Sunday, March 21, 2010

Climatology - Post-Normal Science

Some might wonder why discussions about climate change often sound as if it was more of a debate about religion than it were about science; and fret about how political the whole issue has become. All this has apparently been because Climate Science is typical of a 'new' kind of scientific process called post-normal science (PNS).

Actually post-normal science (PNS) is not that new. It was first proposed by a pair of academics, Silvio Funtowicz and Jerome Ravetz in 1992 to characterize that type of scientific process that dealt issues of some urgency and where facts are sparse and uncertain. It is in effect, a kind of problem solving approach to complex science related issues. Because of the unavailability of good accurate data, all kinds of data from non-traditional sources can be used in finding urgent resolution to the problem. much of which did not require validation or proof. Much of medical science can be of this sort, where significant uncertainty exists in the management of critical and urgent clinical problems.

The Wikipedia entry reads: "According to its advocates, "post-normal science" is simply an extension of situations routinely faced by experts such as surgeons or senior engineers on unusual projects, where the decisions being made are of great importance but where not all the factors are necessarily knowable. Although their work is based on science, such individuals must always cope with uncertainties, and their mistakes can be costly or lethal. Given the greater importance of climate systems and the fact that less is known about them, conventional methods of inquiry, based on determining all relevant information before proceeding, are too slow and uncertain to deal with an issue too complex to be fully understood and too important to wait for confirmatory results."

Because this form of scientific approach cuts short many of the processes required to generate accurate and detailed data, it is important that the process relies on an 'extended peer community' (EPC) to provide quality assurance for the proposed solutions. This EPC consists "not merely of persons with some form or other of institutional accreditation, but rather of all those with a desire to participate in the resolution of the issue."

Funtowicz and Ravetz further point out that "Statistical theory tends to undervalue another sort of error, ironically called Type III, when the whole artificial exercise has no relation to the real issue at stake. Type III errors are a characteristic pitfall when the ‘normal science’ approach is deployed in post-normal situations. Modelling exercises are particularly prone to this sort of error, as when the gap between the available data and a manageable model on the one hand, and the real policy situation on the other, cannot be bridged."

The PNS approach is without doubt effective and necessary. However it does have a tendency, because of its relative lack of traditional scientific rigour and objectivity, to drift into an approach that is resembles activism or advocacy. Without checks and balances, the solution soon becomes orthodoxy. That is why the 'extended peer community' is essential to keep this paradigm 'honest'

The science of climate change fits exactly into this form of a scientific approach, being complex, urgent and bereft of good accurate data and understanding. The problem with it has been that the protagonists in the story got carried away with their zeal and lost their objectivity. The solution became orthodoxy. They proclaimed the science settled, and excluded the EMS, branding them deniers and skeptics etc. In so doing, they became advocates and activists. Some might say priests of a new religious order.

He writes: "We can understand the root cause of Climategate as a case of scientists constrained to attempt to do normal science in a post-normal situation. But climate change had never been a really ‘normal’ science, because the policy implications were always present and strong, even overwhelming. Indeed, if we look at the definition of ‘post-normal science’, we see how well it fits: facts uncertain,values in dispute, stakes high, and decisions urgent. In needing to treat Planet Earth like a textbook exercise, the climate scientists were forced to break the rules of scientific etiquette and ethics, and to play scientific power-politics in a way that inevitably became corrupt. The combination of non-critical ‘normal science’ with anti-critical ‘evangelical science’ was lethal. As in other ‘gate’ scandals, one incident served to pull a thread on a tissue of protective plausibilities and concealments, and eventually led to an unravelling. What was in the e-mails could be largely explained in terms of embattled scientists fighting off malicious interference; but the materials ready and waiting on the blogosphere provided a background, and that is what converted a very minor scandal to a catastrophe."

An early post by Elizabeth Bury (before Climategate broke) on this issue is also a good read.


Team Building said...

they should have a degree major in PNS. sounds interesting and could pave the way for sg to be the leader in PNS.

gigamole said...

Currently the subject would be covered under courses related to modelling and decision making. The Institute of Math Sciences discusses this to some extent but usual as part of a larger issue of modelling algorithms.

I am not aware the business schools in Singapore offer a major on 'decision making'. Perhaps they should.