CANBERRA, April 6 (Xinhua) -- Investment in Australia's renewable energy sector increased 147 percent in 2017, according to a United Nations (UN) report.

The "Global Trends in Renewable Energy Investment 2018" report, released on Friday, found that investment in renewable energy sources in 2017 was double that in coal, gas and nuclear sources combined.

In Australia alone investment in renewables was 11.07 billion Australian dollars (8.5 billion U.S. dollars), a figure that Martin Rice, acting CEO of Australia's Climate Council, said proved that the transition away from fossil fuels was inevitable.

"Australia is one of the sunniest and windiest countries in the world, so we shouldn't be surprised that investment in renewables, such as wind and solar, is thriving and continues to topple new records around the world," Rice said on Friday.

"If Australia maintains this momentum then we could see the phasing out of coal within the next two decades, transitioning the nation to an energy grid fit for the 21st century and one that slashes our rising greenhouse gas pollution levels."

Under the Australian government's signature energy policy, the National Energy Guarantee, Prime Minister Malcolm Turnbull has not committed to a renewable energy but did commit to reducing emissions by 28 percent from 2005 levels by 2030 under the Paris Agreement.

"The Federal Government's proposed National Energy Guarantee threatens to strangle Australia's renewables boom," Rice said.

"States and territories are leading the charge when it comes to the uptake of renewables and tackling climate change. We must continue our wind and solar surge, and move away from ageing, polluting and inefficient fossil fuels that have no place in our energy future."

Rice highlighted China's leadership on renewable investment with the country accounting for 45 percent of the global total in 2017.