This section is concerned with the relations between human activity and the complex an seemingly unstable natural systems on which we rely. Economic growth and population expansion have created an unprecedented impact on the workings of the world. Mitigating these impacts, and understanding the systems which are involved, will require major changes from the patterns of the past. In particular, as explored elsewhere, much greater interdependency will demand much more complex international institutions.
This section is divided into two sections. The first of them describes the causes of the impacts and the nature of some of the more important. The key point to be taken from this is that there is not one 'environmental' problem but many, and that each has a different set of remedies. The scale of the issues is, however, very great, and there is no reason to suppose that the issues will either disperse of find their own solutions.
The second section is focused on remedies, and places particular stress on energy as a paradigm for many other issues. The multifaceted, complex nature of solutions is highlighted, together with the absolute need for more growth, more technology, more investment in order to create solutions, not neo-mediaevalism or denial.
The biosphere is a construct erected by around 1.4 bn years of biological interchange, crisis and adaptation. It is a network of balances, into which we are suddenly intruding our activities. About half of the land surface has now been transformed as a result of human activity. There was an area the size of Australia under cultivation in 1900: today, it is the size of Asia. We have already captured around a third of the productivity of the planet's biomass, yet demand for maize, rice and wheat will increase by around 40% by 2020, and demand for meat will grow by two thirds. Around 14 million hectares of natural forest is destroyed annually. We deflect around half of the fresh water flows on the planet to our use, a figure projected to rise to around 70% by 2020.
Four major categories of impact are at work.
Figure 1: World oceanic fishery exploitation, and the extinction of US anchovy fisheries.
Figure 2a: The Gulf stream pumps hot water Northwards.
The Gulf stream keeps the North Atlantic around 10oC than its latitude would suggest. Water flows North because it displaces cooler, denser water. Tropical waters are, however, salty and so there is a delicate balance between dense cooling salty water and dense, fresher, cold water. This balance has tipped many times in the past 125,000 years, as Figure 2b shows. The drivers of these erratic cycles are chiefly astrophysical, as the Earth's orbit around the sun varies in a number of predictable ways. The forces which tip these gentle, gradual drivers into erratic response certainly include the Gulf stream and other current instabilities.
Figure 2b: Climatic instability, probably associated with failures in the Gulf stream.
Unstable systems are perturbed at some peril. The last cold spell had Europe under kilometre think layers of ice. Another would end current civilisation.
What are we doing that lead to such a perturbation? Human effluents are now a significant component of atmospheric chemistry. Unexpected consequences - as with sulphate aerosols, nitrous oxide and chlorinated hydrocarbons - have ranged from ozone destruction to cloud nucleation. Natural sources fix about 10 million tonnes of nitrogen every year to natural fertilizer. Human additions to this have doubled the rain of nitrate, and this will exceed natural background by a factor of four by 2020. We know that focused examples of this lead to eutrophication of fresh waters, and we have no idea what effects it has in the oceans. Similar things are true of Sulphur emissions, where fertilization effects are compounded by persistent acidification and mineral leaching.
A fundamental issue is, however, atmospheric thermal balances, the so-called greenhouse effect. Incoming solar radiation is transformed into heat, and then re-radiated as infrared radiation. Much of this is trapped by gases in the atmosphere, primarily by water vapour. The planet is around 20oC warmer than it would be without this. Other greenhouse gases include methane, nitrous oxide and carbon dioxide, as well as a host of others. Humans cause more of all of these to be emitted.
Figure 3: Atmospheric carbon dioxide has risen with industrialisation.
Much work has been done on the consequences of this. Many chains of evidence have been tracked to show that historical levels of carbon dioxide had a profound affect on the climate of the time. The Jurassic, for example, was much warmer today, insofar as volcanism was releasing carbon to the atmosphere but the later weathering of rocks had yet to remove it. More recently, however, close relations are found between greenhouse gas levels and climate instability. One major amplifying factor may be methane, which exists in vast - kilometre thick - deposits in the deep oceans, where it form as a stable, waxy compound called methane hydrate. Falling sea levels - due to ice and snow remaining on land - may cause out-gassing of this, as may redirected scouring currents in the deep ocean.
