The fatalities related to global warming, like respiratory illnesses and cardiovascular diseases have doubled than it was before.
According to a report in New Scientist, the study, carried out by Mark Jacobson at Stanford University in California, reveals that air pollution associated with elevated carbon dioxide levels is already responsible for around 22,000 deaths every year.
When these are added to casualties from extreme weather events, it doubles the number of fatalities that can be linked to global warming.
For the study, Jacobson modeled the effect of CO2 levels on air pollution and estimated the resulting impact on people's health.
Jacobson's model shows that for every 1 °C rise in temperature in the US, there are 1000 additional air pollution-related deaths.
Globally, the model estimates that CO2-related air pollution is causing 21,600 extra deaths per year on average.
A rise in CO2 increases the temperature and water vapour content of the atmosphere, which in turn accelerates ozone production and encourage particulates to hang around in the air.
"Increased ozone causes respiratory illnesses, while particulate matter causes cardiovascular disease," said Jacobson.
"Global temperatures have risen by 0.8 °C since the industrial revolution, and with CO2 emissions accelerating, the problem will get worse," he added.