Greenhouse Gas Emissions and Climate Change | 2020 Vision for a Sustainable Society

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2020 VISION FOR A SUSTAINABLE SOCIETY

MELBOURNE SUSTAINABLE SOCIETY INSTITUTE


The Melbourne Sustainable Society Institute (MSSI) at the University of Melbourne, Australia, brings together researchers from different disciplines to help create a more sustainable society. It acts as an information portal for research at the University of Melbourne, and as a collaborative platform where researchers and communities can work together to affect positive change. This book can be freely accessed from MSSI’s website: www.sustainable.unimelb.edu.au.


Cite as: Pearson, C.J. (editor) (2012). 2020: Vision for a Sustainable Society. Melbourne Sustainable Society Institute, University of Melbourne Published by Melbourne Sustainable Society Institute in 2012 Ground Floor Alice Hoy Building (Blg 162) Monash Road The University of Melbourne, Parkville Victoria 3010, Australia Text and copyright © Melbourne Sustainable Society Institute All rights reserved. No part of this publication may be reproduced without prior permission of the publisher. A Cataloguing-in-Publication entry is available from the catalogue of the National Library of Australia at www.nla.gov.au 2020: Vision for a Sustainable Society, ISBN: 978-0-7340-4773-1 (pbk) Produced with Affirm Press www.affirmpress.com.au Cover and text design by Anne-Marie Reeves www.annemariereeves.com Illustrations on pages 228–231 by Michael Weldon www.michaelweldon.com Cover image © Brad Calkins | Dreamstime.com Proudly printed in Australia by BPA Print Group


Foreword

T

he last two centuries have seen extraordinary improvements in the quality of human lives. Most people on earth today enjoy access to the necessities of life that was once available only to the elites. Most people enjoy longevity, health, education, information and opportunities to experience the variety of life on earth that was denied even to the rulers of yesteryear. The proportion of humanity living in absolute poverty remains daunting, but continues to fall decade by decade. The early 21st century has delivered an acceleration of the growth in living standards in the most populous developing countries and an historic lift in the trend of economic growth in the regions that had lagged behind, notably in Africa. These beneficent developments are accompanied by another reality. The improvements are not sustainable unless we make qualitative changes in the content of economic growth. The continuation of the current relationship between growth in the material standard of living and pressures on the natural environment will undermine economic growth, political

stability and the foundations of human achievement. The good news is that humanity has already discovered and begun to apply the knowledge that can reconcile continued improvements in the standard of living with reduction of pressures on the natural environment. The bad news is that the changes that are necessary to make high and rising standards of living sustainable are hard to achieve within our current political cultures and systems. Hard, but not impossible. That is a central message from this book, drawn out in Craig Pearson’s concluding chapter. This book introduces the reader to the many dimesions of sustainability, through wellqualified authors. Climate change is only one mechanism through which current patterns of economic growth threaten the natural systems on which our prosperity depend. It is simply the most urgent of the existential threats. Climate change is a special challenge for Australians. We are the most vulnerable of the

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developed countries to climate change. And we are the developed country with the highest level of greenhouse gas emissions per person. There are roles for private ethical decisions as well as public policy choices in dealing with the climate change challenge. This book is released at the time of ‘Rio+20’, a conference in Brazil to review the relatively poor progress we have made towards sustainability in the past 20 years, and soon after the introduction of Australia’s first comprehensive policy response to the global challenge of climate change. Australia’s emissions trading scheme with an initially fixed price for emissions permits comes into effect on 1 July 2012. The new policy discourages activities that generate greenhouse gases by putting a price on emissions. The revenue raised by carbon pricing will be returned to households and businesses in ways that retain incentives to reduce emissions. Part of the revenue will be used to encourage production and use of goods and services that embody low emissions. The policy has been launched in controversy. Interests that stand to gain from the discrediting of the policy argue that it is unnecessary either because the case for global action to reduce greenhouse gas emissions and the associated climate change has not been proven, or that the new policy places a disproportionate burden on Australians. The health of our civilisation requires us to bring scientific knowledge to account in public policy. Everyone who shares the knowledge that is the common heritage of humanity has

