March 12 is China's 12th tree-planting day. A bulletin released by the National Greening Committee shows that more than 56 billion trees have been planted voluntarily over the past three decades.

China is now the world's leading tree planter. This is also a hot subject at the ongoing political sessions in Beijing where NPC deputies and CPPCC members have proposed a new term "forest carbon sinks".

Forest Carbon Sinks are a natural or manmade forest of trees that accumulate and store carbon dioxide from the atmosphere, helping reduce the gases that lead to global warming.

As the forest gets larger, the amount of carbon absorbed into the Forest Carbon Sink also increases.

CPPCC member Liu Xiuchen said, "The amount of carbon dioxide in the world has increased five-fold. The most effective way to deal with this is to plant more trees."

A one cubic meter increase in leaf cover in a forest absorbs 1.83 tons of carbon dioxide, and releases 1.62 tons of oxygen. Therefore, afforestation is the most economic way of reducing the amount of carbon dioxide in the air.

China established a carbon dioxide sink office affiliated to the State Forestry Bureau in 2003.

Li Nuyun, vice director of State Forestry Bureau,said, "The government has invested a lot of money to plant trees over large areas. Meanwhile, we have dedicated a lot to tackling global climate change through nationwide voluntary tree planting."

China promised at last year's Copenhagen climate meeting that its carbon dioxide emissions will reduce by around 40 percent to 45 percent by 2020 compared with 2005.

Deputies and members from the two sessions have also called for the establishment of a ecological benefit-sharing and related responsibility-taking mechanism.