Australia’s Great Barrier Reef, one of the largest living organisms is the world, is facing increasing threat from anthropogenic climate change. It is predicted that at just 1.5 degrees warming, 70-90% of coral reefs will be extinct, causing widespread environmental, economic and societal harm. It is not well understood, however, what the effect of losing the Great Barrier Reef will be on local climate. Marine organisms, including corals and their symbionts, produce the chemical dimethyl sulfide (DMS). DMS, when released into the atmosphere, can interact with radiation, cloud and precipitation via aerosol effects. Coral reefs have been shown to produce significant amounts of DMS, however, the importance of this source of atmospheric sulfur on climate has not previously been quantified. In this work, we use a chemistry-climate model to determine the influence of this aerosol source on climate. With this method, we can infer possible climatic impacts of mass coral extinction. Preliminary results indicate the loss of the Great Barrier Reef, in today’s climate, would cause large seasonal changes in precipitation over Queensland. These results are hypothesised to be caused through changes in large scale atmospheric circulation, as opposed to indirect aerosol effects. Whilst more research is necessary, we suggest that the extinction of coral reefs may have further implications than we currently realise.