Alok Sharma, who is the president of the 26th United Nations Climate Change Conference, said that he is worried over how to get the long-promised funding for poorer nations to flip to cleaner energy and deal with the climate change impacts. The British official is all set to preside over an upcoming UN climate summit.

Sharma in a speech in Paris jolted the richer nations into action in the last weeks before the October 31 - November 12 event in Glasgow, Scotland.

He said that securing the previously promised annual package of climate change funding for poorer nations "is vital to the success of the summit."

“Without finance, tackling climate change is well-nigh impossible. So developed countries must deliver on the $100 billion a year promised to developing nations. This is a totemic figure. A matter of trust. And trust is a hard-won and fragile commodity in climate negotiations," Associated Press quoted Sharma as saying.

"Thinking about this does keep me awake at night," he added.

He was also the UK's secretary of state for business before he stepped down to oversee the COP26 conference. The official put pressure on the Group of 20 nations that together account for the bulk of global wealth and trade and around 80% of polluting emissions that contribute to global warming.

Earlier this year in July, G-20 nations were all in unison about the fact that they will lay out 'ambitious' targets to reduce emissions by 2030 before the COP26 meeting. Sharma said that some of the richer nations haven't yet done so and "must deliver".

"I say to those G-20 leaders: They simply must step up ahead of COP26," he said.

The COP26 is the 26th United Nations Climate Change Conference. It will be held in Glasgow, Scotland under the presidency of the United Kingdom. The conference is expected to incorporate the 26th Conference of the Parties (COP) to the United Nations Framework Convention on Climate Change (UNFCCC), the 16th meeting of the parties to the Kyoto Protocol (CMP16), and the third meeting of the parties to the Paris Agreement (CMA3).

(With inputs from Associated Press)