. It now goes to the Russian Duma for the final vote, seen by many as a formality in the wake of the cabinet's decision.
Even if every signatory meets its emissions-reduction goal, the effort would barely slow the rate of increase of CO2 and have virtually no effect on climate.