Movie and music pop stars often like to spout off about fashionable political causes.  But perhaps in an effort to offset all that hot air, a growing number of celebrities are planting trees as a way to neutralize their greenhouse gases.  According to the London Daily Telegraph, a British company is planting these trees around the world for 10 pounds a piece.  Actor Leonardo Dicaprio has planted thousands to offset the 11 tons of CO2 he produces in making his films each year, and even the Rolling Stones paid for a forest on the Isle of Sky to offset their emissions from a nine-day British tour.  But one has to wonder if there are enough trees in the world to cover Alex Baldwin and the Dixie Chicks.