Natural resources include air, water, plants, animals, soil and energy sources like fossil fuels and sunlight. Fossil fuels like coal, oil and natural gas were formed over millions of years from the remains of ancient organisms. They are non-renewable resources that are being depleted. There are three main types of environmental pollution - air, water and soil pollution, which are caused by human activities and harm the environment, wildlife and human health. Major pollutants include greenhouse gases that cause issues like global warming, and waste and chemicals that contaminate air, water and soil.