According to National Geographic, non-renewable energy sources, such as fossil fuels, are energy dense and easy to extract and transport, but the ecological damage caused by burning such fuels makes them a dangerous option for the future of life on Earth. In addition, non-renewable energy sources are by definition limited, and the supplies will eventually run out if humanity continues to use them at current rates.
Fossil fuels come from the carbon in plant and animal remains, and store a large amount of energy due to the chemical changes caused by pressure and heat over millions of years. This is why most vehicles on the road use petroleum-based fuels, and why most electricity in America comes from coal or natural gas generation. Renewable sources offer cleaner energy, but it can take a large number of windmills or solar panels to equal the electricity generation capacity of a single fossil fuel-fired plant. In addition, extracted coal or oil from the ground can be shipped anywhere in the world for later use, while renewable energy facilities must be built in one place and the energy transmitted in the form of electricity. However, burning fossil fuels releases carbon that was trapped for millions of years underground, increasing the carbon dioxide content in the atmosphere and increasing the greenhouse effect.