Climate activists set off on a three-day hike from Landquart in eastern Switzerland to the ski resort of Davos on Sunday to draw attention to global warming at the World Economic Forum this week.

Some were disguised as flowers or koala bears - a reference to the bushfires currently ravaging their habitat in Australia - and holding banners including: "Let's ignore the Donalds and listen to the Gretas", referring to U.S. President Donald Trump, and "Make the world cool again".