After reading “Cool heads needed on global warming” in the Business section of Melbourne’s The Age, I got the final boot I needed to get this site up and running.
The author of this post, Dr Len Walker a civil engineer and fellow of the Australasian Institute of Mining and Metallurgy, describes his views on the “near-hysteria” surrounding global warming and why the global share-market should have no fear.
Walker’s inaccuracies begin with the spurious “fact” that the earth has cooled slightly since 1998. This is a misleading statement taken out of its scientific context. The slight cooling Walker refers to temperatures has occurred in the upper atmosphere (the stratosphere, at 14-22km). According to NOAA’s 2005 climate assessment report, this is consistent with the depletion of ozone in the lower stratosphere, compounding evidence of the severity of recent climate change. It seems the link between global warming and ozone depletion is lost on Walker.
Closer to home, global surface temperatures in the troposphere have increased at a rate near 0.6°C/century, accelerating over the past 25 to 30 years to a striking rate of 1.8°C/century. Put simply, rises in global temperatures seen in Figure 1 are undeniable, rapid and unrelenting.
Figure 1. Global air temperatures, 1850-2005.
Source: University of East Anglia’s Climatic Research Unit.
According to NASA climatologists, global warming is now 0.6°C in the past three decades and 0.8°C in the past century. It is no longer correct to say that “most global warming occurred before 1940″. More specifically, there was slow global warming, with large fluctuations, over the century up to 1975 and subsequent rapid warming of almost 0.2°C per decade until present. These trends are anything but “trivial”.
According to the UK’s University of East Anglia’s Climatic Research Unit, widely recognised as one of the world’s leading institutions concerned with the study of natural and anthropogenic climate change, the 1990s were the warmest decade in the observational temperature records.The warmest year of the entire series has been 1998, with a temperature of 0.548°C above the 1961-90 mean.
According to NASA, 2005 was year 2005 was the warmest year in over a century. Australia also officially recorded its warmest year on record in 2005. Ten of the eleven warmest years in the series have now occurred in the past eleven years (1995-2005). The only year in the last eleven not among the warmest eleven is 1996 (replaced in the warm list by 1990). Worldwide, the provisional figures for 2006 using data from January to November, place the year as the sixth warmest year. 2007 is likely to be the warmest year on record globally, beating the current record set in 1998, say climate-change experts at the UK’s Met Office.
Figure 2. Global and hemispheric temperature trends.
Source: University of East Anglia’s Climatic Research Unit.
It is misleading to cite changes in the Earth’s long-term, natural climate variability as evidence that current conditions are no cause for concern. Analyses of over 400 proxy climate series (from tree-rings, corals, ice-cores and historical records) shown in Figure 3, indicate that the 1990s is the warmest decade of the millennium and the 20th century the warmest century. The warmest year of the millennium was likely 1998, and the coldest was probably A.D. 1601 (but with much greater uncertainty).
Figure 3. A number of palaeoclimatic reconstructions of past global temperatures using natural climatic data from tree-rings, corals, ice-cores and documentary records.
Source: NOAA’s World Data Center for Palaeoclimatology
Walker vaguely referred to evidence from Greenland ice-cores that temperatures have increased in the past by up to 7°C. It is worth noting that during this time, approximately 4-5 million people are estimated to have inhabited the earth in simple tribal groups. This is in no way analogous to the conditions were currently face.
More recent evidence from ice-core records drilled from Dome C in Antarctica, the closest we get to finding carbon dioxide somewhat similar to present is close to 800,000 years ago (the Pleistocene). Currently, the planet is in what scientists’ term a ‘non-analogue’ state. That is, the environmental conditions being witnessed today have no historical counterpart any time in our geologic past. During that period, world population was nowhere near the 6.6 billion people the Earth houses today, much less with the technological capacity to alter ecological systems on such as vast scale.
The Stern Review, led by Prof. Sir Nicholas Stern is the most comprehensive ever undertaken on the economics of climate change. The first sentence of the executive summary states that “the scientific evidence is now overwhelming: climate change presents very serious global risks, and it demands an urgent global response.”
The report goes on to suggests that climate change threatens to be the greatest and most widespread market failure ever seen, and it provides prescriptions including environmental to minimise the economic and social disruptions. He stated that “our actions over the coming few decades could create risks of major disruption to economic and social activity, later in this century and in the next, on a scale similar to those associated with the great wars and the economic depression of the first half of the 20th century”.
Claiming that the information on climate change is “claimed by an exclusive few” is a fallacy. The Intergovernmental Panel on Climate Change (IPCC) was established by the World Meteorological Organisation (WMO) and United Nations Environmental Program (UNEP) to “assess on a comprehensive, objective, open and transparent basis the scientific, technical and socio-economic information relevant to understanding the scientific basis of risk of human-induced climate change, its potential impacts and options for adaptation and mitigation”.
The IPCC will deliver the first volume of its Fourth Assessment Report on February 2 2007. It has utilised more than 2500 expert scientific reviews, 850 contributing authors, 450 lead authors from at 130 countries over the past six year to produce four volumes that will make up the forthcoming IPCC report. The reports are freely available for download and are translated into all the UN languages.
This could hardly be referred to as “restrictive sources” of an “exclusive few”. In contrasts to decisions made in CEO boardrooms, the scientific community is built upon rigorous peer review, transparency and objective critique. At best, Walker contributes to the “sound and fury” clouding the rational assessment of the seriousness of global climatic change.It is dangerous views as those held by the likes of Walker that “urgently need to be challenged and discussed in an open forum”.
In terms of films such as Al Gore’s An Inconvenient Truth “stirring emotions” that inaction on cutting fossil fuel use will bring disaster, this reaction is long overdue. The concentration of carbon dioxide in the Earth’s atmosphere currently stands at roughly 380 parts per million (ppm), an increase of more than 35 percent over pre-industrial levels, largely due to the burning of fossil fuels. At the current rate of increase, the world could reach 550 ppm well before the end of the century, with severe implications for human well-being and the Earth’s natural systems.
Due to the phenomenon of environmental inertia, even when anthropogenic emissions do begin to decrease, atmospheric CO2 will continue to rise for up to as much as a century. Global temperatures will continue to increase for an even longer period, locking the world into continuous feedback of unforeseen climatic change. Effective management of the Earth system under such conditions will depends on early and consistent actions. Action needed now, not in some vague, distant future.
There is simply too much at stake to keep muddying the waters.
