Archive for the ‘Climate’ Category

Fielding Offside on Climate Change

July 14th, 2009 2 comments

Australian senator Steven Fielding is becoming notorious for his recently acquired stance on climate change. He appears to have been heavily influenced by the fringe dwellers of the climate debate.

Graph from Fieldings website - complete with scientifically unsound title

Graph from Fielding's website - complete with scientifically unsound title

A page on his website states his case and documents elements of his own “debate”, including 3 questions he has posed, the answers provided by the Australian government and further comments and analysis by several hand-picked dissenting scientists.

A careful read of all the referenced documents reveals that not only did the government provide clearly argued answers to each of the questions he posed, but also that those answers strongly refute the premises of climate change skepticism. For those who don’t have the time to read the whole thing, the exact questions and a summary of the government’s answers (in my own words, for brevity and clarity) follow, below.

The subsequent response to the government’s answers by Fielding’s chosen scientists also makes for interesting reading – not so much for its scientific content (notably not peer reviewed itself), but rather as an example of how it is so easily possible for fringe scientists to argue a paper-thin case with the appearance of scientific gravitas, when in fact all they are doing is focusing on isolated pieces of tangential factors and evidence, and completely ignoring the mass of evidence which points in completely the opposite direction.

The most damning part of their answer however, in my opinion, is their assertion that Fielding’s questions “remain unanswered” by the government. Fielding has seized on this absurd assertion and now wears it like a badge of honour. Whatever their level of scientific credibility, their personal impartiality in this matter is clearly compromised.

Fielding Question 1

Is it the case that CO2 increased by 5% since 1998 whilst global temperature cooled over the same period (see Fig. 1)?  If so, why did the temperature not increase; and how can human emissions be to blame for dangerous levels of warming?

Government’s Answer

The surface air temperature is just one component in the climate system (ocean, atmosphere, cryosphere). There has been no material trend in surface air temperature during the last 10 years when taken in isolation, but 13 of the 14 warmest years on record have occurred since 1995. Also global heat content of  the ocean (which constitutes 85% of the total warming) has continued to rise strongly in this period, and ongoing warming of the climate system as a whole is supported by a very wide range of observations, as reported in the peer-reviewed scientific literature.

Fielding Question 2

Is it the case that the rate and magnitude of warming between 1979 and 1998 (the late 20th century phase of global warming) was not unusual in either rate or magnitude as compared with warmings that have occurred earlier in the Earth’s history (Fig. 2a, 2b)?  If the warming was not unusual, why is it perceived to have been caused by human CO2 emissions; and, in any event, why is warming a problem if the Earth has experienced similar warmings in the past?

Government’s Answer

While the Earth’s temperature has been warmer in the geological past than it is today, the magnitude and rate of change is unusual in a geological context. Also the current warming is unusual as past changes have been triggered by natural forcings whereas there are no known natural climate forcings, such as changes in solar irradiance, that can explain the current observed warming of the climate system. It can only be explained by the increase in greenhouse gases due to human activities.

Fielding Question 3

Is it the case that all GCM computer models projected a steady increase in temperature for the period 1990-2008, whereas in fact there were only 8 years of warming were followed by 10 years of stasis and cooling. (Fig. 3)? If so, why is it assumed that long-term climate projections by the same models are suitable as a basis for public policy making?

Government’s Answer

It is not the case that all GCM computer models projected a steady increase in temperature for the period 1990-2008.  Air temperatures are affected by natural variability.  Global Climate Models show this variability in the long term but are not able to predict exactly when such variations will happen. GCMs can and do simulate decade-long periods of no warming, or even slight cooling, embedded in longer-term warming trends.

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