What do Al Gore, Rupert Murdoch, and the Rolling Stones have in common? They are all advocates of being "carbon neutral," the New Oxford American Dictionary's Word of the Year for 2006.
Being carbon neutral involves calculating your total climate-damaging carbon emissions (your "carbon footprint"), reducing them where possible, and then balancing your remaining emissions, often by purchasing a carbon offset: paying to plant new trees or investing in "green" technologies such as solar and wind power.