Shanghai, one of the world's most populous cities, will today enact strict green policies limiting disposable takeaway utensils and hotel room essentials, as it officially rolls out a major recycling overhaul.

Key points: China contributed to almost a third of the global renewables investment in 2018

China contributed to almost a third of the global renewables investment in 2018 But the Asian power remains the world's largest producer of carbon emissions

But the Asian power remains the world's largest producer of carbon emissions China provides billions of dollars in support for overseas coal plants per year

The ban on the provision of a slew of single-use items such as chopsticks, forks, shower caps and toothbrushes unless requested by customers comes amid Beijing's green push to tackle pollution and their ambition to become a global leader in clean technology.

While China remains the world's largest producer of carbon emissions — where air pollution is still responsible for more than 1 million premature deaths a year — the Asian power is also the biggest investor in renewable energy.

The latest report by the UN's renewable energy advisory body, REN21, shows China led renewable energy investment worldwide for the seventh successive year, contributing to almost a third of the global renewables investment in 2018 at $US91.2 billion ($130.2 billion).

By comparison, the United States spent $US48.5 billion and European investment hit $US61.2 billion.

China's growing renewable energy supply and dominance in renewable energy technology — including being the world's leader in the production and sale of electric vehicles — has led some observers to highlight's China potential as a global green leader.

A report released by the International Renewable Energy Agency (IRENA) in January this year argued that countries with the ability to take advantage of new renewable energy technologies can expect to enhance their global influence and reach.

"No country has put itself in a better position to become the world's renewable energy superpower than China," said the report.

"In aggregate, it is now the world's largest producer, exporter and installer of solar panels, wind turbines, batteries and electric vehicles, placing it at the forefront of the global energy transition."

China effectively 'exporting their emissions'

Coal consumption accounted for 59 per cent of the total energy consumption in China last year. ( Reuters: Jason Lee )

While China has significantly expanded its renewable energy capacity over the past decade, a separate report released ahead of the annual G20 Summit in Osaka last week suggested that the country still had a long way to go to be a true climate leader.

The report by the Overseas Development Institute (ODI) and others showed G20 countries have almost tripled the subsidies they give to coal-fired power plants in recent years — despite pledging a decade ago to phase out all fossil fuel subsidies.

As China moves to cut coal consumption and promote renewable power at home, China provides billions of dollars in support for overseas coal plants per year, according to the latest findings.

Ipek Gencsu, research fellow at ODI and lead author of the report, noted that the top recipients — Bangladesh, Indonesia, Pakistan and Vietnam — were "countries which are in earlier stages of their development" and have also signed up to China's Belt and Road Initiative.

"So in a way, they're kind of exporting their emissions," Ms Gencsu told the ABC.

"Our analysis shows China spends $US9.5 billion per year financing coal abroad. They could instead be spending this money on clean technologies."

China hopes coal-fired power plants will become a thing of the past. ( ABC News: Brant Cumming )

Ms Gencsu said while China can be considered a leader in green technologies, it cannot be a "green superpower" or climate leader without tackling their ongoing major support to the coal industry, as well as to other fossil fuels.

"There's no future in coal. The real business opportunities lie in clean technologies, and that's where the world is going," she said.

"Countries are dragging their feet, and governments are dragging their feet and continuing to provide a lifeline to this sector."

She added that G20 governments had to set an example to developing nations and to keep the world on track to halt the global warming temperature rise at 1.5 degrees Celsius.

China is among 195 signatory countries that pledged to keep global warming "well below" 2 degrees Celsius under the Paris climate agreement in 2015.

In addition to tackling toxic levels of pollution, experts say energy security is another reason why China has prioritised investing in diverse sources and suppliers of energy.

Could China completely run on clean energy?

In the middle of China's coal heartland of Datong, solar panels fill the hilltops. ( ABC News: Brant Cumming )

Sarah Ladislaw, director of the energy and national security program at the Centre for Strategic and International Studies, said China's is the largest market for renewable and nuclear power in the world but still heavily reliant on coal.

"China alone makes up about 50 per cent of global coal consumption, and coal is about 60 per cent of total Chinese energy consumption," she said.

"China aspires to reduce the role of coal in the economy and it can make significant strides in that direction."

In 2018, coal consumption accounted for 59 per cent of the total energy consumption — down from 60.4 per cent in 2017, according to a report by the China Electric Power Planning and Engineering Institute.

Meanwhile clean energy consumption — including natural gas, hydropower, nuclear power and wind power — increased from 20.8 per cent to 22.1 per cent.

According to the latest REN21 report, China also leads the world in total renewable power capacity, particularly in hydropower, solar PV and wind power.

The number of new grid-connected nuclear plants tripled in 2018, with 80 per cent of these located in China.

Late last year, China shocked the world when a team of scientists announced that plasma in their Experimental Advanced Superconducting Tokamak (EAST) — dubbed the "artificial sun" — reached a whopping 100 million degrees Celsius, the temperature required to maintain a fusion reaction that produces more power than it uses to run.

In April, local media reported that a new research facility in Chengdu city would have a machine capable of generating plasma — a hot ionised gas — of up to 200 million degrees Celsius.

Min Yuan, a Beijing-based research associate at the World Resources Institute, told the ABC that zero carbon was not only a long-term vision for China but also for many developed countries due to technical and institutional barriers.

"Globally, there [already] exists zero or net zero carbon pilot projects such as zero carbon buildings, communities, et cetera," he said.

"But completely phasing out coal — [there] is still a long way to go."

'Australia can do much better'

China provides billions of dollars in support for overseas coal plants per year. ( ABC News: Brant Cumming )

Ms Ladislaw said the pledges put forward as Paris targets are insufficient to reduce emissions and keep global average temperature rise to less than 2 degrees Celsius, and China is not alone in having a target that can and should be made more ambitious.

"The goal to make targets and plans more ambitious was a critical part of the Paris Agreement and subsequent process," she said.

"China can do more and I suspect will likely take steps to do more in the coming years.

"It could adopt a more stringent [approach to] the emissions intensity reduction target, set a long-term target on carbon neutrality, create more specific sectoral policies."

China could have a more ambitious climate target, experts say. ( ABC News: GFX/Jarrod Fankhauser )

Tania Urmee, a renewable energy expert at Murdoch University in Perth, said a country's carbon emissions should also be considered on a per capita basis.

She said available data showed China's emissions per capita were about 7.4 tonnes last year whereas Australia — with a population roughly on par with Shanghai — recorded an emission per capita of 21.5 tonnes.

"From my perspective, Australia can do much better," Dr Urmee said

"In terms of renewable energy resources, we have more than China."

Ms Gencsu said while the world has come a long way — with governments making critical commitments — the pace has been too slow to meet the realities of climate change.

"So while we have to appreciate the great work that's been done by governments, the commitments and the advances in clean technologies, unfortunately, we can't just sit and celebrate quite yet," she said.

"We have to keep working hard as the global community, and especially look for leadership from the G20 countries to aim higher, to do better and to absolutely stop financing fossil fuels, because, without that, it's very hard to say that we're on the right track."