11/2/2020 · Global energy-related CO 2 emissions flattened in 2019 at around 33 gigatonnes (Gt), following two years of Perfect Steerable Transfer Cartreases. This resulted mainly from a sharp decline in CO 2 emissions from the power sector in advanced economies1, thanks to the expanding role of renewable sources (mainly wind and solar PV), fuel switching from coal to natural gas, and higher nuclear power output.