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T h e A u s t r a l i a n C o l l a b o r at i o n
A Collaboration of National Community Organisations
Climate change and Australia
Climate change is one of the great issues of our time.
According to Sir David King, formerly the UK Government’s chief scientific adviser, “climate change is the most
severe problem that we are facing today”. Science broadcaster, Sir David Attenborough, has recently said: “I was
sceptical about climate change. I was cautious about crying wolf. But I’m no longer sceptical. Now I do not have
any doubt at all. I think climate change is the major challenge facing the world.” Prominent scientist James Lovelock has been even more outspoken, stating that the world
and human society face a disaster to a greater extent and
on a faster timescale than almost anyone realises, adding
that the consequences for humanity are likely to be far
worse than any war.
Climate change refers to the variation in the climate
occurring through natural processes (climate variability)
and human (anthropogenic) activities. The natural greenhouse gas effect, which includes water vapour, is the process by which the atmosphere warms the planet. Energy
from the sun enters the atmosphere and some is absorbed
by the surface of the Earth. This energy radiates from the
Earth’s surface into the atmosphere. Heat is absorbed by
the atmosphere and radiated back to the surface, which
causes a net warming effect.
While the Earth’s climate is constantly changing, in recent
times there have been rapid rises in surface air and water
temperatures, also referred to as ‘global warming’. In
2007, the United Nations Intergovernmental Panel on
Climate Change (IPCC ), made up of the world’s leading
climate researchers, released its fourth assessment report
concluding that the global average surface temperature
increased by at least 0.7°C over the twentieth century.
Global warming has contributed to retreating alpine and
continental glaciers, receding ice sheets, rising sea levels,
as well as regional changes in rainfall, cloud cover and
floods, droughts, hurricanes and heat waves. Climate
records reveal that the past two decades have been the
warmest of the last thousand years.
The IPCC ’s 2007 Fourth Assessment report represents
a consensus view of the latest research into climate science, and adaptation and mitigation responses. IPCC
reports have the agreement of all UN member governments. The IPCC’s findings are backed by more recently
released analyses of climate science, such as the Royal
Society’s “Climate change: a summary of the science”,
released in 2010 and in Australia, the Climate Commission’s 2011 report on climate science, risks and responses:
“The Critical Decade”.
The enhanced greenhouse effect
Scientists now broadly agree that most of the global warming observed over the last 50 years has been caused by
human activity leading to increasing concentrations of so
called ‘greenhouse gases’ in the atmosphere, including
carbon dioxide (from burning fossil fuels such as coal, oil
and gas), methane, nitrous oxide, and several other artificial chemicals such as chlorofluorocarbons (CFCs). Since
pre-industrial times, levels of carbon dioxide have
increased by approximately 42 per cent: from 278 parts
per million (ppm) to 395 ppm in 2011 (based on a preliminary reading in May 2011 by the US government’s Earth
Systems Research Laboratory in Hawaii).
The IPCC’s 2007 report states that concentrations of carbon dioxide are at their highest levels for at least 650,000
years. The International Energy Agency recently reported
that despite a slight dip in emissions in 2009 following the
Global Financial Crisis, global emissions reached a record
high in 2010 at 30.6 Gigatonnes. In December 2010, the
United Nations World Meteorological Organization (WMO)
announced that total radiative forcing of all long-lived
greenhouse gases increased by 27.5 per cent from 1990 to
2009, demonstrating the rising atmospheric burdens of
carbon dioxide, methane and nitrous oxide.
Global mean surface air temperatures are continuing to
rise. During the most recent decade, 2001-2010, the global
average temperature was 0.46°C above the 1961-1990
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Model Projections of Future Warming Under Various Emissions Scenarios
NOTE: The grey bars at the right indicate the best estimate (solid line within each bar) and the likely range assessed for the six SRES
marker scenarios. Source: IPCC, 2007 http://www.ipcc.ch/publications_and_data/ar4/wg1/en/spmsspm-projections-of.html
Projected global average surface warming and sea level rise at the end of the 21st century showing ‘best estimates’ and ‘likely range’.
Source IPCC, 2007.
average, the warmest decade on record. Over the last three
decades, the rate of warming has been 0.17°C per decade.
The Bureau of Meteorology (BOM) estimates that Australia
has warmed by an average of 0.7°C over the past century
and recently announced that 2009 was the hottest year on
record in Australia’s history.
Using a range of scenarios with different story lines of population, development, and so on, the IPCC projects that
Earth’s surface temperature could likely increase between
1.1°C to 6.4°C by 2090-2099 relative to surface temperatures in the period 1980-1999.
Sea levels are projected to rise as the oceans warm up and
glaciers and land-based ice sheets melt. Between 19612003, the sea-level rate rose by 1.8mm per year. The rate
of increase has almost doubled to 3.2mm per year between
1993-2009. The IPCC projects that by 2100, sea level
increases over the century could reach 59cm and likely
more when ice melt is taken into account. Many scientists
now believe that they are likely to be much greater.
