With climate change intensifying and scientists warning that humanity is running out of time to limit global warming to 1.5°C over pre-industrial levels, 2021 has been a fraught year for the planet. The Emissions Gap Report 2021: The Heat Is On is the 12th edition in an annual series that provides an overview of the difference between where greenhouse emissions are predicted to be in 2030 and where they should be to avert the worst impacts of climate change.