A new study from researchers at MIT has concluded that if China follows through on its climate policies targeting the reduction of CO2 emissions, the monetary savings stemming from air quality and human health will greatly exceed the cost of meeting those goals in the first place.
The new study, Air quality co-benefits of carbon pricing in China, published in the journal Nature Climate Change this week, was authored by four experts from MIT which included a mix of economists and atmospheric scientists. The study focused on analyzing the air quality co-benefits of reducing CO2 emissions in a country like China, and comparing them to the economic costs of climate policy. The researchers estimated that by meeting its greenhouse gas emissions reduction target, China would not only improve its air quality and meet international climate standards, but would simultaneously reduce deaths due to air pollution across every province in the country. Reducing deaths from pollution would produce a specific benefit to society, estimated at $339 billion in savings in 2030, that would be approximately four times the cost of meeting the emissions reduction goal in the first place.
“The country could actually come out net positive, just based on the health co-benefits associated with air quality improvements, relative to the cost of a climate policy,” said study co-author Noelle Eckley Selin, an associate professor in MIT’s Institute for Data, Systems, and Society and the Department of Earth, Atmospheric and Planetary Sciences (EAPS). “This is a motivating factor for countries to engage in global climate policy.”
“Air pollution is an immediate problem that is directly linked to many of the economic, energy-related activities that are also responsible for greenhouse gases,” added the study’s other co-author, Valerie Karplus, the Class of 1943 Career Development Assistant Professor of Global Economics and Management in MIT’s Sloan School of Management. “We wanted to understand to what extent you could address air quality by targeting carbon dioxide through a representative climate policy, carbon pricing.”
The MIT team developed a new modelling approach, called the Regional Emissions Air Quality Climate and Health (REACH) framework, which combined an energy-economic model with an atmospheric chemistry model. The researchers ran four stringency scenarios on the energy-economic model which simulated how a given climate policy would change a province’s economic activity, energy use, and its emissions of carbon dioxide and air pollutants. The four scenarios were: a no-policy, business-as-usual scenario; and three different policy scenarios that aimed to reduce CO2 emissions by 3%, 4%, and 5% per year, respectively, through 2030 — the 4% scenario is in line with China’s current pledge to reach peak CO2 emissions before 2030.
These results were then inputted into the atmospheric chemistry model, the results of which were able to show an accurate idea of how many deaths a certain policy would result in from air quality.
“When you price carbon dioxide emissions, that incentivizes reducing or switching from using fossil fuels to cleaner, more expensive sources of energy, which has economic costs,” Karplus explained. “The total economic impact of these shifts can be quantified in our model.”
The results are morbidly fascinating. Under the team’s no-policy modelling scenario, China would see more than 2.3 million premature deaths stemming from pollution by 2030. If the country were to implement a climate policy to reduce CO2 emissions by 3%, 4%, and 5% per year, it would avoid 36,000, 94,000, and 160,000 premature deaths, respectively. Put into monetary values, these avoidance of death scenarios would result in health co-benefits equal to $138.4 billion, $339.6 billion, and $534.8 billion, respectively.
“In China, as you go to tighter and tighter climate policies, you continue to reduce pollutant emissions from coal, whereas the US has already reduced a lot of its air pollution from coal through end-of-pipe technologies,” Karplus said. “The incremental reductions you’re taking are coming from a fuel with a very high carbon content, which is also the major source of air pollution.”
“This is really a sustainability story,” concluded Selin. “We have all these policy goals for a transition toward a more sustainable society. Mitigating air pollution, a leading cause of death, is one of them, and avoiding dangerous climate change is another. Thinking about how we might inform policy to address these objectives simultaneously, when they actually interact economically and atmospherically, is important to sort out from a science perspective.”