The ocean is the world’s largest storage space for carbon, having absorbed about a quarter of all carbon dioxide emitted by humans since the 1960s. This absorption quality of the ocean has been known to researchers since the late nineteenth century, but the carbon storage cannot keep up with the rate at which we are emitting it and the storage rate is much more variable than previously understood.
A recent scientific review assesses the current knowledge of ocean carbon absorption, its variability, and driving factors, with contributions from research supported by the Climate Program Office’s Climate Observations and Monitoring (COM) Program. An international team of researchers, including COM-supported scientist Galen McKinley of Columbia University, found that the ocean’s carbon intake is proportional to human carbon dioxide emissions through time, but varies about 20% around this trend. The variation is due to changes in weather and climate at certain latitudes, along with large events external to the climate system like volcanic eruptions. The team also predicts that the total uptake will likely decrease in the future in response to effective climate policy and reduced storage capacity. The review, published in Nature Reviews Earth and Environment, argues that we need more observations and data to project the ocean’s future evolution in absorbing carbon and to support long-term decision making, especially for mitigation strategies. This project contributes to a COM-led initiative to develop marine and atmospheric datasets by combining observations and modeling methods.