Rapper Will.I.AM caused controversy in England earlier this week (begs21May12) by turning up for a climate change debate in a gas-guzzling helicopter.
The Black Eyes Peas star, who is in Britain as he films singing show The Voice, was the guest of honour at the U.K.'s prestigious Oxford University for a special talk on the environment.
He told the audience, "Climate change should be the thing that we are all worried and concerned about as humans on this planet, how we affect the planet, our consumption, and how we treat the place that we live in."
Will.i.am made the trip by air to save time as he was later due in Taunton, south-west England to carry the Olympic torch ahead of the London 2012 Games this summer (12) - but his method of transport to the climate talk was questioned by onlookers.
Climate expert Myles Allen tells Britain's Daily Star, "The irony didn't escape everybody. But he's committed to the issues and he's written songs about it."
Perry appeared on James Corden's 'The Late Late Show' on Monday and addressed her long-standing rivalry with Swift.