A newly published scientific paper presents the radical notion that forests actually attract moist air from the oceans. In the past we have assumed that plants grow where the water falls, but there seems to be evidence that if you plant and sustain a forest it will bring in the moisture it needs.

Conversely cutting down a forest may reduce rainfall in the area by up to 90%.

The basis of the claims being made is that the cycle of evaporation and condensation produces far bigger changes in air pressure than previously  thought. The difference in air pressure at two points is what drives the flow of air from place ot place.

Of course it is early days yet in the discussion of this idea. However climate science at the moment is not able to explain all of our climate variability solely in terms of physics and has to resort to huge fudge factors to make prediction line up with reality- and even then the climate models tend to be highly inaccurate.

Commentators are suggesting that it's possible that covering large parts of Australia in trees would actually increase rainfall and diminish the arid areas.

If proven, this is a dilemma for the Greens of course. On the one hand it provides great motivation for tree planting. On the other hand, it suggests that CO2 is far less important in the determination of climate than previously thought and we will be able to give up on the futile push for costly "renewable" energy schemes.

If you want more technical details check Joanne Nova's blog