Monday, 2 January 2012

Relevant letters ex The Australian 2/ Jan 2012




Climate change a slogging match of claim v claim

MIKE Sandiford's venture into the climate debate is welcome, notably for its absence of personal abuse ("Cherry-picking contrarian geologists tend to obscure scientific truth" 31/12-1/1) .
Ian Plimer was referred to as "contrarian" rather than "denier" and even the term "climate change" was not used.
Does this mean we can expect some real scientific debate on this topic rather than the name calling that has characterised it in the past?
If so I would like to make a few points. Certainly Plimer appears to get it wrong when he compares Siple ice core CO2 concentrations with those measured more recently at Mauna Loa. Surely Plimer has got the numbers back-to-front.
The issue is not quite so clear-cut when it comes to global average temperature. NASA data does indeed show 2010 as the hottest on record, but this is not the case for the equally authoritative HadCRUT3 temperature record from the Hadley Centre Climate Research Unit, which clearly shows that 1998 was the hottest year.
It is the trend that matters and both data sets indicate that the rapid global warming of the 1970s and 80s has ceased. Sandiford seems convinced of the heat-trapping effect of CO2. As a physicist I am sceptical for the reason that convection, not radiation, controls lower atmosphere temperature.
I would have thought active submarine volcanoes recently discovered along the Gakkel ridge near the North Pole provide a more convincing explanation of Arctic warming. Perhaps geologists are unaware that submarine tectonic heating is never included in climate models.
John Reid, Cygnet, Tasmania
I AM disappointed with the level of debate on climate change as represented in Mike Sandiford's article.
His analysis of Heaven and Earth, by Ian Plimer, shows that the significant difference of opinion on the causes of climate change continue to be subject of claim and counter claim.
Sandiford is entitled to contrarian views and to rightly assert that the climate has warmed 0.68C in the past century, and that the past 10 years are the highest recorded.
The question of why we have had significant cool and hotter-than-now periods has not been adequately explained. Sandiford could have assisted the debate by offering an analysis of past climate changes, or do we await the next ice age unprepared?
The issue is not that the climate has warmed or that atmospheric carbon dioxide has increased. Both of these facts are acknowledged by sceptics and warmers alike. The issue is what proportion of that increase is attributable to ACO2 and why.
The Intergovernmental Panel on Climate Change reports the largest single driver of global warming is not ACO2 but the consequent water vapour. Cloud cover and solar radiation remain significant uncertainties.
We would be wise to assess the IPCC uncertainties and, instead of jumping at shadows, rationally, economically and scientifically assess our options. May 2012 be the year of rational debate.
Peter Clark, Mount Gambier, SA
MIKE Sandiford does not mention that CO2 has no correlation with temperature on any time scale except for the last quarter of last century, and then only if the sun's likely effect on cosmic rays and clouds is ignored.
Changes in CO2 do not match temperature for the last decade, century, millennium or on million-year time scales. There have been periods of the past when CO2 was low and temperatures were much higher than the present, as well as periods when CO2 was a lot higher than today with temperatures much lower.
His faith in the NASA Global Institute for Space Studies surface temperature record is a little misplaced. This thermometer-based record has bad coverage and is affected by local land-use changes. But the satellite record has global coverage, is much more accurate and shows 1998 as being warmer than 2010.
Squabbling over the odd hundredth of a degree is not significant.
With ocean thermal expansion also at negligible levels and the CERN experiments likely to confirm the link between solar activity and clouds in the near future, the climate alarmist house of cards is starting to crumble.
Mike Sandiford would do well to look more closely at the data.
Bob Irvine, Buddina, Qld

No comments:

Post a Comment