Chapter 1 The climate strikes back
The central role of the Intergovernmental Panel on Climate Change
Climate change presents 'mind-blowing' political consequences
Climate change in the context of other eco 'gloom and doom' sotries
What do we mean by 'climate change'?
So is it happening? Early warning signs of climate change
Why is climate change a problem? Who for, where and when?
Major reasons for concern about future climate change
How does driving a car make the sea-level rise?
Conclusion: a chain of causes and effects
Chapter 2 A citizen's guide to climate science
The Earth's complex climate system
Fossil fuels and the carbon cycle
Uncertainties in our understanding of radiative forcing
Is climate change real and are humans the cause?
Future climate change
The science behind climate change is settling but remains unsettled
Chapter 3 Planetary engineering
What took us so long to realize?
The United Nations Framework Convention on Climate Change and the Kyoto Protocol
One small step for the planet, one giant leap towards a global carbon economy
Chapter 4 Tuning in: integrated assessments of climate futures
An integrated approach to thinking climate change through
From emissions to decisions: integrated assessment models
Models and policymakers
Future emissions: exploring the uncertainties
Emissions scenarios as a way of thinking about an uncertain future
Quantifying the challenge: baselines and target stabilization levels
Sharing the burden: equity and climate change
Chapter 5 Listening out: climate, politics, philosophy
Bringing strangers into the equation
Being fair to the future
People in place: connecting environmental change, philosophy and politics
Chapter 6 Climate change and sustainability - inseparable
Career of the concept of sustainable development
Intellectual foundation of sustainable development
Making sustainability count
Chapter 7 Changing the world
Globalization and envrionmental change
Governance, citizenship and sustainability
Making it happen - sustainability in practice
Conclusion - the increasingly World Wide Web
Java Climate Model
Greenpeace: Extreme Weather
Philosophy and the Environment: Gaia Theory
Sustainable Development Commission
U.S. Department of State International Information Programs
All Routes Block 3 Links
Back to OU
The IPCC's Third Assessment Report is the most comprehensive and authoritative source of scientific information on the current status and future implications of climate change. However, the dynamics of the foramal IPCC peer review process combined with the complexity of the underlying science provide plenty of opportunities for sceptics to point towards many remaining uncertainties in this assessment of climate change.
Climate change is now a key component of global political and cultural consciousness and is being linked to the broader notion of sustainable development.
Clear evidence of temperature-related changes in various physical and biological systems is mounting, which together constitute early warning signs of global climate change. If the IPSS's projections of the scale of future climate change over the rest of the century are reasonably accurate, the warning signs are likely to become much clearer and louder within the next two decades or so.
Climate change will have negative and positive effects on different parts of the climate system and in different regions of the world. There will be some clear losers and some winners. Overall, the latest integrated assessment models suggest that climate will be a net problem for humanity; that is, its costs will outweigh any benefits. As GMST rises, the overall cost increases significantly.
Climate change presents a variety of different types of risk associated with increases in global mean surface temperature. Those risks increase dramatically as projections of temperature change increase.
The greenhouse effect is not about imaginary glass sheets at the top of the atmosphere. It is more accurately described as the absorption and re-emittance of solar radiation that has been re-emitted by the surface and the atmosphere as infrared radiation by some trace gases such as carbon dioxide.
A small change in the concentrations of greenhouse gases acts to temporarily increase the internal rate of thermal recycling between the atmosphere and the surface. The contribution of different greenhouse gases to global warming can be compared using the Direct Global Warming Potentials. DGWPs allow the warming effect of different quantities of different greenhouse gases to be expressed in mass units of CO2e. Climate change is the result of a causal chain of effects, processes and consequences as shown in Fig 1.25 (and below).
human activity (eg driving a car) produces .... greenhouse gas emissions that lead to ... increased greenhouse gas concentrations that cause ... an enhanced greenhouse effect which results in ... increasing GMST that causes both direct and indirect ... changes in physical and biological systems (eg sea-level rise)
climate change is driven by both internal and exgernal influences on the Earth's climate system. The climate system is held in balance through the interaction of many positive and negative feedbacks between components and biogeochemical processes. These processes happen at a wide range of rates - some happening within weeks, others taking centuries. Once disturbed, some processes in the climate system (eg sea-level rise) will take centuries to settle down again.
