Acid rain from SOx and NOx emissions from fossil fuel combustion has resulted in the acidification of components of the hydrosphere, harming surrounding ecosystems. The emission of sulfur dioxide and nitrogen oxides to the atmosphere by human activities primarily fossil-fuel burning has led to the acidification of rain and freshwater aquatic systems. Humans have a huge effect on the carbon cycle when we burn wood, fossil fuels (such as oil, coal, and natural gas), and other forms of carbon. This action releases the stored carbon into the atmosphere, where it becomes a greenhouse gas. Greenhouse gases are gases in the atmosphere that absorb and release heat. The interaction between the carbon cycle and the hydrosphere (water cycle) contributes to the cycling of carbon in several ways: Dissolution and Carbon Dioxide Exchange: Carbon dioxide (CO2) is a key component of the carbon cycle. It's absorbed by water bodies, such as oceans, through a process of dissolution. The burning of fossil fuels, which rapidly releases carbon dioxide (CO2), a greenhouse gas into the atmosphere, increasing average global temperatures and causing ocean acidification. Agricultural activities that release carbon dioxide and methane (CH4, a greenhouse gases) into the atmosphere. Increasing carbon dioxide levels may increase photosynthesis rates in some plants, but this can also make plants less nutritious. Increasing average global land and ocean temperatures and changes in precipitation patterns also affect plant and algae growth, and can make certain species more susceptible to disease. The carbon dioxide that humans release to the atmosphere by burning fossil fuels is increasing the acidity of the ocean. This phenomenon is ocean acidification, impacts marine life and the people who depend on them. Plants constantly exchange carbon with the atmosphere. Plants absorb carbon dioxide during photosynthesis and much of this carbon dioxide is then stored in roots, permafrost, grasslands, and forests. Plants and the soil then release carbon dioxide when they decay. Plants absorb carbon from the environment in photosynthesis and return it in respiration. Animals obtain their carbon by eating plants; they release carbon in respiration. Microorganisms return carbon to the environment when they decompose dead plants and animals. The two cycles interact directly where carbon is transported dissolved or suspended in running water. Transport of weathering products and organic matter from the continents to the oceans is an important aspect of carbon cycling which is directly linked to water flux.