There are over 860 billion tonnes of proven coal reserves worldwide. This means that there is enough coal to last us around 118 years at current rates of production.  In comparison to this, proven oil and gas reserves are equivalent to around 46 and 59 years at current
production levels. Coal outlasts oil and gas combined.

Coal reserves only include what is considered economically recoverable at any given time, taking into account available mining technology and costs. Coal resources, on the other hand, include all potential coal deposits. Coal resources are around 17 times
larger than coal reserves and account for over two thirds of all non-renewable energy sources, including conventional and non-conventional hydrocarbons, such as oil and gas. Coal is simply the world’s most abundant energy fuel.