Speaking to CNN on the sidelines of talks in Glasgow, Scotland, the British Prime Minister struck a somber tone on the state of the climate emergency, saying "I think you've got to be doom and gloom until we fix this thing" and insisting the world was "inching forward" on solving the crisis.

"The threat is huge, I think it's been very humbling to listen to some of the testimonies from countries like Bangladesh, the Maldives, the Seychelles in the front line," Johnson told CNN. "Are we starting to inch forward with COP? Arguably we are, and in some important ways you're seeing some good commitments on trees and forests, some contributions accelerating the move away from coal."

He also said his government was committing to reducing its reliance on coal, despite the prospect of a controversial new mine opening in northwest England.

"I don't want more coal, and our government doesn't want more coal. We'll do what we're legally able to do," Johnson said.

Johnson also struggled to explain his decision not to wear a mask at all times while sitting next to 95-year-old environmentalist David Attenborough during the summit on Monday. The Prime Minister sparked criticism after he was pictured in some photographs without a mask next to the veteran broadcaster and climate campaigner, though Johnson was seen wearing a mask in other photos of the pair.

Asked about the controversy, Johnson stumbled before saying: "I've been wearing masks in confined spaces with people I don't normally talk to ... it's up to people to take a judgment whether they're at a reasonable distance from someone ... that's the approach we take."

Johnson and Attenborough pictured at the COP26 summit on Monday.

Johnson also praised Attenborough's address to COP26 delegates on Monday as "spellbinding" and drove home the magnitude of the crisis.

"I thought David Attenborough's presentation yesterday morning was absolutely spellbinding because he set out for everybody to understand so clearly the link between the rising carbon and the percentage in the world's atmosphere and the rise in temperature. You see that link over thousands of years and suddenly you see this spike in carbon and the beginnings of the rise in temperature and you know what is going to come."

Johnson was also asked about his 2013 claim that the previous British government had "put in a load of wind farms that failed to pull the skin off a rice pudding." He responded by saying that "everybody has the right" to change their mind and hailed the developments in technology were the driving force for his change of heart.

"If you look at the sophistication of the cells ... the size of the turbines ... propeller blades twice the size of the London Eye ... imagine that. These are enormous creations. They're actually rather beautiful."

Asked about the seesawing nature of US policy on climate and whether the world could trust any American administration on the issue, Johnson struck an optimistic tone.

"What's changed now is the voters in our countries want change and want us to fix this thing. I believe this goes for all great Western democracies. But I think it also goes for populations around the world," Johnson said. He cited the example of Covid-19, saying that when populations "see something that they think is a natural disaster," they change their behaviors.

"People can see climate change is happening. They can see wildfires and flooding. They can see that something out of the normal weather events is taking place," Johnson said. "And it's moving up their agenda."

"I believe Joe [Biden] understands that, and I think people are enthusiastic about his agenda to fix it. But i think any future president of the United States is going to be responding to strong, strong, democratic pressure to join and support the rest of the world in fixing climate change."

Johnson also sought to defend his government's widely-criticized handling of the Covid-19 pandemic and said he did not plan to bring in further measures, including mandating the wearing of masks, despite a recent rise in cases and deaths in the UK.

The Prime Minister said that while he was "watching the data all the time" and that we "have to remain humble in the face of the nature of what the disease can do," he believed that at the moment "we don't see any reasons to deviate the plan that we're on."

He went on to hail the UK's vaccine rollout, saying that the UK was "starting to deal with Covid as part of our lives."