WE HAVE AT last begun to realise, at least in the UK, that global warming is already happening, that the consequences of this warming could be catastrophic and that we have to act very soon to reduce the amount of carbon dioxide we release into the atmosphere.

Since the problem has been, in large part, created by the industrialised nations and since the consequences (drought in regions previously dependent on rain-fed agriculture, rising sea levels affecting low-lying areas) will be mostly felt by the non-

industrialised nations, it is essential that the industrialised nations, including the UK, begin to plan to reduce their carbon emissions drastically: by some 30% by 2020 and by some 90% by mid century.

We depend to such a huge extent today on energy from the fossil fuels (oil, natural gas, coal) that this is going to require a quite dramatic change in lifestyle and it is important that, instead of viewing this change in a negative way, we begin to see how attractive, how much better than the present, this low- or zero-carbon, sustainable future could be.

Already, large offshore wind farms are being installed, or projected, in the wide reach of the Thames estuary, off Kent and Essex, and in the Bristol Channel between North Devon and Wales. The potential for offshore wind is vast, and if we include wave and tidal current power, it is certainly realistic to expect that most of the electricity we need could come from our surrounding seas by mid century, without any need for nuclear power. It can reasonably be expected that photovoltaic panels (generating electricity from sunlight) will come down in price dramatically before long, with a reduction also in their embedded energy, that is, the energy used in their production.

All this sounds very hopeful, but electricity forms only a fifth of the energy we use. Much of our other energy use is in heating buildings in winter and in transport, commuting and holidays, as well as in the production and distribution of food and drink.

Clearly, we have to begin to insulate all buildings to a much higher standard and move to a much greater dependence on locally produced food, and then to redesign our cities so that day-to-day life is based on walking, cycling or short rides on public transport.

Biofuels are a potential disaster, possibly leading to more rainforest being destroyed to produce palm oil. Although we can grow Miscanthus grass, willow and poplar in the UK, my own solution for the future is for the UK to greatly increase the area of mixed, native woodland, to control flooding, to provide local timber for housing, to provide wood chips as an energy source, and to provide areas of recreation near all major cities.

What I have tried to do in my book The Energy Challenge is to develop a detailed, realistic scenario for a UK zero-carbon future, showing exactly where energy could come from, and how we could reduce our energy use to match the energy available (backed up by calculations, in the Notes which follow the main text). Speculative as a future scenario must inevitably be, such long term projection is essential if we are to make the right energy decisions today.

The Energy Challenge: Finding Solutions to the Problems of Global Warming and Future Energy Supply is published by Troubador at £12.95.

Geoffrey Haggis is a retired physicist living in South Devon.