Gambling on climate change - no safe bets

Gambling on Climate Change

Lectures on the Global Warming Gamble 

Extract of -
The Global Warming Policy Foundation
2011 Annual GWPF Lecture
Westminster Cathedral Hall | 26 October 2011

One Christian Perspective on Climate Change
Cardinal George Pell
Archbishop of Sydney

Let me begin by thanking the Global Warming Policy Foundation for the invitation to deliver this lecture.

Why might a Catholic bishop comment?

We might ask whether my scepticism is yet another example of religious ignorance and intransigence opposing the forward progress of science as is alleged in the confrontations between Galileo and the Papacy in the early seventeenth century, when the Church party on the evidence of scripture insisted that the sun moved around the earth.

It is not generally realized that in 2001 at least, one of the IPCC Third Assessment Report’s Working Groups agreed: “In climate research and modelling, we are dealing with a coupled, non-linear, chaotic system, and therefore that the long-term prediction of future climate states is not possible”.

Arnold helped to explain why the systems around us work, how fluids flow. Like Lorenz, he found that small changes had an immense impact on outcomes. For him long-range weather forecasting was effectively impossible, because small events could have dramatic, unforeseen consequences.

A small event - dramatic, unforeseeable consequences

Changes in Carbon Dioxide and Temperature

Fluctuations in temperature (red line) and in the atmospheric concentration of carbon dioxide (yellow) over the past 649,000 years.
"SMALL" Change: The vertical red bar at the end is the increase in atmospheric carbon dioxide levels over the past two centuries and before 2007.

From "A brief history of the universe"

• Human beings first arrived in Europe about 35,000 years ago.
• The first cities were only built 8,800 years ago.

An observation on Cardinal Pell's Lecture

Cardinal Pell highlights key attributes of climate science that give little reason for comfort:

• "In climate research and modelling, we are dealing with a coupled, non-linear, chaotic system, and therefore that the long-term prediction of future climate states is not possible" and
• "small events could have dramatic, unforeseen consequences."

The implications of this description are perhaps a little obscure.

An example of a non-linear system is a house-of-cards. It is susceptible to sudden collapse when a single card is moved even though it is seemingly stable when other small changes are made. That is, small events can have dramatic, unforeseen consequences.

There are three unfortunate characteristics of such systems -

• Very small changes can create completely unexpected and seemingly disproportionate changes with little warning.
• Predicting behaviour of the system will be very difficult. 
• Removing a "trigger" that seemingly precipitated a disproportionate change will most likely fail to restore the system to its previous state.