Suddenly, I feel a climate change coming on: The Heretic, Richard Bean’s entertaining new play, picks up on the dreadful slack left behind by Greenland at the National and delivers a very funny, topical new take on earth sciences, which have come into their own as a subject in universities after the blah-blah years of psychology and media studies.

The heretic in question is Juliet Stevenson’s self-contradictory, self-deprecating Dr Diane Cassell (“I’m a scientist. I don’t ‘believe’ in anything”), a paleogeophysics lecturer in a Yorkshire university who is challenging orthodox views in her field and undermining sponsorship.

She’s suspended, and then sacked, by her professorial head of faculty, Kevin Malone (anxiety-ridden James Fleet) - with whom she is vestigially in love after a long-ago one-night stand - in a hilarious scene featuring a pre-programmed human resources officer (Leah Whitaker) and Diane’s lawyer, a puppet polar bear - Sooty reborn as “Whitey.”

Diane, who’s been studying sea-levels in the Maldives, is at the centre of another spider’s web involving her grungy Greenpeace activist, anorexic daughter Phoebe (Lydia Wilson, following through strongly from Blasted at the Lyric, Hammersmith) and her brilliant new flaky, self-harming student Ben (Johnny Flynn).

And the lumbering security officer Geoff (massive Adrian Hood), who speaks plain Yorkshire and has been in the army, proves a convenient hidden weapon when the Sacred Earth Militia come to call and Phoebe goes into heart attack mode: only the outer farce lines of this play need a little sorting.

Diane goes on Newsnight unauthorised - filmed insert complete with Jeremy Paxman saying he knows all about chaos after 30 years at the BBC - and the play shifts from designer Peter McKintosh’s functional departmental office to Diane’s country retreat on Boxing Day: a round of Scrabble becomes a family internet hacking game into the rival university’s tree ring data, and a Mel Gibson cinematic climate change blockbuster charade.

Mr Bean makes mighty fine jokes all along the way - I like Ben’s idea of the perfect bloke-ish death being extravagant suicide on Top Gear - and Stevenson glows like an agreeable firebrand all night, reminding us how rare is her onstage mix of intellectual probity and heart-breaking concern. Only the cheap-looking celebratory red dress at the end is a fashion error. Otherwise, she surely needs to lead this play into the West End, following the Court successes with Enron, Jerusalem and Clybourne Park.