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a responsibility to explain the realities to others wherever and whenever they can. The argument that the new policy places a disproportionate burden on Australians can be answered by seeking honestly to understand what others are doing. The critics of Australian policy argue that the world’s two largest national emitters of greenhouse gases, China and the United States, are doing little or nothing to reduce emissions, so that it is either pointless or unnecessary for us to do so. China has advanced a long way towards achieving its target of reducing emissions as a proportion of economic output by 40 to 45 per cent between 2005 and 2020. It has done this by forcing the closure of emissions-intensive plants and processes that have exceptionally high levels of emissions per unit of output, by imposing high emissions standards on new plants and processes, by charging emissionsintensive activities higher electricity prices, by subsidising the introduction of low-emissions activities, and by new and higher taxes on fossil fuels. China has introduced trials of an emissions trading system in five major cities and two provinces. This adds up to a cost on business and the community that exceeds any burden placed on Australians by the new policies – bearing in mind that the revenue from Australian carbon pricing is returned to households and businesses. The US Government has advised the international community of its domestic policy target to reduce 2005 emissions by 17 per cent by 2020. President Barack Obama said


to the Australian Parliament that all countries should take seriously the targets that they had reported to the international community, and made it clear that the United States did so. United States efforts to reduce emissions are diffuse but far-reaching. They now include controls on emissions from electricity generators, announced in March 2012, effectively excluding any new coal-based power generation after the end of this year unless it embodies carbon capture and storage. From the beginning of next year they will include an emissions trading system in the most populous and economically largest state, California. The United States is making reasonable progress towards reaching its emissions reduction goals, with some actions imposing high costs on domestic households and businesses. Australia has now taken steps through which we can do our fair share in the international effort, at reasonable cost. It would be much harder and more costly to do our fair share without the policies that are soon to take effect. What Australians do over the next few years will have a significant influence on humanity’s prospects for handing on the benefits of modern civilisation to future generations. This book will help Australians to understand their part in the global effort for sustainability. Ross Garnaut University of Melbourne 15 April 2012

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Contents Foreword by Ross Garnaut Table of Contents

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Author Biographies

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Drivers

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1 Population Rebecca Kippen and Peter McDonald

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2 Equity Helen Sykes

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3 Consumption Craig Pearson

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4 Greenhouse Gas Emissions and Climate Change David Karoly

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5 Energy Peter Seligman

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People

47

6

Ethics Craig Prebble

48

7

Culture Audrey Yue and Rimi Khan

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8

Awareness and Behaviour Angela Paladino

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9

Local Matters Matter Kate Auty

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10 Public Wisdom Tim van Gelder

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11 Mental Health Grant Blashki

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12 Disease Peter Doherty

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13 Corporate Sustainability Liza Maimone

104

14 Governance John Brumby

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Natural Resources

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15 Ecosystem-Based Adaptation Rodney Keenan

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16 Water Hector Malano and Brian Davidson

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17 Food Sunday McKay and Rebecca Ford

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18 Zero Carbon Land-Use Chris Taylor and Adrian Whitehead

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Cities

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19 Changing Cities Peter Newman and Carolyn Ingvarson

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20 Affordable Living Thomas Kvan and Justyna Karakiewicz

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21 Built Environment Pru Sanderson

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22 Infrastructure Colin Duffield

184

23 Transport Monique Conheady

192

24 Adaptive Design Ray Green

200

25 Handling Disasters Alan March

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Outcomes

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26 Twenty Actions Craig Pearson

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Further Reading

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Index

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04 Greenhouse Gas Emissions and Climate Change David Karoly

T

he global climate system has warmed over the past hundred years, mostly as a result of human-caused increases of greenhouse gases in the atmosphere, primarily carbon dioxide, methane and nitrous oxide. These increases result from emissions of greenhouse gases from human activities, including from burning coal, oil and natural gas as energy sources, from industrial activity and from land clearing. Continued emissions of greenhouse gases will cause even greater climate change this century, with substantial impacts on human and natural systems. International agreements to address climate change by reducing greenhouse gas emissions have been in place since the adoption of the United Nations Framework Convention on Climate Change (UN FCCC) in 1992. One hundred and ninety-four countries, including Australia and the United States, have ratified the UN FCCC. Its principal objective is ‘stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system’. In 2009, at the Conference of Parties to the UN FCCC in Copenhagen, governments agreed that greenhouse gas emissions should be reduced to a level so that

