Air pollution is now recognized as one of the biggest killers in the world, yet the relative contribution of different types of emissions has so far been difficult to calculate. However, after a combination of data from numerous atmospheric chemistry models and satellite-generated emission estimates, researchers have now concluded that 1.05 million deaths in 2017 were responsible for fossil fuel combustion, with this number more than halving. Considering the highest number of deaths due to air pollution in China and India, the study authors calculated that eliminating coal, oil and natural gas combustion in these two countries could reduce global deaths from fossil fuel emissions by 20 percent.
Presenting their findings in the journal Nature Communications, the researchers noted that “eliminating fossil fuels worldwide could avoid nearly 1 million deaths, 20% of which was associated with the use of fossil fuels in China and India alone.” The authors of the study used updated emissions datasets to calculate the level of microscopic particles called PM2.5 in 204 countries around the world. Measuring less than 2.5 micrometers, these particles are able to enter the human lung and cardiovascular system, causing respiratory distress and heart disease.
Overall, the team found that fossil fuel burning accounted for 27.3 percent of all PM2.5-related deaths in 2017, while the use of solid biofuels such as wood and charcoal contributed a further 20 percent. The researchers wrote, “The use of solid biofuels was the primary source of emissions from residential areas and had an impact on combustible fuels in 78 countries, especially across the tropics. Commonly used for cooking and heating in residential settings. Combustion of biofuels up to 40% is observed. Globally, residential emissions led to 740,000 deaths in 2017, while air pollution by industry and the energy sector killed 450,000 and 390,000 people, respectively.
Agriculture and transportation, meanwhile, both contributed about eight percent of PM2.5 deaths worldwide. To conduct their research, the study authors combined their increased global emissions data with the Global Burden of Disease, gaining unprecedented detail about the health effects of PM2.5 in different parts of the world.