From a Mail and Guardian article dated November 8th, 2006:
Kenyan Nobel Peace Prize laureate Wangari Maathai on Wednesday launched a massive drive aimed at curbing global warming and related environmental damage by planting a billion new trees by the end of next year.
On the sidelines of a key United Nations climate-change conference in Nairobi, Maathai announced the start in January of the Billion Tree Campaign to combat rampant deforestation, reverse desertification and reduce soil erosion.
Maathai won the 2004 Nobel Peace Prize for her work with the Greenbelt Movement, which she founded to promote human rights and sustainable development by planting trees first in her native Kenya, then throughout Africa and the world.
"In the year 2007 we shall target over a billion trees," said Maathai, the first African woman honoured by the Nobel committee, noting that trees provide natural protection against the effects of climate change.
"We want to commit ourselves to action and we want to call the whole world to participate in this action," she said, calling on the people around the world to get their hands dirty while diplomats haggle over treaties.
"We know the signs and we know the data ... but what is really important even long after this conference is what we do," Maathai said. "That is why this campaign is so important."
Trees are key to reducing the amount of carbon dioxide in the atmosphere generated by the use of fossil fuels and every year an average tree converts 12kg of the gas into enough oxygen for a family of four per year, according to the UN.
But, replacing trees lost by deforestation over the past decade will require planting an area the size of Peru, a task equivalent to planting 14-billion trees every year for a decade, the UN says.