NAIROBI, Kenya - A Kenyan environmentalist and Nobel Peace Prize winner called on people around the world to plant 1 billion trees in the next year, saying Wednesday the effort is a way ordinary citizens can fight global warming.

Wangari Maathai, who in 2004 became the first black African woman to win a Nobel in any category, urged participants to ensure the trees thrive long after they are planted.

"It's one thing to plant a tree, it's another to make it survive," said Maathai, who founded Kenya's Green Party in 1987 and focused on planting trees to address the wood fuel crisis here.

Maathai said the campaign is meant to inspire ordinary citizens to help the environment.

"This something that anybody can do," Maathai said Wednesday at the U.N. conference on climate change, which has drawn delegates from more than 100 countries to Kenya.

Scientists blame the past century's 1-degree rise in average global temperatures at least in part on the accumulation of carbon dioxide, methane and other heat-trapping greenhouse gases in the atmosphere — byproducts of power plants, automobiles and other fossil fuel burners.

Africa is the continent expected to suffer most from shifting climate zones and droughts, like the one now in its fourth year in East Africa.

Destroying trees through burning contributes to global warming, releasing about 370 million tons of greenhouse gases every year — about 5 percent of the world total — scientists say. Planting trees can offset climate change in part because they absorb carbon dioxide.

The tree-planting project, organized by the        United Nations Environment Program, shows that "action does not need to be confined to the corridors of the negotiation halls," said Achem Steiner, UNEP's executive director.

The project calls on participants — including individuals, schools and governments — to sign up on UNEP's Web site and register the trees they planted.

Also Wednesday, some climate conference participants said the results of Tuesday's midterm elections in the United States were a good sign for environmental issues. The U.S. — the world's biggest emitter of greenhouse gases — has rejected mandatory emissions cuts, saying they could hamstring the economy and because poorer countries are exempt.

On Tuesday, Americans swept Democrats into power in the House of Representatives for the first time in a dozen years and largely dismantled the GOP Senate majority.

"        President Bush still has two more years in office so it's very unlikely that the U.S. negotiating posture will change," said Alden Meyer of the Union of Concerned Scientists.

But, he said, the fact that Democrats, many of whom support emissions caps, took control of the House means climate and energy issues will be prominent in the 2008 presidential campaign.