What is the difference between fossil fuel reserves and resources?

• A. Resources are the portion recoverable with current technology and economics; reserves are the total amount available.
• B. Reserves are the total amount available; resources are the portion recoverable now.
• C. Reserves and resources are identical concepts.
• D. Resources are the total amount available; reserves are the portion recoverable with current technology and economics.

Answer: (D)

The main idea is that resources are the total amount of fossil fuel that could exist or be discovered, while reserves are only the portion that can be mined or produced profitably with current technology and prices. Resources include both what’s already found and what might be found in the future, including portions that aren’t economical to extract right now. Reserves are a subset of that total—the part that is economically and technically viable to recover under present conditions. That’s why the statement that resources are the total amount available and reserves are the portion recoverable with current technology and economics is correct. If technology improves or prices rise, some of the resource that isn’t currently economical can become reserves.