Carbon is the backbone of life on Earth. We are all carbon-based life forms. Most of Earth’s carbon is stored in rocks while the rest of carbon on Earth cycles between the ocean, atmosphere, plants, soil, and fossil fuels. The constant flow of carbon between the reservoirs seen here is called the carbon cycle. Over the course of Earth’s lifetime, the carbon cycle seems to maintain a balance that prevents all of Earth’s carbon from entering the atmosphere or from being stored only in rocks.
During what scientists call the slow carbon cycle, carbon slowly moves between rocks, soil, ocean, and atmosphere in the slow carbon cycle. The movement of carbon through the slow cycle is the result of precipitation, chemical weathering, plate tectonics, and the rock cycle. It takes somewhere between 100-200 million years for carbon to move through the slow cycle. Conversely, the fast carbon cycle is measured not in millions of years but in life spans. The fast carbon cycle is the movement of carbon through life forms on Earth, or the biosphere. It is primarily fueled by photosynthesis.
Throughout Earth’s history, the fast and slow carbon cycles have maintained a relatively steady concentration of carbon in the atmosphere, land, plants, and ocean. But when anything changes the amount of carbon in one reservoir, that change can be felt in the others. What or who has had the biggest impact on the carbon cycle? People. We alter the carbon cycle by burning fossil fuels and clearing land.
Without human combustion, the carbon in fossil fuels would leak slowly into the atmosphere through volcanic activity over millions of years in the slow carbon cycle. By burning fossil fuels we accelerate the process, releasing vast amounts of carbon into the atmosphere every year. When we clear forests, we remove a dense growth of plants that had stored carbon as biomass. By removing a forest, we eliminate plants that would otherwise take carbon out of the atmosphere as they grow. Emissions of carbon dioxide by man from the burning of fossil fuels have been growing steadily since the industrial revolution. About half of these emissions are removed by the fast carbon cycle each year, the rest remain in the atmosphere. Human activity, therefore, is moving carbon from the slow cycle into the fast and as a result, altering the dynamics of Earth’s geochemical and biological balance.
The major source of imbalance in the carbon cycle is the result of
Responses
A human activities.human activities.
B volcanic activity.volcanic activity.
C shift in Earth's orbit.shift in Earth's orbit.
D changes in weather patterns.changes in weather patterns.