Cop26 president Alok Sharma has said G20 divisions remain over ending the use of unabated coal power.
Mr Sharma, who will lead the UN climate conference in November 2021 in Glasgow, said it was vital the G20 countries stepped up to the plate to help tackle global warming.
He was speaking after two days' worth of high-level talks in London, which were attended by ministers from more than 50 countries and dedicated to the environment.
Mr Sharma has repeatedly urged wealthy countries to come together and end the use of unabated coal in order to reach climate targets set out in the 2015 Paris Agreement.
Coal use is regarded as unabated when it is burnt for power or heat without using technology to capture the ensuing emissions, a system not yet widely used in power generation.
“We weren’t able to get every country in the G20 to agree to language on unabated coal phase-out. It’s as simple as that. Of course, for me, that’s very disappointing and it was very disappointing for those countries that are supportive of this policy,” Mr Sharma said on Monday.
His comments come only days after the G20 Climate and Energy meeting in Naples, where he had called for an agreement on unabated coal use.
Mr Sharma has previously said that limiting global temperature rises to 1.5°C above pre-industrial levels, as set out in the Paris Agreement, will not be possible if unabated fuel use is not ended.
“It’s certainly the case that unless we are going to get all countries signed up to unabated coal phase-out then keeping 1.5 within reach is going to be extremely difficult,” Mr Sharma said on Monday.
He referred to the chaos caused by storms in the UK at the weekend as evidence of how important tackling climate change is.
“We have discussed the critical issues in the Cop26 negotiations. As we have done so, heavy rains and flash floods have swept London,” he said.
“A sobering reminder of the urgency of our task.”