Peter Dawson reviews Sunburnt Country’ – Dr Joelle Gergis’ new book on Climate Change
Climate Scientist, Dr.Joelle Gergis’s book pulls together from wide-ranging sources the story of the Australian climate since white settlement, but also reaches back 1000 years and more. She seeks to convince us that the climate change challenge we face is, by every measure, real, menacing and urgent. It is both a comprehensive and a compelling answer to the climate sceptics.
Dr.Joelle Gergis, one of Australia’s most internationally recognised climate scientists, in her book Sunburnt Country, provides us with a wide-ranging, engaging and accessible history of our climate back to ancient times. Much of it is based on major research projects that she led. These include the South-Eastern Australian Recent Climate History (SEARCH) project, a landmark initiative, spanning the sciences and humanities to reconstruct the region’s climate variability from first European settlement in 1788; and the Past Global changes (Pages) working group on Australasian climate variability of the past 2,000 years until the project’s completion in 2017. Her team won the 2014 Eureka Prize for Excellence in Interdisciplinary Scientific Research – informally known as the ‘Oscars of Australian science.’ In February 2018 she was selected to serve as a lead author for the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report.
The aim of the SEARCH project was to develop climate reconstructions from 1900 back to 1788. The team comprising leading climate scientists, water managers and historians, partnered with a large range of Australian institutions. Apart from climate records which were sparse in early years but improved over time, the team drew on historical accounts, tree-ring research using cores from ancient New Zealand kauri trees (dendrochronology) with estimated ages of up to 2,500 years, coral growth rings and ice cores from the iconic Law Dome in Antarctica going back to 1250. The ice cores showed that carbon dioxide concentrations were stable over the millennium until the early nineteenth century then rose sharply from around 280 ppm (parts per million) at the start of the industrial era to 409 ppm in May 2017. The last time carbon dioxide levels were at 400 ppm was three million years ago; before human beings existed on the Earth.
The link between greenhouse gas concentrations and temperature was demonstrated by (Joelle Gergis’s mentor), Professor David Karoly, and Bureau of Meteorology scientist Dr Karl Braganza and published in 2005 (Journal of Climate). It was shown that it was impossible to arrive at the observed increases in temperature by natural phenomena alone without the inclusion of human influences. Gergis also cites a study by Professor David Karoly and Dr Sophie Lewis in 2013 which showed that the best estimate of the contribution of human-induced factors to temperature rise between from the 1950s until then was 0.6 degrees Centigrade or 60 percent of the warming experienced over Australia since the 50s. The likelihood of such increases occurring through natural factors alone was once in 12,300 years!
Gergis notes the work of Mike Mann and others published in 1998 and showing that global temperatures declined slowly for around 900 years then, in the late twentieth century abruptly rose; which became known as the ‘hockey stick’ model. It attracted attacks by sceptics including hate mail and even death threats as well as intensive interrogation; but was later vindicated. Her own research strongly supported this work, showing that the period 1971 to 2000 was the warmest in 1000 years. This also attracted the ire of sceptics in Australia. She writes: ‘When my team published Australia’s first 1000 year temperature reconstruction my life would also become a nightmare.’
About the likely consequences of global warming, Gergis writes; ‘If we continue on our current big emissions path, global average temperatures are projected to increase by between 2.6 degrees C and 4.8 degrees C (above 1986-2005 levels) by the end of the century. An increase of 3 degrees C is considered extremely likely.’ Some areas may become too hot for human habitation. Sea levels will rise and inundate important infrastructure and urban areas, and there may be severe impacts on agriculture and thus on our ability to feed ourselves.
Gergis has given us a comprehensive update on the science of climate change and its implications for Australia and the planet. It marshals an extraordinary range of evidence to refute the sceptics and interest groups that seek to discredit the science and inhibit necessary change. It is a must-read for concerned citizens outside the immediate circles of climate science. Ironically the technologies required to reverse the process are available but so far the political will falls short, especially in Australia.
This article was first published in Peter Dawson’s Creative Capital Blog (creativecapitalblog.com).
Peter Dawson is the author of Creative Capital, an account of Canberra’s globally-successful technology start-ups and Creative Capital Blog.