Four Degrees of Global Warming

Australia in a Hot World

Peter Christoff

• Publisher: Routledge
• Year: 2013
• eBook ISBN: 9781135937492
• Edition: 1
• Topic: Economics
• Subtopic: Development Economics
• Index: Economics

At Copenhagen in December 2009, the international community agreed to limit global warming to below two degrees Celsius to avoid the worst impacts of human-induced climate change. However climate scientists agree that current national emissions targets collectively will still not achieve this goal. Instead, the 'ambition gap' between climate science and climate policy is likely to lead to average global warming of around four degrees Celsius by or before 2100. If a 'Four Degree World' is the de facto goal of policy, we urgently need to understand what this world might look like.

Four Degrees of Global Warming: Australia in a Hot World outlines the expected consequences of this world for Australia and its region. Its contributors include many of Australia's most eminent and internationally recognized climate scientists, climate policy makers and policy analysts. They provide an accessible, detailed, dramatic, and disturbing examination of the likely impacts of a Four Degree World on Australia's social, economic and ecological systems.

The book offers policy makers, politicians, students, and anyone interested climate change, access to the most recent research on potential Australian impacts of global warming, and possible responses.

1 Introduction

Four degrees or more?

Peter Christoff

This book is based on a simple premise. Public debate and policy choices about climate change should be based on the best available evidence about the risks we face. Decisions about how much and when we should cut our emissions, and how much we should spend on adaptation, should be determined by what we understand and accept are the costs and consequences of failing to take sufficient action.

Australia has committed itself to trying to help limit global warming to 2°C. Yet there is widespread agreement that current mitigation efforts – including Australia’s – will lead to global average warming of 4°C or more from pre-industrial levels by the end of this century … to a Four Degree World.

The central aim of this book is to make us aware of the likely social, ecological and economic implications of catastrophic climate change for Australia and its region. If 4°C of global warming is the outcome – the de facto goal – of present policy settings, we should look at what we will encounter in a Four Degree World. If we don’t like these prospects, then perhaps this book may encourage us to think differently about our current commitments and to choose an alternative future.

A heat like no other

Summer in Australia is often marred by hellishly hot days. However, the summer of 2013 was exceptional in several ways. January 2013 produced the hottest month on record. It started fires and broke temperature records across the country. It prompted international media coverage.

Following four months of very warm temperatures, an ‘extensive dome of heat’ hung over the continent (Braganza, in Hannam, 2013). Successive days of extreme heat covering most of the continent are rare and isolated. Yet for seven days, from 2 January to 8 January, the continental average temperature exceeded 39°C. Previously, Australia had only once seen four days in a row over 39°C, in 1972.

On Monday 7 January the continental average temperature rose to 40.3°C (105°F), the hottest maximum on record, breaking the previous high of 40.17°C on 12 December 1976. The next day, Sydney reached 42.3°C, and on 18 January, 45.8°C – almost 20° above the monthly average and breaking the previous record of 45.3°C set in 1939. Hobart hit 41.8°C, its highest temperature on record, while in Perth, suffering its fiercest heatwave in 80 years, hospitals experienced a wave of admissions of people suffering from heat-related symptoms.

These days also created extreme wildfire conditions across the country. The New South Wales fire service issued ‘catastrophic’ fire warnings – the highest level on the scale – in four areas of the State. In Victoria, the Country Fire Authority’s fire warning website crashed under unprecedented community demand for information as temperatures rose above 40°C in parts of that state.

Across Australia, over 500 wildfires were ignited. Towns and lives were lost. When 100 homes in Dunalley, Tasmania, were incinerated, 2,700 people sheltered on beaches and were stranded at community refuges on the Tasmanian Peninsula, many later evacuated by sea. Images of the aftermath and stories about tragedies of individual and community loss appeared in media footage.

Climate scientists stress that while the cause of an individual weather event, including heatwaves, is always linked to specific weather conditions, ‘it is possible to determine the influence of climate change on the frequency of occurrence of such an event’ (Plummer et al., 2013). Changes in the frequency and intensity of extreme events are the most obvious manifestations of a changing climate. The extreme weather events of January 2013 in Australia – and others elsewhere – display the influence of a warming world. Plummer et al. (2013) report that ‘Australia has warmed steadily since the 1940s, and the probability of extreme heat has now increased almost five-fold compared with 50 years ago.’

Recent research has shown Australia’s preparedness for even gradual, low-level climate change is poor. In Canberra in 2003, fires killed 4 people and destroyed 500 homes. In Victoria, the Black Saturday fires in 2009 killed 173 people and more than a million animals, destroyed over 2,000 homes and caused over $4.4 billion damage (VBRC, 2010). Much is required to adapt to even low levels of warming.