Every time we drive a car, use electricity from coal-fired
power plants, or heat our homes with oil or natural gas,
we release carbon dioxide, the main greenhouse gas
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influenced by human activities, into the air. Another
major source of greenhouse gas emissions is the destruction of forests and carbon-rich soil. Not only does this
cause a serious loss of biodiversity (species and ecosystems), but millions of tonnes of carbon dioxide are being
released into the atmosphere adding to the greenhouse
effect. Due to the slow rate in which carbon dioxide can
be absorbed back into carbon reservoirs in the earth and
oceans, climate change is predicted to continue long after
the stabilisation of greenhouse gas concentrations.
Of particular Australian concern is that, at approximately
27 tonnes of greenhouse gas emissions per person per
year, emissions by Australians are considerably higher
than New Zealand (13 tonnes), Japan (10 tonnes) and the
United States (21 tonnes) and more than double the average per person for industrialised countries.
Projected Australian impacts
Of all industrialised countries, Australia is one of the most
vulnerable to the effects of climate change. Climate change
is likely to have a range of adverse impacts on natural
environments, human health, cities and towns and key
sectors of the economy, such as agricultural production,
international trade and tourism. The National Farmers
Federation has described climate change as potentially the
greatest challenge facing Australian farmers this century.
The Climate Commission’s 2011 science update states that
many of the impacts of climate change are due to extreme
weather events rather than changes in temperature, rainfall or other climatic parameters. The relationship between
climate change and extreme events remains complex and
contested, but certain headway has been made in establishing concrete links. Moderate changes in rainfall or
temperature can lead to disproportionately large increases
in the intensity and frequency of extreme events. In Australia, high temperature extremes have increased markedly in the past decade while low temperature extremes
have decreased. The occurrence of large and intense bushfires in southeast Australia appears to be increasing, with
climate change a potential contributing factor. There is no
clear evidence for links between climate change and the
global frequency of tropical cyclones, though it is predicted
that there will be increases in the heavy rainfall that
attends cyclones as the climate warms.
There is much debate on the relationship between climate
change and modes of natural variability effecting Australia’s water cycle. Recent improvements in understanding
the climatic processes that affect rainfall do indicate connections between climate change and the observed drying
trend in southeast Australia, particularly in spring, as well
as the observed reduction in rainfall in Western Australia.
Approximately 50 per cent of the rainfall reduction is
thought by some scientists to be attributable to climate
change. It is a contested area, but what can be said with
certainty is that climate change will effect rainfall, though
the effect may be to increase the incidence of both floods
and droughts. On a global scale, several studies anticipate
an increase in heavy precipitation events in many parts of
the world, including tropical Australia. The unpredictability of flood and drought events creates risks for water
availability, thus increasing rather than decreasing the
need to reduce emissions.
Although difficult to accurately predict, a plausible sea
level rise by 2100 compared to 2000 is between 0.5 and
1.0 metre, though higher figures cannot be discounted.
In Australia, there are significant regional differences in
the sea-level rises already recorded: while rises of near or
below the global average have occurred along the eastern
and southern coasts, rises of almost double the global average have occurred along the northern coastline. A rise of
half a metre might not seem much, but it can lead to large
increases in the frequency of events such as high tides and
storm surges. Indeed, recent modelling for areas around
Sydney and Melbourne shows that a rise of half a metre
would increase the likelihood of extreme events by factors
of 1000, or 10,000 for some locations. Over the past few
years, people in the Torres Strait Islands have been
affected by unprecedented tidal flooding and may in future
be forced to seek refuge on the Australian mainland. Tens
of thousands of refugees from South-Pacific islands threatened by sea-level rise might also need to be looked after.
The $32 billion tourism industry will also be substantially
affected by climate change. A sea-level rise of 10 to 30cm,
combined with rainfall changes, would cause massive
damage to the Kakadu National Park’s freshwater ecosystems. A 1°C temperature increase could cause the loss of
highland rainforest habitat for particular species in the
World Heritage listed tropical rainforests of North Queensland. Most climate scenarios for the rest of this century see
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coral reefs converted into algae-dominated ecosystems,
with global temperature increases of as little as 1°C causing extensive coral bleaching. The death of coral reefs
would strike a massive blow to the Australian tourism
industry. The impact of tropical cyclones and storm surges
represents another major concern for tourism, habitat
destruction, health and the economy in general.
Climate change could have a dramatic influence on health
and living conditions in Australia. Heat-related deaths
could increase substantially with up to 2,500 deaths per
annum in 2020 and up to 6,500 deaths in 2050. Many
mosquito-borne diseases, such as Dengue fever and Ross
River virus, could be found as far south as Brisbane and
even Sydney. Poor communities will experience the greatest impact of altered health and living conditions caused
by global warming.
