The climate activist Vanessa Nakate has warned that the planet is “on the verge of the abyss” as she challenged world leaders to prove wrong those who doubt that Cop26 can be a success.

The Ugandan activist told the conference that thousands of activists and people living in countries affected by climate change “do not see the success that is being applauded” at the summit.

Ms Nakate, 24, said: “We are – as United Nations secretary general Antonio Guterres recently said – on the verge of the abyss.

“As the IPCC report said, the science is now unequivocal.

“The latest available science tells us that, in order to avoid the worst impacts of the climate crisis, we must reduce global Co2 emissions by somewhere between 7% and 11% this year and next year, and every year until we get to zero.”

She argued that “only immediate and drastic action will pull us back from the abyss”, but said she was sceptical of the promises made by world leaders, businesses and the financial sector.

Ms Nakate continued: “There have been 25 Cops before this one and every time leaders come to these climate negotiations with an array of new pledges, commitments and promises.

“And as it comes and goes, emissions continue to rise.

“This year will be no different. CO2 emissions are forecast to jump in 2021 by the second-biggest annual rise in history.

“So I hope you can understand why many of the activists who are here in Glasgow, and millions of activists who could not be here, do not see the success that is being applauded.”

Addressing world and business leaders, Ms Nakate said: “I am here to beg you to prove us wrong.

“We see them making fancy speeches, we hear about new pledges and promises, but we are drowning in promises.

“Promises will not stop the suffering of the people, pledges will not stop the planet from warming.”

She added: “The truth is that the atmosphere doesn’t care about commitments. It only cares about what we put into it or stop putting into it.

“Humanity will not be saved by promises. It’s hard to believe business and finance leaders when they haven’t delivered before. They have not been faithful in their promises. They have not been honest in fulfilling their commitments.”

Ms Nakate was speaking during an event called “racing to a better world” at the climate summit, alongside Scottish First Minister Nicola Sturgeon.

Ms Sturgeon said: “The reason I’m sitting here with Vanessa is that I recognise that people like me, our feet do need to be held to the fire.

“Spending a bit of time over Cop26 with Vanessa has reminded me of the need to constantly push ourselves and challenge ourselves to do ever more difficult things.”