Climate Change?

There are no passengers on spaceship earth. We are all crew.  Marshall McLuhan

My main bugbear with the subject of human caused environmental change is the misleading arguments, bad science, emotion and dogma rather than rational evidence based approach used by many people on all sides of the debate.  This of course is common where science and politics intersect: where either science may be used as a pretext for belief based policy, or where belief is held up as being superior to science.  Science is based on reason, logic, and empirical scientific methodology; which is often counter-intuitive to the “common sense”, beliefs, superstitions and compliance with social networks we are programmed to give precedence to.

I was therefore interested to read the Guardian article headed “Climate change should be excluded from curriculum, says adviser”.   As it turns out he was presenting an argument, not on the validity of climate change, but instead on a principle as opposed to rule based approach to how the curriculum should be written, as well as concentrating on the basics of science.  I remember concentrating on the basics of science when I was at school, and don’t think it will do anything to reverse the decline in science graduates we are experiencing.  But that’s anecdotal - the research seems to suggest that the way you teach science rather than content is the most important factor.  However, I digress.

Ok, I know nothing about climate science – so where do I start?

I am told that there is a “scientific consensus” is that human generated climate change is real, and will cause many perhaps irreversible adverse changes to the environment.  The term adverse is used in a human centric way here; Venus demonstrates that planets can exist quite comfortably with runaway greenhouse gas effects.

I’m slightly uncomfortable with the idea of “scientific consensus” – science is surely based on evidence, not agreement?  This may be based on both scientific argument and the scientific method, but still represents people’s judgement and opinion – both notoriously fallible – even if they are masters of the particular field, and the judgement represents the majority viewpoint.   

It is often pointed out as a criticism of the concept that there are historical examples of it being wrong.  Let’s ignore Galileo, who is sometimes used, as he was a pioneer of the scientific method arguing against religious dogmatism.  Both the theories of continental drift and the bacterial cause of stomach ulcers are better examples.  However they both actually demonstrate the strength of scientific consensus – in the face of evidence the consensus will change.  Where there is a significant change from established science needed (as in both these cases) a high standard of evidence and documentation is required – or as Carl Sagan might say “extraordinary claims require extraordinary proof”.

Of course, while this might strengthen consensus as being a valid tool from a scientific standpoint, it does nothing to make it useful for creating public policy.

This is taken care of by the precautionary principle; that if an action or policy has a suspected risk of causing harm to the public or to the environment but there isn’t scientific certainty about the likelihood, size or nature of the harm, the burden of proof that it is not harmful falls on those taking the action.  In an absolute sense this is nonsense, as a complete lack of harm is impossible to prove, and if it had been used historically we may not have cars, cellphones, aspirin, electricity networks or the Nintendo Wii.  There are correlations between the level of education and nearsightedness in individuals, and industrial development and nearsightedness in populations.  Yes, under an absolute interpretation of the precautionary principle we should all go back to living in pre-literate rural communities.

But the principle is much more nuanced than that.  It is based partly on the old English common law of “duty of care” which requires you, when doing something which could harm others, to take precautions not to do so.  Most versions require some evidence of the likelihood and severity of harm.  Many allow for a consideration of the cost of precautionary measures.  A good analogy of the principle is found in obligations under health and safety legislation for both employees and employers, and in workplace hazard management practices.

While irreversible or highly damaging human caused climate change is a prediction – and therefore open to debate - human caused environmental degradation is incontrovertible.  We destroy natural habitats, we deplete resources, and we poison the soil, the air and water.   On a localised scale we can see the economic consequences of issues such as overfishing and agricultural land loss through soil salinity from irrigation; desertification; health, environmental and economic costs of industrial accidents such as Bhopal and Chernobyl, and large scale environmental destruction like the Aral Sea. 

  Formerly part of Aral Sea

The problem of extrapolating long term global consequences of this degradation is because it is part of a chaotic system.  The characteristics of this sort of system are that what happens is very dependant on the initial conditions, so unless you know those initial conditions in their entirety, you cannot predict the systems future behaviour with accuracy.  As scientists modify their predictive models based on evidential feedback they reduce the uncertainty around those initial conditions – which may or may not make them more accurate - and the models indicate long term global warming and consequent environmental change.

Natural variations in temperature and weather have occurred in the past and are believed to have had significant effects for human populations – from the ice age to the theory that drought caused the collapse of Mayan civilisation, so we can expect any human caused change to have consequences.  So we have a situation in which there is uncertainty, effects that for all practical purposes on a human timescale are irreversible, and consequences to us and future generations of those effects.  

 

Yet we continue down this path.  This is analogous to a situation called the “Tragedy of the Commons”, based on an example of medieval European common land on which each herder is entitled to let their cows graze.  It’s in each herder’s interest to put as many cows as possible onto the commons, even though it will lead to overgrazing, because the herder receives all the benefits from each additional cow, while the damage is shared right across the group.  If all the herders do this though eventually the commons will be destroyed, to the detriment of all.  This is summarised by Wikipedia as “a dilemma arising from the situation in which multiple individuals, acting independently and rationally consulting their own self-interest, will ultimately deplete a shared limited resource, even when it is clear that it is not in anyone's long-term interest for this to happen.”

We can see this analogy in these comments about bringing agriculture into New Zealand’s emissions trading scheme:  Imposing the emissions trading scheme on New Zealand agriculture would hurt the country's economy unless other countries were doing the same thing, says Fonterra Cooperative Group chairman Henry van der Heyden.  "Why do anything to the detriment of our competitive advantage?"

This is a classic commons argument.

There are two solutions to the commons dilemma.   The first is to privatise the resources.  This is proven to be effective, but it is unlikely that we will ever have (or want) Global Inc.  The second is to regulate, but as we’ve seen from Kyoto and other attempts, this seems equally unlikely.