Grahan Readfearn – Climate sceptics see a conspiracy in Australia’s record breaking heat

by
Mike Norman
My articles My siteAbout meMy booksMy videos
Follow on:TwitterFacebook

Bureau of Meteorology says claims from one climate sceptic that it has corrupted temperature data are false

The deniers like to call themselves skeptics, but they will believe without question anyone who comes along criticising the main body climate science, without doing any further research on this themselves. This is hardly skepticism.

Many of Australia’s climate observatories had to be moved because of the heat from expanding cities corrupting the data. This is science at work. None of the data has been 'hidden', as Tony Heller claims, and all the data is out in the open, as well as why the scientists moved the observatories and how this corrected the data.

When it comes to Australian weather conditions before 1910, what does the science tell us? 

The original raw data is all still there – it has not been corrupted. Anyone can go and get that original data.

Pre-1910 there was not much of a spread but also there was more uncertainty about how the temperatures were being measured. By 1910, most temperatures were being measured in a Stevenson Screen. A lot of measurements were taken at Post Offices but in many cases these were moved out to airports around the middle of the 20th century. That produces artificial cooling in the data.

Towns for example in coastal New South Wales originally had temperatures taken near the ocean because that’s where the town was. But as the town grew the observations would move inland and that is enough to affect temperature and rainfall.
Are we supposed to just ignore that? A scientist can’t ignore those effects. It’s not science to just go ahead and plot that raw data.

Contrary to assertions in some parts of the media, the Bureau is not altering climate records to exaggerate estimates of global warming. 

Our role is to make meteorological measurements, and to curate, analyse and communicate the data for use in decision making and to support public understanding.

To undertake these tasks, the Bureau employs highly skilled technicians and scientists and invests in high quality monitoring equipment.

The Bureau measures temperature at nearly 800 sites across Australia, chiefly for the purpose of weather forecasting. The Australian Climate Observations Reference Network – Surface Air Temperature (ACORN-SAT) is a subset of this network comprising 112 locations that are used for climate analysis. The ACORN-SAT stations have been chosen to maximise both length of record and network coverage across the continent. For several years, all of this data has been made publicly available on the Bureau’s web site.

Temperature records are influenced by a range of factors such as changes to site surrounds (eg. trees casting shade or influencing wind), measurement methods and the relocation of stations (eg. from a coastal to more inland location). Such changes introduce biases into the climate record that need to be adjusted for prior to analysis.

Adjusting for these biases, a process known as homogenisation, is carried out by meteorological authorities around the world as best practice, to ensure that climate data is consistent through time.

At the Bureau’s request, our climate data management practices were subject to a rigorous independent peer-review in 2012. A panel of international experts found the Bureau’s data and methods were amongst the best in the world.

The Bureau’s submissions to the review were published on the Bureau’s website, as were the findings of the review panel.
The Bureau’s methods have also been published in peer-reviewed scientific journals.

 Both the raw and adjusted ACORN-SAT data and the larger unadjusted national data set all indicate that Australian air temperatures have warmed over the last century. This finding is consistent with observed warming in the oceans surrounding Australia. These findings are also consistent with those of other leading international meteorological authorities, such as NOAA and NASA in the United States and the UK MetOffice. The high degree of similarity is demonstrated in Figure 1 (above).

The Bureau strives to ensure that its data sets and analysis methods are as robust as possible. For this reason we place considerable emphasis on quality assurance, transparency and communication. The Bureau welcomes critical analysis of the Australian climate record by others through rigorous scientific peer review processes.