Interesting to read the latest anti climate change op-ed piece by Professor Bob Carter in the Courier Mail the other day.
Instead of contesting the tone of his argument, I will stick to what Professor Carter describes as the ‘salient facts’ with which he uses to show that climate change is nothing but “hysteria”:
The accepted global average temperature statistics used by the Intergovernmental Panel on Climate Change showed that no ground-based warming has occurred since 1998. Oddly, this eight-year-long temperature stasis has occurred despite an increase over the same period of 15 parts per million (or 4 percent) in atmospheric CO2.
Whilst this finding of the IPCC is an interesting point (see Graph a below), this fact alone does not disprove climate change: what is more misleading is what Professor Carter isn’t telling you.
Carter chooses ground-based warming measurements alone for this argument. Published literature (in both the journals Science and Nature) regarding satellite-based temperatures (1979-2002) suggest a warming of 0.19 – 0.26°C (1,2). Further to this, continuing analysis of satellite data during the 1998 – current day (until April 2007) from two seperate research groups within the US indicate a warming of 0.14 – 0.184°C (3,4). Given that Professor Carter is a geologist dealing with ‘ancient climate change‘, it is telling that such a recent argument should form the mainstay of his response. In addition, the IPCC states that “Observations since 1961 show that the average temperature of the global ocean has increased to depths of at least 3000 m and that the ocean has been absorbing more than 80% of the heat added to the climate system.” (5).
An interesting and well written rebuttal to such arguments (over longer geological time frames) has been written as part of New Scientist‘s series, ‘Climate Myths’ entitled “Ice cores show CO2 rising as temperatures fell” (link).
… lower atmospheric satellite based temperature measurements, if corrected for non-greenhouse influences such as El Nino events and large volcanic eruptions, show little if any global warming since 1979, a period in which atmospheric CO has increased by 55ppm (17 percent)
Although I am not quite sure what ‘corrected’ infers to, I assume Professor Carter is referring to the published work of John Cristy who analysed satellite measurements and concluded that the lower troposphere had cooled relative to the surface temperatures since 1979 (6). Two journal articles published in the journal Science in 2005 have since strongly suggested that the initial analysis is flawed: after correcting for satellite drift in the original study, the troposphere (lower atmosphere) was shown to be warming, not cooling (7), and the tendancy for cooler daytime vs night time temperature readings was shown to result from an artifact of solar-heating of weather balloons (8). Taken these corrections into account (which again, are well referred to in the literature), Professor Carters argument of “little if any global warming” are all too common from the skeptics.
…there are strong indications from solar studies that the Earths current temperature stasis will be followed by climatic cooling over the next few decades.
Professor Carter’s counter-argument is neither new or particularly innovative (indeed, the 2007 IPCC report discusses this in detail). In a recent paper entitled “Pattern of strange errors plagues solar activity and terrestrial climate data” (9), strongly disputes such claims as those between solar activity and temperature similar to those made by Carter. Further analysis of solar output since 1978 highlights the 11 year sunspot cycle, yet fails to identify upwards or downwards trends (10)
Indeed, as Professor Carter entertains:
“NASA is an agency that knows a thing or two about climate change”
In a well referenced article in the New York Times in 2006, climate scientist James Hansen, Director of NASA’s Goddard Institute for Space Studies claimed that his superiors at the agency were trying to ‘censor’ information ‘going to the public’. Although this claim has been disputed by NASA who responded that “…we promote openness and we speak with the facts“, Professor Carter might like to heed the warning of Mr Acosta, Deputy Assistant Administrator for Public Affairs at NASA:
“…government scientists (are) free to discuss scientific findings, but policy statements should be left to policy makers and appointed spokesmen.”
|Surface and Satellite temperatures (a)||Surface Temperature records (b)||Global Temperature records (c)|