US President Donald Trump has accused climate change scientists of having a "political agenda" as he cast doubt on whether humans were responsible for the earth's rising temperatures.
But Mr Trump also said he no longer believed climate change was a hoax.
The comments, made during an interview with CBS's 60 Minutes, come less than a week after climate scientists issued a final call to halt rising temperatures.
The world's leading scientists agree that climate change is primarily human-induced.
Last week's report by the Intergovernmental Panel on Climate Change (IPCC) - the leading international body evaluating climate change - warned the world was heading towards a temperature rise of 3C.
Scientists say that natural fluctuations in temperature are being exacerbated by human activity - which has caused approximately 1C of global warming above pre-industrial levels.
The report said keeping to the preferred target of 1.5C above pre-industrial levels will mean "rapid, far-reaching and unprecedented changes in all aspects of society".
Climate change was just one issue touched on during the wide-ranging interview, during which Mr Trump also:
- Said that "the day before" he took office the US had been on the verge of "going to war with North Korea"
- Said Russian President Vladimir Putin was "probably" involved in assassinations but added, "I rely on them, it's not in our country"
- Said Russia had meddled in the 2016 elections but added, "I think China meddled also"
- Refused to say whether he would reinstate the migrant child separation policy but added "there have to be consequences" for entering the US illegally
- Said he believed he had treated Christine Blasey Ford with "respect" after mocking her testimony in front of thousands at a rally, and that "had I not made that speech, we would not have won"
What did Trump say about climate change?
During Sunday's interview, Mr Trump cast doubt on making any changes, saying the scientists "have a very big political agenda".
"I don't think it's a hoax, I think there's probably a difference," he told journalist Lesley Stahl.
"But I don't know that it's manmade. I will say this. I don't want to give trillions and trillions of dollars. I don't want to lose millions and millions of jobs. I don't want to be put at a disadvantage."
Mr Trump added that temperatures "could very well go back" - although he did not say how.
What did Trump say before?
He said climate change was a hoax during his election campaign in 2016 but has generally avoided taking a clear stance on the issue since taking office.
However, he announced the US would withdraw from the Paris climate change agreement, which commits another 187 other countries to keeping rising global temperatures "well below" 2C above pre-industrial levels and "endeavour to limit" them even more, to 1.5C.
At the time, Mr Trump said he wanted to negotiate a new "fair" deal that would not disadvantage US businesses and workers.
It sparked speculation that the former reality television star still believed climate change had been invented.
However, Nikki Haley, the US ambassador to the UN, later said Mr Trump "believes the climate is changing and he believes pollutants are part of the equation".
How great is the climate threat?
The report released last week by the IPCC says climate change can only be stopped if the world makes major, and costly, changes.
That means reducing global emissions of CO2 by 45% from 2010 levels by 2030, and reducing coal use to almost zero and using up to seven million sq km (2.7m square miles) for land energy crops.
If the world fails to act, the researchers warn, there will be some significant and dangerous changes to our world, including rising sea levels, significant impacts on ocean temperatures and acidity, and the ability to grow crops such as rice, maize and wheat.
Renewable energy creates jobs, too
By Roger Harrabin BBC Environment Analyst
President Trump's views on climate change have swung widely - like his comments on many issues.
Vanishingly few informed scientists now disagree that humans have been driving recent climate change, and that further heating will create serious risks for the climate.
They don't expect the climate will materially cool again in a natural cycle.
The president says he doesn't want to spend trillions of dollars and lose millions of jobs by cutting emissions.
Of course he doesn't - but all governments feel the same way. Instead, they are trying to reframe the huge investment needed in renewable energy as a money-making enterprise.
The UK's Industrial Strategy, for instance, sets out to create jobs in clean industries to replace those lost in dirty factories.
And in the US itself, the solar industry is creating far more jobs than the coal sector. Does the president know that?