The G20 group of major economies spend $452 billion per year supporting fossil fuel industries, despite their primary role in causing climate change, according to a study released on Thursday.
The report, which comes ahead of a crunch UN meeting in Paris to try to forge a global deal to avoid disastrous levels of climate change in December, accused governments of undermining their own climate change policies.
"G20 governments are handing out approximately $452 billion a year to prop up the production of fossil fuels -- despite pledges to phase out subsidies and prevent catastrophic climate change," the study by British think tank the Overseas Development Institute and Oil Change International found.
Support for fossil fuels like oil and coal by G20 nations -- which include Australia, Brazil, the European Union and the United States -- was four times higher than the entire world`s support for renewable energy, such as solar or wind power, it found.
That included direct spending and tax breaks ($78 billion), investments in the sector by state-owned enterprises ($286 billion), and public finance such as loans from government-owned banks ($88 billion), last year and the year before.
Investment continued despite diminishing returns in coal, and new oil and gas reserves being hard to reach.
"G20 governments are paying fossil fuel producers to undermine their own policies on climate change," said Shelagh Whitley, of the Overseas Development Institute.
"Scrapping these subsidies would rebalance energy markets and allow a level playing field for clean and efficient alternatives."
Some 100 heads of state and government will meet in Paris to secure a deal to stave off catastrophic levels of global warming caused by greenhouse gas emissions from burning fossil fuels.
It aims to seal a global deal to limit global warming to two degrees Celsius (3.6 degrees Fahrenheit) over pre-Industrial Revolution levels, although scientists say the world currently is on track to overshoot that target.
The study noted that Britain was the only nation in the smaller G7 group of developed countries significantly increasing its support for the fossil fuel industry.
It said China was by far the biggest investor in fossil fuel production, spending $77 billion annually, while national subsidies in the US amounted to $20 billion.
The report recommended a strict timetable for ending fossil fuel production subsidies, increased transparency of subsidies, and more support for low- carbon development.
"Continuing to fund the fossil fuel industry today is like accelerating towards a wall that we can clearly see," Stephen Kretzmann, director of Oil Change International, said in a statement.
"G20 leaders need to slow down and turn us around before we hit climate disaster."