The reason why is because global fossil fuel consumption is on the rise, and new reserves are becoming harder to find. Those that are discovered are significantly smaller than the ones that have been found in the past.

Oil: Consumption (Predictions): Over 11 Billion tonnes Annually. If we carry on as we are, our known oil deposits could run out in just over 53 years.

Gas (Predictions): If we increase gas production to fill the energy gap left by oil, our known gas reserves only give us just 52 years left.

Coal: Although it’s often claimed that we have enough coal to last hundreds of years, this doesn’t take into account the need for increased production if we run out of oil and gas, our known coal deposits could be gone in 150 years.

For example, oil reserves are a good example: 16 of the 20 largest oil fields in the world have reached peak level production – they’re simply too small to keep up with global demand.

During the year of 2015, fossil fuels made up 81.5% of total U.S. energy consumption. The number is most likely increasing every year.

(fyi: the graph provided is showing future energy reserves for coal, gas and oil. approxiamately.)