Air pollution from fossil fuels like coal and diesel was responsible for 1 in 5 deaths worldwide, according to new research from Harvard University, carried out in collaboration with the University of Birmingham, the University of Leicester and University College London.

That amounts to 8.7 million deaths globally in 2018! That’s double the previous high-end estimate of fine-particle pollution mortality.

The burning of fossil fuels, especially coal, petrol, and diesel, is a major source of airborne fine 21 particulate matter (PM2.5), and a key contributor to the global burden of mortality and disease.

Highlights of the study:

1. Regions with the highest concentrations of fossil fuel-related air pollution, including Eastern North America, Europe, and South-East Asia, have the highest rates of mortality.

2. India has almost 2.5 million deaths. In comparison, China was estimated to have 3.9 million deaths, according to the study.

3. Researchers estimated that exposure to particulate matter from fossil fuel emissions accounted for 18% of total global deaths in 2018.

The earlier Global Burden of Disease Study, the largest and most comprehensive study on the causes of global mortality had put the total number of global deaths from all outdoor airborne particulate matter, including dust and smoke from wildfires and agricultural burns, at 4.2 million.

According to the researchers, the Global Burden of Disease Study relied on satellite and surface observations to estimate the average global annual concentrations of airborne particulate matter, known as PM2.5.

The problem with that method is that satellite and surface observations cannot tell the difference between particles from fossil fuel emissions and those from dust, wildfire smoke or other sources, they said.

“With satellite data, you’re seeing only pieces of the puzzle,” said 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.

“We hope that by quantifying the health consequences of fossil fuel combustion, we can send a clear message to policymakers and stakeholders of the benefits of a transition to alternative energy sources,” said co-author Joel Schwartz, an environmental epidemiologist at the Harvard T.H. Chan School of Public Health.