Research brief: If dimethyl sulfide emissions ceased, Earth would warm 0.5C in a decade

The study finds important regional consequences for precipitation and clouds formation if large changes in dimethyl-sulfide emissions were to occur. In a hypothetical case where all marine DMS emissions cease completely, we find the Earth would warm by approximately 0.5 degrees C over a ten-year period.

Marine organisms such as phytoplankton produce a chemical (dimethyl sulfide or DMS), which when released in to the atmosphere can ultimately contribute to concentrations of tiny particles known as aerosols. Aerosols are an important part of our climate system, interacting with the energy balance of the earth and cloud formation. However, natural aerosol emissions are one of the largest sources of uncertainty in climate modelling, including those resulting from DMS.

In this study, a chemistry-climate model is used to probe the uncertainty bounds of DMS. The study finds important regional consequences for precipitation and clouds formation if large changes in DMS emissions were to occur. In a hypothetical case where all marine DMS emissions cease completely, we find the Earth would warm by approximately 0.5 degrees C over a ten-year period

Our results show that much better constraints on DMS (and marine aerosol in general) are required to improve climate simulations.

Paper: Fiddes, S. L., Woodhouse, M. T., Nicholls, Z., Lane, T. P., and Schofield, R.: Cloud, precipitation and radiation responses to large perturbations in global dimethyl sulfide, Atmos. Chem. Phys., 18, 10177-10198, https://doi.org/10.5194/acp-18-10177-2018, 2018.