A-68 iceberg, the largest iceberg on the planet. It is some 160 kilometres long and weighs around 1 trillion tonnes with a surface area of 5,800 square kilometres. It broke off the Larson C ice shelf in July 2017. Ice shelves are collapsing rapidly due to climate change. They are attacked on three fronts, by warmer air above, by increased rainfall, and by warmer ocean currents from below.