global temperature increases are limited to less than two degrees Celsius above pre-industrial levels. The scientific evidence that underpins the conclusions on climate change come from the overwhelming majority of the world’s climate scientists. A small but vocal group of commentators and scientists dispute these conclusions, arguing that the observed climate change is mainly natural, that future climate change due to human causes will be minor and that higher concentrations of greenhouse gases in the atmosphere are beneficial. Therefore, they argue that there is no need to reduce greenhouse gas emissions from human activity. Misinformation and bad science are the basis of their arguments and these are addressed below. This is followed by consideration of the question: what reductions in greenhouse gas emissions globally and in Australia are needed to achieve the agreed target of limiting global warming to two degrees? This decade is the critical decade for achieving this target, as international and Australian actions by 2020 on reducing greenhouse gas emissions will determine the risk of global warming exceeding two degrees. Business as usual emissions will certainly lead to this target being

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2020

Global average temperature anomaly (˚C)

0.6

Met Office Hadley Centre and Climate Research Unit NOAA National Climatic Data Center NASA Goddard Institute for Space Studies

0.4 0.2 0 -0.2 -0.4 -0.6 -0.8 1850

1900

Year

1950

2000

Figure 1. Global average surface temperature variations for the period 1850–2010 relative to 1961–90 from three different observational datasets. The grey shading shows the uncertainty in a single annual global average temperature estimate. There has been a significant increase of global average temperature by about 0.8 degrees Celsius in the last decade relative to 1850–1900. Source: World Meteorological Organization.

exceeded. Very substantial emission reductions in Australia and other developed countries are needed by 2020 to ensure that there is a low risk of exceeding this target over the next 100 years.

Climate Change and Greenhouse Gas Concentrations Climate is a major factor affecting society, including the distributions of natural ecosystems and agriculture. Global climate has varied substantially in the past, with much colder ice ages and warmer inter-glacial periods occurring regularly about every hundred

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thousand years over the last million years. These are due to periodic variations in the earth’s orbit around the sun and feedbacks in the climate system. The present inter-glacial period has lasted about 10,000 years and has been a period of relatively stable climate, during which all human civilisation has developed and our population has grown rapidly. Over the past century, the global average temperature has increased significantly (Figure 1). While global warming over the last hundred years is only about 0.8 degrees Celsius, this is larger than the variations in


Greenhouse Gas Emissions and Climate Change

global average temperature at any other time over the past 1000 years. Evidence for this global warming can be found in many different components of the climate system: increases in temperatures over the land and in the ocean, retreat of glaciers on land, retreat of sea ice in the Arctic, reductions in snow cover in winter, and increases in temperature and in moisture content in the lower atmosphere (Figure 2). More than 90 per cent of the extra heat in the climate system over the past 50 years has gone into warming the ocean layers below the surface, not into warming the atmosphere. The clearest evidence of global warming is found in this increase in sub-surface ocean temperatures. The other clear evidence of global warming is the observed increase in global-average sea

level, due to the warming of ocean waters and melting of ice on land. Greenhouse gases in the atmosphere affect the energy balance of the climate system by limiting the loss of long-wave or heat radiation from the earth and the atmosphere to space, effectively trapping more energy in the climate system. The most important greenhouse gases in the atmosphere for global warming are the ones with long lifetimes: carbon dioxide, methane and nitrous oxide. These are called long-lived greenhouse gases because the processes that remove them from the atmosphere take tens to hundreds of years to return their concentration to normal after more is added to the atmosphere. Concentrations of these long-lived greenhouse gases were very

Air temperature near surface (troposphere) Humidity Glaciers Temperature over oceans

Snow cover

Sea surface temperature Sea level Sea ice Temperature over land Ocean heat content

Figure 2. Indicators of warming of the climate system over the last hundred years, based on observed changes in different components. Upward arrows show increasing trends, while black downward arrows show decreases. Source: Bulletin of the American Meteorological Society, 2010

