Why are fossil fuels classified as non-renewable sources of energy? What steps should be taken to conserve these sources?

(N/A) Fossil fuels are formed from the remains of prehistoric plants and animals buried deep under the earth millions of years ago.
They were covered by sediments like mud and sand in the absence of oxygen.
Under high pressure, high temperature, and the action of anaerobic bacteria, these remains were converted into coal, petroleum, and natural gas over millions of years.
Since these specific conditions are not currently prevailing, no new fossil fuels are being formed.
Therefore, they are classified as non-renewable sources of energy.
Steps to conserve these fuels include:
$1$. Use alternative energy sources such as solar energy, wind energy, tidal energy, geothermal energy, and biomass energy.
$2$. Follow the principle that "Energy saved is energy produced."
$3$. Use energy judiciously by switching off lights and fans when not in use.
$4$. Use energy-consuming appliances like geysers and electric irons carefully.
$5$. Reduce the use of private motor vehicles; instead, use public transport or carpool to save fuel.