Nostalgia is natural. I love the nostalgia section in our local newspaper, even though I'm not a native of the city. And it is always tempting to hark back to the past – very rarely do you hear anybody say "well, it's much better these days." Personally, I think it comes from evolution – in a natural eco-system the creatures that fear unfamiliar sights, sounds and smells will live longer than those who don't.
But sometimes nostalgia can reach a level of self parody. While most of us marked last Friday's coal-free day in the UK as a remarkable achievement, the Telegraph published a bizarre lament for the days of smog, smut and "the tang of sulphur" (right).
In my view, coal is fast becoming the litmus test for progressive/conservative split in politics with Donald Trump, Marine Le Pen and Tony Abbott backing coal. Prominent 'lukewarmer' Matt Ridley's inherited family fortune came from coal (and still does). Often 'clean coal' is invoked to deflect criticism, but coal is always a theme.
The far left dabble in this pool of fossilised nostalgia too, with the UK's Labour leader Jeremy Corbyn plugging clean coal to bring back mining jobs. One of my favourite bonkers conspiracy theories is that Margaret Thatcher 'invented' climate change to kill off the UK's coal industry. Yeah, right.
It is easy to sneer (as I just have), but we have to remember the power of nostalgia and the lure of 'it could be like our childhood again'. The renewables revolution may seem like a miracle to the readers of this blog, but change always threatens someone. And it is those people we need to engage with – on their terms – rather than preaching to the green choir.