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stable for most of the past 10,000 years, based on air bubbles extracted from ice cores drilled in the ice sheets in Greenland and Antarctica. However, the concentrations of carbon dioxide, methane and nitrous oxide have all increased dramatically over the past century. Carbon dioxide is the most important longlived greenhouse gas in terms of its effect on the energy balance of the climate system. The longest continuous instrumental observations of the concentration of carbon dioxide in the atmosphere have been taken at the Moana

Loa Observatory in Hawaii since the late 1950s (Figure 3). These show increases from below 320 parts per million (ppm) in 1960 to about 390ppm in 2010, an increase of more than 20 per cent. A century ago, the carbon dioxide concentration was about 280ppm, so the increase since that time has been about 40 per cent. For the other important long-lived greenhouse gases, methane concentrations have increased over the past century from about 700 parts per billion (ppb) to 1800ppb in 2010, an increase of more than 150 per cent, while

Atmospheric CO2 at Mauna Loa Observatory

380

360

340

320

1960

1970

1980

1990

2000

2010

Figure 3. Observed background concentrations of carbon dioxide in the atmosphere (in parts per million, ppm) at the Mauna Loa Observatory in Hawaii over the period 1960–2010. Background concentrations of carbon dioxide at Mauna Loa are representative of the global concentrations and are the longest series of such direct observations anywhere in the world. The red line shows the seasonal variations of atmospheric carbon dioxide at Mauna Loa, associated with the global uptake and release of carbon dioxide by plants on land, mainly from the Northern Hemisphere. The black line is a smoothed curve, showing the variations over periods of longer than one year. It shows the pronounced increase of carbon dioxide from below 320ppm in 1960 to about 390ppm in 2010. Source: NOAA, United States.

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Greenhouse Gas Emissions and Climate Change

nitrous oxide concentrations have increased from about 270ppb to more than 320ppb, an increase of more than 20 per cent. While the global climate system has warmed over the past 100 years and the concentrations of long-lived greenhouse gases in the atmosphere have increased, we cannot simply conclude that one has caused the other, nor that human activity has caused the increases in both. We must first consider the evidence for the causes of the increases in greenhouse gases, and then the evidence showing whether the recent global warming is due to the increase in greenhouse gases in the atmosphere, and not other natural factors. There are multiple lines of evidence that human activity has caused the increase in longlived greenhouse gases in the atmosphere and that these increases are not due to other factors, such as emissions from volcanoes or losses from the oceans (Figure 4). The chemical signature of the increase in carbon dioxide in the atmosphere shows that it is primarily from burning fossil fuels and from land clearing. Emissions of carbon dioxide into the atmosphere from burning fossil fuels have increased to about 30 billion tonnes per year, nearly doubling over the past 20 years (Figure 5). The stable concentrations of the long-lived greenhouse gases for the past millennium and then the recent simultaneous increases point to human activity as the cause. Emissions from volcanoes cannot be the explanation, as carbon dioxide emissions from volcanoes are too small and have a different chemical signature to that observed, and volcanoes do not also

emit methane and nitrous oxide. Losses of carbon dioxide from the oceans cannot be the explanation, as carbon dioxide concentrations in the oceans have increased over the past 50 years but are still lower on average than in the atmosphere, showing that carbon dioxide on average is being mixed from the atmosphere to the oceans. These different lines of evidence have led to the conclusion that the main cause of the observed increase in long-lived greenhouse gases over the past century is human activity: burning fossil fuels such as coal, oil and natural gas, land clearing, agriculture and industrial activity. There are also multiple lines of evidence that the increase in concentrations of greenhouse gases in the atmosphere due to human activity has been the main cause of the recent observed global warming (Figure 4). Scientists have compared the observed patterns of recent temperature changes in the atmosphere and the oceans with the patterns (fingerprints) expected from different factors, such as increasing greenhouse gases, changes in sunlight, or natural climate variability. They find that the observed changes over the last 50 and last 100 years agree well with the fingerprint from increasing greenhouse gases and other human-caused changes in the climate system, and cannot be explained by increases in sunlight, changes in cosmic rays, or natural climate variations. For example, the observed temperature changes over the land show more warming on average at night than in the daytime and more warming in winter than in summer, in agreement with the fingerprint of increasing greenhouse gases but opposite

