A nice move by Jet Blue. You can use a calculator on a partner site to work out the carbon cost of your trip, and then make a contribution to cover that cost through a carbon off-set. I like the opt-in nature of this. Jet Blue are not hiding from their business being a polluter, but nor are they shaming anyone or forcing the issue. If you care, here is something you can do about it. The airline is also taking part in other green programs. Smart thinking and something you expect and welcome from the Jet Blue brand.