A report released Tuesday shows the emissions from use of fossil fuels was responsible for one in five premature deaths around the world in 2018 — significantly more than was previously thought.
The study shows that burning fossil fuels have dire implications for the health of human beings, in addition to being a major contributing factor in climate change.
"Our study adds to the mounting evidence that air pollution from ongoing dependence on fossil fuels is detrimental to global health," co-author Eloise Marais, an associate professor at University College London, said in a statement. "We can't in good conscience continue to rely on fossil fuels, when we know that there are such severe effects on health and viable, cleaner alternatives."
In 2018, 8.7 million people died prematurely as result of air pollution from fossil fuels, according to the new research from Harvard University in collaboration with the University of Birmingham, the University of Leicester and University College London. (2018 was the year with the most complete information, among other factors, according to Marais.) That is more than twice the previous estimate of 4.2 million deaths from a previous benchmark study (though that study also included deaths from things like dust and smoke from wildfires and agricultural burns, not just from fossil fuel).
For the new study, the research team used a global 3-D model of the chemical make up of the atmosphere called GEOS-Chem, open-source software which allows a higher resolution study of the air and what is in it at any specific location.
Previous methods of research do not distinguish between the type of particulates found in the air because they used satellite technology, according to a statement.
"With satellite data, you're seeing only pieces of the puzzle," Loretta J. Mickley, senior research fellow in chemistry-climate interactions at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and co-author of the study, said in the statement. "It is challenging for satellites to distinguish between types of particles, and there can be gaps in the data."
For the Harvard study, "we wanted to map where the pollution is and where people live, so we could know more exactly what people are breathing," Karn Vohra, a graduate student at University of Birmingham and first author of the study, said in the statement.
Broadly speaking, it is more dangerous to live in a country where there are more particulates in the air from burning fossil fuels. "There are higher death rates in countries where there are more fossil fuels burned," Marais tells CNBC Make It. "These include countries such as India and China."
Of course, 2020 bucked almost every trend, and fossil fuel emissions were no exception. The coronavirus pandemic locked down travel across the globe, limiting greenhouse gas emissions.
But "the studies focusing on air quality changes due to lockdown in response to the pandemic have also generally found that the improvement in air quality was dramatic, but short lived," Marais says. "Studies looking at the effect of this short respite from poor air quality on health will only start to emerge now, as a full year of data is needed to relate long-term exposure to air pollution to health."
In response to the Harvard study, the U.S. Energy Information Administration (EIA) tells CNBC Make It the governmental agency does not comment on "reports by outside parties."
Correction: This story has been corrected to reflect that the Harvard report found about one in five premature deaths in 2018 were due to pollution from fossil fuels.