Language
Country/Area
No result found
The mystery of the ocean carbon cycle: How does it affect global climate?
The marine carbon cycle refers to the exchange of carbon within the ocean and between it and the atmosphere, the Earth's interior, and the seafloor. This complex and multifaceted process involves a range of natural interactions that enable carbon to flow around the globe, ensuring it is available for use by all forms of life. As global climate change intensifies, the ocean carbon cycle not only affects the marine ecosystem, but also has a profound impact on climate change.
The ocean carbon cycle is the core process of the global carbon cycle, which includes two forms of inorganic carbon and organic carbon, and flows carbon through the conversion between living and non-living matter.
The three main processes, or "pumps," of the ocean carbon cycle are by which carbon dioxide from the atmosphere is absorbed into the ocean and then exchanged and distributed within the ocean. The three pumps are: the dissolution pump, the carbonate pump and the biological pump. The short-term active carbon pool on Earth’s surface is estimated to be approximately 4 trillion metric tons of carbon, of which 95% (about 38,000 Gt C) is stored in the oceans, primarily in the form of dissolved inorganic carbon.
Ocean plants and algae (primary producers) contribute the largest annual carbon flows. And even though marine life stores relatively little carbon (about 3 GtC) compared to terrestrial vegetation, these organisms exchange almost the same amount of carbon—about 50 GtC each.
The ocean carbon cycle works in a very delicate way. It not only regulates the acidity and alkalinity of the water, but also affects the concentration of carbon dioxide and its presence in the atmosphere. As human activities increase, the ocean's absorption of carbon has shown significant changes. According to reports from NASA, the World Meteorological Organization, the IPCC and other organizations, before the Industrial Revolution, the ocean was a major source of carbon dioxide, but now it has become a major carbon sink.
In recent decades, the ocean has acted as a sink for anthropogenic carbon dioxide, absorbing about a quarter of the carbon dioxide produced by humans through fossil fuel burning and land-use changes.
However, although the ocean's absorption of carbon dioxide has slowed down the growth of carbon dioxide in the atmosphere to a certain extent, it has also led to ocean acidification. The effects of climate change are becoming increasingly evident, with rising temperatures in the oceans and atmosphere. The slowdown in global warming from 2000 to 2010 may be linked to an increase in upper ocean heat.
The operation of the ocean carbon cycle is not only related to carbon, but also closely linked to the cycles of nitrogen and phosphorus, with the approximate ratio of C:N:P being 106:16:1, which makes the carbon and nitrogen and phosphorus uptake of the biological community Becoming quite regular.
In this cycle, carbon in the ocean can be divided into organic carbon and inorganic carbon. Inorganic carbon mainly exists in the form of carbon dioxide and its derivatives, while organic carbon originates from the production processes of marine organisms. The ocean's biological pump converts inorganic carbon into organic carbon through biological production, which can then be consumed or sink to the seafloor. The complexity of this process and the diversity of life forms all guide the flow of carbon.
However, today's human activities have interfered too much with this natural balance. Whether it is overfishing or plastic pollution, they pose a challenge to the ocean carbon cycle. Overall, the intensification of human impacts has led to a potential weakening of the ocean's carbon absorption capacity, and the ocean in the future may not be able to absorb carbon dioxide as effectively as in the past.
As changes occur in the ocean's carbon cycle, threatening the health of many ecosystems, are humans aware of the profound impacts of their actions on this system?
