"A nod is as good as a wink to a blind 'oss"

That old saw conveys pithily an important truth about the practical study of human beings.

The problem we are facing, or in many cases failing to face, is profound and complex. Although it can be stated as a physical problem - the rise in carbon dioxide, methane and other gases in the earth's atmosphere, the reason for this rise is human behaviour, which is much harder to explain and influence.

At present some people are trying to state the response to this problem as mainly individual ethics. While it is good practice for individual families to attempt to reduce their carbon dioxide output, the real gains will come from the whole human community working together. That means governments and business making an effort.

Capital v. Income energy
At the core of a plan to reduce the output of warming gases will be investment in what I think we should call "income energy". This is in contrast to our main sources of energy at present, which are capital. People who meet their day to day expenses by running down capital end up poor. Our whole society will certainly end up poor if we don't stop running down the capital represented by coal and oil.

Individuals can do something towards this. For example, I have a solar water heating system that provides me with hot water for about 6 months of the year. It includes an electric pump to circulate the water to the roof. That electricity comes from a photovoltaic system that turns full sunlight into electricity.

I get around town on a bike, having no car. Luckily I live in a small town that still has shops and a major outdoor market within cycling distance. Cycling is good for the health. Since my wife took up the bike she has gained a great deal.

There is a cadre of people in several countries made up of people who do run their whole households on solar and wind energy. You can read detailed descriptions of their efforts in the American magazine Home Power. Paradoxically, although the US government (George W Bush) has been hostile to the very concept of Climate Change, there are probably more people in America attempting to live on solar energy than in any other country. (The new president Barack Obama seems to be well aware of the seriousness of the problem).

If all roofs were covered with photovoltaics we could generate megawatts of electricity without emitting any warming gases. PV surfaces have a very long life so that depreciation costs are low, even if capital costs seem large. Maintenance costs are also low, consisting mainly of regular washing - in my case with a garden hose and a sponge down, maybe monthly.

Yes, there are other things that have to be done. It is hard, or at least expensive, to store electricity, so an electricity system that has a large PV input needs an alternative for the night time, and cloudy periods. I have noted that in Kenya the hydropower in the rivers could be used as a pumped storage system. In Europe there may be scope for similar systems. Hydrogen will probably be an important means of storage, for example for energy collected in arid zones with clear skies.

But to tackle seriously the output of warming gases we shall need governments to act. The current ruling ideology (see Naomi Klein) in most western countries derives from Milton Friedman who argued that governments should do almost nothing, leaving nearly everything to the corporate sector. I strongly disagree with this ideology, whose real purpose seems to me to be to increase the wealth of the rich, and create a larger gap between rich and poor. I am sure there will be a role for state owned businesses, and certainly for laws directing the so-called private sector in what they may and may not do. For people more interested in implementing Friedman's ideology than in the practical policies of climate this will sound like socialism - one of their demons. Too bad for them.

One layer of the problems with changing our energy systems is that we are all used to having power available whenever we wish. That may not always be possible with income systems. For example, I may wash the clothes only when the hot water is at 42 ^oC. On some days that doesn't occur until the afternoon. So, on those days that is when I wash. If the usual washing day is cloudy I may put off clothes washing to another day, or after watching the weather forecast do it a day earlier.

It is already possible to have electric meters that vary the price of electricity by time. At present night time electricity can be much cheaper than daytime. In a system with a strong PV component, daytime electricity might be cheaper.

The private car is made possible by a vast consumption of capital energy - oil products. Will it be possible to power private cars with income energy? Personally I doubt it, at least not on the scale presently found. That has implications for the whole land use policies in many western countries where low density housing is common. The existing housing, especially in the US and Australia, becomes difficult to live in if motor fuel becomes much more expensive than at present.

Karl Marx said Labour Power was the only real source of wealth - everything else was superstructure. It would be truer to say that energy is the source of our wealth plus human labour or ingenuity. The financial and economic systems have to adapt to the new types of energy - income sources. As the oil industry is in fact a plundering activity, more like piracy than honest industry, its demise would change the source of income of the super-rich. It seems unlikely that oil and coal companies would be the best organisations to manage the income sources, mainly because they have such huge parasitical bureaucracies.

Some other Income energy sources:

• wind power
• wave power
• tidal (e.g. Severn Barrage)
• OTEC
• biogas
• sugar (but there are problems with possible soil deterioration and forest clearing)

George W. Bush's favourite - alcohol from grain - should not be considered, as its use on a large scale would cause famine.