What's green, and earning money?

Expect to hear more about the Danish island of Samsø which, thanks to a massive community effort over the past decade, is now self-sufficient in renewable energy.

The 4,000 inhabitants spent €54 million (raised in local taxes and investment), to install nearly a dozen wind turbines on land, and the same again offshore, plus banks of solar panels, and some biomass generators.

The scheme has been so successful it is selling electricity to the mainland and generating an income for the locals -- albeit about €68 per household a year.

Shows what can be done. Looks pretty idyllic too -- we predict a boom in ecotourism there.

Hotel towels and 'green wash'

Hotels worldwide have cottoned onto the benefits of not changing guest towels every day. Usually, there is a sign inviting us to join them in doing our bit to help the environment.

But are they really helping the environment? Or hoping to save money on their laundry bills?

I've been pondering this since reading about how hotels can make their 'towel reuse signs' more effective by wording them carefully. You can read about the study in the enjoyable and generally thought-provoking book Yes! 50 secrets from the science of persuasion.

Sure, less laundry is 'a good thing' -- it translates into less water wasted, less energy and detergents used, and less linen trucked around the place. But let's have a little honesty here.

I have yet to see a hotel announce that, thanks to guests reusing their towels, the company saved €xxx on its laundry bill last year, which it donated to a named environmental charity*, and with your help they'll save, or 'raise', even more this year.

Now, that's a wording that would really convince me not just to reuse my towels -- but even bring my own.

*With the receipt displayed proudly in the hotel lobby

The latest in environmental tourism?

It would take the French.

A tethered gas balloon in Paris's 15th arrondissement has been taking tourists up for aerial views of the city since 1999. Now, it has been coupled to an air quality monitoring and display system, to give real time information on air quality in the city and at major traffic junctions.

Sensors will monitor levels of nitrogen dioxide, ozone, and particulate matter. And, if we understand this correctly, 'Ballon Air de Paris' will change colour depending on air quality: red for highly polluted air, through to yellow for 'mediocre', and green for very clean.

Perfect, you'd have thought, for keeping an eye on air quality in Beijing in the run up to the Olympics? No, you're right. It would never take off!