What are the costs if climate change increases the risk of extinction of plants and animals? What value can be placed on reducing the risk of extinction of the white rhinoceros or American pika? And do people consider these things valuable even if they will never see a white rhinoceros or a pika in person?

That value — the “existence value”— is one of the ecological costs being calculated by researchers at UC Davis and Fordham University in order to improve the models currently used to calculate climate change damages, what’s known as the social cost of carbon.

“Valuing the cost of greenhouse gas emissions is incredibly difficult, but it is important because agencies in the United States are required to do a cost-benefit analysis of major regulations,” said Frances C. Moore, an assistant professor in the Department of Environmental Science and Policy at UC Davis, and the principal investigator for the project.

Although the social cost of carbon is critical for understanding the benefits of climate policy, the science underpinning current estimates is less than solid.

pika with flowers in mouth

An endangered American pika. (Wikipedia Creative Commons)

“Much of the documented scientific basis for the model damage functions is 20 years old or more,” said Moore. “This means the current estimates of the social cost of carbon do not capture all that we now know about climate change impacts.”

To address these shortcomings, the research team received a $750,000 grant from the National Science Foundation’s Coupled Natural Human Systems Program.

“This project is trying to combine the ecological understanding of climate change — what the ecological effects are going to be in terms of changes in terrestrial vegetation and extinction risks of species — with valuation techniques from environmental economics,” said Moore.

Moore’s research focuses on the economic and social impacts of climate change. Earlier this year, she was lead author on a study using Twitter data that revealed people quickly normalize extreme weather related to climate change.

High stakes

The stakes for better assessing the impact of species and ecosystem loss are high. According to a 2019 United Nations report, the world is on track for an increase, not a decrease, in greenhouse gas emissions: about 10.7 percent above 2016 levels by 2030.

A separate 2019 United Nations report found that around 1 million animal and plant species are now threatened with extinction, many within decades. The same report found that three-fourths of the land-based environment and about two-thirds of the marine environment have been significantly altered by human actions.

Noted conservation scientist David Wilcove estimates that in the United States alone there are 14,000 to 35,000 endangered species, or about 7 to 18 percent of U.S. flora and fauna.

two female and one male scientists outside in front of a tree

Xiaoli Dong and Frances C. Moore, who are both assistant professors in the Department of Environmental Science and Policy at UC Davis, with Marc N. Conte, an associate professor in the Department of Economics at Fordham University, outside Wickson Hall at UC Davis. (Photo: UC Davis)

Marc Conte, an associate professor in the Department of Economics at Fordham University, and Xiaoli Dong, an assistant Professor in the UC Davis Department of Environmental Science and Policy, are co-investigators on the NSF grant.

The team hopes their work will yield a better tool to predict the real costs of climate change by including things that add value to the health of the planet but may not have an easy-to-calculate price tag.

Read more about this project at the UC Davis Office of Research website.


Lisa Howard is a writer with the UC Davis Office of Research. @LisaHwrd

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