Monetizing the impacts of ocean warming and acidification on shellfisheries of the United States and Canada

Anthropogenic greenhouse gas emissions are driving changes in marine environments and affecting marine fisheries. In the coming decades, ocean warming and acidification will cause changes in the habitable range and stocks of commercially valuable shellfish species. This study estimates the monetary impacts to shellfish consumers in the US and Canada using an inverse demand and consumer welfare model. Taking harvest forecasts for 17 types of shellfish under two greenhouse gas emissions scenarios through the end of this century, we model consumer substitution patterns, changes in expenditures, and annual welfare impacts in shellfish markets. Finally, we use the welfare results to estimate a reduced form damage function that can be used in existing integrated assessment models for climate policy analysis. We find that US consumers experience damages far greater than Canadian consumers due to the relative size of the markets in each country and differences in habitat suitability as waters off the coasts of both countries become warmer and more acidic. The net present value of impacts through 2100 to US consumers is about $11.3 billion USD and $850 million USD for Canadian consumers. Our model results also allow us to monetize the impacts of warming and acidification separately, showing that most of the consumer welfare impacts are attributable to warming and a small fraction of total damages can be attributed to acidification.