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Unraveling the Unseen Players in the Ocean - A Field Guide to Water Chemistry and Marine Microbiology
Published on: November 5, 2014
The oceanic sink for anthropogenic CO2.
Christopher L Sabine1, Richard A Feely, Nicolas Gruber
1National Oceanic and Atmospheric Administration (NOAA) Pacific Marine Environmental Laboratory, 7600 Sand Point Way NE, Seattle, WA 98115, USA. chris.sabine@noaa.gov
Science (New York, N.Y.)
|July 17, 2004
Summary
The ocean absorbed 48% of human-caused carbon dioxide (CO2) emissions between 1800 and 1994. This research quantifies the oceanic CO2 sink and its role in mitigating atmospheric CO2 levels.
Area of Science:
- Oceanography
- Climate Science
- Biogeochemistry
Background:
- Rising atmospheric carbon dioxide (CO2) concentrations are a primary driver of climate change.
- Understanding the global carbon cycle, including oceanic and terrestrial sinks, is crucial for climate modeling.
- Previous estimates of oceanic CO2 uptake have varied, necessitating refined measurements.
Purpose of the Study:
- To quantify the global oceanic anthropogenic carbon dioxide (CO2) sink from 1800 to 1994.
- To determine the proportion of fossil-fuel and cement-manufacturing emissions sequestered by the ocean.
- To infer the net CO2 flux from the terrestrial biosphere during the same period.
Main Methods:
- Utilized inorganic carbon measurements from a global ocean survey conducted in the 1990s.
- Employed a tracer-based separation technique to distinguish anthropogenic CO2 from natural oceanic carbon.
- Calculated the cumulative oceanic CO2 uptake over the specified historical period.
Main Results:
- Estimated a global oceanic anthropogenic CO2 sink of 118 +/- 19 petagrams of carbon for 1800–1994.
- Determined that the oceanic sink absorbed approximately 48% of total anthropogenic CO2 emissions.
- Inferred that the terrestrial biosphere acted as a net source of CO2, releasing 39 +/- 28 petagrams of carbon to the atmosphere.
- Indicated that the ocean is currently storing about one-third of its long-term potential anthropogenic CO2 capacity.
Conclusions:
- The ocean plays a significant role in mitigating anthropogenic CO2 emissions, absorbing nearly half of emissions from 1800–1994.
- The terrestrial biosphere has been a net source of atmospheric CO2 during this period, contrary to some assumptions.
- The ocean's capacity to absorb anthropogenic CO2 is substantial, but current uptake represents only a fraction of its total potential.
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