Non-renewable energy refers to energy sources that cannot be replenished in a short time frame. These sources include fossil fuels like coal, oil, and natural gas, which are formed from the remains of ancient plants and animals over millions of years. Once extracted and used, they cannot be replaced quickly, leading to depletion. The use of non-renewable energy has significant environmental impacts, including air pollution and greenhouse gas emissions. As these resources are consumed, they contribute to climate change and other ecological issues. Transitioning to renewable energy sources, such as solar and wind power, is essential for sustainable energy practices.