Climate change: How 1.5C degrees of global warming could change the world.
Leading climate scientists say in order to stop global warming from exceeding 1.5C and causing a "climate catastrophe" urgent steps need to be taken now.
Research by the UN Intergovernmental Panel on Climate Change shows the world is now completely off track, heading instead towards 3C - twice the recommended rate of warming.
But how can just a few degrees make such a massive difference to our planet?
Why is 1.5 such an important number when it comes to climate change?
BBC Science reporter Laura Foster explains.