Ban private jets except in tightly controlled circumstances such as someone needing to get somewhere in secret
Subsidise rail travel and reopen railway lines
Subsidise bus travel and reopen bus routes
Invest in a lot more cycle infrastructure - look at Netherlands to see what can be done, no VAT on bikes or services related to bikes
Ban ownership of SUVs/particularly polluting cars in the UK
Ban garden bonfires, disposable BBQs and private use of fireworks to decrease air pollution; also ban on patio heaters
Have tax free childcare and fully paid maternity leave for first child/ren (ie twins) but not for subsequent children - nobody "needs" more than one child so if you want more you pay for your own childcare and mat leave
Stop businesses leaving their lights on overnight or when they are closed
Loads more trees but not next to houses they can fall on
An absolute ban on greenfield development unless every other option has been exhausted - you might, for example, need to build a school or hospital on a new site, but not houses. Linked to that, have more incentives to bring empty homes into use and stop second home ownership to reduce the "need" to concrete over the countryside
Taxes on cruises and ski-ing; and higher aviation taxes for business travel - Teams and Zoom exist, so use them.
Do something about water leaks!
I've got a feeling all of this would cost an awful lot; not sure where I'd get the money to do it all. Taxes on cruises/aviation would only go so far 