The United Nations released its annual report on global emissions on Thursday, stating that while China was leading the way on climate change, others must take urgent action to combat a forecast 2.9 to 3.4 degree temperature rise this century.

China was one of only three G20 members－along with the European Union and India－that were on track to meet their pledges under the Paris Agreement, which comes into force today.

"China is big on the emissions side but also on the solutions side," said Erik Solheim, executive director of the UN Environment Programme."China leads the way for progressive nations in terms of actions."

He said Beijing's efforts to harness energy from renewables were crucial.

"China is bringing down the price of solar at a speed never thought possible, it has five times the high-speed rail of any other nation," Solheim explained at the launch of the report in London."The leadership is no longer coming from Europe."

UNEP said that, even if the Paris pledges are implemented, the world must cut a further 25 percent from projected 2030 emissions to avoid "human tragedy". Meeting the target of limiting temperature rise this century to 1.5 degrees would significantly reduce－though not eliminate－the likelihood of more-intense storms, longer droughts, a rise in sea levels, and other severe climate impacts, the report said.

UNEP did state that 2015 was a year that inspired cautious optimism in terms of developments in the renewable energy sector. The report found that global new investment in renewable power and fuels reached a record $265.8 billion, more than double the$130 billion allocated to new coal and natural gas power generation.

China dominated contributions to the global total, increasing its investment by 17 percent to $102.9 billion, some 36 percent of the global total.

In 2015, China led the world in investment in renewable power and fuels, and in net additions to hydropower, wind, and solar capacity, according to the Renewable Energy Policy Network's Global Status Report 2016.

China also topped the global list for its total capacity, or generation, from renewable power.