Glossary

Aerosol(s) A collection of airborne solid or liquid particles with a typical size between 0.01 and 10 m that reside in the atmosphere from periods of hours to days or months. They may be natural or anthropogenic in origin. They influence climate directly through absorbing or scattering radiation or indirectly by acting as cloud condensation nuclei afforestation Planting of new forests on lands that historically have not contained forests Agenda 21 A document accepted by the participating...

The goal of environmental stewardship

Early in this chapter I invited you to imagine a voyage on Spaceship Earth. Let me leave you with two further metaphors to provide some perspective on sus-tainability especially as it is seen from the rich developed world. The first metaphor represents unsustainability I owe it to Professor Bob Goudzwaard20 of the Free University of Amsterdam. He asks us to imagine our position in the developed world to be like that of a passenger in a comfortable seat on a high-speed train - a train a grande...

What the individual can do

I have spelled out the responsibilities of experts of all kinds - scientists, economists, technologists, politicians, industrialists, communicators and educators. There are important contributions also to be made by ordinary individuals to help to mitigate the problem of global warming.15 Some of these ensure maximum energy efficiency in the home - through good insulation (see box on page 342) against cold in winter and heat in summer and by making sure that rooms are not overheated and that...

The conception and conduct of environmental research

While completing the writing of this last chapter for the third edition in 2004 I attended the opening of the Zuckerman Institute for Connective Environmental Research at the University of East Anglia - a centre devoted to interdisciplinary research on the environment. An opening lecture was given by William Clark, Professor of International Science, Public Policy and Human Development at Harvard University.18 I was particularly struck by his remarks concerning the changes that are necessary in...

The challenge to all sections of community

In facing the challenge, it is important to recognise that the problems raised by global warming are not only global but long term the timescales of climate change, of major infrastructure change in energy generation or transport or of major changes in programmes such as forestry are of the order of several decades. The programme of action must therefore be seen as both urgent and evolving, based on continuing scientific, technical and economic assessments. As the IPCC 1995 Report states, 'The...

Poverty and population growth

The Prince of Wales, in addressing the World Commission on Environment and Development on 22 April 1992, spoke as follows 7 I do not want to add to the controversy over cause and effect with respect to the Third World's problems. Suffice it to say that I don't, in all logic, see how any society can improve its lot when population growth regularly exceeds economic growth. The factors which will reduce population growth are, by now, easily identified a standard of health care that makes family...

Not the only global problem

Global warming is not the only global problem. There are other issues of a global scale we need to see global warming in their context. Four problems of particular importance impact on the global warming issue. The first is population growth. When I was born there were about 2000 million people in the world. At the beginning of the twenty-first century there were 6000 million. During the lifetime of my grandchildren it is likely to rise to 8000 or 9000 million.6 Most of the growth will be in...

Global warming global pollution

A hundred years ago, the French painter Claude Monet spent time in London and painted wonderful pictures of the light coming through the smog. London was blighted by intense local pollution - from domestic and industrial chimneys around London itself. Thanks to the Clean Air Acts beginning in the 1950s, those awful smogs belong to the past - although London's atmosphere could be still cleaner. Today, however, it is not just local pollution that is a problem but global pollution. Small amounts...

Energy policy in the UK

A number of important reports concerned with energy policy have been published in the UK since the year 2000. The first of these is Energy in a Changing Climate published in 2000 by the Royal Commission on Environmental Pollution (RCEP)74 - an expert body that provides advice to government. It supported the concept of 'contraction and convergence' (Figure 10.5) as a basis for future international action to reduce greenhouse gas emissions and pointed out that application of this concept would...

IEA World Energy Outlook

In chapters 10 and 11, I have already referred extensively to the work of the International Energy Agency (IEA) and to their Energy Technology Perspectives published in June 2008 that outlines an energy future up to 2050 that aims at stabilization of atmospheric carbon dioxide consistent with a rise in global surface temperature of less than 2 C. The IEA's annual World Energy Outlook (WEO) is the most important world publication in the energy field. The WEO published in November 2008 includes...

V

Figure 11.26 Technical options for reducing greenhouse gases up to 2030 and their cost in euros per tonne of carbon saved as estimated by workers in the Stockholm office of McKinsey & Company. Only some of the main options are labelled. Options below the line produce net savings, above the line net costs. The x-axis shows abatement for each of the options below 'business as usual' in GtCO2e per year. By 2030 they total 26 GtCO2e per year, enough to meet the 450 ppm stabilization curve shown...

A zero carbon future

In Chapter 10 beginning on page 293, after an analysis of the increasing seriousness of the consequences of global warming as the temperature rises, arguments were put forward for setting a target for the increase of global average temperature of no greater than 2 deg C above its pre-industrial level. Inspection of the profile of CO2 emissions in the IEA BLUE Map scenario published in Energy Technology Perspectives 2008 (Figures 11.4 and 10.3), which aims to meet this target, shows that the...

