Trees Are Nature's Climate Air Conditioners, Study Finds
by Jeremy Elton Jacquot, Los Angeles
on 11. 1.08

Image from twoblueday
If you're reading this, I probably don't need to waste my time trying to convince you that trees are great. They absorb carbon dioxide, they can be used to power small remote sensors and they're pretty darn nice to look at too. Now a new study by a team of scientists from Germany and the UK has discovered another beneficial property: they can block out the sun (and not just by providing shade), as The Guardian's David Adam reports.
Terpenes make forests nature's "climate air conditioners"
Boreal trees in countries like Canada, Scandinavia and Russia release chemicals known as terpenes that help thicken the clouds above them, producing an albedo effect that causes more sunlight to be reflected back into space. Terpenes, which are the major components of the essential oils found in many types of plants, have often been used as flavor additives for food, as fragrances for perfumes and in alternative medicine for aroma therapy. Some scientists think the trees may release them to protect themselves from air pollution or even to communicate (!).
Cutting down trees could be a double whammy for the climate
Dominick Spracklen, one of the study's leaders and the author of a forthcoming article in the Royal Society journal Philosophical Transactions A, believes this function makes trees the planet's "air conditioners." As a result, he says that cutting down trees could worsen climate change to a larger degree than was previously thought, and that protecting them, and planting new ones, should be one of our primary climate mitigation measures.
Adam explains the underlying sciences:
The 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 1,000m above the forests, and would reflect an extra 5% sunlight back into space.
Discovery means trees could act as negative feedback on the climate
This may not sound like much but, as Spracklen puts it, every little bit helps. Since trees release more terpenes under warmer conditions, Spracklen and his colleagues think forests could act as a negative feedback on climate, weakening the impact of rising temperatures. While mainly found in forests of pine and spruce trees, they said that most other trees produced the chemicals as well (though maybe not as much) so the cooling effect should also be seen elsewhere.
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nice photo
When we drive from our small town to our farm, which is surrounded by forest, the temperature drops more than 6 degrees along the way. The closer we get to the treed area, the cooler it gets. In the winter, with the deciduous trees' leaves gone, this does not happen. Instead the parts of the forest with coniferous trees are warmer since their needle filled branches screen out the cold and wind.
I always knew that trees were good. Makes me mad when trees are cut down to make way for farmlands and cities. Trees are home to a host of aminals, birds and insects!
Trees stole my family.
Other research shows that forests are very effective at absorbing the sun's energy, and thus warm the planet more than if they were not there. Without the green canopy, more of the light that does reach the trees would be reflected into space, instead of absorbed and converted into heat.
Ironic that Terpenes, a waste product released by trees, is to be regarded as somehow morally superior to other particulate polution released by factories which also is documented to encourage cloud formation.
This is an interesting study, but don't trees need sunlight to live? Why would they produce a substance that decreases their access to sunlight? Curious. I wonder if plants, especially grasses do the same.
This was taught in my text books at grade school...like alot of things scientists are "discovering"...these days.
Did they (and everyone else) just forget all this?
I mean my text books didn't say it in so many words, but they talked about how trees create their own sorts of climate in areas.
This reminds me of scientists "discovering" that trees help keep the air cleaner.
Seriously...what gives?