Fossil fuels

Carbon dioxide variations over the last 400,000 years, showing a rise since the industrial revolution.Beginning with the industrial revolution in the 1880s and accelerating ever since, the human consumption of fossil fuels has elevated CO2 levels from a concentration of ~280 ppm to ~387 ppm today.These increasing concentrations are projected to reach a range of 535 to 983 ppm by the end of the 21st century.It is known that carbon dioxide levels are substantially higher now than at any time in the last 750,000 years.[9] Along with rising methane levels, these changes are anticipated to cause an increase of 1.4–5.6 °C between 1990 and 2100 (see global warming).