Power from nuclear fusion

When at extremely high temperatures the nuclei of hydrogen (or one of its isotopes, deuterium or tritium) are fused to form helium, a large amount of energy is released. This is the energy source that powers the Sun. To make it work on Earth, deuterium and tritium are used from 1 kg, 1 GW can be generated for one day. The supply of material is essentially limitless and no unacceptable pollution is produced. A temperature of 100 million degrees Celsius is required for the reaction to occur. To...

Technology for the longer term

This chapter has concentrated mostly on what can be achieved with available and proven technology during the next few decades. It is also interesting to speculate about the more distant future and what relatively new technologies may become dominant during the twenty-first century. In doing so, of course, we are almost certainly going to paint a more conservative picture than will actually occur. Imagine how well we would have done if asked in 1900 to speculate about technology change by 2000...

Mitigation technologies and potential in

Table 11.2 summarises the various technologies and practices addressed in the last few sections (including also those relating to methane and forestry addressed in Chapter 10) and the possible contributions from different sectors both now and by 2030 to the required reductions in greenhouse gases.63 Figure 11.23 shows a range of estimates from a number of studies for the mitigation of CO2e emissions from the different sectors assuming different levels of the carbon price in terms of US per...

Tnh

< 20 < 50 < 100 < 20 < 50 < 100 < 20 < 50 < 100 < 20 < 50 < 100 < 20 < 50 < 100 < 20 < 50 < 100 < 20 < 50 < 100 < 20 < 50 < 100 US per t CO2e US per t CO2e US per t CO2e US per t CO2e US per t CO2e US per t CO2e US per t CO2e US per t CO2e Energy supply Forestry Waste Total Figure 11.23 Estimates of the economic potential for global mitigation in 2030 for different sectors as a function of carbon price in terms of US per tonne CO2e. The ranges...

Policy instruments

Action in the energy sector on the scale required to mitigate the effects of climate change through reduction in the emissions of greenhouse gases will require significant policy initiatives by governments in cooperation with industry. Some of these initiatives are the following 61 putting in place appropriate institutional and structural frameworks energy pricing strategies (carbon or energy taxes and reduced energy subsidies) reducing or removing other subsidies (e.g. agricultural and...

Other renewable energies

We have so far covered the renewable energy sources for which there is potential for growth on a scale that can make a substantial contribution to overall world energy demand. We should also mention briefly other renewable energy technologies that contribute to global energy production and which are of particular importance in certain regions, namely geothermal energy from deep in the ground and energies from the tides, currents or waves in the ocean. The presence of geothermal energy from deep...

Local energy provision in Bangladesh

In a box earlier in the chapter on page 337, I outlined the components of a strategy for energy provision, one of which emphasised the value of local and distributed sources of energy as opposed to centralised sources in large units serving large grid networks. An example of local provision is Grameen Shakti (meaning Rural Power) in Bangladesh - a subsidiary of Professor Yunus's famed Grameen Bank - that has developed an affordable solar home system (Figure 11.19) offered to rural communities...

The photovoltaic solar cell

The silicon photovoltaic (PV) solar cell51 consists of a thin slice of silicon into which appropriate impurities have been introduced to create what is known as a p-n junction. The most efficient cells are sophisticated constructions using crystalline silicon as the basic material they possess efficiencies for conversion of solar energy into electricity typically of 15 to 20 experimental cells have been produced with efficiencies well over 20 . Single crystal silicon is less convenient for mass...

Solar water heating

The essential components of a solar water heater (Figure 11.15) are a set of tubes in which the water flows embedded in a black plate insulated from behind and covered with a glass plate on the side facing the Sun. A storage tank for the hot water is also required. A more efficient (though more expensive) design is to surround the black tubes with a vacuum to provide more complete insulation. Over 10 million households worldwide have solar hot water systems.49 Figure 11.15 Design of a solar...

Wind power on Fair Isle

A good example of a site where wind power has been put to good effect is Fair Isle, an isolated island in the North Sea north of the Scottish mainland.48 Until recently, the population of 70 people depended on coal and oil for heat, petrol for vehicles and diesel for electricity generation. A 50-kW wind generator was installed in 1982 to generate electricity from the persistent strong winds of average speed over 8 m s-1 (29 km h-1 or 18 mph). The electricity is available for a wide variety of...

Wind energy

Two hundred years ago windmills were a common feature of the European landscape for example, in 1800 there were over 10 000 working windmills in Britain. During the past few years they have again become familiar on the skyline especially in countries in Western Europe (for instance, Denmark, Germany, UK and Spain) and in western North America. Slim, tall, sleek objects silhouetted against the sky, they do not have the rustic elegance of the old windmills, but...

Biofuels

Biofuels are currently produced from starch, sugar and oil feedstocks that include wheat, maize, sugar cane, palm oil and oilseed rape. The best-known example of their use comes from Brazil where since the 1970s large plantations of sugar cane have produced ethanol for use as a fuel mainly in transport, generating, incidentally, much less local pollution than petrol or diesel fuel from fossil sources. Residues from ethanol or sugar production are used to generate electricity to power the...

