John Murphy (Reid, Australian Labor Party) Share this | Hansard source

I move:

That this House acknowledges that climate change is:

(1)

real; and

(2)

human-induced.

Mr Deputy Speaker, as you know, I have been speaking for many years in parliament on the need to take urgent action in relation to climate change. In 2003, one of the hottest summers on record, a health crisis occurred in Europe in which an estimated 40,000 people died from heat stress. In France, 14,802 heat related deaths were recorded in that summer of extremes, mostly amongst the young, the sick and the elderly, unable to cope with the extreme temperatures.

The terrible year of 2003 brought some of the highest temperatures on record, yet 2006 saw another heatwave, with the warmest July since the first official records, in the Netherlands, Belgium, Germany, Ireland and the United Kingdom. And in this year, even more records were broken, with the period from April to June being the warmest ever recorded for land areas in the Northern Hemisphere. Not only is the evidence for global warming ever strengthened but there are also the less well recognised threats of rising sea levels, caused by melting ice and the thermal expansion of seawater, and ocean acidification, caused by the dissolution of carbon dioxide gas.

The global warming problem can be separated into three distinct issues: measurements, causes and consequences. The first issue, measurements, is the collection of observations carried out over decades that show a clear warming trend. In particular, NASA has recently issued the following findings: (1) that the decade January 2000 to December 2009 was the warmest on record; (2) that the most recent annual Arctic Sea ice coverage minimum, a strong indicator of arctic temperatures, was the second lowest in satellite observations; and (3) that the land ice sheets on Greenland and Antarctica are both losing ice and that Antarctica has been losing 100 cubic kilometres of ice per year, while other reports show that Greenland is losing 200 cubic kilometres of ice per year.

The British Met Office and the US National Oceanic and Atmospheric Administration’s recent combined report entitled State of the climate also warns unequivocally that the world is warming and has been for the last three decades. The report states, firstly:

… the first six months of this year were the hottest on record.

Secondly:

… “variability” in different regions, such as the cold winter in Britain, does not mean the rest of the world is not warming.

And thirdly, that greenhouse gases are the glaringly obvious cause of the 0.56 degrees warming over the last 50 years. The CSIRO, in its own recent State of the climate report, states that (1) the mean temperature in Australia has increased by about 0.7 degrees since 1960; (2) the decade 2000-2009 has been the warmest on record; and (3) the geographic distribution of rainfall has changed significantly over the last 50 years and rainfall has decreased in the south-east and south-west. The CSIRO report concludes that there is a nine out of 10 chance that the warming observed since 1950 has been driven by greenhouse gas emissions.

The second issue relating to global warming is the identification of the factor or factors causing this phenomenon. As reported recently in New Scientist, Aradhna Tripati and her colleagues at the University of California, Los Angeles, have found that the chemical composition of fossil shells is linked to atmospheric carbon dioxide concentrations and have been able to reliably reconstruct the levels of atmospheric carbon dioxide for the last 20 million years. This and other studies have shown that carbon dioxide is a principal influence in controlling the earth’s climate and, in particular, these investigations provide an insight into the sensitivity of the climate to changing atmospheric carbon dioxide levels.

Climate sensitivity to atmospheric carbon dioxide levels is defined as ‘the effect on mean global temperatures of the doubling of atmospheric carbon dioxide levels’. Richard Alley, of Pennsylvania State University, reports that a climate sensitivity figure of three degrees, also supported by the Intergovernmental Panel on Climate Change, is in accord with the available data. Although many details remain to be settled, the evidence is now very clear: if we double the pre-industrial level of carbon dioxide of around 280 parts per million we can expect a rise in global temperatures of three degrees in the short term and possibly as much as seven degrees over the centuries to follow.

