Since the industrial revolution, the burning of coal, oil and gas has released millions of tonnes of carbon dioxide, methane, and other greenhouse gases into the atmosphere, causing global warming. By 2020, the Earth's average temperature had risen by over 1°C since pre-industrial levels. The United Nations Intergovernmental Panel on Climate Change has calculated that continuing to burn coal, oil, and gas reserves will heat the planet by between 0.8 degrees to 2.5 degrees, per 1000 gigatonnes of burning carbon and there are 2900 gigatonnes of carbon in proven reserves. Burning a fraction of the coal, oil, and gas reserves will therefore lead to uncontrollable planetary heating, resulting in widespread crop failures, and the 6th mass extinction event. By the end of 2019, there had been increasing incidents of wild fires in Australia, the Amazon rainforest in Brazil, and the Arctic forests in Russia, as well as increased risks of hurricanes in the United States and Caribbean, and flooding. In 2015, the vast majority of countries signed the Paris Agreement committing to limit global carbon emissions to prevent temperature rises by over 2 degrees, with an ambition to limit temperature rises to 1.5 degrees. Activists and politicians, particularly younger people, have become increasingly vocal in demanding a "Green New Deal" in the US, or a Green Industrial Revolution in the UK, to end the use of fossil fuels in transport, energy generation, agriculture, buildings, and finance. In late 2019, the EU announced a European Green Deal, although this was said to fall far short of the goal of ending fossil fuel use in the bloc by 2050.