Biomass energy

Second in current importance as a renewable energy source is the use of bio-mass.37 The annual global primary production of biomass of all kinds expressed in energy units is about 4500 EJ ( 107 Gtoe). About 1 of this is currently turned into energy mostly in developing countries - we have labelled it 'traditional biomass'. It has been estimated that about 6 of the total could become available from energy crops taking into account the economics of production and the availability of suitable...

Hydropower

Hydropower, the oldest form of renewable energy, is well established and is competitive economically with electricity generated by other means. Some hydroelectric schemes are extremely large. The world's largest, the Three Gorges Figure 11.12 Growth of renewable power generation in the IEA BLUE Map energy scenario, 2000-2050. project on the Yangtze River in China, generates about 18 GW of electricity. Two other large schemes, each of over 10 GW capacity, are in South America at Guri in...

Energy and carbon dioxide savings in industry

Industry currently accounts for nearly one-third of worldwide primary energy use and about one-quarter of carbon dioxide emissions of which 30 comes from the iron and steel industry, 27 from non-metallic minerals (mainly cement) and 16 from chemicals and petrochemicals production.27 Substantial opportunities exist for efficiency savings in all these areas. The application of appropriate control technologies, other best-available technologies (BAT) and more widespread combined heat and power...

Example of a ZED Zero Emission fossilfuel Development

BedZED (Figure 11.8) is a mixed development urban village constructed on a brownfield wasteland in the London Borough of Sutton, providing 82 dwellings in a mixture of apartments, maisonettes and town houses together with some work office space and community facilities.22 The combination of super-insulation, a wind-driven ventilation system incorporating heat recovery, and passive solar gain stored within each unit in thermally massive floors and walls reduces the energy needs so that a 135 kW...

Insulation of buildings

About 1500 million people live in cold climates where some heating in buildings is required. In most countries the energy demand of space heating in buildings is far greater than it need be if the buildings were better insulated (Figure 11.7). Table 11.1 provides as an example details of two houses, showing that the provision of insulation in the roof, the walls and the windows can easily lead to the energy requirement for space heating being more than halved (from 5.8 kW to 2.65 kW). The cost...

Efficiency of appliances

There is large potential for reducing the electricity consumption from appliances used in domestic or commercial buildings. If, in replacing appliances, everyone bought the most efficient available, their total electricity consumption could easily drop by more than half. Take lighting for instance. One-fifth of all electricity used in the United States goes directly into lighting. This can easily be reduced by the wider use of compact fluorescent light bulbs which are as bright as ordinary...

Thermodynamic efficiencies

When considering the efficiency of energy use, it can be important to distinguish between efficiency as defined by the First Law of Thermodynamics and efficiency as defined by the Second Law. The second particularly applies when energy is used for heating. A furnace used to heat a building may deliver say 80 of the energy released by full combustion of the fuel, the rest being lost through the pipes, flue, etc. That 80 is a First Law efficiency. An ideal thermodynamic device delivering 100...

Where are we heading Components of energy strategy

(1) Planning for the long term must be a priority. Long timescales up to 50 or 100 years are involved in many factors that make up the climate change issue, for instance, the lifetime of carbon dioxide in the atmosphere, the lag due to the ocean in the realisation of climate change or the typical life of energy infrastructure. (2) Not all potential technologies are at the same stage of development. Promising technologies need to be brought to the starting gate so that they can properly compete....

Buildings energy conservation and efficiency

If we turn lights off in our homes when we do not need them, if we turn down the thermostat by a degree or two so that we are less warm or less cool or if we add more insulation to our home, we are conserving or indeed saving energy. Figure 11.6 Where are we heading - the need for an energy strategy. The boat flies national and UN flags to illustrate the need for national and international strategies. Figure 11.6 Where are we heading - the need for an energy strategy. The boat flies national...

A longterm energy strategy

Before presenting details of the implementation, I want to step back and consider how the choices between the great variety of proposed solutions and potential technologies are to be made. It is relatively easy to present paper solutions, but how do we decide between them and find the best way forward There is no one solution to the problem and no obviously best technology different solutions will be appropriate in different countries or regions. Simplistic answers I have often heard are Leave...

Projections for energy investment

The International Energy Agency has also estimated the future financial investment in global energy that will be necessary between 2005 and 2050 under their Reference or Baseline Scenario and the additional investment required to achieve the ACT and the BLUE Map energy scenarios.7 The total cumulative energy investment needs for the Reference scenario over this period is estimated to be about US250 trillion (million million) or about 6 of cumulative world GDP over the period. By far the largest...

Future energy projections

In Chapter 6 were described the SRES scenarios sponsored by the IPCC that detail, for the twenty-first century, a range of possibilities regarding future energy demand (based on a range of assumptions concerning population, economic growth and social and political development), how that demand might be met and what greenhouse gas emissions might result. In that chapter were also described the implications for those scenarios regarding climate change. Chapter 10 explained the imperative set out...

World energy demand and supply

Most of the energy we use can be traced back to the Sun. In the case of fossil fuels (coal, oil and gas) it has been stored away over millions of years in the past. If wood (or other biomass including animal and vegetable oils), hydropower, wind or solar energy itself is used, the energy has either been converted from sunlight almost immediately or has been stored for at most a few years. These latter sources of energy are renewable they will be considered in more detail later in the chapter....