Prime Minister Gillard, touring the fire-ravaged ruins of towns in Tasmania, warned that ‘we need to prepare for more scorchers’ and that extreme bushfires were a part of life in a hot and dry country, and that ‘we do know over time that as a result of climate change we are going to see more extreme weather events’ (Darby, 2013).

But for what exactly should we prepare?

* * *

Our planet now is only some 0.8°C warmer than it was in pre-industrial times. This change seems slight, especially when considered against the fluctuations in temperature we experience daily. Yet, even with such a small increase, since the start of the twenty-first century we have already witnessed many climate change-related impacts. These include record-breaking weather events in both the southern and northern hemispheres, such as the hottest summer on record in Europe in 2003, in which some 70,000 are estimated to have died (Robine et al., 2007) and the wettest summer in England and Wales in 2007. In 2010, the worst recorded flood in Pakistan directly affected the lives of some 20 million people. It was accompanied the hottest summer in Russia, which caused massive wildfires and led to the deaths of an estimated 56,000 people. Record-breaking heatwaves occurred in a number of states in the United States in 2011, and 2012 was its warmest year on record. Australia too just has had its longest and most severe drought on historical record, a series of devastating fires, floods and damaging cyclones, and now an unprecedented national heatwave.

Scientists agree that these events are highly unlikely to have occurred without the influence of global warming. What, then, if global warming reaches much higher levels? In this coming century, extreme events and significant underlying changes in temperatures, rainfall, storms and to the productivity of our oceans and landscapes will challenge our ability to live comfortably on this continent.

Negotiating blindly

Until relatively recently, the idea of a Four Degree World seemed fanciful – the stuff of alarmism, a genre of horror–science fiction. Scientists, science journalists and climate commentators increasingly talked and wrote about critical systemic thresholds and global tipping points and the risks of ‘dangerous’ and runaway climate change (e.g. CACC et al., 2002; Schellnhuber et al., 2006; Lynas, 2007; Pearce, 2007; MacCracken et al., 2008). But until the failure of negotiations at Copenhagen, these discussions remained peripheral to the mainstream debate over the prospect of global warming in the twenty-first century, the carefully phrased reports of the InterGovernmental Panel on Climate Change (IPCC) and slow progress with international climate negotiations.

When the international community adopted the United Nations Framework Convention on Climate Change (UNFCCC) in 1992, it committed itself to preventing ‘dangerous anthropogenic interference with the climate system’ (Article 2). Defining what such dangerous interference or ‘dangerous climate change’ might be depends on a value judgement about danger and impact, which will vary geographically (with climate change threatening earlier and more ‘dangerous’ consequences in northern latitudes, low-rainfall and low-lying areas, and for poorly adapted communities [e.g. Crowley, 2011]). Concerted action depends on reaching consensus about these definition.

Parties to the Convention agreed they would accept their ‘common but differentiated responsibilities’ in reducing greenhouse emissions and dealing with adaptation. Under the treaty, developed industrialized countries – the major contributors to greenhouse emissions and historical beneficiaries of fossil fuel use – would act first.

In 1997, the Kyoto Protocol was established to enable implementation of the UNFCCC’s goals. It required developed countries to adopt mitigation targets during its first commitment period. These targets, determined through political agreement in a multilateral forum, reflected neither scientific advice nor principles for equitable burden-sharing between nations. The agreement was criticized by environmental NGOs for doing too little in this first period: the developed countries’ targets lacked ambition; aggregate reduction of global emissions during the first commitment period would have been about one per cent of the total.

The Protocol was immediately rejected by the United States, which refused to ratify it because the Protocol failed to set emissions reductions targets for major developing economies, notably China (despite this claim being explicitly at odds with the requirements of the UNFCCC). Although the US failed to destroy the Protocol, it managed to delay the agreement coming into force until 2005 and thereby postponed concerted international action to reduce emissions. The Protocol’s first commitment period only began in 2008 and ran until the end of 2012.

Once Kyoto was in force, the prospect of its second commitment period – or of a successor post-2012 agreement – loomed. This new arrangement would be conditioned by changing global conditions, including China’s growing global economic role and ecological footprint. In 2006 China overtook the United States as the world’s largest annual aggregate emitter of carbon dioxide, (although the United States’ cumulative and per capita emissions remain much greater). This reflected both its rapid internal economic development and growing wealth and the effects of economic globalization, which since 1992 had turned China into the manufacturing hub of an ever more intensely trade-oriented and carbon-intensive world (see Davis and Caldeira, 2010). Along with other major emergent developing countries, such as India and Brazil, China’s growing contribution to aggregate global emissions, along with that of other major emergent developing countries such as India and Brazil, could not be overlooked.

