Travelling by plane has never been more popular, with four billion passengers flying every year. But aviation emissions contribute to climate change, and scientists say we need to do more to tackle the problem.
1. What do you know about global warming? Are you concerned about the problem?
2. Specify different ideas you can do to reduce emission of carbon footprint when you fly.
3. Had you ever heard about "carbon footprint" before? What are your impressions?