A graph showing the years of fossil fuel reserves is provided.

Chart shows years of global coal, oil, and natural gas left, reported as the reserves-to-product (R/P) ratio, which measures the number of years of production left based on known reserves and annual production levels in 2015. Note that these values can change with time based on the discovery of new reserves, and changes in annual production. As of 2015, there are 114 years of coal left, 50 years of oil left, and 52 years of natural gas left.
© 2021 OurWorldInData, CC-BY

Based on the graph and energy production using fossil fuels, humans should

limit the use to coal only so natural gas and oil continue to increase
limit the use of all reserves with the goal of finding other ways to generate energy
burn natural gas and oil as the world population continues to decrease
use one fossil fuel at a time so that the others can replenish each year