Temperature Record

One central problem for those who promote the idea of man made global warming is the earth’s temperature record – on almost all time scales.

In the last decade, there has been no clear warming trend (as the UK Met Office and IPCC’s own figures demonstrate). In the last century, much of the warming occurred prior to 1940, when human emissions of CO2 were relatively small compared to today. During the post-war economic boom (when one would have expected the temperature to rise) the world cooled, from the 1940s till the mid-70s (again, this is evident from accepted data used by the IPCC).

But it’s important to look back further in time 1,000 years. The climate record which used to be accepted as the standard account of this period was published in the first IPCC report. But this account posed a problem. A thousand years ago there was time a warm period – apparently warmer than today (known to climatologists as the Medieval Warm Period). This was followed by a relatively cold period (known as the Little Ice Age), from which, over the past two to three hundred years, seem to have made a slow, welcome recovery.

This was all rather undermined the idea that current temperatures were either unusual or alarming.

In subsequent IPCC reports the original graph was replaced by another – the famous ‘Hockey Stick’ (so-called because it looks like one). The Hockey Stick was a lot more dramatic, and was featured proudly on the top of the front page of the new IPCC reports. But was it true? The Hockey Stick debate is very telling, and we urge readers to review the links below.

Further back in time, still within our current ‘interglacial period, we find more warm spells – notably what geologists call the ‘Holocene Maximum’ when, for a few thousand years, the earth was significantly warmer than we find it today.

Over longer time periods of course, the earth has been far, far hotter than it is today (with tropical forests covering much of the earth) and also far, far colder, with much of the earth buried under miles of ice. The Earth’s climate has always changed, and changed without any help from us.

But there is another problem, a very major problem, for those who promote the idea of CO2-led global warming. According to global warming theory, if an enhanced greenhouse effect is responsible for warming the earth, then the rate of temperature rise should be greatest in that part of the earth’s atmosphere known as the troposphere, specifically in the tropics. And yet the observations, from weather balloons and satellites have consistently shown that not to be the case. I urge readers to look at the Christy et al papers below. The latest one was recently published in the Journal of Geophysical Research (2007).

More Information:

Arctic Temperatures – testimony by Syun-Ichi Akasofu, Director Int’l Arctic Research Centre
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Harvard Gazette article – temperature over 1000 years
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"An Economist’s Perspective on Climate Change and the Kyoto Protocol" By Ross McKitrick – with particular reference to Figure 3
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Hockey Stick debate explained
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"What is the ‘Hockey Stick’ Debate About?" By Ross McKitrick*
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Wegman report summary
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Wegman Report in full
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Getting rid of the medieval warm period
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Witches and Weather
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Satellite and balloon temperatures See the work of John Christy and Roy Spencer, University of Alabama in Huntsville. Especially the Congressional Hearings which explain their work in simple terms
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T. R. Oke, “City Size and the Urban Heat Island,” Atmospheric Environment 7 (1987): 769-79
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W. E. Dean et al., “The Variability of Holocene Climate Change: Evidence from Varved Lake Sediments,” Science 226(1984): 1191-194
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R. E. Vance et al., “7,000-Year Record of Lake-Level Change on the Northern Great Plains: A High-Resolution Proxy of Past Climate,” Geology 20 (1992):870-82
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Henry Lamb, I. Darbyshire, and D. Verschueren, “Vegetation Response to Rainfall Variation and Human Impact in Central Kenya during the Past 1,100 Years,” The Holocene 13 (2003): 285-92
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E. T. Brown and T. C. Johnson, “The Lake Malawi Climate Record: Links to South America.” Geological Society of America Abstracts with Programs 35, no. 6 (September 2003): 62

G. H. Haug et al., “Climate and the Collapse of the Maya Civilization,” Science 299 (2003): 1731-735
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S. Stine, “Extreme Drought in California and Patagonia during Medieval Time,” Nature 369 (1994): 546-49
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B. Schilman et al., “Global Climate Instability Reflected by Eastern Mediterranean Marine Records during the Late Holocene,” Palaeogeography, Palaeoclimatology, Palaeoecology 176 (2001): 157-76
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M. M. Naurzbaev and E. A. Vaganov, “Variation on Early Summer and Annual Temperature in East Taymir and Putoran (Siberia) over the Last Two Millennia Inferred from Tree Rings,” Journal of Geophysical Research 105 (2000): 7317-326
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H. Xu et al., “Temperature Variations of the last 6,000 Years Inferred from O-18 Peat Cellulose from Hongyuan, China,” Chinese Science Bulletin 47 (200): 1584
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Jean. M. Grove, The Little Ice Age (Cambridge, UK: Cambridge University Press, 1988)
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C. J. Caseldine, “The Extent of Some Glaciers In Northern Iceland during the Little Ice Age and the Nature of Recent Deglaciation,” The Geographical Journal 151 (1985): 215-27
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H. H. Lamb, Climate, History and the Future (London: Methuen, 1977), 156

H. H. Lamb, Climate, History and the Modern World (London: Routledge, 1982) 162

D. A. Graybill and S. B. Idso, “Detecting the Aerial Fertilization Effect of Atmospheric C02 Enrichment in Tree Ring Chronologies,” Global Biogeochemical Cycles 7 (1993): 81-95
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L. Keigwin, “The Little Ice Age and Medieval Warm Period in the Sargasso Sea,” Science 274 (1996): 1503-508
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