Jennifer Marohasy

a forum for the discussion of issues concerning the natural environment

Opinion

The Mathematics of Connectivity and Bushfires: A Note from David Ward

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HUNGARY has produced many outstanding mathematicians and physicists. Perhaps there is a connection with rampant violin playing.

One of these was Paul Erdös who was the twentieth century’s most prolific mathematician, with 1475 papers to his credit. He rivals Leonhard Euler, the Swiss genius of the eighteenth century. There is a worthwhile biography of Erdös called ‘The Man Who Loved Only Numbers’, by Paul Hoffman (1998).

On a recent thread at this blog (Wise Men Excluded from Bushfire Royal Commission), I raised the issue of fuel connectivity, and suggested that it helped to explain the uncontrollable spread of bushfires over large areas of Victoria a few months ago.

The tonnage of available fuel determines the intensity, and convection column strength, and the number of flying embers, but connectivity determines ground spread. Wind is important, but large fires, of course, create their own wind. It seems to me that the application of Occam’s Razor makes climate superfluous to the argument, beyond there being weather dry enough for a fire to burn. Given dry fuel, fierce fires can occur even at mild temperatures. Surely we have all lit a pot-belly stove on a winter’s day.

Although I doubt if he had ever seen a bushfire, or a gumtree, Erdös had useful ideas on connectivity in networks. With a Hungarian colleague, he published papers about ‘giant patches’. These form when random connections are made between a set of random points (Erdös and Renyi 1959, 1960).

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Pondering Problems with Computer Climate Models: A Note from Michael Hammer

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SCIENTISTS have put a huge amount of effort into generating computer models of our climate system.  These models are very sophisticated and complex and their outputs suggest that increasing carbon dioxide will lead to significant temperature rises for our planet.  Indeed the model outputs now represent the main evidence in support of the anthropogenic (man induced) global warming hypothesis.   Why shouldn’t we take careful note of these results?

Computers are a tool allowing many calculations to be done extremely rapidly.  If we can describe a system we wish to explore via a set of interrelated equations we can then get a computer to repeatedly solve these equations with a small assumed time increment between each set of solutions and do it quickly. The output describes the future as predicted from the input equations.  This is a computer model.  It is important to remember that the model output is completely and exclusively determined by the information encapsulated in the input equations.  The computer contributes no checking, no additional information and no greater certainly in the output.  It only contributes computational speed.

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More Low-Carbon Research Needed: A Note from Bjorn Lomborg

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WE are often told that tackling global warming should be the defining task of our age — that we must cut emissions immediately and drastically. But people are not buying the idea that, unless we act, the planet is doomed. Several recent polls have revealed Americans’ growing skepticism. Solving global warming has become their lowest policy priority, according to a new Pew survey.
 
Moreover, strategies to reduce carbon have failed. Meeting in Rio de Janeiro in 1992, politicians from wealthy countries promised to cut emissions by 2000, but did no such thing. In Kyoto in 1997, leaders promised even stricter reductions by 2010, yet emissions have kept increasing unabated. Still, the leaders plan to meet in Copenhagen this December to agree to even more of the same — drastic reductions in emissions that no one will live up to. Another decade will be wasted.
 
Fortunately, there is a better option: to make low-carbon alternatives like solar and wind energy competitive with old carbon sources. This requires much more spending on research and development of low-carbon energy technology. We might have assumed that investment in this research would have increased when the Kyoto Protocol made fossil fuel use more expensive, but it has not.

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More Worst AGW Papers: A Note from Cohenite

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SINCE Copenhagen the intensity of doom and gloom [D&G] has been ratcheted up with such anthropogenic global warming luminaries as Will Steffan and David Karoly declaring their previous predictions not dire enough and so have been superseded by much worse predictions.

Jay Leno has a good response to this;
“According to a new U.N. report, the global warming outlook is much worse than originally predicted. Which is pretty bad when they originally predicted it would destroy the planet.”

The question is, is there any evidence to support the worsening D&G?

Professor Chris Field was recently reported on the ABC doing D&G about an increase in fossil fuel emissions, but this quickly died when the penny dropped that the main increase in emissions was coming from China and India, not to mention the fact that temperature was declining concurrently.

With increased emissions insufficient to sustain the D&G could the peer-reviewed literature provide justification? Peer-review is the life-blood of AGW and lo-and-behold it was apparent that the D&G was backed up by several new and recycled papers. 10 of these papers which offer ‘evidence’ for the D&G are discussed. All of them exhibit the usual defects of pro-AGW papers; reliance on modeling regardless of contradictory or non-existent ‘real-world’ data.

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Defining the Greens (Part 5)

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IT is wrong to assume that the Greens are luddites and in particular anti-technology. 

This is a criticism often levelled against them because, as a group, they tend to oppose many new technologies, for example, the genetic modification of crops and nuclear energy.

However, the Greens are passionately pro solar technology. 

The only problem with this technology is that it tends to be uneconomical without massive government subsidies which I understand are not a problem for the Greens – subsidies that is.

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