The earth has a limited supply of oil, gas and coal at least in practical terms. It takes millions of years for the earth to transform dead organic material into these fossil fuels. The supply of fossil fuels we are using today come from organic materials buried generally at least 20 million years ago, and some that were buried more than 200 million years ago.
This is different from renewable materials, like wood, that can be planted again, so the supply can be renewed.
Fossil fuels are considered non-renewable sources of energy because when they are burnt, they are finished. When the last barrel of oil has been pumped out of the ground there is no more. It is non-renewable. Similarly with coal and natural gas.
The origins of most fossil fuels is over 60 million years old, from the dinosaur age (Mesozoic Era) and the carbon age (within the Paleozoic Era). When that supply is gone it is gone forever so it is a non renewable resource.
Renewable fuel grows back or can not be depleted.
- Wind can't be stopped it will always blow.
- Trees grow back if we allow them.
- Oil is under the ground and once it is gone it is gone.
Because fossil fuels take hundreds of millions of years to form under the Earth's surface. It will take another million years for more to be produced, so we only have a limited supply.
Eventually, more fossils will be made, but by then we will have run out by how much we use them now. If we stop using them so much than we wont die like we are going to.
So essentially, all fossil fuels are considered non-renewable.
Fossil fuels are considered nonrenewable resources because,
fossils fuels are made from the remains of dead plants or animals.
It takes more than a million years for the fuels to form from the
fossils. It is a long process.
They take millions of years to form.
Humans cannot produce them or cause them to reproduce. Trees, corn and other organic matter for ethanol can be grown. Oil and coal are a product of the planet and take millions of years to form.