If, as seems likely, the Tories held Uxbridge as a reaction to Sadiq Khan's ULEZ extension, well, we ain't seen nothing yet.
The UK has reduced its CO2 emissions by more than any other country** since 1990 - but this was achieved by (a) going for the low-hanging fruit (i.e. phasing out coal) and (b) de-industrialisation. Although this hasn't been remotely cost-free, the costs have been loaded onto electricity bills and, frankly, haven't really been noticed. But that phase of the game is rapidly coming to a close: very little low-hanging fruit remains down decarbonisation way.
The cost of such potential still to be exploited in the power generation sector is rising rapidly
Aside from incremental efficiencies that arise naturally from technical evolution, we've barely started on home heating, transportation, agriculture and much of heavy industry. And decarboning those will be very costly indeed.
And then there's Behaviour. Less travel. Less meat. Less creature comfort. The greens, from Swampy and Greta to John Selwyn Bummer (© Jasper Carrot) have all been pressing government to start 'changing behaviours' - that's our behaviours - and while they'd rather that to be via 'leadership' and 'persuasion', there's little doubt that ultimately they mean compulsion.
I have a strong suspicion they won't be getting any change out of any UK politicians of any party (except just maybe a few Green Party hopefuls) this side of the next GE. In this context, Khan is right out there on his own - and being rapidly disowned by Starmer, naturally enough. Miliband has been well and truly sat on, so really it's only Ed "Drax" Davey we still need to hear from on the subject.
** France, of course, would claim to have had a lower-CO2 starting-point, thanks to its nukes