The Australian Government’s response
In 1997, Australia signed the Kyoto Protocol to the United
Nations Framework Convention on Climate Change
(UNFCCC), an international agreement designed to limit
global greenhouse emissions. Former Prime Minister John
Howard refused to ratify the Protocol during his term in
office. Following the election of the new Government led
by Kevin Rudd in November 2007, the Government’s first
official act was to ratify the Kyoto Protocol. Australia is
working towards its Kyoto target of limiting emissions to
108 per cent of 1990 levels by 2012. Australia may be able
to meet its target - a very generous one compared to those
of other nations - because mass clearing of native vegetation has largely been stopped.
Other greenhouse gas emissions have, however, continued
to increase. At the December 2009 meeting of the
United Nations Framework Convention on Climate Change
(UNFCCC) held in Copenhagen (see separate fact sheet),
there were some achievements but the expectations of
agreement on targets were never close to being met and
the overall impression left by the meeting was one of
disappointment and failure. This in turn had significant
political ramifications in Australia. The Rudd Government
decided to defer the introduction of its Carbon Pollution
Reduction Scheme until 2012-2013. On this account
Rudd’s leadership and commitment to his previously
announced climate policies was seriously called into
question leading to a fall in the Government’s and Rudd’s
personal ratings.
Following the September 2010 federal election, as part of
an agreement with Independent and Greens to allow the
ALP to form a government, a high level climate change
committee was formed and chaired by Prime Minister
Gillard. The committee consists of Government Ministers,
Australian Greens, independent members of parliament
and outside experts. In September 2011, the Government
introduced to Parliament the first of 18 bills to establish
the government’s carbon price regime and also launched
a statutory body to advise the government of the day on
pollution caps, carbon budgets, the credibility of international emissions units, and the performance of the carbon
pricing mechanism. The bills will establish a fixed
$23-a-tonne price on carbon pollution from mid-2012 and
an emissions trading scheme with a floating price to begin
three years later. To lessen the impact on households, most
of the money raised from the carbon tax will fund tax cuts,
pension increases and higher family payments. The bills
passed into law in November 2011, but without the support of the Opposition.
Australia’s legislation is all the more important in the
light of the Conference of Parties talks held in Durban,
South Africa in December 2011. Four major outcomes
were achieved at the talks (see UN Climate Change Conferences fact sheet), but very much more needs to be done.
It is a critical race against time for the nations of the world
if they are to limit warming to a maximum of 2˚C.
Instead of waiting for consensus and the formal implementation of a legally binding international agreement for
emissions reductions, individual countries need to be taking their own initiatives. A potential outcome is an investment boom in clean energy and innovation. Thirty-two
other countries are now taking domestic action.
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Useful sources
Commonwealth of Australia, Department of Climate
Change and Energy Efficiency. (2011). “The Critical Decade: climate science, risks and responses”.
This report was prepared in anticipation of the important
policy decisions to be made in 2011. It informs both policymakers and the public on the science of climate change
and its ramifications for mitigation strategies and risk
response in Australia.
http://climatecommission.gov.au/topics/the-critical
-decade/
CSIRO and Bureau of Meteorology. (2010). “State of the
Climate”.
A snapshot providing observations and analysis of Australia’s climate and the factors that influence it.
http://www.csiro.au/resources/State-of-the-ClimateSnapshot.html
Royal Society (UK). (2010). “Climate change: a summary
of the science”.
A summary of the current scientific evidence on climate
change, emphasising areas where the science is broadly
accepted, where there is still debate, and where significant
uncertainties remain.
http://royalsociety.org/policy/publications/2010/climatechange-summary-science/
United Nations Environmental Program (UNEP). (2009).
“The Climate Change Science Compendium”.
A review of major scientific contributions to the Earth Systems and climate field that have been released through
peer-reviewed literature or from research institutions
between 2006 and 2009.
http://www.unep.org/pdf/ccScienceCompendium2009/
cc_ScienceCompendium2009_full_highres_en.pdf
Flannery, T. (2006). “The Weather Makers: The History
and Future Impact of Climate Change”. Melbourne: Text
Publishing.
This book, by an internationally acclaimed scientist and
explorer, is an examination of the history, science and
politics of global warming and climate change.
Authors
Dr Nicola Henry, Dr Siobhan Murphy and Jen Rae, PhD
researcher RMIT University.
Last revised January 2012.
United Nations Environmental Program (UNEP). (2010).
“UNEP Year Book 2010”.
The United Nations Environmental Programme’s annual
report covering the latest science related to its six areas of
activity: climate change, disasters and conflicts, ecosystem
management, environmental management, harmful substances and resource efficiency.
http://www.unep.org/yearbook/2010/PDF/3_climate_
change_2010_low.pdf
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