UNEP announced their Plant for the Planet: Billion Tree Campaign today, an effort to help dampen global warning.

"Under the Plant for the Planet: Billion Tree Campaign, individuals, children, youth and community groups, schools, non-governmental organizations, business and industry, farmers, local authorities, and national governments are urged to plant trees as a small but practical step to combat what UNEP says is probably the key challenge of the 21st century. So far over 157 million tree planting pledges have been received." More

The campaign was inspired by 2004 Nobel Peace Prize winner Wangari Maathai of the Green Belt Movement in Kenya.

Get involved: Tree-planting pledges can be entered on the campaign website.