Realising the Climate Convention Objective

Having recommended a choice of stabilisation level, a large question remains how can the nations of the world work together to realise it in practice It is instructive first to look at annual emissions of greenhouse gases expressed as CO2e and per capita. Averaged over the world in 2004 they were about 6.5 t CO2e ( 1.8 t C) per capita but they varied very much from country to country (Figure 10.4). For developed countries, including transitional economy countries, in 2000 they averaged 16 t...

The choice of stabilisation level

The last few sections have addressed the main greenhouse gases and how their concentrations might be stabilised. To decide how appropriate stabilisation levels should be chosen as targets for the future we look to the guidance provided by the Climate Convention Objective (see box on pages 291-2), which states that the levels and timescales for their achievement should be such that dangerous interference with the climate system is avoided, that ecosystems are able to adapt naturally, that food...

Stabilisation of carbon dioxide concentrations

Carbon dioxide, as we have seen, is the most important of the greenhouse gases that is increasing through human activities. As we saw in Chapter 3, emissions of carbon dioxide into the atmosphere from anthropogenic sources result from fossil fuel burning (about 80 ) and from land-use changes (about 20 ) - mainly deforestation. Reduction in emissions from land-use changes was considered earlier in the chapter. Reductions in emissions from fossil fuel burning will be the subject of the next...

Reduction in sources of greenhouse gases other than carbon dioxide

Methane, nitrous oxide and the halocarbons are greenhouse gases, less important than carbon dioxide, all of which show increases at the present time. In Figures 6.1 and 6.2 and Table 6.1 are shown the emissions, atmospheric concentrations and radiative forcing of these gases estimated for the twenty-first century under the various SRES scenarios, assuming no special action to reduce them. Is it possible that these further increases can be slowed or eliminated We consider them in turn. Methane...

The worlds forests and deforestation

The total area covered by forest is almost one-third of the world's land area, of which 95 is natural forest and 5 planted forest.9 About 47 of forests worldwide are tropical, 9 sub-tropical, 11 temperate and 33 boreal. At the global level, the net loss in forest area during the 1990s was an estimated 940 000 km2 (2.4 of total forest area). This was the combined effect of a deforestation rate of about 150 000 km2 per year and a rate of forest increase of about 50 000 km2 per year. Deforestation...

Forests

We now turn to the situation of the world's forests and the contribution that they can make to the mitigation of global warming. Action here can easily be taken now and is commendable for many other reasons. Over the past few centuries many countries, especially those at mid latitudes, have removed much of their forest cover to make room for agriculture. Many of the largest and most critical remaining forested areas are in the tropics. However, during the last few decades, the additional needs...

Carbon trading

Carbon trading is an innovative market-based solution to the problem of reducing greenhouse gas emissions3. Its main rationale is that, by attaching a price to carbon dioxide emissions, trading schemes will generate powerful economic incentives to cut emissions and channel investment efficiently. Emissions trading works by setting limits on total allowable emissions that are then converted into tradable permits to be distributed amongst participants. For example, a company with commitments to...

The Kyoto mechanisms

The Kyoto Protocol includes three special mechanisms to assist in emissions reductions. Joint implementation (JI) allows industrialised countries to implement projects that reduce emissions or increase removals by sinks in the territories of other industrialised countries. Emissions reduction units generated by such projects can then be used by investing Annex I countries to help meet their emissions targets. Examples of JI projects could be the replacement of a coal-fired power plant with a...

The Kyoto Protocol

At the first meeting after its entry into force held in Berlin in 1995, the Parties to the Climate Convention (i.e. all the countries that had ratified it) decided that they needed to negotiate a more specific and quantified agreement than the Convention on its own provided. Because of the principle in the Convention that industrialised countries should take the lead, a Protocol was formulated that required commitments from these countries (known as Annex I countries) for specific quantitative...

The Montreal Protocol

The chlorofluorocarbons (CFCs) are greenhouse gases whose emissions into the atmosphere are already controlled under the Montreal Protocol on ozone-depleting substances. This control has not arisen because of their potential as greenhouse gases, but because they deplete atmospheric ozone (see Chapter 3). Emissions of CFCs have fallen sharply during the last few years and the growth in their concentrations has slowed for some CFCs a slight decline in their concentration is now apparent. The...

Stabilisation of emissions

The target for short-term action proposed for developed countries by the Climate Convention was that, by the year 2000, greenhouse gas emissions should be brought back to no more than their 1990 levels. In the run-up to the Rio conference, before the Climate Convention was formulated, many developed countries had already announced their intention to meet such a target at least for carbon dioxide. They would do this mainly through energy-saving measures, through switching to fuels such as...

Some extracts from the United Nations Framework Convention on Climate Change signed by over countries in Rio de Janeiro

Firstly, some of the paragraphs in its preamble, where the parties to the Convention CONCERNED that human activities have been substantially increasing the atmospheric concentration of greenhouse gases, that these increases enhance the natural greenhouse effect, and that this will result on average in an additional warming of the Earth's surface and atmosphere and may adversely affect natural ecosystems and humankind. NOTING that the largest share of historical and current global emissions of...

