"By 2070, India will achieve the target of net-zero emissions," Modi said, adding that India is aiming to meet half of its energy needs from renewable power by 2030.

In a written statement sent to the leaders summit, President Xi Jinping reiterated the country's commitment to reducing emissions.

"We will foster a green, low-carbon and circular economic system at a faster pace, press ahead with industrial structure adjustment, and rein in the irrational development of energy-intensive and high-emission projects," he said.

UN Secretary-General Antonio Guterres expressed his frustration at the lack of progress made on climate change. According to new UN projections, current emissions' reductions pledges from COP members, known as Nationally Determined Contributions, will miss the 2 to 1.5 C target by a wide margin.

Guterres said that as things stand the NDCs will "condemn the world to a calamitous 2.7 degree increase".

"We are still careening toward climate catastrophe," Guterres said. "We are digging our own graves."

United Kingdom Prime Minister Boris Johnson, who is the host of COP 26, likened global warming to a doomsday device, counting down toward disaster.

"It's one minute to midnight on that doomsday clock and we need to act now," he said.