A new report from the International Monetary Fund makes a compelling case for why countries should end subsidies for fossil fuels: It would save millions of lives.

Governments subsidize energy in many ways. Some countries sell gasoline and diesel at prices lower than the cost of producing or importing those fuels. But by far the biggest way countries reduce the price of energy is by not taxing it enough to account for the damage that burning fossil fuels causes to human health and to the climate.

The I.M.F. estimates that calculated properly, energy subsidies will amount to $5.3 trillion this year, or 6.5 percent of the global gross domestic product. China, the largest emitter of greenhouse gases, will be responsible for nearly half of that amount, or $2.3 trillion, and the United States will be the second biggest at $699 billion.

The arguments for cutting subsidies are not new. But the I.M.F.’s exhaustive research makes the case even stronger and more timely. The fund calculates that by raising taxes on fossil fuels, basically eliminating the subsidies, nations would reduce premature deaths caused by air pollution by 55 percent. That would make a big dent in the 3.7 million premature deaths that the World Health Organization links to all outdoor air pollution for just 2012.