The Climate Convention

The United Nations Framework Convention on Climate Change (FCCC) signed by over 160 countries at the United Nations Conference on Environment and Development held in Rio de Janeiro in June 1992 came into force on 21 March 1994. It has set the agenda for action to slow and stabilise climate change. The signatories to the Convention (some of the detailed wording is presented in the box below) recognised the reality of global warming, recognised also the uncertainties associated with current...

Notes For Chapter

J., Ephraums, J. J. (eds.) 1990. Climate Change The IPCC Scientific Assessments. Cambridge Cambridge University Press, p. 365 Executive Summary, p. xii. Similar but more elaborate statements are in the 1995, 2001 and 2007 IPCC Reports. 2 For a detailed description of how the output from climate models can be combined with other information in climate studies see Mearns, L. O., Hulme, M. et al. 2001. Climate scenario development. In Houghton, J. T., Ding, Y.,...

Further Reading And Reference

IPCC AR4 Climate Change 2007 Synthesis Report Metz, B., Davidson, O., Bosch, P., Dave, R., Meyer, L. (eds.) 2007. Climate Change 2007 Mitigation of Climate Change. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge Cambridge University Press. Technical Summary Chapter 2 Framing issues (e.g. links to sustainable development, integrated assessment) Chapter 3 Issues relating to mitigation in the long-term context Chapter 12...

Some global economics

So far our attempt to balance uncertainty against the need for action has been considered in terms of issues. Is it possible to carry out the weighing in terms of cost In a world that tends to be dominated by economic arguments, quantification of the costs of action against the likely costs of the consequences of inaction must at least be attempted. It is also helpful to put these costs in context by comparing them with other items of global expenditure. The costs of anthropogenic climate...

The Precautionary Principle

Some of these arguments for action are applications of what is often called the Precautionary Principle, one of the basic principles that was included in the Rio Declaration at the Earth Summit in June 1992 (see box below). A similar statement is contained in Article 3 of the Framework Convention on Climate Change (see box on pages 291-2 in Chapter 10). We often apply the Precautionary Principle in our day-to-day living. We take out insurance policies to cover the possibility of accidents or...

Why not wait and see

The debate about climate change not only addresses how much action is required but also when it needs to be taken. In the light of scientific uncertainty, it has often been argued that the case is not strong enough for much action to be taken now. What we should do is to obtain as quickly as possible, through appropriate research programmes, much more precise information about future climate change and its impact. We would then, so the argument goes, be in a much better position to decide on...

Narrowing the uncertainty

A key question constantly asked by policymakers is 'How long will it be before scientists are more certain about the projections of likely climate change, in particular concerning the regional and local detail ' They were asking that question 20 years ago and then I generally replied that in 10 to 15 years we would know a lot more. As we have already seen, there is now more confidence that anthropogenic climate change has been detected and more confidence too in climate change projections than...

The IPCC Assessments

Because of the scientific uncertainty, it has been necessary to make a large effort to achieve the best assessment of present knowledge and to express it as clearly as possible. For these reasons the IPCC was set up jointly by two United Nations' bodies, the World Meteorological Organization (WMO) and the United Nations Environmental Programme (UNEP).3 The IPCC's first meeting in November 1988 was timely it was held just as strong political interest in global climate change was beginning to...

The scientific uncertainty

Before considering the 'weighing' process and the cost of action, we begin by explaining the nature of the scientific uncertainty and how it has been addressed by the scientific community. In earlier chapters I explained in some detail the science underlying the problem of global warming and the scientific methods that are employed for the prediction of climate change due to the increases in greenhouse gases. The basic physics of the greenhouse effect is well understood. If atmospheric carbon...

Weighing the uncertainty

Pocerady power station in the Czech Republic is the backdrop to a commerical crop of sunflowers THIS BOOK is intended to present clearly the current scientific position on global warming. A key part of this presentation concerns the uncertainty associated with all parts of the scientific description, especially with the prediction of future climate change, which forms an essential consideration when decisions regarding action are being taken. However, uncertainty is a relative term utter...

The will to act

Many of the principles I have been enunciating are included at least implicitly in the declarations, conventions and resolutions that came out of the United Nations Conference on Environment and Development held in Rio de Janeiro in June 1992 indeed, they form the background of many statements emanating from the United Nations or from official national sources. We are not short of statements of ideals. What tend to be lacking are the capability and resolve to carry them out. Sir Crispin...

Equity intergenerational and international

In our world community of human beings we are not all equal. Equality may be cited as an aim but before it can be pursued its terms need careful definition. Reality is full of inequities of many kinds. In the context of global warming, because it is long term and global, two equity issues are particularly important - both have already been mentioned. Firstly, there is our responsibility to future generations. A basic instinct is that we wish to see our children and grandchildren well set up in...

