Life’s a bitumen nightmare as cities get hotter than hell


The streets, glowing red in the image taken, recorded a maximum temperature of 33 degrees. The bitumen surrounded by concrete were fully 4 degrees hotter than the maximum temperature recorded at Observatory Hill that day. The most conspicuous red zone on the map was the huge rectangle of concrete at the Hungry Mile, west of the Harbour Bridge. (The Hungry Mile is officially known as Barangaroo, a ridiculous name for a major new precinct.) What is proposed for the Hungry Mile/Barangaroo? A new forest of office towers with barely a fig leaf of trees. What is proposed for the expansion of Sydney? More density, more tower clusters, more hot spots built along major transport arteries.

That is why, contrary to the weather reports we see each day, it is not the outer suburbs, furthest from the moderating coolness of the sea, that are the hottest, it is the areas with the highest concentrations of roads, traffic and high-rise towers. Their stored heat leads to more air-conditioning at night, and so the heat-sink cycle goes.

Modern culture is built around creating urban heat sinks, yet governments obsess less about this real-world, everyday problem than the more abstract problem of carbon pollution. Fixing the first problem would help ameliorate the second.

But are there any grand plans for turning the web of our major city’s blacktops into pale-surfaced roads? No. Any master plan for increasing the vegetation on footpaths and common areas? No. Any plans for retrofitting the kerb guttering and stormwater system so more water can soak into roadside green areas? No.

All this is fantasy stuff for our engineers and planning departments. Instead, we build desalination plants, install more air-conditioners, and cram in more office and apartment towers, while the Rudd government runs a gangbusters immigration program, with an extra 300,000 people a year coming through legal immigration and backdoor immigration via the student visa program – the plan they chose not to tell voters about before the last election.

Sydney will absorb more of this than anywhere else. The heat sinks in Sydney and Melbourne will just get hotter. Multiply this by thousands, and you have a defining global trend.

Humanity recently crossed a historic divide. In 1955, 68 per cent of the world’s population lived in rural areas and 32 per cent in urban areas. Last year, the majority tipped the other way. More people live in urban areas than rural areas. In 20 years the balance is estimated to be 60-40 urban-rural, a momentous change in less than a century.

So the impact of climate warming caused by the urban heat sink effect is real for the majority of the world’s population. Beyond that, the story becomes more complex. In December, 2007, professors Ross McKitrick and Patrick Michaels argued in a paper (published in the Journal of Geophysical Research – Atmospheres) that half the global warming trend recorded from 1980 to 2002 could be attributed to the urban heat island effect.

More provocatively, McKitrick commented that the most widely published graph showing a dramatic global temperature rise was ”an exaggeration”, adding, ”I have also found that the UN agency promoting the global temperature graph has made false claims about the quality of their data.”

This was a direct affront to the UN’s scientific consensus, which argues urban areas had made little impact on global warming trends. Some of the bedrock research for this position was done by Phil Jones, head of the Climatic Research Unit at the University of East Anglia.

One of his papers was published in Nature in 1990, co-authored by Wei-Chyung Wang, who studied data from Chinese weather stations. Their paper concluded that urban heat caused a negligible effect on rising recorded temperatures. After Jones became a figure of controversy, he was asked for the location of the weather stations used in the study. Only after intense pressure were details released, but the locations of the rural weather stations were not included. When Wang was asked about the omissions he said he could no longer find the records.

Last October, McKitrick wrote in the National Post: ”I have been probing the arguments for global warming for well over a decade. In collaboration with a lot of excellent co-authors I have consistently found that when the layers get peeled back, what lies at the core is either flawed, misleading or simply non-existent. The surface temperature data is a contaminated mess.”

Last Thursday the University of East Anglia announced an ”independent external reappraisal” of the research produced by the Climatic Research Unit. Jones, already suspended, will remain stood down during the inquiry.

So should the argument that the world’s urban population exploding from 900 million to 3.4 billion in little more than 50 years has had a negligible impact on the earth’s temperature and the world’s weather stations. That, too, is due for a reappraisal.