If you want to see an example of the unintended long-term impacts of human activity, look no further than Sellafield. The nuclear industrial complex in Cumbria is full of ageing buildings. Many of them contain nuclear material.
None of those buildings were constructed with decommissioning in mind.
And yet, decommissioning is all that is happening at Sellafield now. It's a complicated and hazardous exercise that is expected to take 100 years.
It's an astonishing undertaking, and I could give you more facts and figures about it. If I did, though, I'd be giving you less reason to watch the BBC programme The Lakes with Simon Reeve.
The three-part series is available on iPlayer (until sometime toward the end of 2022). His visit to Sellafield is in episode 3, but I heartily recommend that you watch the complete set.
A site processing nuclear waste is obviously an extreme example of the kind of impact I'm thinking about, but I can't say that some of the lessons didn't resonate with me.
I've done a lot of work recently centred on achieving long-term sustainable outcomes in construction; about adopting 'whole life' thinking when it comes to construction materials; and about designing buildings for adaptability and reuse.
We're really only just getting to grips with these things, when they're an essential part of a lower carbon, less resource intensive future.
If we don't do them, and do them quickly, what will remain for us to deal with? Maybe not nuclear waste, but what other costs - economic and social - might we have to bear? And for how long will we have to bear them?
Let me say again that I really recommend the series. It provides plenty of other takeaways on matters of sustainability that go far beyond the built environment.
The three episodes look at food production and the way we use land; the restoration of peat bogs and wetlands; and how communities face up to tourism and the loss of traditional industries. Beyond the sombre and weighty nature of my questions, there are many moments of optimism.
You also get to see what it's like to rent a church on AirBnB. If nothing else, that's intriguing, right?