In 2001 the English version of The Skeptical Environmentalist by the Danish statistician, Bjorn Lomborg, was published. It marked the beginning of an increasingly vehement debate about the impact of Human activity upon the levels of Carbon Dioxide in the atmosphere and the potential that this has for changing the climate of the Planet. Lomborg himself was skeptical about some of the findings of others, and he was able to highlight some weaknesses in some of the work that had been conducted up until then. In turn, however, the response to The Skeptical Environmentalist, was extremely hostile. Lomborg's scientific skills, indeed his very integrity were bitterly attacked. Yet, in fact much of Lomborg's work underlined the very high likelihood that CO2 emissions were the result of the activity of man, and that they could in turn lead to significant alterations in climate.
The scientific work in studying the climate contains some of the most difficult mathematical questions that humans have faced. The extraordinary complexity of the planetary climate requires huge computing power even to approximately model it- and the most sophisticated climate modelling programs can outstrip even economic modelling in their detail and complexity. It is- in short- a very serious business.
Furthermore, the fundamental question is not whether or not human activity alters the climate- the evidence is utterly overwhelming that it does. The question is how much human activity is changing the incredibly complicated and interlinked systems that allow life to flourish on Earth as- so far as we can tell- no where else. As one of the Apollo Astronauts said "we are living in the Garden of Eden- and we don't take very good care of it".
Scientists owe some of their understanding of the atmospheric greenhouse effect by the pure research done on the atmosphere of Venus. The consequences of a runaway greenhouse effect have been to bake Venus at extraordinary high temperatures and render Earth's near twin uninhabitable to any life form that we can recognise. We do not know what the impact of large scale release of CO2 by mankind is, but we have seen on Venus that the consequences could include impairing or even ending the capacity of the Planet to support mankind, even if the risks of this may be quite small, the fact is that we are playing a game a game of Russian roulette and we do not understand how many bullets are in the chamber nor how many chambers there actually are.
In that sense the large number of "climate change deniers" are kind of missing the point. They may dispute the meaning of data, they may imply that a few scientists have done poor work and that they manipulate results that are biased against the "climate change denier" lobby. However there is no scientific doubt whatsoever that human activity has changed and is changing the climate. They may dispute how much it matters, but they cannot- indeed do not- dispute that it happens. The problem is that if it does matter, it matters a lot. We are injecting great instability into a fiercely complicated system, that we still do not fully understand. It is a matter of simple prudence that we should try to moderate human impact on the atmosphere.
Then there is a second, allied, aspect to the debate about climate change: it is the issue of sustainability. We have created a society that is not just profligate in energy use, but in many other resources. We do not know how much oil and gas or coal exists in the Earth's crust, but we do know that it is finite. We do not know how many metals, from Iron to Platinum to Uranium exist, but we know that these are finite too.
Humans are a very young species- perhaps not older than 100,000 years in our modern form. civilisation, including agriculture is far younger than that: less than 10,000 years. Compared to the roughly 4.5 billion years of the existence of the solar system, and our planet amongst it, or the roughly 500 million years since the explosion of life in the Cambrian era, we are mere mayflies. As a matter of common sense we should be reusing the resources that we have and conducting our economic business in a way that allows us to continue to benefit from the bounty that the earth provides us with. That means using constantly renewed sources of energy, such as solar, and it also means using more living things to serve our purposes. For example, bacteria or plants that can breakdown waste products so that they are no longer toxic, perhaps even breaking down CO2 itself. We do not have to reject technology in order to create sustainable ways of doing things, although in some ways we simply need to relearn old technologies: the creation of modern maritime wind power could reduce the third of CO2 emissions that come from shipping for example.
As we await the deliberations of the Copenhagen summit, we already know what we have to do, we just have to make the decisions to do it. If we do things now, the costs and consequences are likely to be dramatically lower than if we wait. It is time to be quite clear: even if the total risks arising from the dramatic elevation in CO2 may be small (which is debatable), some of the potential consequences are so severe as to be unacceptable. As for sustainability: it is already a certainty that we are using up finite resources. It is only a matter of time before we will be forced to take action- now might be a good time to act while we still have some cushions and margins for error.
We need to get into better habits and avoid the kind of waste that our rather short-sighted, disposable culture is embedding in our social values. This is a process of reform that could take a while. Human beings may take time to see that their short term wishes may not be in the interests of their long term survival.