Final answer:
Oil (petroleum) and natural gas are examples of fossil fuels, which also include coal. These are non-renewable energy sources from ancient organic matter, contributing to high carbon dioxide emissions upon combustion. The shift towards renewable energy sources is fueled by environmental concerns and climate change.
Step-by-step explanation:
Oil and natural gas are examples of fossil fuels. Fossil fuels are energy sources derived from the remains of ancient plants and animals that have been transformed over millions of years due to heat and pressure underground. They include forms like coal, oil (petroleum), and natural gas, which possess high hydrocarbon content. When these fuels are burned, they release the energy that was once captured by these organisms through the process of photosynthesis. Coal, for instance, started being used more extensively around the mid-19th century along with the rise of industrialization, followed by oil and later on natural gas.
Renewable energy sources contrast with fossil fuels, as they can be replenished within a human timescale and include solar, wind, and biomass energy. Fossil fuels have been the dominant source of energy but they are non-renewable and contribute to carbon dioxide emissions and consequently global warming. As a result, there's a growing shift towards renewable resources.