The third issue regarding global warming is the predicted consequences of the continued emission of carbon dioxide into the atmosphere. Although the fossil evidence is clear, predictions of climate change over the next few decades have to rely upon mathematical models that simulate the complex processes that drive the climate. When climatologists add the well-understood effects of atmospheric carbon dioxide levels into these models they see results that are in accord with observations. It is this agreement of model calculations with real-world conditions that gives confidence that the predictions of future warming are essentially correct.

There are two other serious problems that do not depend upon theoretical studies or fossil evidence to raise an alarm. The first concern is the increase in sea levels brought about by the simple physical processes of the thermal expansion of seawater and the melting of glacial and polar ice. According to the CSIRO, from 1870 to 2007, global average sea levels have risen by close to 200 millimetres, at an average rate of 1.7 millimetres during most of the 20th century and at an accelerating rate, corresponding to increasing global average temperatures of three millimetres between 1993 and 2009.

The CSIRO Division of Marine and Atmospheric Research warns: ‘Worldwide, in excess of 150 million people live within one metre of the current high-tide level and a further 250 million people live within five metres of the high tide.’ Recent observations from satellites and tide gauges show that the increase in sea levels is tracking close to the maximum forecast issued by the Intergovernmental Panel on Climate Change in 2001 and will lead to an estimated global average rise of 880 millimetres above 1990 levels by 2100. There is sufficient heat accumulated in the atmosphere and oceans that make it virtually certain that millions of people will be flooded from their homes over the coming decades.

Another concern is the acidification of sea water caused by the dissolution of carbon dioxide gas into the oceans. Measurements show that approximately one-third of the carbon dioxide gas that has been released by the burning of fossil fuels since the industrial revolution has dissolved in sea water, and this dissolved carbon dioxide gas is causing the ocean waters to become increasingly acidic. A high-school chemistry textbook will tell you that when carbon dioxide gas dissolves in water it will react with the water to produce carbonic acid, which partly dissociates to form carbonate, bicarbonate and hydrogen ions. Hydrogen ions are found in all aqueous solutions of acids, and the acidity of a solution is determined by the concentration of hydrogen ions. This concentration is usually expressed as pH, which for complex reasons is found to be seven in neutral solutions, greater than seven in alkaline solutions and less than seven in acidic solutions.

Sea water is normally slightly alkaline, and across the planet the pH of the surface layers of sea water—which are the habitat of most sea creatures—have become more acidic by 0.12 pH units since the beginning of the industrial revolution, so that the pH of surface layers of sea water is now approximately 8.1. This increase in acidity of the surface layers of ocean water of 0.12 pH units actually represents an increase of 30 per cent, or nearly a one-third increase, in the acidity of ocean waters.

In November 2008, scientists from the CSIRO and the University of New South Wales published a paper that reported on seasonal changes in carbonate and ocean acidity. The scientists found that the level of acidification where the shells of important plankton organisms start to dissolve corresponds with an atmospheric concentration of 450 parts per million. As of September 2010 the concentration of atmospheric carbon dioxide had reached 386 parts per million and was increasing at an annual rate of two parts per million.

At this rate, we shall see the tipping point of the acidification of ocean ecosystems by no later than 2040, if not sooner. Dr Ben McNeil, senior research fellow at the University of New South Wales Climate Change Research Centre, warned that, because vulnerable organisms such as pteropods are at the bottom of the food chain, ocean acidification could lead to large-scale ecosystem changes affecting not just plankton but other marine life including fish, whales and dolphins. Dr McNeil went on to warn that, right now, we do not really know the ramifications of these changes. I would submit today that they would be extremely serious. Acidification of sea water by carbon dioxide emissions is putting at risk entire ocean ecosystems, and humans will not be immune to the consequences of a collapse. Such an event would be an extraordinary disaster, the more so since we will have been forewarned well in advance.

Finally, the strength of the evidence of human responsibility for global warming, ocean acidification and rapidly rising sea levels is now well beyond reasonable doubt. Such is the magnitude of these threats that urgent action to greatly reduce carbon dioxide emissions is absolutely essential.

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