“The G20 has proven that it can be nimble and take action on economic issues, so we’re looking to these countries to do the same for the climate,” said Alvaro Umana, the former environment and energy minister of Costa Rica who is co-chair of Climate Transparency.

As the host of the G20 gathering, China is trying to instil dynamism into the cause by ratifying the Paris Agreement just days before the summit.

It is also promoting green finance at the Hangzhou summit so that environmentally friendly projects have easier access funding through loans and bonds.

Gerd Leipold, a former executive director of Greenpeace International also with the climate consortium, said: “For the group of 20 countries, climate change is increasingly as much an economic issue as an environmental and ethical problem.”

The political differences on climate change issues have also been greatly reduced compared with 2009, when emerging and industrialised nations disagreed widely on who should bear the brunt of emission reductions.

“Years ago, countries like China and India did not like climate change issues to be discussed outside the UN framework, but after the surprisingly good outcome from Paris, UNFCCC is very keen to broaden the venues for discussions to make the Paris Agreement a reality,” Leipold said.

Jiang Kejun, a senior researcher at the Energy Research Institute of the National Development and Reform Commission, said China should make good use of the G20 presidency to establish its leadership on climate change issues.

Unlike a few years ago, China is already gaining an upper hand at the international negotiations.

“Meanwhile, our research shows that the G20 will actually become beneficiaries of a quicker transition from a brown economy [referring to carbon-intensive growth] to a green one, by owning most of the green and low-carbon technology that is key to addressing global warming,” Jiang said.

According to Climate Transparency’s research, the 20 countries’ energy-related greenhouse gas emissions rose by 56 per cent between 1990 and 2013, although that growth has flatlined in the past two years, due in large part to China’s stalled growth in coal consumption.

The G20’s current commitments to the Paris Agreement will see the group shaving 15 per cent from their projected carbon emissions by 2030, which was “far from sufficient” to stop global temperatures rising by more than 2 degrees, Climate Transparency said.

The consortium calculated that the G20 emission cuts would need to be six times greater than their current pledges to achieve that goal.