Air travel is the fastest growing source of greenhouse gas emissions and this hasn’t gone unnoticed: the Institute for Public Policy Research (IPPR) is urging the UK government to introduce cigarette-style health warnings on all advertising for air travel warning that “Flying Causes Climate Change.” The UK’s Tory party has crafted a “Greener Skies” plan which includes such radical proposals as imposing a personal flight allowance.

We talked to travelers at London’s Heathrow Airport and found that in the age of cheap seats, not too many were prepared for a “Green Air Miles Allowance” or any kind of radical change in their traveling behavior.