In Earth’s past, the carbon cycle has changed in response to climate change. Ice ages developed when Northern Hemisphere summers cooled and ice built up on land, which in turn slowed the carbon cycle. Similarly, at the end of the last Ice Age, 10,000 years ago, carbon dioxide in the atmosphere rose dramatically as temperatures warmed.
- Today, changes in the carbon cycle are happening because of people through activities like burning of fossil fuels, clearing of land etc. Without human interference, the carbon in fossil fuels would leak slowly into the atmosphere through volcanic activity over millions of years in the slow carbon cycle.
- The changes in the carbon cycle impact each reservoir.
- Carbon dioxide molecules provide the initial greenhouse heating needed to maintain water vapor concentrations.
- When carbon dioxide concentrations drop, Earth cools, some water vapor falls out of the atmosphere, and the greenhouse warming caused by water vapor drops.
- Likewise, when carbon dioxide concentrations rise, air temperatures go up, and more water vapor evaporates into the atmosphere— which then amplifies greenhouse heating.
- Increase in CO2 concentrations not only leads to warmer oceans but also to more acidic oceans.
- Warmer oceans could also decrease the abundance of phytoplankton. This could limit the ocean’s ability to take carbon from the atmosphere through the fast carbon cycle
- Carbonic acid reacts with carbonate ions in the water to form bicarbonate. Ocean Acidification will convert more carbonate ions (which are required for shell building by marine organisms) into bicarbonates, the animals need to expend more energy to build their shells. As a result, the shells end up being thinner and more fragile.
- In the long run, this reaction will allow the ocean to soak up excess carbon dioxide because more acidic water will dissolve more rock, release more carbonate ions, and increase the ocean’s capacity to absorb carbon dioxide