Though it has been widely assessed as the lowest point in US political discourse in decades, the interaction billed as a “debate” between US president Donald Trump and former vice-president Joe Biden was remarkable in that the two candidates actually spoke about the climate crisis - a historically neglected subject.

The 10 minutes in which Mr Biden and Mr Trump spoke about the environment doubles the total amount of time given to the biggest issue facing our species in all 2,000 minutes of presidential debates since 1988, according to climate scientist Eric Holthouse.

A climate question from moderator Chris Wallace was hotly anticipated as the US grapples with the impacts of a warming world. It was also the first time a question on the issue has cropped up in over a decade.

As record-breaking wildfires and hurricanes have burnt and battered large parts of the country - turning skies orange, and leaving vast areas underwater, several commentators have suggested this election could be defined by the growing concern about the climate.

While Mr Trump has pulled the US out of the Paris climate agreement and rolled back numerous laws designed to reduce emissions, and who has promised voters next to nothing in the way of dealing with the threat of climate breakdown, Mr Biden is campaigning with an ambitious $2 trillion climate plan, which includes making the energy sector a net-zero contributor to emissions in just 15 years.

When asked about the rapidly increasing number of fires burning through communities in California, Mr Trump repeatedly - and spuriously - laid the blame on “forest management”, while also claiming his decision to pull out of the Paris agreement and weaken climate regulations had been to support businesses.

Asked what he believed about the science of climate change and what he would do to confront it, the president said: “I want crystal clean water and air. I want beautiful clean air. We have the lowest carbon - if you look at the numbers right now, we are doing phenomenally.

“But I haven’t destroyed our businesses - our businesses aren’t put out of commission. If you look at the Paris Accord it was a disaster from our standpoint and people are actually very happy about what’s going on because our businesses are doing well.

“As far as the fires are concerned, you need forest management. The forest floors are loaded up with trees - dead trees - that are years old, and they’re like tinder, and leaves and everything else. You drop a cigarette in there and the whole forest burns down.”

He said the government was planting a billion trees (it’s very exciting for a lot of people”) and also said he was supportive of new electric cars.

It is unclear what the “billion tree project,” as he called, it is. In February at his State of the Union address Mr Trump said his administration was joining “the one trillion trees initiative”, which is an initiative sponsored by the UN and aims to restore forests around the world.

He also claimed an unnamed European leader who presided over a state where people live in “forest cities” had told him California’s fires were all due to poor forest management.

Asked why he had rolled back the Obama Clean Power Plan, which limited carbon emissions from power plants, Mr Trump responded: “Because it was driving energy prices through the sky.”

But Mr Biden rejected Mr Trump’s stance on business and energy being impacted by climate policies and instead argued the move to a greener economy could result in economic growth.

He said that during the Obama administration’s recovery act, which was brought in following the global financial crisis, the government “was able to bring down the cost of renewable energy to cheaper than or as cheap as coal and gas and oil”.

“Nobody’s going to build another coal-fired plant in America, no-one’s going to build another oil-fired plant in America. They’re going to move to renewable energy,” he said in comments which represent a major shift in top level US politics.

He also promised to rejoin the Paris agreement, to support the installation of hundreds of thousands of charging points for electric vehicles, and a scheme to provide improvements to the insulation of buildings.

“There are so many things we can do right now to create thousands and thousands of jobs. We can get to net-zero in terms of energy production, by 2035, not only not costing people jobs, but creating millions of good-paying jobs,” he said.

In a confusing statement, Mr Biden appeared to support the so-called “green new deal” - a policy package designed to address the climate crisis and wealth inequality - which he said “would pay for itself”, but he then later stated he did not support the green new deal, and instead supported what he called the “Biden plan”.

However, his own website clearly states he believes the green new deal is “a crucial framework for meeting the climate challenges we face”.

But his website also has a page titled “The Biden plan to build a modern, sustainable infrastructure and an equitable clean energy future”, which appears to be a rebranded policy package.

Joe Biden’s running mate, Kamala Harris attacked the president’s suggestion “forest management” was the solution to tackling the wildfires. 

"It’s Donald Trump attempting to distract from his failure,” she told MSNBC.

Rejecting the president’s claim that “science doesn’t know” what’s causing the fires in her home state of California, Ms Harris said: “Science does know. Science knows we are facing a crisis in terms of the rapid changes to our climate, most of which can be addressed by changing and adapting in terms of our behaviour. Joe Biden offered a clear plan for not only what we need to do to save our environment and climate, but also what his plan will do in terms of the creation of millions of jobs.”

She added: “Donald Trump, on every issue that was discussed tonight, had no plan.”