A natural resource that is considered non-renewable is "fossil fuels," which include coal, oil, and natural gas. These resources are formed over millions of years from the remains of ancient plants and animals subjected to heat and pressure underground. Non-renewable resources are limited in supply, meaning they cannot be replenished within a human timeframe. The extraction and consumption of fossil fuels contribute significantly to energy production but also raise concerns regarding environmental impact, greenhouse gas emissions, and climate change.