TOYAKO, Japan (CNN) -- A call from the world's most powerful nations to establish the goal of halving greenhouse gas emissions worldwide by 2050, was criticized by environmentalists Tuesday.
Oxfam members dressed as G8 leaders hold balloons representing the carbon their countries emit per capita.
The agreement by the Group of Eight industrialized economies -- which includes the United States, Japan, Germany, Britain, France, Italy, Canada and Russia -- was struck during the G-8 summit in northern Japan.
The goal must be compatible with "economic growth and energy security," the leaders said in a statement. They also said it must be done with cooperation from all major economies, including China and India.
However critics argued that the 50 percent reduction target was insufficient, and have called for ambitious midterm targets for countries to cut emissions by 2020.
"At this rate, by 2050 the world will be cooked and the G-8 leaders will be long forgotten," Antonio Hill, spokesman for Oxfam International, told The Associated Press.
"The G-8's endorsement of a tepid 50 by 50 climate goal leaves us with a 50-50 chance of a climate meltdown. Rather than a breakthrough, the G-8's announcement on 2050 is another stalling tactic," he said.
Kim Carstensen, Director of the WWF Global Climate Initiative, was equally scathing: "So little progress after a whole year of minister meetings and negotiations is not only a wasted opportunity, it falls dangerously short of what is needed to protect people and nature from climate change."
Ben Wikler of AVAAZ, a group that champions environmental concerns, said: "The failure to act on 2020 targets is a failure to take responsibility, and our members around the world feel that there is a childishness to not taking responsibility."
The European Union is on record as wanting an agreement to require developed countries to cut their emissions by 25 to 40 percent of 1990 levels by 2020. The United States, Japan and Canada oppose those targets.
Previous efforts to prompt coordinated global action on climate change have stalled.
Ten years ago, the U.N. Framework Convention on Climate Change passed the Kyoto Protocol with the goal of limiting greenhouse gas concentrations in the atmosphere. The United States was the only one among 175 parties -- including the European Union -- to reject it. U.N. Secretary-General Ban Ki-moon gives his view »
Washington has long argued that China and India should be required to address their rapidly rising emissions. President George W. Bush opposed the Kyoto Protocol because it did not include strict emissions limits for China and India.
During the Bali conference on climate change last year, the United States reluctantly signed onto an agreement calling for two years of additional negotiations on reducing carbon dioxide emissions.
"The negotiations must proceed on the view that the problem of climate change cannot be adequately addressed through commitments for emissions cuts by developed countries alone. Major developing economies must likewise act," the White House said in a statement.The Bali pact is meant as a guide for more climate talks, which will culminate in Copenhagen, Denmark, in 2009.