Eco-worrier: Johnny Flynn as Ben in Richard Bean's "The Heretic"
The stage has discovered climate change: don't expect a let-up any time soon. After an early success with Earthquakes in London last year, the National has another go at the threat to poor old mother earth with Greenland.
It's penned by a committee of four youngish playwrights. Trouble is, it feels like it. Not even the combined talents of Moira Buffini (Handbagged) and Matt Charman (The Observer) can save this episodic sprawl.
Greenland's message is about as subtle as a Greenpeace handout. "The ice is melting, mum, and I'm really scared," cries a character. Oh, do get a grip.
The arguments and tensions around climate change should make for dramatic tension. Here though, we start from the firm premise that 95 per cent of scientists agree on anthropogenic global warming and the play never really shows any curiosity about its conviction that Armageddon is only a few decades away.
We're supposed to identify with the strife of a couple where one is passionately environmental and the other frequents Starbucks. Alas, the domestic Green goddess is so irksome she practically makes you want to go out and buy a patio heater in the interval.
It's a shame about the ideological monotony, as the play has accomplished directors in Bijan Sheibani and Ben Power. They make the Lyttleton's cavernous stage look otherworldly, whether lighting the violet-tinged wastes of the North Pole with a ghostly shimmer or blasting the stalls with a shower of paper rain. Recyled, naturally.
There's only one touching moment, when the scientist studying the impact of warming on guillemots watches his younger self pick up a tiny bird frozen to death by the premature flight of its mother.
A shouty character boycotting a supermarket is suspended in a shopping trolley above the stage — presumably in the hope that hydraulics can compensate for lack of dramatics.
At the heart of this mess is the Copenhagen summit of 2009. It's hard enough to make summits interesting: harder still if you feature one that is a year and a half old and a grand failure.
I liked the spiky love affair involving a scientist lugging his laptop round Copenhagen in pursuit of the manic female spin-doctor. But since the star-crossed lovers are as partisan as everyone else in Greenland, it's hard to give a toss whether they get it together before the planet overheats.
The Heretic at the Royal Court is a different creature: a quirky, inquiring joy of a piece. It's helped by a top-notch lead. Juliet Stevenson is Diane, a redbrick tutor who finds her earth sciences faculty fashionable, just as her data on rising sea-levels in the Maldives are producing inconveniently optimistic results for a department seeking investment from an insurance company.
Diane is locked into perma-strife with her anorexic daughter (Lydia Wilson): "Are you joining Greenpeace to save the world or as part of an ongoing project to destroy your mother?"
Soon she's under disciplinary proceedings after a sceptical blast on Newsnight, and in trouble with her ethically invertebrate faculty boss (and old lover) Kevin.