According to scientists Greenland has lost 3.8 trillion tonnes of ice since 1992. All that ice making its way into the ocean has already caused the sea level to rise by more than a centimetre. Greenland alone holds enough frozen water to raise the sea by 7.4 metres were it to melt. In Antarctica, almost all the losses come from glaciers being warmed to the point where they slide slightly faster into the ocean and “calve” into icebergs. This happens in Greenland too. But Greenland also has much warmer summers than Antarctica, and this means around half of its ice is also lost through summer melting exceeding winter snowfall. In summer 2019, unusually warm air caused widespread melting across the entire ice sheet. Global warming will cause "catastrophic" biodiversity loss across the world if greenhouse gas emissions aren't curbed, with some ecosystems liable to collapse as soon as 2030. Scientists predict that Earth is on course to heat up to four degrees Celsius by 2100.