Figure 4: Recent climate, interpreted from many independent measures.
The figure shows around 17 measures of temperature in the recent past, expressed as two composite series and a yellow outlier regions which contains around 95% of the uncertainty associated with the measures. Plainly, something has happened, although quite what is still open to interpretation.
If we suffer climate change which is linear - that is, things simply become somewhat warmer - then this of itself will have a major impact of what can grow where, and the range in which disease are encountered. The oceans will gradually expand as they warm, and sea levels will rise. Low lying areas, such as Bangladesh, for example, will suffer extensive and permanent flooding.
Few expect this smooth increase to occur. It is more likely that more energy in the weather systems will express itself with more weather: stronger storms, more rain, shifting patterns of rainfall. The middle term impacts of his could be far greater. This is particularly true of marginal areas, such as the Middle East and much of Africa. However, all of this may contribute to oceanic current changes, which - as with el Nino - are the primary medium term determinant of our weather patterns. As already noted, there are very major instabilities within these systems. The geological record indicates that change occurs very suddenly: in years, rather than in decades.
What drives these changes? Essentially, two forces make them occur, endlessly replicated and endlessly variable. Three forces can rein them in. The drivers of change are human population growth and the expansion of economic activity. The mitigating forces are efficiency, substitution and regulation.
Population growth is not only rapid, but it is disproportionately focused on cities. A person living in a city travels more, creates more non-biodegradable waste and uses more energy from non-renewable sources than does their economic peer in the country.
Figure 5: World population growth and the growth of cities.
The expansion is focused on Africa and Asia, whilst Europe and the US contract. Figure 6 shows the population density across the world, where denser colours mean more people per unit area. It is clear from a glance at such a picture how heterogeneous local conditions will be, how varied will be local impact and how many mixed environmental, social, economic and related issues local leaders will have to juggle.
Figure 6: The density of world populations in 2000.
As populations become richer, they use more resources, where these be newspapers or television programs, joules of energy or litres of water. Cities usually become richer more quickly than do cites, and wealth concentrates and creates pollution foci. Urban issues are often different from rural ones, despite a supposed common development level, and measures suitable to the one are disastrous to the other. Major differences between the quality of life in the city and the country can lead to migration, greatly exacerbating problems. The population of Lima in Peru rose from about a million to nearly six million in the years immediately after unsuccessful land reforms. Huge pueblos jovenes sprawled across sand dunes, lacking water, power, sanitation, communications, policing or schools. Peru is only now recovering from this.
The pace at which demand increases is set by a complex pattern of issues: which sectors of the economy are growing, how efficient they are individually, whether they substitute one things for another (coal for gas, for example), whether they import resource-dense items (such as refined fuels or metals) or whether they make them locally. Each of these issues are driven by standards, by prices; and virtually all of them are within the grasp of the state. Many of them increase inequalities and rural-urban disparities.
Regulatory measures can have a profound effect. Despite very considerable increases in economic activity, the industrial nations consumer barely more energy than they did a decade ago, despite low prices. This is chiefly due to mandated efficiency standards, as well as a pronounced shift to services, which tend to use lower amounts of energy per unit of value added. Figure 6 shows the impact of regulation on emissions in the US and the UK. The coal miners' strike created the blip seen in 1983 for Sulphur and soot, where old inefficient fuel oil stations were brought on stream.
Figure 7: UK and US urban pollution levels have fallen despite much increased activity.
The scope for efficiency gains are very great. Electricity from under-boiler generation often runs at 5-10% in the poor nations, and has an upper limit set by the technology of some 33%. Combined cycle technologies can take this to nearly 50%. Reheated inter-cooled, perhaps steam-injected, combined cycles can push this to nearly 70%. Fuel cells technologies may well attain over 80% efficiency from gasified solids, such as biomass, and do better than this on natural gas.