The Earth's climate is changing. The IPCC has concluded that 'most of the observed warming of the past 50 years is attributable to human activity.' Three pices of scientific evidence are at the heart of this conclusion: (i) increasing atmospheric concentrations of carbon dioxide, methane and nitrous oxide; (ii) increasing global mean surface temperature; (iii) observed changes in a variety of indicators that support this include sea-level rise and weather indicators.
We have so far burned about a fifth of the known fossil-fuel reserves and possibly as little as round a twenthieth of what might be there. Rough calculations suggest that stabilization at 450 ppm requires us to limit total cumulative emissions to 670 GtC compared with teh 406GtC that we have already emitted since the start of the Industrial Revolution.
Understanding how various factors affect radiative forcing and therefore GMST provides an insight into the uncertainties that permeate climate prediction. Many different factors and processes in the climate system help determine GMST.
Predicting future climate change is highly uncertain. Thei sis due to a cascade of uncertainties starting in the cause-effect relationships between emissions, concentrations, radiative forcing, global mean surface temperature increases and resulting climate impacts. Climate models are improving steadily, but cannot yet fully replicate the behaviour of the climate system.
Nevertheless, future changes in atmospheric composition and climate are inevitable with increases in temperature and some extreme events, and regional increases and decreases in precipitation, leading to an increased risk of floods and droughts.
There are both beneficial and adverse effects of climate change, but the greater the increase in GMST, the more the adverse effects predominate with developing countries being the most vulnerable. It is difficult to quantify the potential benefits and damage that climate change may cause.
It is plausible that human-induced climate change could set in motion large-scale, high-impact, non-linear, and potentially abrupt changes in physical and biological systems over the coming decades to millennia. The risks of such events rise with the increase in GMST.
The global political response to climate change is relatively recent. Formally beginning in 1994 with the establishment of the UNFCCC, it was triggered by two decades of scientific assessment.
The UNFCCC is the centre peice of the global political response to climate change. The core of the UNFCCC is a framework of a central Objective, some guiding Principles and a series of Commitments. The objective of the convention is celar in one sense, but open to considerable scientific and political uncertainty in other ways. The guiding Principles are littered with potential sources of political uncertainty. The Commitments contained in Article 4 distinguish between those that apply to all countries, and those that apply to developed countries (Annex I countries).
Developing countries distinguish three distinct types of 'climate impact' : actual impacts (eg sea-level rise), economic and social impacts (eg cost of adaptation and mitigation), and economic and social impacts on fossil-fuel-exporting countries as a result of switching to renewable energy sources.
The Kyoto Protocol significantly strengthens the UNFCCC regime. It adds legal teeth to the climate negotiations. Its main innovations are quantified targets for greenhouse gas reduction for developed countries that can be extended ad infinitum, the possibility of emissions trading among Annex I countries and the opportunity for developed countries to embark on clean development projects with developing country partners.
In terms of planetary management, the Kyoto Protocol is only a small step. However, in terms of changing the relationship between economic growth, energy use and greenhouse gas emissions, it is a significan step. These two different perspectives on the same Treaty provide some insight into different views of the significance of the Kyoto climate regime.
Even if Kyoto (in its first commitment period, 2008-12) is implemented fully, it will have a very limited impact on future increases in GMST. Much tougher reduction targets will be requied in the future to stabilize the climate.
The UNFCCC and its Kyoto Protocol are 'living' agreements at the heart of the global political response to climate change. The Kyoto 2012 targets are the first small steps of many more that will be necessary if we are to stabilize the climate by cutting emissions by up to 60-90% compared with their present levels.
An integrated approach to thinking through climate change takes into account the balance of costs (however defined) between (a) business as usual (doing little or nothing), (b) adaptation and (c) mitigation. There are costs, risks and trade-offs associated with all three response options. Different nations view these differently. For large emitters, such as the US, China, Europe and India, all three costs are important. For small emitters, such as small island states, the balancing act is much simpler; they must balance the cost of climate damage against the cost of adaptation to climate change.
Five key factors determine the cost of climate stabilization; baseline assumptions; the climate stabilization level; speed of stabilization; the burden-sharing regime; and rules governing use of Kyoto mechanisms.