Stewards of the Earth

The relationship between humans and the Earth that I have been advocating is often described as one of stewardship. We are on the Earth as its stewards. The word implies that we are carrying out our duty as stewards on behalf of someone else - but whom Some environmentalists see no need to answer the question specifically, others might say we are stewards on behalf of future generations or on behalf of a generalised humanity. A religious person would want to be more specific and say that we are...

Environmental values

What do we value in the environment and how do we decide what we need to preserve, to foster or improve At the basis of our discussion so far have been several assumptions regarding the value or importance of different fundamental attitudes or actions, some of which I have associated with ideas that come from the underlying environmental science. Is it legitimate, however, to make connections of this kind between science and values It is often argued that science itself is value free. But...

The technical fix

A third common attitude to the Earth is to invoke the 'technical fix'. As a senior environmental official from the United States said to me some years ago, 'We cannot change our lifestyle because of the possibility of climate change, we just need to fix the biosphere.' It was not clear just what he supposed the technical fixes would turn out to be. The point that he was making is that, in the past, humans have been so effective at developing new technology to meet the problems as they arise,...

Back to nature

Almost the reverse of this attitude is the suggestion that we all adopt a much more primitive lifestyle and give up a large part of industry and intensive farming - that we effectively put the clock back two or three hundred years to before the Industrial Revolution. That sounds very seductive and some individuals can clearly begin to live that way. But there are two main problems. The first is that it is just not practical. The world population is now some six times what it was 200 years ago...

Exploitation

Humankind has over many centuries been exploiting the Earth and its resources. It was at the beginning of the Industrial Revolution some 200 years ago that the potential of the Earth's minerals began to be realised. Coal, the result of the decay of primaeval forests and laid down over many millions of years, was the main source of energy for the new industrial developments. Iron ore to make steel was mined in vastly increased quantities. The search for other metals such as zinc, copper and lead...

Earth in the balance

Al Gore, Vice-President of the United States in the Clinton Administration, entitled his book on the environment Earth in the Balance,1 implying that there are balances in the environment that need to be maintained. A small area of a tropical forest possesses an ecosystem that contains some thousands of plant and animal species, each thriving in its own ecological niche in close balance with the others. Balances are also important for larger regions and for the Earth as a whole. These balances...

Questions

1 For your local region, find out about its water supply and how the water is used (e.g. by domestic users, agriculture, industry, etc.). What are likely to be the trends in its use over the next 50 years due, for instance, to population changes or changes in agriculture or industry What are the possibilities for increased supply and how might these be affected by climate change 2 For your local area, find out about current environmental problems such as sea level rise due to subsidence,...

SUMMARY

The main impacts of climate change will be due to sea level rise, increases in temperature and heat waves and a more intense hydrological cycle leading on average to more frequent and intense floods, droughts and storms (see Table 7.6 for a summary of impacts of extreme events). There are many ways in which the environment is being degraded due to human activities, for instance, through over-withdrawal of ground-water, loss of soil or deforestation. Global warming will exacerbate these...

Estimates of impacts costs under businessasusual BAU from the Stern Review

Using the PAGE 2002 Integrated Assessment Model (IAM),75 the Stern Review considers estimates of cost to the world's economies over the next two centuries if emissions of greenhouse gases continue on a 'business-as-usual' (BAU) path taking global average temperature increases possibly to 4 C by 2100 (cf. Figure 6.4) and 8 C by 2200. It is pointed out that modelling over many decades, regions and possible outcomes demands that distributional and ethical judgements are made systematically and...

Costing the total impacts

We now turn to consider all the impacts of anthropogenic climate change, attempts that have been made to express their cost in monetary terms and the validity of the methods employed. The IPCC 1995 Report contained a review of four cost studies71 of the impacts of climate change in a world where the atmospheric carbon dioxide concentration had doubled from its pre-industrial level,72 the most detailed studies being carried out for the United States. For those impacts against which some value of...

The insurance industry and climate change

The impact of climate on the insurance industry is mainly through extreme weather events. In developing countries there may be very high mortality from extreme weather but relatively small costs to the industry because of low insurance penetration. In developed countries the loss of life may be much less but the costs to the insurance industry can be very large. Figure 1.2 illustrates the large growth in weather-related disasters and the associated economic and insured losses since the 1950s...

Costing the impacts extreme events

In the previous paragraphs the impacts of climate change have been described in terms of a variety of measures for instance, the number of people affected (e.g. by mortality, disease or by being displaced), the gain or loss of agricultural or forest productivity, the loss of biodiversity, the increase in desertification, etc. However, the most widespread measure, looked for by many policymakers, is monetary cost or benefit. But before describing what has been done so far to estimate the overall...

Adaptation to climate change

As we have seen, some of the impacts of climate change are already apparent. A degree of adaptation63 therefore has already become a necessity. Numerous possible adaptation options for responding to climate change have already been identified - examples are given in Table 7.2. Because it takes some decades for the oceans to warm, there also exists a substantial commitment to further climate change even if carbon dioxide emissions were to be halted. Urgent action is therefore necessary to...

