"Much more interesting and important is the breakdown of post-tax subsidies. The most dramatic difference, compared with the pre-tax figures, is for coal which is the biggest source of post-tax subsidies, amounting to 3.0 percent of global GDP in 2011 and rising to 3.9 percent in 2015.17 The considerable size of coal subsidies reflects the substantial undercharging for its environmental impacts—coal is the most carbon-intensive and air-pollution intensive energy product (per unit of energy), yet no country really imposes meaningful taxes on coal use from an environmental perspective (Parry and others 2014)."
Global GDP in 2015 was about US$78trillion so 3.9% is US$3trillion or AU$4.2trillion in global subsidies for coal alone.
