Ethical banks used to be considered niche, interesting or appealing only to a small number of people. But as environmentally responsible investing increased, banks started jumping on the bandwagon, an idiom meaning to become involved in an activity because it's popular, and not because you're really interested in it. As

a result, some banks have been accused of greenwashing, attempting to appear environmentally friendly without actually doing anything serious to protect the environment.

But remember, banks rely on customers' money, and are likely to change their behaviour when customers threaten to take their money elsewhere. This idea inspired British film director Richard Curtis to start his campaign, Make My Money Matter. On TV, Richard has raised millions of pounds for the BBC's charity Comic Relief, but even he was surprised by the amount of money saved by doing one simple thing, moving your pension to an environmentally sustainable fund. And as Richard told BBC Radio 4 programme Costing the Earth, he was even encouraged by former Governor of the Bank of England, Mark Carney.

You know, when I started this, everyone said, well, you know, all the mechanisms and all the accounting and all the transparency isn't quite there yet, but Mark Carney said to me, go for it, because it will be the more that people become interested, the more transparent companies will have to be, the more examples they'll give you of good things that you're investing in, so that as it will get better, the more the spotlight is put on exactly what an ethical or sustainable pension is doing.