https://phys.org/news/2018-11-latest-climate.html > What are the most important actions the U.S. and other governments need to take if they want to ensure the planet does not exceed a 1.5 degrees Celsius increase? > Keeping global average warming to less than 1.5 degree Celsius (2.7°F) above 19th-century temperatures would require a radical and immediate transformation of global energy and agricultural systems in order to bring global net carbon dioxide emissions close to zero by 2050.