Impacts on Africa

Africa is one of the most vulnerable continents to climate change and variability, a situation that is exacerbated by existing developmental challenges such as endemic poverty complex governance and institutional dimensions limited access to capital, including markets, infrastructure and technology ecosystem degradation and complex disasters and conflicts - all of which contribute to Africa's weak adaptive capacity to climate change.61 Some projected climate impacts for Africa are summarised as...

Heatwaves in Europe and India

Record extreme temperatures were experienced in Europe during June, July and August 2003. At many locations temperature rose to over 40 C. In France, Italy, the Netherlands, Portugal and Spain, over 20, 000 (possibly as many as 35 000) additional deaths were attributed to the unrelenting heat. Spain, Portugal, France and countries in Central and Eastern Europe suffered from intense forest fi res.59 Figure 7.19 illustrates the rarity of this event showing that it is well outside normal climate...

The impact on human health

Health from increased malnutrition and from a prevalence of conditions more likely to lead to the spread of diseases from a variety of causes. How about direct effects ofthe climate change itselfon human health Humans can adapt themselves and their buildings so as to live satisfactorily in very varying conditions and have great ability to adapt to a wide range of climates. The main difficulty in assessing the impact of climate change on health is that of unravelling the influences of climate...

Forestclimate interactions and feedbacks

Various interactions and feedbacks are in play between forests and climate. Extensive changes in the area of forests due to deforestation can seriously affect the climate in the region of change. Changes in carbon dioxide, temperature or rainfall associated with climate change can have a major impact on the health or structure of forests that can in turn feed back on the climate. We consider some of these effects in turn. Changes in land use such as those brought about by deforestation can...

The impact on ecosystems

A little over 10 of the world's land area is under cultivation - that was the area addressed in the last section. The rest is to a greater or lesser extent unman-aged by humans. In Figure 7.13 are illustrated the world's major ecosystems (or biomes) with their global areal extent showing how they have been transformed by land use. Ecosystems are of great importance to human communities. They provide supplies for human communities in the provision of food, water, fuel, wood and biodiversity....

Modelling the impact of climate change on world food supply

An example illustrating the key elements of a detailed study of the impact of climate change on world food supply is shown in Figure 7.12.45 A climate change scenario is fi rst set up with a climate model of the kind described in Chapter 5. Models of different crops that include the effects of temperature, precipitation and carbon dioxide are applied to 124 different locations in 18 countries to produce projected crop yields that can be compared with projected yields in the absence of climate...

The carbon dioxide fertilisation effect

An important positive effect of increased carbon dioxide concentrations in the atmosphere is the boost to growth in plants given by the additional carbon dioxide. Higher carbon dioxide concentrations stimulate photosynthesis, enabling plants to fix carbon at a higher rate. This is why in glasshouses additional carbon dioxide may be introduced artificially to increase productivity. The effect is particularly applicable to what are called C3 plants (such as wheat, rice and soya bean), but less so...

Desertification

Drylands (defined as those areas where precipitation is low and where rainfall typically consists of small, erratic, short, high-intensity storms) cover about 40 of the total land area of the world and support over one-fifth of the world's population. Figure 7.10 shows how these arid areas are distributed over the continents. Desertification in these drylands is the degradation of land brought about by climate variations or human activities that have led to decreased vegetation, reduction of...

Impact on agriculture and food supply

Every farmer understands the need to grow crops or rear animals that are suited to the local climate. The distribution of temperature and rainfall during the year are key factors in making decisions regarding what crops to grow. These will change in the world influenced by global warming. The patterns of what crops are grown where will therefore also change. But these changes will be complex economic and other factors will take their place alongside climate change in the decision-making...

Impacts in coastal areas

A rise in average sea level of 10 to 20 cm by 2030 and about up to 1 metre by the end of the next century may not seem a great deal. Many people live sufficiently above the level of high water not to be directly affected. However, half of humanity inhabits the coastal zones around the world.11 Within these, the lowest lying are some of the most fertile and densely populated. To people living in these areas, even half a metre increase in sea level can add enormously to their problems. Their...

Sensitivity adaptive capacity and vulnerability some definitions

Sensitivity is the degree to which a system is affected, either adversely or beneficially, by climate-related stimuli. These encompass all the elements of climate change, including mean climate characteristics, climate variability, and the frequency and magnitude of extremes. This may be direct (e.g. a change in crop yield in response to a change in the mean, range or variability of temperature) or indirect (e.g. damage caused by an increase in the frequency of coastal flooding due to sea level...

The impacts of climate change

Droughts in the Masai region of Africa. Droughts in the Masai region of Africa. THE LAST two chapters have detailed the climate change in terms of temperature and rainfall that we can expect during the twenty-first century because of human activities. To be useful to human communities, these details need to be turned into descriptions of the impact of climate change on human resources and activities. The questions to which we want answers are how much will sea level rise and what effect will...

Longerterm climate change

Most of the projections of future climate that have been published cover the twenty-first century. For instance, the curves plotted in Figures 6.1 to 6.6 extend to the year 2100. They illustrate what is likely to occur if fossil fuels continue to provide most of the world's energy needs during that period. From the beginning of the industrial revolution until 2000 the burning of fossil fuels released approximately 300 Gt of carbon in the form of carbon dioxide into the atmosphere. Under the...

