Hi Jennifer,
The draft ‘Summary for Policymakers’ of the Fourth Report of the Intergovernmental Panel on Climate Change has been widely leaked to the Press.
Its crucial conclusion is as follows:
“It is very likely that anthropogenic greenhouse gas increases caused most of the observed increase in globally averaged temperatures since the mid-20th century.”
The widely available graph of the globally averaged annual temperature anomalies between 1857 and 2005 shows, for the period since the mid-20th century:
1. No warming between 1950 and 1978
2. No warming between 1998 and 2005
The only ”observed” warming over the period is from 1978 to 1998, 20 years only, out of the 55 years.
The actual warming involved over this short period of 1978 to 1998 was 0.53ºC.
The above statement considers that it is very likely that most of this 0.53ºC was caused by anthropogenic (human-induced) greenhouse gas increases. “Most” of this would be between 0.3ºC and 0.5ºC, the amount that the statement considers to be due to human influence.
This temperature rise is negligible.
None of us would notice if it happened instantly, let alone over 50 years.
It is below the amount considered in the weather forecasts. Yet this small temperature rise over 55 years is routinely blamed for all manner of climate disasters.
The IPCC pronouncement is not a certain one. The term “very likely” is defined as amounting to a probability above 90%. In other words, there is one chance in ten that they are wrong. Also, the probability is based on the opinion (or guess) of “experts” who are financially dependent on an expectation of positive results.
Finally, there has been no “warming” at all since 1998, now eight years. “Global Warming” seems to have come to an end.
This temperature record is quite incompatible with the computer climate models, so why should we believe their pessimistic forecasts for the future?
It should also be noted that there has been negligible warming in New Zealand since 1950. The mean temperature for 2006 was 0.7ºC below that for 2005. According to the temperature record for Christchurch, there was no warming since 1910, with a maximum temperature in 1917.
Cheers,
Vincent Gray
Wellington, New Zealand

Jennifer Marohasy BSc PhD has worked in industry and government. She is currently researching a novel technique for long-range weather forecasting funded by the B. Macfie Family Foundation.