Nature’s way of recycling carbon atoms. In this process, carbon atoms continually travel from the atmosphere to Earth and then back into the atmosphere. Carbon is released when organisms die, volcanoes erupt, fires blaze, fossil fuels are burned, and through a variety of other mechanisms. Humans play a major role in the carbon cycle through activities such as burning fossil fuels or land development. This surplus of carbon dioxide changes our climate, increasing global temperatures, causing ocean acidification, and disrupting the planet’s ecosystems. Carbon dioxide is removed from the atmosphere by phytoplankton (microscopic organisms in the ocean) and plants. Because of deforestation, the absorption cannot keep up with rising carbon levels.