But when we come to transport the signs are massively less promising. As the third world gets richer more and more cars are being driven. All the efforts to reduce the amount of fossil fuel burnt by each individual car are being dwarfed by the impact of vast numbers of new cars pumping out pollution. When I went to China 30 years ago the whole of Beijing was full of bicycles and I only saw the occasional car. Now the city is clogged with some of the worst traffic jams and worst pollution on the planet. That trend is in the process of being copied across Africa and it is going to take an heroic effort by the manufacturers of electric cars and by city planners to overcome the problem on anything like the timescales that scientists tell us we need to follow to limit the giant and completely unpredictable experiment we are conducting on our planet.
But it is when you start to think about air traffic that it is easy to get most concerned. Aircraft take decades to design and build. There is absolutely no sign of a workable aircraft in early stage design that will reduce the damage aircraft do to the environment by anything remotely equivalent to the steady increase in their use. Put simply aircraft are going to increase in numbers as people across the world continue to raise their income levels. More people are going to decide to travel for business and more tourists are going to want to explore our fascinating planet. That is going to happen regardless of any efforts we might make to fight the culture of excessive consumption. Just ask yourself these two simple questions. Would you be willing to never go on a foreign holiday again? Will greater income in third world countries lead to more flights or fewer?
So we have to be realistic. There is going to be a big increase in air traffic and it is going to result in a dangerous increase in air emissions. In these circumstances policy planners need to think hard and long about the appropriate actions. I think the following measures are necessary:
1. Try to control the size of the increase by taxing flights realistically. If we want to travel by air then we need to pay the full cost of the externalities we are generating. I loved paying £50 to fly to the south of France but it doesn't represent a realistic reflection of the real costs.
2. Put government investment into the long term project of developing alternative aircraft engine technology. The free market provides insufficient incentive for any company to do this at the necessary speed and governments need to intervene.
3. Invest in better rail routes and make sure they are competitively prices against air travel whenever there is a realistic choice. This is one of the many reasons why I disagree with most Green Party members over HS2. I think it is a necessary and helpful addition to rail capacity that will take traffic off roads and reduce flights.
4. Develop regional airports not one main London Heathrow complex because that will at least cut down on travel to the airports. It also helps balance the regional and the London economies better. It helps no one if people get in their cars and drive from Leeds to Heathrow airport whenever they wish to fly to the States.
5. Intensify the efforts to reduce carbon emissions elsewhere because in the short term only a major effort to offset the damage is likely to work. Make every new building project generate more energy than it uses. Seriously increase the subsidies for people in older homes to install helpful new insulation technologies. Develop tidal barrages and offshore wind. Put moveable solar panels on all available brownfield sites. Subsidise green energy technology to speed its implementation and tax more heavily fossil fuel technology. Invest in an easily accessible national network of electric car charging points. And of course don't make the problems even worse by going for fracking.
Put simply we have a big problem. We are running out of time to deal with climate change and in one major area of technology there are strong social, economic and technological forces that are almost certain to make the problem worse. Faced with this situation there are two potential approaches. One is to do absolutely nothing and to hope that the free market will eventually sort out the problem or that somehow the problem will magically go away. That isn't going to happen because in this field of human activity the technological solutions are a long way down the track and too expensive at the moment to be worth seriously investing in by anyone hoping to make a profit by being ahead of the game.
We therefore have to recognise the realities of the situation and adopt policies that minimise the damage and redouble the efforts to compensate for it and achieve overall emissions reductions elsewhere.
I leave the reader to judge whether they heard any serious and helpful discussion of these issues from the UK government as it announced its decision to go ahead with Heathrow expansion. All I heard was a determination to ignore unwelcome realities. I am sure that the naive hopes expressed by the government will be of immense comfort to the residents of West London as they contemplate yet another increase in the number of flights over their heads.