More than 20 km shorter: that's how much Columbia Glacier in #Alaska has retreated in the last 30 years. But there is some good news: read it here 🗻🛰️🌍https://t.co/KUGoxGsFUi pic.twitter.com/xiBSvGrJki

— ESA EarthObservation (@ESA_EO) May 11, 2018