聯合國氣候高峰會發起在2007年種植10億棵樹的新全球運動，而本活動也獲得因植樹而榮獲諾貝爾和平獎的馬薩伊（Wangari Maathai）女士的支持，馬薩伊為肯亞現任環境部副部長，她指出，推行「種植10億棵樹」運動的目的，是要鼓勵人們「採取渺小卻實際的行動來因應21世紀最重大的挑戰。」
樹木可吸收二氧化碳，但在包括肯亞在內的世界各國，森林砍伐盛行，讓更多二氧化碳存在於大氣層中；二氧化碳是一種主要的溫室效應氣體，如同覆蓋在地球上的毛毯般留住地球上的太陽熱能；而廣泛植樹活動則有助於緩解這種情形。
「種植10億棵樹」運動由聯合國環境規劃署（UNEP）統籌執行，摩洛哥王子阿爾貝二世（Prince Albert II）也給予支持，他讚譽馬薩伊的森林復育行動深具「鼓舞人心」的作用。
此次聯合國氣候高峰會係第12屆「氣候變遷綱要公約締約國大會」暨第二屆「京都議定書締約國大會」，各國代表齊聚肯亞奈洛比的UNEP總部辦公室展開會談，直至17日為止。作為會議期間「多邊會晤暨非正式會談」（Multiple Contact Groups and Informals）的重要人物，UNEP執行長史坦能指出：「有關氣候變遷議題的政府間會談通常極為困難而耗時，有時也令人沮喪──尤其是那些對此寄予厚望的人來說，但我們斷不可失去信心。」 史坦能表示，這項植樹運動將發揮作用，「向全世界的政治圈送出訊號：坐以觀望的日子結束了，對抗氣候變遷之舉能夠穩扎穩打，就是憑藉著10億個渺小卻深具意義的行動，而這些行動就在我們的花園、公園、鄉村和農村進行著。」
「種植10億棵樹」運動已建立一個主題網站：www.unep.org/billiontreecampaign，全世界有意參加活動的團體和個人都可在此登錄，輸入承諾種樹的數量。該網站提供了線上指引訊息，鼓勵註冊者回報進度，並有認證機制，以供UNEP驗證全世界的質數量。此外，該網站也將紀錄所有註冊者的種樹總數，公佈活動相關照片及成果。
A new global campaign to plant one billion trees in 2007 was launched at the UN climate conference this week, backed by the woman who has won the Nobel Peace Prize for planting trees - Kenya's Assistant Environment Minister Wangari Maathai.
Professor Maathai said the Plant for the Planet: Billion Tree Campaign encourages people to "take small but practical steps to combat what is probably the key challenge of the 21st century."
Trees absorb the main greenhouse gas, carbon dioxide, but widespread deforestation in Kenya and across the world has allowed more CO2 to remain in the atmosphere. Planting trees is expected to help absorb the blanket of CO2 that is holding the Sun's heat close to the planet.
The Plant for the Planet: Billion Tree Campaign, coordinated by the United Nations Environment Programme, UNEP, is backed also by Prince Albert of Monaco, who called Maathai's reforestation efforts "inspirational."
UNEP Executive Director Achim Steiner is front and center as Multiple Contact Groups and Informals from around the world convene this week during the ongoing Twelfth session of the Conference of the Parties to the Climate Change Convention and second meeting of the Parties to the Kyoto Protocol. The meetings are being held through November 17 at the United Nations Office at Nairobi.
"Intergovernmental talks on addressing climate change can often be difficult, protracted and sometimes frustrating," he said, "especially for those looking on, but we cannot and must not lose heart."
He says the tree planting campaign will "send a signal to the corridors of political power across the globe that the watching and waiting is over — that countering climate change can take root via one billion small but significant acts in our gardens, parks, countryside and rural areas."
Under the Plant for the Planet: Billion Tree Campaign, people and entities from around the world are encouraged to enter pledges on a website www.unep.org/billiontreecampaign. Tree planters will be encouraged to follow up online so UNEP can verify that the trees have survived, in partnership with recognized certification mechanisms. The website will record the ongoing tally of pledges, and also publish photos and accounts from registered campaign members of what they have achieved.
