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listed in the very sentence being modified. This comes as close to outright lying as anything we have found so far. The truth is, there is no way to correct for most measurement errors, including the urban heat island effect. The magnitude of these errors, which may be quite large, is simply unknown. The supposed corrections that have been made to date are guesswork. Nor does there seem to be any reference to the fact that this is a "convenience sample", not a random sample of the Earth's sur- face, as required by sampling science, unless it is the innocent- sounding term, "data gaps". Reference to data gaps suggests that sometimes a station did not record, or that the data is bad—not that there is, in actuality, no data for most of the Earth, most of the time. So the fact that we merely have a convenience sample is either omitted or cleverly disguised. Statistical theory is perfectly clear that a random sample is required in order to estimate confidence levels. But the "sample" in question is just those stations that happened to measure temperatures in the last 140 years. No random sample of the Earth's surface would look like this set of stations, which provide virtually no data for most of the Earth's surface—the oceans, poles or tropics—for most of the period. The sample the UN IPCC is using is called in statistics a convenience sample; that is, data is taken where it is most convenient. Convenience samples provide some information about the population being sampled; in this case, the temperature everywhere on Earth for 140 years. But statistical theory is adamant that you cannot legitimately infer the mean of the population or assign any confidence level from a convenience sample. Thus the UN IPCC's statistics regarding temperature are completely misleading. While beyond the scope of this particular issue, it should be noted that the 1,000-year temperature record shown in figure 1b involves the same misleading statistics. However, the case is much worse because, in the 1,000-year record, temperature is not even measured. Moreover, the number of items in the convenience sample is tiny. It is preposterous to claim to know the temperature of the entire Earth from such a sample. We simply do not know if the entire Earth has warmed or not. The most we know is what has happened in certain places and times, and likely measurement error makes even this information highly uncertain. Satellite versus Surface Temperatures The satellite temperature record contradicts the surface record. This is a deep dilemma for climate change science. The gaping inconsistency between the recent warming shown in the surface temperature record and the absence of warming in the satellite record is simply shrugged off. The UN IPCC WGI SPM page 4 begins with this section head- line: "Temperatures have risen during the past four decades in the lowest 8 kilometres of the atmosphere." As explained below, this statement is highly misleading. The section itself consists of these three rather convoluted paragraphs: "Since the late 1950s (the period of adequate observations from weather balloons), the overall global temperature increases in the lowest 8 kilometres of the atmosphere and in surface temperature have been similar at 0.1°C per decade. "Since the start of the satellite record in 1979, both satellite and weather balloon measurements show that the global average tem- perature of the lowest 8 kilometres of the atmosphere has changed NORTHERN HEMISPHERE 1000 1200 1400 1600 1800 200C Year NEXUS ¢ 25 SPM Figure 1b: Variations of the Earth's surface temperature for the past 1,000 years OCTOBER — NOVEMBER 2002 www.nexusmagazine.com