Final answer:
Fossil fuels are exhaustible because they form over millions of years and are being consumed at a pace faster than they can be replaced. With oil and natural gas projected to run out in 60 and 120 years, the need to transition to alternative energy is urgent.
Step-by-step explanation:
Fossil fuels are exhaustible natural resources because they are formed over millions of years from plant and animal remains and cannot be replenished on a human timescale. As we continue to extract and consume them at a rapid rate, the finite supply of fossil fuels is declining. As of now, fossil fuels such as coal, oil, and natural gas still dominate our energy consumption, particularly in transportation. However, we are already facing challenges with the depletion of oil and natural gas, which are projected to exhaust in about 60 and 120 years respectively.
The problem is compounded by the reality that we have not yet created a comprehensive plan for a post-fossil-fuel future, despite the necessity to shift towards alternative energy sources. This transition is critical not only because of the exhaustion of our fossil fuel inheritance but also due to the climate change implications of their use. Fossil fuels are also tightly interwoven with our infrastructure and economy, which makes the conversation about sustainability and transition even more pressing.