Regional climate models

Most of the likely changes that we have presented have been on the scale of continents. Can more specific information be provided about change for smaller regions In Chapter 5 we referred to the limitation of global circulation models (GCMs) in the simulation of changes on the regional scale arising from the coarse size of their horizontal grid - typically 300 km or more.30 Also in Chapter 5 we introduced the regional climate model (RCM) which typically possesses a resolution of 50 km and can...

Changes in climate extremes

The last section looked at the likely regional patterns of climate change. Can anything be said about likely changes in the frequency or intensity of climate extremes in the future It is, after all, not the changes in average climate that are generally noticeable, but the extremes of climate - droughts, floods, storms and More More cold record weather cold weather extremes of temperature in very cold or very Increase in mean warm periods - which provide the largest impact on our lives (see...

Regional patterns of climate change

So far we have been presenting global climate change in terms of likely increases in global average surface temperature that provide a useful overall indicator of the magnitude of climate change. In terms of regional implications, however, a global average conveys rather little information. What is required is spatial detail. It is in the regional or local changes that the effects and impacts of global climate change will be felt. Figure 6.6 Projected pattern average of surface temperature...

Equivalent carbon dioxide COe

In many of the modelling studies of climate change, the situation of doubled pre-industrial atmospheric carbon dioxide has often been introduced as a benchmark especially to assist in comparisons between different model projections and their possible impacts. Since the pre-industrial concentration was about 280 ppm, doubled carbon dioxide is about 560 ppm. From the curves in Figure 6.2 this is likely to occur sometime in the second half of the twenty-first century, depending on the scenario....

Model projections

Results that come from the most sophisticated coupled atmosphere-ocean models of the kind described in the last chapter provide fundamental information on which to base climate projections. However, because they are so Table 6.1 Radiative forcing (W m-2) globally averaged, for greenhouse gases and aerosols from the year 1750 to 2005 and from SRES scenarios to 2050 and 2100 a Including both direct and indirect effects. demanding on computer time only a limited number of results from such models...

Emission scenarios

A principal reason for the development of climate models is to learn about the detail of the likely climate change this century and beyond. Because model simulations into the future depend on assumptions regarding future anthropogenic emissions of greenhouse gases, which in turn depend on assumptions about many factors involving human behaviour, it has been thought inappropriate and possibly misleading to call the simulations of future climate so far ahead 'predictions'. They are therefore...

The future of climate modelling

Very little has been said in this chapter about the biosphere. Chapter 3 referred to comparatively simple models of the carbon cycle which include chemical and biological processes and simple non-interactive descriptions of atmospheric processes and ocean transport. The large three-dimensional global circulation climate models described in this chapter contain a lot of dynamics and physics but no interactive chemistry or biology. As the power of computers has increased, it has become possible...

Regional climate modelling

The simulations we have so far described in this chapter are with global circulation models (GCM) that typically possess a horizontal resolution (grid size) of 200 or 300 km - the size being limited primarily by the availability of computer power. Weather and climate on scales large compared with the grid size are described reasonably well. However, at scales comparable with the grid size, described as the regional scale,29 the results from global models possess serious limitations. The effects...

Is the climate chaotic

Throughout this chapter the implicit assumption has been made that climate change is predictable and that models can be used to provide predictions of climate change due to human activities. Before leaving this chapter I want to consider whether this assumption is justified. The capability of the models themselves has been demonstrated so far as weather forecasting is concerned. They also possess some skill in seasonal forecasting. They can provide a good description of the current climate and...

Comparison with observations

More than 20 centres in the world located in more than ten countries are currently running climate models of the kind I have described in which the circulations of the atmosphere and the ocean are fully coupled together. Some of these models have been employed to simulate the climate of the last 150 years allowing for variations in aspects of natural forcing (e.g. solar variations and volcanoes) and anthropogenic forcings (i.e. increases in the concentrations of greenhouse gases and aerosols)....

Validation of the model

In discussing various aspects of modelling we have already indicated how some validation of the components of climate models may be carried out.17 The successful predictions of weather forecasting models provide validation of important aspects of the atmospheric component, as do the simulations mentioned earlier in the chapter of the connections between sea surface temperature For climate change over periods up to a decade, only the upper layers of the ocean have any substantial interaction...

Models for climate prediction

For models to be successful they need to include an adequate description of the feedbacks we have listed. The water vapour feedback and its regional distribution depend on the detailed processes of evaporation, condensation and advection (the transfer of heat by horizontal air flow) of water vapour, and on the way in which convection processes (responsible for showers and thunderstorms) are affected by higher surface temperatures. All these processes are already well included in weather...

The climate system

So far the forecasting of detailed weather over a few days and of average weather for a month or so, up to perhaps a season ahead, has been described in order to introduce the science and technology of modelling, and also because some of the scientific confidence in the more elaborate climate models arises from their ability to describe and forecast the processes involved in day-to-day weather. Forecasting for the African Sahel region The Sahel region of Africa forms a band about 500 km wide...