In 1991 the writer (WSH) reviewed the Jones et al temperature data for Australia along with a wider selection of Australian data while associated with the Tasman Institute in Melbourne. The Executive Summary of that unpublished report which was circulated to interested parties, has survived in digital form and is presented here for the first time.

[Note, the Tasman Institute was a free market think tank in Melbourne for about a decade, closing in the late 1990’s.]

Executive Summary
The major work by P.D. Jones and his team at the Climate Research Unit, University of East Anglia (Jones, et al 1986a) contains the most up-to-date compilation of the land temperature trend for the southern hemisphere. In examining in detail the long term trend in temperature records for Australia, this paper provides a critique of the data used by the East Anglia study.

Our conclusion is that Australian temperatures have exhibited no upward trend over the past century. This conclusion is in contrast to the continental warming trend implicit in the East Anglia study from the stations chosen. The main reasons why our conclusions differ are that the East Anglia study:

• included a number of heat island affected city records;

• excluded other long term records from rural Australia.

The East Anglia study drew heavily upon data from major urban centres. One reason for this is the likelihood that such centres’ temperature records have been kept more professionally; in addition, it is easier to trace the need for adjustments due to station shifts in major centres. Clearly, there are deficiencies in temperature measurements in earlier years and it may well be that the records from more remote stations are inferior to those of the city sites. However, an examination of peaks and troughs for city and remote sites show a consistent pattern after adjustment for the trend. This indicates that one possible source of error – human error – is unlikely to be systematically present.

A comparison of trends in the Australian stations used in the East Anglia study with those of stations situated in the same geographic region shows the warming reported by the study to be due to local heat islands rather than a continental warming trend. Heat islands are widely recognised as occurring in urban areas because of human settlement and infrastructure causing the retention and emission of heat on a local level. Although the East Anglia study claims to have taken this factor into account in deriving its trends, we consider it to have done so inadequately. Our own findings, that the dominant reported trends in Australia are due to local heat islands, are consistent with those others have produced, especially in the U.S.

The following graphs compare the average temperature trend for the 25 regional and remote Australian stations, for which data was available over the years since 1882, with the average temperatures for the six Australian capital cities. The East Anglia study used five Australian capital cities out of its 13 long term stations.

The East Anglia study contains other data with the potential to cause bias, notably truncation of data in many stations, so that they covered only the most recent 30 years. During those 30 years, some warming undoubtedly occurred following a general cooling period up to the 1940’s, a phenomenon which can be observed in Figure 1 above.

This study does not attempt to produce a temperature trend for Australia as a whole, although the trend of the remote stations where long term data is available provides a guide. Perhaps of greater significance, our detailed examination of the Australian data reflects adversely on the entire data set used by the East Anglia study, a data set that has been highly influential in providing apparent corroboration of global warming.