This week has seen record-breaking temperatures across Europe, with highs of 40 degrees being experienced in several countries for the first time.

At the same time, another 'first' occurred, with 225,000 commercial flights being recorded.

Environmental journalist John Gibbons thinks it's no coincidence.

He says that aviation is "one of the fastest growing sources of emissions", and that each individual flight is generating hundreds of tonnes.

Can the environmental cost of air travel be justified, and do we need to modify our habits?

John says: "I think we as individuals really need to understand the limits of the system that we're operating inside and we've got to act according to them."

Listen to the interview in full by pressing the play button on this page.