The world subsidises energy consumption to the tune of more than $200,000 per second, with about 60 per cent of that going to support coal, according to researchers at the International Monetary Fund.
In a paper published by the IMF, the authors found that energy subsidies are much more than previously estimated. These will rise to $US5.3 trillion ($6.6 trillion) in 2015, or about 6.5 per cent of total global output.
For some developing nations, such as in the former Soviet Union and Pakistan, the subsidies approach 18 per cent of GDP.
About 80 per cent of the subsidies are the result of environmental damage from burning fossil fuels, with about one-quarter of that portion attributed to climate change impacts, the four IMF researchers led by David Coady said.
Removing subsidies would help reduce greenhouse gas emissions by 20 per cent, the study found, adding the issue of energy support will be high on the agenda at the Paris climate summit planned for December in France. Premature deaths related to air pollution would also be cut by more than half.
"Among different energy products, coal accounts for the biggest subsidies, given its high environmental damage and because (unlike for road fuels) no country imposes meaningful excises on its consumption," the authors said.
Of the total tab, coal's subsidy this year will amount to $US3.15 trillion, with the global warming cost put at $750 billion and local air pollution $2.37 trillion.
The IMF researchers said efficient energy pricing was "urgently needed", noting that energy taxes "remain the most effective and practical tool" to account for the externalities of energy use.
The authors also suggested that "countries should take advantage of the low international energy prices and gradually move toward efficient energy pricing".
The Abbott government delivered on its promise to scrap the carbon price in July last year. Fairfax Media sought comment on the IMF study from Environment Minister Greg Hunt and Industry Minister Ian Macfarlane.
Australian Greens Deputy Leader, Larissa Waters, said the scale of global fuel subsidies supporting "the dying fossil fuel industry" were staggering.
"Governments could be investing that money into reducing poverty, instead of propping up big mining companies and holding up the transition to renewable energy," Senator Waters said.
"In Australia, the Greens' costed policy shows getting rid of subsidies for big mining companies to buy cheap fuel would save more than $10 billion," she said.
