A police officer peeks over the edge of a banner on Broadway during the Flood Wall Street protest on Monday in New York City. The protest came on the heels of the climate change march on Sunday that attracted over 300,000 protestors as global leaders gathered across town for the UN climate summit. Photo: AFP

UN Secretary General Ban Ki-moon on Tuesday urged world leaders to set the world on a new course to reverse global warming at the UN climate summit in New York.

"Climate change threatens hard-won peace, prosperity, and opportunity for billions of people," Ban said. "We are not here to talk. We are here to make history," AFP reported.

Ban was joined by former US vice president and climate crusader Al Gore, Hollywood celebrity Leonardo DiCaprio and Chinese actress Li Bingbing. A succession of global leaders are to take the podium to speak, including US President Barack Obama. 

Chinese Vice-Premier Zhang Gaoli, a special envoy to the meeting on behalf of President Xi Jinping, joined some 120 world leaders at the summit, amid growing pressure exerted on China in climate talks.

During his meeting with Ban on Monday, Zhang said China will offer $6 million to support South-South cooperation on climate change.

On the global stage, divergence remains between China and developed powers over the common but differentiated responsibilities to curb climate change. A study released by the Global Carbon Project on Sunday exerted more pressure on China ahead of the UN climate summit and Paris conference in 2015, which is due to yield an accord on reducing greenhouse gas emissions after 2020.

The study found that in 2013, carbon dioxide emissions from China were more than combined US and EU emissions, and for the first time, China's per capita carbon emissions surpassed those of the EU.

Making comparisons between China and Europe is an error and disregards history, said Zou Ji, a deputy dean of the School of Environment and Natural Resources at the Renmin University of China, citing differences between development and industrial structure.

"China has yet to complete its industrialization and is acting as the world's factory, with coal as the main energy source," Zou said. 

Chen Dongmei, head of the China Program at the Institute for Industrial Productivity, said that coal consumption, the major source of carbon emissions from the steel, cement and coal chemical industries, is expected to see a turning point from 2020-30. However, experts disagree over whether coal consumption will peak and then decrease, continue to rise or level off at that point.  

It is very likely, said Chen, that the government will impose caps on energy consumption and emissions during the 13th Five-Year Plan (2016-20).

"With low expectations [for  breakthroughs] in global climate talks, China is likely to do that out of domestic concerns," Chen said, citing concerns over social instability caused by pollution and a need to shift growth from a high-energy consumption model.