From 2007 onwards the prospects for timely and effective international climate agreement improved and then faltered. In 2007, the 13th Conference of Parties (COP) to the UNFCCC decided on the Bali Action Plan, a roadmap for developing a successor to the Kyoto Protocol’s first commitment period and its targets. The Plan would be developed over the next three years and finalized at Copenhagen in 2009.

By 2007 there was emergent agreement in policy and scientific circles that 2°C warming above the pre-industrial global average was the highest level that could be endured before the risks of dangerous climate change, including abrupt and catastrophic climatic shifts, became too high.

In response, the IPCC’s Fourth Assessment Report (4AR, published in 2007) suggested that developed countries need to reduce their emissions by 25 per cent to 40 per cent below 1990 levels in 2020, and by –80 to –95 per cent by 2050, with developing countries contributing ‘a substantial deviation from their baseline’, if we are to stabilize long-term levels of greenhouse gas concentration levels at 450 parts per million (ppm) CO₂ equivalent (Box 13.7) (IPCC, 2007b). Even so, this concentration level would merely offer around a 50-per cent chance of limiting global average warming to 2°C (Meinshausen. 2006a, 2006b).

The Copenhagen Diagnosis, produced by an eminent body of climate scientists to update the IPCC’s 4AR (Allison et al., 2009), confirmed that global emissions would need to peak between 2015 and 2020 and then decline rapidly if warming was to be limited to a maximum of 2°C. Greenhouse emissions – if stabilized at 2009 levels for 20 years – would mean the planet had less than a one in four chance of staying below 2°C.

The climate negotiations in 2009 in Copenhagen spectacularly failed to produce a new agreement containing legally binding and targets that reflected best scientific advice and equity principles. The story of Copenhagen is well known: its failure – involving a standoff between the United States and China, the overwhelming influence of national political constraints on ambitious international commitments and the occluded decision-making processes of the UNCCC – threatened the very future of ongoing multilateral climate negotiations.

Nevertheless, last-minute wrangling between the heads of state of the major emitters produced an informal political statement – the Copenhagen Accord – that saved the conference from collapse (Christoff, 2010). Signatories to the Copenhagen Accord for the first time formally agreed to a definition of dangerous climate change, ‘recognising the scientific view that the increase in global temperature should be below 2 degrees Celsius’ (Para 1, UNFCCC, 2010). They also agreed that ‘deep cuts in global emissions are required according to science … so as to hold the increase in global temperature below 2 degrees Celsius’ (Para 2, UNFCCC, 2010).¹

The Accord process also produced non-binding ‘unconditional’ and ‘conditional’ pledges from most developed and some major developing states for 2020 emissions targets but it failed to deliver longer-term targets for 2050. Rather than being the product of a negotiated agreement reflecting scientific advice and equity-based formula to produce a robust and defensible target, these ‘bottom-up’ pledges were what individual nations decided they could manage based on their domestic political circumstances and economic capacity.

This has generated a crisis for international climate negotiations. In effect, expedient unilateralism has replaced concerted multilateralism. Negotiators continue to hope that this ‘bottom-up’ process of target setting will somehow manage to stagger slowly and blindly towards a collective goal capable of meeting the objective of averting dangerous climate change, at a time when the time available for effective action is rapidly diminishing.

The targets pledged included some within the range suggested by the IPCC (Norway’s, Germany’s and the EU’s are in line with the IPCC’s conservative reduction range of –25 to –40 per cent), but most were not. In all, the aggregate reduction pledged would make achieving the aggregate global reductions necessary to keep below 2°C impossible.

Following Copenhagen, most Annex I countries pledged an unconditional national target and also a more ambitious conditional target dependent on other countries pledging comparable reductions. The Netherlands Environmental Assessment Agency and consultancy Ecofys noted that the unconditional (‘low’) pledges would result in a total Annex I emission reduction target of 4 per cent to 18 per cent below 1990 levels by 2020. The conditional (’high’) pledges amount to a reduction target of 9 per cent to 21 per cent (den Elzen et al., 2010: 11). In all, these pledges fall well short of the cuts suggested by the IPCC.

Even if current pledges are fully implemented, global total greenhouse gas emissions in 2020 are likely to be between 53 and 55 billion tonne...

Table of contents

• Cover Page
• Half Title Page
• Title Page
• Copyright Page
• Table of Contents
• Figures and tables
• Contributors
• Acknowledgements
• Acronyms and abbreviations
• 1 Introduction Four degrees or more?
• Part I Climate science and four degrees
• Part II Ecological impacts
• Part III Social and economic impacts
• Part IV Adaptation
• Appendix: Description of the Climate Models and Analysis Methods
• Index