Integrated assessment models help decision-makers think through the implications of different courses of action in responding to climate change. They link biogeochemical changes in the climate to socio-economic impacts in four steps: emissions scenarios; atmospheric concentrations; changes in climate; and socio-economic impacts. There are uncertainties in each step and these cascade from one step to the next.
The use of quantitative models as decision support tools is a critical part of envrionmental policy-making. Uncertainties abound in environmental modelling, pervading even the simplest models. Modelling future global emissions is a highly complex task, as there are considerable uncertainties in the prediction of all three key driving forces of global emissions models (population, income trends and technological change).
Good scenarios comprise a plausible set of quantified variables, allied to a convincing story line. The IPCC uses scenario analysis extensively in its assessments of possible future climate change as a way of overcoming issues about complexity and uncertainty. The IPCC TAR identifies four families of scenarios - two centred on economic development and two on environmental improvements. The scenarios are not predictions or forecasts, and none is more likely than another. They all also assume 'no new climate policies' in the future, but some of them also represent very low carbon futures.
The concept of emissions baselines is pivotal to the understanding of different perspectives on the nature of the climate stabilization challenge. A 'baseline' is a non-climate intervention scenario. there is no single basline; different studies, scientists, policymakers and analysts all make different judgements about the future baseline depending on how optimistic or pessimistic, normative or descriptive, they are about changes in key driving forces (population, income and technological change).
The difference between the baseline and future climate stabilization targets (eg 450, 550 or 650 ppm) is a proxy measure of the political, economic and social challenge of managing climate change. The economic and social costs of stabilization are greater, the higher the baseline or the lower the stabilization levels. Conversely, the cost of stabilization is lower for lower baselines or higher stabilization levels.
Emissions from developing countries are growing frive times faster than in the industrialized world, and will very shortly make up the lion's share of global emissions. Climate change is a global problem, which requires a global response. It is unlikely that developed countries will continue to act alone without the cooperation of developing countries. However, we are right at the start of establishing exactly on what basis - and by which rules - developed and developing countries should share the burden of emission reduction. In the next decades we are likely to witness intense and controversial negotiations of how all nations can move forward together as a global community in the search for an equitable approach to achieving Article 2 of the UNFCCC.
Debates on action on climate change relate to every scale of human activity, and require us to look at questions of equity, vulnerability and responsibility across time and space.
Developed world lifestyles and consumption patterns are the source of major global problems - climate change above all. Solutions do exist but they demand both investment and commitment - from individuals and government at all scales.
Economics presents both opportunities and problems in the search for environmental and social security and quality in the future. Methods such as discounting can be contentious, but the internalizing of externalities can be fruitful.
Alternative ways of thinking about environmental problems are numerous. Lovelock's Gaia hypothesis is one that offers a different starting point, based on the drawing togethre of geological, atmospheric and biological sciences. It argues for thinking of the Earth in terms of Gaia - a single living organism.
The Gaia hypothesis has inspired one political philosopher to propose a political system reliant on cooperation correcting the over-extension of Darwinist understanding of competition and evolution into social and political philosophy.
A balance sheet of both environmental economics and Gaian approaches suggests that there is no single store of practical or philosophical answers to guide our repsonses to climate change. Rather, we shall need to take a critical and open-minded approach to a range of disciplines.
Climate change marks a distinct change in the way environmental problems are understood. The aggregate of individual actions is now seen to be resulting in physical global environmental changes, as opposed simply to despoliation of the natural world or exhaustion of resources.
The range of disciplines, including ecology, thermodynamics and environmental economics, have shaped both environmentalism and the concept of sustainable development.
There are counter arguments to environmentalism that have stood the test of time, having been consistently posed since the early 1970s.
Climate change and questions about the nature of development are inextricably bound up together. The issue lent force to the concept of sustainable development and brought about a 'second wave' of support for environmentalism. The concept serves as a political compromise between environment and development concerns. Its implementation has proved much harder than defining it.
Attempts have been made to express progress towards sustainable development in terms of carefully chosen indicators and indices. Though they have not caught the public imagination, they could serve to take environmetnal concerns into the frame of thinking of mainstream government and business decision-makers.