More great news about trees!

We already know that trees are good for the environment - they remove carbon from the atmosphere, helping to reduce global warming.

It now turns out they are even better for the environment than we thought!

COFORD , the National Council of Forest Research and Development (Ireland) have recently announced in their Forestry and Wood December update 2008 that a chemical released by trees can help to cool the planet.

Scientists from the UK (Institute for Climate and Atmospheric Science at Leeds University) and Germany have discovered that trees release a chemical that thickens clouds above them, thereby reflecting more sunlight and cooling the Earth.

One of the scientists, Dominick Spracklen said ""We think this could have quite a significant effect. You can think of forests as climate air conditioners."

The chemicals are Terpenes (which give pine forests their distinctive smell) and there release had puzzled scientists for years, with some believing that the trees released them to communicate, while others say they could offer protection from air pollution.

The research team found the terpenes react in the air to form tiny particles called aerosols. The particles help turn water vapour in the atmosphere into clouds. Spracklen said the team's computer models showed that the pine particles doubled the thickness of clouds some 1,000 m above the forests, and would reflect an extra 5% sunlight back into space.

He said: "It might not sound a lot, but that is quite a strong cooling effect. The climate is such a finely balanced system that we think this effect is large enough to reduce temperatures over quite large areas. It gives us another reason to preserve forests."

Because trees release more terpenes in warmer weather, the discovery suggests that forests could act as a negative feedback on climate, to dampen future temperature rise. The team looked at forests of mainly pine and spruce trees, but Spracklen said other trees also produce terpenes so the cooling effect should be found in other regions, including tropical rainforests.

So trees not only remove Carbon from the atmosphere but also thicken the clouds above them, helping to further reduce global warming.

Read the full COFORD document here