This blog was originally posted on the website Valuing Nature.

Here's a short video that Richard Wilson shot when we interviewed Mark Lloyd about his experience of getting people - from stockbrokers to school children - down to the river Thames in Central London, to help clean it up. What particularly interests me is that Mark's own state of happiness is in some way bound up with the fluctuations in the health of a river with which he identifies.

Even in the short time that we spent on this beach near Canongate tube station, he instilled in me some sense of empathy for the river, and I left wanting to 'help it' in its ecological recovery. This wasn't a sense of moral 'ought' that came from learning, rationally, about the challenges the river confronts; it was an empathy that came from spending time there with someone who is passionate about it. This has been discussed further in an earlier post.