Workers collect coal at an open mine in Dhanbad in the eastern Indian state of Jharkhand on December 7th, 2017. (Photo: AFP/Getty Images)

Global demand for coal is expected to rise over the next five years, according to a new report from the International Energy Agency. The IEA predicts that, despite a record-breaking drop in demand between 2015 and 2016, global demand will increase by about 3 percent, or 117 million tonnes of coal equivalent, by 2022.

The forecasted rise is driven largely by India, where demand is expected to increase by 115 million tonnes. (Though a huge figure, that's still 100 million tonnes less than the IEA projected demand increase in India the same period last year.)

Still, any growth in coal consumption is bad news for the planet. Coal emits more carbon than any other fuel source, and we all share the same carbon budget. Here are a few reminders as to why coal is such a dirty energy source:

1. It's Bad for the Environment

The mere act of pulling coal from the ground is destructive. In mountain-top mining, for example—as the name suggests—mountain tops are cleared of trees and removed with explosives. Water drains down into the valleys below mountain top mines and carries with it toxic chemicals that pollute waterways. Once out of the ground, burning coal releases huge amounts of carbon dioxide, the primary greenhouse gas behind climate change, plus sulfur dioxides and nitrogen oxides, both of which lead to acid rain and smog. The coal plants themselves suck up billions of gallons of water from nearby waterbodies (along with any tiny fish, larvae, and eggs that happen to be in the way) for steam-powered turbines. Sometimes the plants dump hot waste water back into those same water sources—a form of "thermal" pollution.

2. It's Bad for Human Health

The toxic pollutants emitted into the atmosphere as a result of burning coal—including not just carbon and sulfur and nitrogen oxides, but also mercury and particulate matter like soot—have been linked to respiratory, cardiovascular, and even neurological illnesses. Particulate matter can get lodged in the lungs, increasing the risk for everything from asthma to lung cancer; mercury, which makes its way into humans via the fish we eat, can cause brain damage, blindness, and developmental disorders in developing fetuses. In addition, the risk of death from heart disease is five time higher for those exposed to coal emissions over 20 years compared to other pollutants. All told, some 30,000 premature deaths a year in the United States alone can be attributed to coal-fired power plants.

3. It's Bad for the Economy

Coal would not pass a proper cost-benefit analysis. In the U.S., the damage coal causes to the economy outweighs the power it generates. A 2011 study estimated that coal plants cost the U.S. $53 billion in damages a year. (The researchers used conservative estimates of the health risks of coal and didn't look at the climate risks at all, which means the cost in the U.S., and around the globe, is considerably higher.) If coal use continues at its current levels, let alone rises, global temperatures will rise well over the two degree Celsius goal of the Paris Agreement. That rise in temperature can itself harm the economy: A 2015 study found that, while gross domestic product remained fairly stable when temperatures remained between 32 and 77 degrees Fahrenheit, it quickly drops off with any temperatures above or below that threshold. If current climate projections pan out, the study found, global economic production could drop by 23 percent by the end of the century.

Of course, as Carbon Brief reported, some experts believe the IEA projections for coal demand in India might be an overestimate. India's Ministry of New and Renewable Energy estimates that the country will reach 200 gigawatts of renewable energy by 2022, but the IEA used more conservative approximations of renewable energy generation. If solar and wind energy expand as rapidly as the most optimistic projections, global demand trends could reverse by this time next year.