One of my roles on Sussex Police Authority is give the political lead for the charge for the force to improve its environmental performance: to cut its resource use, reduce the amount of rubbish produced, make police stations havens for biodiversity - all that stuff.
Of course the real work is done by all the officers and staff who are busy implementing targets and strategies - and championing (and occasionally enforcing) them day in, day out.
My role consists of talking up the issue - and gathering political support - at authority meetings, ensuring the annual budget contains the cash necessary to make Sussex one of the 'greenest' forces in the country (this year, for example, I supported the creation of a budget stream to create a new 'Energy Manager' post, both to cut the greenhouse gas emissions and the costs of keeping all those police stations and offices warm in winter and cool in summer).
It's really about leadership - and giving all those staff regular assurances that they have the backing of the police authority.
But it really is pushing at something of an open door. As I have reported here before, Sussex Chief Constable Martin Richards (pictured) has said he thinks the sustainable policing agenda should be 'mainstreamed' - he agrees that the police's aim of keeping people safe (a core strand in the local policing plan) really must keep them safe from climate change as well as burglars, muggers and murderers.
It's not about replacing traditional policing aims with a woolly environmental agenda, it's about the way exactly the same policing is done.
At Brighton and Hove City Council it sometimes doesn't seem to matter how good an environmental idea is - the Tory administration will often ignore it for political reasons: they are pretty petrified of letting us Greens set the agenda for fear we'll end up taking seats from them at the next election.
But members of the police authority don't seem to feel threatened at all by our politics, and seem keen to implement our ideas wherever they can and enjoy a 'Brownie Point' or two from the fact that Sussex is rapidly developing one of the 'greenest' police forces in the country.
All of this is music to my ears, of course, and throws up one of my favourite tasks at the police authority - attending the inspirational quarterly meetings of the Environmental Working Group.
The latest was held at the police's Lewes HQ this week - and was a quick-fire summary of how well the force is already doing.
On waste reduction, recycling levels, energy use per person, encouraging diversity, 'sustainable procurement' - the targets are all being met.
For example, across the whole force, about 58 per cent of all waste is recycled. Carbon emissions from vehicles - including those used in fuel-hungry high-speed pursuits - have gone down and down, and now stand at 0.368 kg per mile (against a target of 0.375 kg/m).
The challenge now of course is to keep improving on this. While energy use per person is going down, for example, total energy use continues to rise - and we;ve got to turn that around.
But I'm pretty confident that we will. With the support of the police authority and the Chief Constable - and such a dedicated team of HQ staff - I really think Sussex POlice will soon end up as a beacon for environmental good practise to be emulated across the country - especially when carbon trading kicks in and those forces 'dragging their heels' will end up seriously out of pocket.