Swiss Alps postcards sent to world leaders, calling for climate change fight

Copies of a postcard calling for action against climate change are seen on the Aletsch glacier under Jungfraujoch in Switzerland, on March 20, 2019. Some 900 postcards from youths all over the world were stamped and sent on Wednesday from Europe's highest postbox on the Jungfraujoch peak, Switzerland, to global leaders, calling for action against climate change. (Xinhua/Xu Jinquan)