I have been reading and thinking about climate change lately – partly as a result of Prime TV’s screening of The Great Global Warming Swindle (see Swindlers List) and the discussion at Poneke’s bog (see Frog agog with umbrage over Prime plan to screen anti-Gore documentary). Here are some of my thoughts on the controversy.
1: Inevitably the science of climate change is complex.
We are looking at a complex global system and need a large amount of information from a wide variety of sources. Conclusions derived from “cherry-picking” data, or based on wishes or beliefs are obviously unreliable or just false. Similarly, arguments promoted by petitions and simple appeal to qualifications are suspect.
Individual investigations or data sets are inadequate in this situation. I think the approach of the IPCC which attempts to develop a scientific consensus from reviews of all the published scientific findings is the most credible approach.
2: There is scientific agreement that anthropogenic activity (greenhouse gases) contributes to our current climate change.
Inevitably this agreement is provisional (we see details changing with each IPCC report) as the science improves and more data is available.
The extent of this agreement covers a spectrum which is perfectly natural. I have seen the assessment that 70% of climate scientists support the IPCC conclusions while 15% think they are overestimates and another 15% think they are underestimates.
Sometimes climate change deniers raise the issue of individual scientists whose work has been included in IPCC documents but who disagree and wish their names reviewed. This shows a misunderstanding of such reviews. The documents are not petitions. There will be many scientists whose work has been included (reviewed) but who personally do not accept the overall findings of the review. They may legitimately feel (based on their own limited findings) the overall conclusions are underestimates or overestimates.
3: The different assessments of anthropogenic contribution to global warming arise from two major sources.
- Some scientists think the influence of carbon dioxide and other greenhouse gases on global temperature is either less than, or more than, the IPCC assessment.
- There are different predictions of future inputs of greenhouse gases into the atmosphere. These produce different assessments of future changes in global temperature.
4: Modelling future climate change is a problem.
Science does have difficulty predicting the future (but it usually does far better than non-scientific methods). We inevitably rely on computer models for this. These have problems with the extent to which they can describe the natural processes underlying climate changes. They are also dependent on the quality, and amount, of data available for input.
The quality of climate change models is improving with time. New, more realistic models are becoming available. Computing power is also improving. We also accumulate more data with time. This is a major reason for changes in the assessments revealed in the different IPCC reports.
One of the important tests of climate change models has been their ability to predict the details of climate change that we already have information for. This testing provides important feedback, enabling improvement of models.
A convincing demonstration the reliability of the IPCC assessment is shown by the way that models are able to describe recent changes in global temperatures using either natural causes or anthropogenic causes alone. (In the figure the black line shows measured global temperatures and the grey line temperature predicted by current models. Both natural and anthropogenic inputs are required.)
5: Political activists don’t decide the science
And we shouldn’t let them.
I think many environmental activists treat their causes like a religion – often relying on faith rather than evidence and using the religious techniques of shame and guilt to advance their cause. This turns people off. These attitudes play right into the hands of climate change deniers.
Some of the deniers use similar methods. Interestingly, many creationists and proponents of “intelligent design” (ID) are active campaigners for climate change denial.
Activists often rely on single arguments or data sets to support their position. They often start with a belief and then look for supporting evidence. Which is very much against the scientific method.
A common, and disturbing, attitude with many climate change denial activists is their smearing and slandering of science and scientists – playing the man rather than the ball. ID proponents also use this technique (e.g. the film Expelled: No Intelligence Allowed).
6: The controversy is largely political and economic
Some scientific controversy is unavoidable, given the complexity of the problem. And the majority scientific assessment will change with time – inevitably providing fuel for deniers who wish to discredit the science.
But the public controversy is not a real reflection of the limited scientific controversy. It is a reflection of arguments over policy and economics. Most governments now accept the scientific consensus and are reflecting on policies aimed at relieving the situation. These policies inevitably have economic impacts – and there’s nothing like economic impact to create political passion.
Given the degree of scientific consensus on anthropogenic contribution to current global warming we should recognise the controversy for what it is – differences related to policy and economics.
We can accept science but still disagree strongly with specific policy proposals.
7: Should we bother doing anything?
After all climate change occurs anyway. There have been big changes in the past and will be big changes in the future. Biological species have become extinct in the past and will in the future – that’s evolution.
All true. But the difference today is the changes are much more rapid. Unprecedented results in terms of species extinction and social disruption are expected. I think it’s a no-brainer. If we can do something to reduce these disruptions we should.
8: But is climate change our only problem?
It’s just part of a wider group of problems arising from the success of our species. Our growth in population and dominance on this planet. We have huge problems arising from resource depletion, waste creation and pollution of our environment.
We will, I hope come to grips with our contribution to climate change but will still have to deal with these other problems. And with future problems we cause.
It’s the sort of situation that has driven other species to extinction. Our only hope is that we have the intelligence to reason, to learn from our mistakes and to plan for our future.
However, we are still bound by superstition and denial. There is no guarantee that intelligence and reason will win.