The science of climate change is not my target. It is clearly a fact that the world's regional climates are changing substantially and at unprecedented speed, and this is a result of greenhouse gases produced by human activity (in particular by the industrialisation of the West). Denying the science is just silly. But 'science' does not have the legitimacy or resources to tell us what we should do about climate change. We have to work that out for ourselves.
It is often said, and very plausibly, that climate change is difficult for human minds and our political institutions to grasp and act on because of its global scale and long-term and complex causal mechanisms. Stephen Gardiner has called it a 'perfect moral storm'. One way of dealing with such difficult problems is to moralise them. This seems to be the strategy currently favoured by mainstream environmentalists. Morality concerns strict but simple universal rules that everyone should follow without regard to personal situations or consequences - on the model of laws. On this model, one's carbon footprint is a crime (against the planet presumably) which one should feel guilty about and strive to mitigate. As of course are other people's carbon emissions: they deserve to be shamed or otherwise forced into submission by the righteous ones.
In trying to tackle climate change by directly dealing with the causal mechanism of CO2 levels we have framed the situation as an enormous collective action problem - how to persuade 7 billion people to adopt the new morality of carbon rationing (and prevent free-riding). Everyone who thinks this through recognises that it is impossible to realise without enormous government coercion (severe rationing along the lines of China's one-child policy). That requirement explains many climate change warriors' antipathy to democratic principles on this point - it seems easier to persuade all 200 governments to be adopt carbon authoritarianism than to persuade all those people individually (e.g. James Lovelock). However even the government coercion approach fails - see the failures of every inter-governmental treaty, from Kyoto to Copenhagen - and the reasons are obvious.
The moralisation approach undermines itself since it frames climate change narrowly in terms of righteousness. Inevitably deliberation about action gets bogged down in an interminable blame-game about what justice requires - who had their industrial revolution first, etc. Furthermore, the moral duties of different actors do not all point the same way: poor country governments have a clear and over-riding moral duty to help their citizens achieve the high quality of life which the West takes for granted, and which is inevitably energy (carbon) intensive. And then there is the practical economics: the world still has lots of coal, especially in the poor world, that can produce electricity at 3c per kwh (which renewables cannot possibly compete with without radical technological breakthroughs, even with the strongest moral rhetoric). No comprehensive global political solution to greenhouse gases is possible. We need to go back and think again.
The moralisation approach contrasts with a fuller ethical thinking in which values are considered and debated explicitly and openly. Righteousness simplifies but it doesn't try to understand. No-one emits carbon deliberately 'for fun', but rather we engage in activities which are more or less valuable to us - such as flying across the Atlantic to visit grandparents - which happen to emit carbon as a byproduct. To ignore the value of these human activities and see them instead as moral crimes is to do a violence to the very humanness of the lives (including those of future generations) that we are supposed to be so concerned about preserving. The single-minded focus on carbon reduction even distracts us from protecting other valuable parts of our environment, like the wilderness areas that would be industrialised with biofuel plantations, dams, and windmills. We need a broader ethical debate about what the consequences of climate change will be for what we humans have reason to value (e.g. polar bears - not that important; rising sea levels - very important) so that we can take really credible actions to protect them.
Perhaps surprisingly, such a fuller ethical analysis can benefit greatly from economic reasoning and tools [previously]. Economics is often supposed to be cold and heartless. But sometimes a hardnosed logistical approach is helpful, and economics is actually very good at addressing complex problems involving multiple agents with divergent interests that cannot all be satisfied i.e. our 'perfect moral storm' (as e.g. Bjorn Lomberg has pointed out). It uses quantitative methods to disaggregate the different causal mechanisms in play (such as different sources of CO2 equivalents) and different effects on social welfare (such as the impact of more frequent extreme weather on cities and agriculture). Then it constructs models focussing on the most significant mechanisms and uses the models to test alternative policy proposals for their costs and benefits to social welfare (including other things we value besides those related to climate). Its analysis suggests different packages of policy bundles (not only markets for carbon) that would follow from different values we assign to different aspects of social welfare, as well as incorporating the degree of uncertainty remaining in the science and politics of climate change.
This is an essentially pragmatic approach - breaking the 'end of the world' into human-sized and human-relevant problems and solutions and ordering them by their importance, feasibility and (opportunity) costs. It builds on the fact that while the central causal mechanism behind global climate change is greenhouse gas emissions (important to understanding and modelling the phenomenon itself), solutions need not directly engage with that causal mechanism in the short term. After all, it is the effects of climate change on the things we care about that is important, not some abstract CO2 molecule count. We do not need to fixate entirely on CO2 emissions when other options exist to mitigate the effects of climate change that actually concern us, and seem much cheaper and more effective. i.e. we can trade off some level of climate change we can live with against the excessive costs and implausibility of seeking to end all carbon emissions immediately. Piecemeal actions are easier to achieve and even at national and regional levels can be significant. For example, soot emissions from old-fashioned coal-burning power stations are particularly bad for climate change but relatively easy to regulate and mitigate.
In the longer term, the greenhouse gas build-up must be dealt with, of course, and that will have to be by technological advances that remove CO2 from the atmosphere, such as genetically modified algae and trees, while also reducing the carbon intensity of our high energy life-styles (for which we already have some existing technologies, such as nuclear power). Such innovations require no prior global agreement to set in train. A high price on carbon in a few large rich countries (preferably via a non-regressive carbon tax) supplemented with regulations where markets don't work (e.g. to force the construction industry to build more energy efficient buildings) and research subsidies would provide the necessary incentives. Nor do they require global agreement for take-up since they will be attractive on their own merits (clean, efficient, cheap).
The pragmatic approach does not depend on reaching an impossible global agreement on a perfect solution requiring moral or political coercion. Instead it offers feasible paths through the moral storm while respecting the existing interests and values of the human beings concerned. It is more democratic than the moralising approach because it works within our existing democratic institutions (no need for a 'global government') and offers transparent arguments within our present valuational framework (rather than requiring us to assume a new and narrow set of values). It is also fairer. While the moralists' orientation to stasis places excessive burdens on the world's poorest, the pragmatic approach naturally pushes the greatest obligations and costs onto those (rich governments) most able to act. There will of course be new humanitarian demands which the rich world must honour - e.g. from low-lying Bangladesh or the Maldives - but we already know how to build sea-walls and they're much cheaper than stopping the economy and much more likely to work.
At present too many supporters of tackling climate change are guilty of the same moral and cognitive melt-down in the face of its complexities that they accuse their detractors of. They are wrong to see the development of human freedoms and well-being as a distraction or even a threat to the world. They are wrong to fixate on an abstract and impossible problem (350 CO2 ppm) and seek a perfect solution without reference to wider ethical issues, and political and practical feasibility. They are wrong to give up so easily on democratic politics and human ingenuity and settle for retreating into the darkness of 'sustainability'. We best fulfil our duty to future generations by making this world a better place for all the people in it [previously]. Not by leaving them the world in the same exact state we found it, but by ensuring that we leave them all with possibilities enough and as good as we in the rich world have had for living good lives. If not better!