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2020

10 indicators of a human fingerprint on climate change Less heat escaping to space Shrinking thermosphere Cooling stratosphere Rising tropopause

More fossil fuel carbon in the air

Less oxygen in the air

30 billion tonnes of CO2 per year More heat returning to earth

Nights warming faster than days

More fossil fuel carbon in coral

Figure 4. Indicators of the human fingerprint on climate change, showing evidence that observed climate change is primarily due to human causes. Source: the Skeptical Science website (www.skepticalscience.com).

to what is expected from increasing sunlight. These have led to the conclusion that it is now beyond a reasonable doubt that human activity is the main cause of the observed global warming over the last hundred years.

The Two-Degree Target Given the large increase in carbon dioxide concentrations that has already occurred (Figure 3), the long lifetime for natural processes to remove this carbon dioxide

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increase and the continued growth of carbon dioxide emissions from human activity (Figure 5), substantial future warming of the global climate system is inevitable, with substantial negative impacts on human and natural systems. So, the question is: What reductions in greenhouse gas emissions globally are needed to achieve the internationally agreed target of limiting global warming to two degrees? This global warming target is consistent with stabilisation of greenhouse gas concen-


Greenhouse Gas Emissions and Climate Change

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Observed CO2 Emissions vs. IPCC Scenarios

30 CO2 Emissions per year (billions of tonnes)

B2 A1 28

A1T A2 A1F1

26

24

22

20 1990

1992

1994

1996

1998

2000

2002

2004

2006

2008

2010

Figure 5. Observed global carbon dioxide emissions (in billions of tonnes per year) from burning fossil fuels, estimated by the International Energy Agency (IEA) for the period 1990 to 2010. Note that emissions have increased from about 21 billion tonnes per year in 1990 to more than 30 billion tonnes per year in 2010. Also shown are representative emission projections for 2000 to 2010 from the IPCC ‘Special Report on Emissions Scenarios’. These show that the observed emissions have increased at a rate consistent with the highest projected emission growth, even while the Kyoto Protocol and other international actions were seeking to slow emissions growth.

trations in the atmosphere at a level of about 450ppm carbon dioxide equivalent. Carbon dioxide equivalent is a measure that combines the warming effects of all long-lived greenhouse gases in the atmosphere into the equivalent concentration of carbon dioxide in the atmosphere. The current carbon dioxide equivalent concentration is much higher than the concentration of carbon dioxide alone, as it includes the effects of methane and nitrous oxide. While the concentration of carbon dioxide in 2010 was 390ppm (Figure 3), the

concentration of all long-lived greenhouse gases in the atmosphere in 2010 was already 470ppm carbon dioxide equivalent, according to the US National Oceanic and Atmospheric Administration (NOAA) Annual Greenhouse Gas Index, substantially above the 450ppm target. Hence, there has already been a significant overshoot of the greenhouse gas concentrations needed to avoid global warming of two degrees Celsius. Without rapid and substantial global reductions of greenhouse gas emissions, it will be impossible to limit the increase in global average temperature to less than two degrees.

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2020

Figure 6. Top: Carbon dioxide emissions from fossil fuels (in billions of tonnes per year) for two scenarios: one ‘business as usual’ (red) and the other keeping global temperature rise below 2 degrees C, with cumulative emissions from 2000 to 2050 of 1000 billion tonnes of carbon dioxide (blue). Bottom: Projections of global-mean temperature rise based on these emission scenarios to 2100. The darkest shaded range for each scenario indicates the most likely temperature rise (50 per cent chance of falling within this range). Source: The Science of Climate Change: Questions and Answers, 2010.

