Approximately how long are fossil fuels going to last (at the present level of consumption) ?

Oil : about 50years

Gas: about 52years

Coal: about 114years

Explanation:

Oil

Globally, we currently consume the equivalent of over 11 billion tonnes of oil from fossil fuels every year. Crude oil reserves are vanishing at a rate of more than 4 billion tonnes a year, so if we carry on as we are, our known oil deposits could run out in just about 50 years.

Gas

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.

If we step up production to make up for depleted oil and gas reserves, our known coal deposits could be gone in 114 years.