Abstract
One hypothesis regarding global climate regulation by marine phytoplankton was proposed in 1987. This is called the CLAW hypothesis that describes the negative feedback loop through controlling the emission of biogenic sulfur compounds, dimethylsulfide (DMS) as responses to climate parameter changes such as solar radiation and sea surface temperature, resulting in controlling non sea-salt sulfate aerosols, cloud condensation nuclei (CCN) and cloud albedo, thus eventually mitigating the initial changes. However, verification of this hypothesis has not yet been concluded. This is mainly due to lack of our understandings both on the processes and responses described in this hypothesis, because of complexities in the processes of DMS production and loss in the seawater, and in those of aerosols and CCN formations in the atmosphere. In this paper, the progress of recent research on these processes and responses is briefly reviewed, and contribution of DMS to the climate regulation is discussed. Although research on climate regulation by DMS has not yet completed, on the basis of discussion with updated results, it can be concluded that this contribution is not sufficient to regulate the global climate.
