Can the last person to leave, please switch off the lights?

You have to admire someone like Gordon Sato. A successful scientist in the United States of America, he now helps the government of Eritrea to grow mangroves.

In six years, 700,000 mangroves now grow on what was once a barren and treeless coast of Hergigo. Camels are fed the leaves, fish flourish in the sheltered shallows and a new eco-system is being created. Mr Sato is 79.

Indonesia has also embraced the benefits of mangroves. Their protection against the power of tsunamis is well documented. Over a thousand acres in Bali have been replanted with, on average, 1300 saplings per acre. And if you visit Mauritius, look out for the new mangroves growing in the south.

Countries currently benefiting from the tourism induistry need to do more to secure their future because many of them could be adversely affected by rising seawater levels. Planting forests including mangroves is one option. Reducing their own consumption of imported fuel is another.

Travel to New Delhi and you will be pleasantly surprised by the reduction in smog levels. They know that air pollution contributes to incidence of heart disease.

All tourist destinations must be seen to be doing something to counteract the effects of airline travel. Richard Branson's team is working to develop butanol as an alternative aircraft fuel, but that will take years to be adopted by airlines.

Even President Bush, perhaps for other legitimate reasons, has plans to reduce his country's dependence on fossil fuels. Ethanol type alternatives will produce less harmful emissions.

Scientists are examining ways of extracting energy from sand and making our most abundant fossil fuel - coal - more eco-friendly. And solar power is already making a difference in India.

One hundred years ago, the problem of a burgeoning population of horse drawn carriages caused concern in London. The petrol engine eradicated that problem, but left another, bigger, mess that cannot be fed to rose bushes. Human ingenuity should not be underestimated, and especially now there are financial incentives.

If we do not believe that something can be done to make this small planet survive a bit longer, then like the dolphins in Douglas Adams' "The Hitchhiker's Guide to the Galaxy", we should all fly off saying, "Thanks for the fish".

But we cannot fly off or be so selfish as to ignore a future of hazards for our grandchildren.