Pollution harms the soil, water and air by introducing materials that make it difficult for natural renewal processes to occur, by harming wildlife and by contaminating the atmosphere with harmful gases that contribute to the possibility of a runaway greenhouse effect. Pollution can occur in many forms, but recycling material and conserving energy can curb the effects of pollution.
One common pollutant of soil is industrial waste. This includes chemicals and solid waste. These products seep into the soil and chemically alter it so that it cannot support the growth of vegetation. What vegetation does grow is often tainted by the presence of harmful chemicals and can harm herbivores that try to eat it.
Water pollution makes it more difficult to treat water and make it potable for humans. It also harms the ecosystem of marine life, because fish and other aquatic animals require a delicate pH balance in the water to survive and thrive. Amphibious animals like turtles can be injured by some trash, like birds getting wings caught in plastic rings used to hold soda cans.
Air pollution, such as carbon monoxide and methane, contributes to the greenhouse effect. The atmosphere has a natural blanket effect to provide Earth with warmth from the sun. The addition of greenhouse gases makes it more difficult for heat and light to reflect back into space, heating Earth more than is suitable for many ecosystems.