Did Michael Gove really try to stop schools in England from teaching about climate change in geography?
His ministerial return, as secretary of state for the environment, food and rural affairs, has prompted a wave of claims that Mr Gove tried to remove the teaching of climate change when he was in charge of the education department.
"This is a man who tried to stop young people in our schools learning about climate change, who tried to take it out of the geography curriculum," said Caroline Lucas, co-leader of the Green Party.
On social media, these claims about climate change have been linked with pictures of Mr Gove's visit to the newly elected President Trump, as though their awkward thumbs up were evidence of some kind of global compact.
But is there any substance to the claims?
Anyone taking geography GCSEs or A-levels this summer will wonder what the row is about, because pupils will have been grilled - probably the wrong word - about climate change and global warming.
And there are plenty of references to climate change in the national curriculum for younger years.
Climate of suspicion
But the row about "climate change denial" goes back to a controversial rewriting of the geography curriculum when Mr Gove was education secretary.
In a draft version, climate change was conspicuous by its absence, prompting a wave of petitions and lobbying demands for its re-inclusion.
And when the final version was produced, climate change had been reinstated.
But instead of ending the argument, there was still a lingering fog of claims about political attempts to stifle the subject.
And the Department for Education had to publish a statement denying that climate change had been removed.
But what really happened?
People who were close to Mr Gove during this time say that the climate change allegations have taken on a life of their own, a Westminster version of an urban myth, without any foundation.
They say it's a complete misreading of what happened - and that rather than downplaying the teaching of climate change, it was to be bolstered by moving it to science.
And in the end, after a consultation, Mr Gove took the decision to keep teaching it as part of geography.
Another source said that climate change ended up being taught in geography and in science, so it hadn't been cut - so it was a meaningless row.
But there are also different versions of events.
Another very senior figure, close to the curriculum reforms, said that shifting climate change into science might have been the "formal" argument.
But they suggest that there was also an "instinctive" distrust of the topic, with lessons about climate change seen as having an underlying, politically driven agenda.
This became a political "tussle", it's claimed.
Another person involved in the rewriting of the geography curriculum remembers ministerial interventions and political horse-trading.
They describe attempts not to "stress the human causes" of climate change as an attempt to placate the "right wing of the Conservative party".
Mr Gove was described as wanting to make specific changes to the wording.
This was the era of the coalition government - and it is claimed that the row was resolved behind the scenes after the intervention of the Department for Energy and Climate Change.
It was also suggested that "Nick Clegg was deployed" - as the deputy prime minister was sometimes involved with such departmental disagreements.
Although Mr Gove might have become the lightning rod in this row, it's worth noting that much of the controversial coverage about cutting climate change from geography was not about Mr Gove at all.
Tim Oates, who chaired the panel reviewing the national curriculum, argued it should be about core scientific knowledge, rather than issues, such as climate change, that might stem from that.
Such topics should be left to teachers to decide to teach rather than be prescribed, he said.
This had prompted reports that climate change "propaganda" was going to be dropped.
In a statement on Monday, Mr Oates said there had been "a lot of knee-jerk reaction and misunderstanding in media reports at the time".
"The debate the national curriculum panel had was not over whether children should understand climate science - I believe that they should.
"The debate was about what fundamental concepts they needed to learn at an early age in order to understand climate science."
"I am not a 'climate change denier' and I never have been," said Mr Oates.
There are other arguments underlying all this. Should ministers, political figures moving in and out of departments, really get involved in the detail of what pupils are taught? Or should this be the domain of subject specialists and education professionals?
And the school climate has changed too. Academies do not have to follow the national curriculum - so for most secondary schools, such requirements no longer even apply.
A spokesman for Mr Gove's new department, Defra, said: "The secretary of state wanted to enhance climate change in the national curriculum when he was education secretary. It was never his intention to remove it."