Why is oil a nonrenewable energy resource?
The natural forming of oil is slower than the rate of consumption
Oil is a carbon based fuel that forms when plant and animal remains are exposed to extreme conditions such as high pressure (eg under a mud layer on the ocean floor.) for thousands of years. Therefore the oil we use today took millennia to form. Currently our dependence on oil to produce petrol etc. has increased to the extent that we are using up the oil faster than the earth can produce more oil. Furthermore most oil-based products (such as petrol) are burnt in their usage. This releases carbon gasses into the air which we are unable to recycle to create more oil.