By now, most of us know that we should be flying less. Travelling by aeroplane accounts for 2% of total global greenhouse gas emissions, and those 39.4 million annual flights pump out toxic nitrogen oxide, cancer-causing exhaust particulates and carbon dioxide; the latter of which absorbs heat and re-emits it back to earth.  

But for most people, completely quitting on flying is unlikely to be an option. So what can we do to reduce the impact of our aviation travel?