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Greenhouse Gas Emissions and Climate Change

Given the long time required for natural processes to remove additional carbon dioxide from the atmosphere, it is the cumulative emissions of carbon dioxide from human activity that determines the increase in carbon dioxide concentrations in the atmosphere and most of the increase in global average temperature. A number of studies, including those by the German Advisory Council on Climate Change (WBGU), by Will Steffen and by Ross Garnaut, have considered this cumulative emissions budget approach to determine the global emissions reductions needed to limit global warming to two degrees Celsius. Continued greenhouse gas emissions from business-as-usual human activity will likely lead to global warming of four to six degrees, while limiting the cumulative emissions of carbon dioxide from burning fossil fuels to a global budget of one trillion tonnes over the period 2000 to 2050 would likely avoid global warming of two degrees (see Figure 6). Global emissions of carbon dioxide from burning fossil fuels during 2000 to 2010 (Figure 5) had already used up about 30 per cent of the cumulative emissions budget in only a fifth of the period. The trajectory of global carbon dioxide emissions from burning fossil fuels needs to peak this decade, fall by at least 70 per cent by 2050 and drop to zero by 2080 to limit global warming to less than two degrees (Figure 6). Rapid, substantial and sustained reductions of greenhouse gas emissions from human activity are needed to follow this trajectory. Delays in action to reduce greenhouse gas emissions will lead to

continued emissions at present levels, which make it more and more difficult to achieve the internationally agreed target. So what is a fair share for Australia of these global emission reductions? To determine this, emissions of greenhouse gases per person are considered. As Australians, we are among the highest emitters in the world at about 27 tonnes per person per year, while Indian emissions are about two tonnes per person per year and Chinese emissions about five. If a cumulative emissions budget is appropriate for determining global emissions reductions, it should also be relevant for assessing a country’s fair share. With a global population of seven billion, the global emissions budget translates into a personal emissions budget of a little more than 140 tonnes of carbon dioxide from burning fossil fuels over the period 2000 to 2050. With current Australian emissions of carbon dioxide from burning fossil fuels at about 19 tonnes per person, this means that we have already emitted about 200 tonnes each over 2000–2011 and used up all our individual 50-year budgets of carbon dioxide emissions and more in only 11 years. While it is obviously not practical to switch off all emissions of carbon dioxide from burning fossil fuels in Australia overnight, that is what the cumulative emissions budget approach shows should be our fair share; zero emissions for the next 40 years because our emissions have been so high in the past. Anything more would not be fair globally, but of course, we don’t live in a fair and equitable world!

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2020

ACTIONS FOR 2020 This is the critical decade for Australian and global actions on reducing greenhouse gas emissions to achieve the internationally agreed target of limiting global warming to only two degrees Celsius. Without these actions, global warming will increase and the associated climate change will have substantial impacts on many human and natural systems. The carbon budget for cumulative carbon dioxide emissions provides a simple approach to determine the necessary global and Australian actions. By 2020, global greenhouse gas emissions must have peaked and started to fall, with binding international agreements established that will lead to global zero net emissions of carbon dioxide from burning fossils fuels by 2080. By 2020, Australian greenhouse gas emissions must have fallen dramatically, by 50 per cent or more, with national legislation established that has much stronger long-term emission reduction targets than the current Clean Energy Future package of the Federal Government. Australia should aim to reduce its net emissions of greenhouse gases to zero before 2050, as its fair share of global action on reducing emissions. Fortunately, there are many existing technologies described in later chapters in this book that provide practical solutions to reducing greenhouse gas emissions in Australia. These include reducing emissions through improving energy efficiency, through zero carbon renewable energy sources, through reductions in

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agricultural emissions and reductions in land clearing, as well as enhancing uptake of carbon dioxide in terrestrial vegetation by reforestation and changes in agriculture.


Further Reading Greenhouse Gas Emissions and Climate Change Allison, I., et al. (2010). The Science of Climate Change: Questions and Answers. Australian Academy of Science. http://www.science.org.au/policy/climatechange.html Garnaut, R. (2011). The Garnaut Review 2011: Australia in the Global Response to Climate Change. CUP. NOAA Annual Greenhouse Gas Index, National Oceanic and Atmospheric Administration, USA. http://www.esrl. noaa.gov/gmd/aggi/ Steffen, W. (2011). The Critical Decade: Climate Science, Risks and Responses. Climate Commission, DCCEE, Australia. http://climatecommission.gov.au/topics/the-critical-decade/ WBGU (2009). Solving the climate dilemma: the budget approach. German Advisory Council on Climate Change, Germany. http://www.wbgu.de/en/special-reports/sr-2009-budget-approach/


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