The United Nations says 2021 must be the year of climate action ahead of US President Joe Biden’s virtual international climate summit at the end of this week. Biden invited 40 world leaders to take part in the climate talks as he tries to put climate action at the forefront of the international political agenda. The UN says despite initial optimism, the COVID-19 pandemic has failed to slow down global warming and the world is now running out of time to make a change.