Carbon is a building block for life on Earth and is found in many different forms. It cycles through living creatures, water, soil, and the atmosphere in a variety of forms. Carbon from living sources (plants and animals) is known as organic carbon. This organic carbon may fill soil with nutrients, dissolve in water, or become buried fossil fuel. Carbon can also be found in a gaseous form, namely CO2 (carbon dioxide). Carbon dioxide can be released from animals during respiration and absorbed by plants during photosynthesis. It is also released by human activities that burn fossil fuels. The accumulation of carbon in the atmosphere is a driving factor behind global warming because it leads to the greenhouse gas effect. To minimize the carbon dioxide released into the atmosphere we can protect plant ecosystems that sequester carbon and stop removing stored carbon from the earth in the form of fossil fuels, instead relying on renewable energy sources.