Internal combustion-powered vehicles are trapped in a technology which can deliver 20-33% mechanical efficiency. Systems which use a small engine, running at peak efficiency, to power a flywheel can run at nearly 60% efficiency, it is alleged, and the losses from using this stored energy to generate electricity and then power the wheel, steer the car and brake it still permit around 45-50% efficiency. If a fuel cell can be used, then much higher efficiencies may be attained. Manufacturers are experimenting with tiny 'crackers', which can break conventional fuels into gases which they fuel cell can burn. Others are considering on-site electrolysis of water, to yield hydrogen which a car owner can buy and which will power vehicles at stunning efficiencies and levels of cleanliness. Off site power could come from extremely efficient power stations, perhaps burning biomass or using other renewable supplies.
Electricity may account for half of all primary energy consumption. There are remarkable technologies - such as ocean thermal power generation - which may have a major impact in some areas. Others may use agricultural waste, or purpose-grown plant material. None of these release net carbon dioxide from combustion. Solar power is expected to become economic in the net few years. It is expected to appear as, for example, roof tiles which generate power, either to power day needs, such as air conditioning, or wind up a rotor somewhere in a village, so that this can be used to drive a turbine for the night.
Similar things can be said of other resource-intensive activities. Materials can be recycled. Good design can make things lighter and longer-lasting. Well-trained people can use resources effectively. Well-designed towns require limited travel and have less traffic congestion.
Efficiency occurs when investment is made at best practice. There are three issues involved in making this happen.
First, regulatory targets need to stretch what is imagined to be the best, such that new products and processes are developed to meet these.
Second, political and regulatory processes need to take full account of the system that the are trying to manage. They must anticipate and defuse social impacts, particularly on commercial lobbies and vulnerable groups. They must avoid paradoxical effects, such as creating one kind of pollution to abate another, as occurs when carbon is burned to take excessive amounts of Sulphur out of road fuels.
Third, there must be investment. Old plant must be retired, not added to, and the new plant must be of the best standards and operated at peak efficiency. Economic imperatives will cause this to occur in the rich world if regulation is properly designed. This is not the case in the poor world, however.
It is a commonplace of the green lobby that the wealth world is 'soiling the planet' and that the poor nations are innately sustainable. Large economies use large amounts of resources, but often do so very effectively. The USA recycles most of its metals, and only 13% of a new car is new steel. Figure 8 shows a Yale University estimate of how sustainable the general practices of various nations have become. The service-focused Scandinavian countries, running on hydropower and building in wood, are regarded as strongly sustainable. The poor nations are, by and large, the least sustainable.
Figure 8: Sustainability appears to rise with income.
The issues of sustainable development are addressed elsewhere. It is centrally the case, however, that institutional stability is necessary before inward investment occurs, and that such investment brings with it efficient equipment, managerial talent and - above all - capital. The sheer scale of the development issue and the pace of demographic change means that investment cannot come from domestic savings or from aid. It must be commercial investment. Reducing risk to such investors and creating a long-term framework for development is the unlikely precursor of sustainability. Such development will consist of conventional, large scale plant chiefly placed in urban centres. It will not be rural 'appropriate development', however much this is a desirable adjunct.
If China or India industrialise on their indigenous coal stocks, using the technologies which they currently employ, then the impact on world systems will be very considerable, and the pollution due to local Sulphur and particulate emissions will be intense. Exactly how this is to be avoided is a political matter, concerned with the stability and orientation of those two countries. Resource efficiency - this time, focused on water and drainage - may have similar impacts around the Arabian Gulf. Deforestation and poor cultivation in Africa may make areas untillable and change hydrological and soil nutrient balances. The list of potential impacts is, therefore, a long one.
Technology can do much to help. It can make things operate more effectively, and it can create alternative ways in which to operate. Third generation nuclear power plants, for example, are derived from particle accelerator technology, and have the promise of creating no radioactive pollution and no greenhouse gas emissions. The technology will also be small scale and require low unit investment. It cannot be used as a weapon. Biotechnology promises efficient crop plants that resist disease and environmental extremes. They may be explicitly fitted for purpose, perhaps as a fuel crop. Farmers may be able to divide scant land into cash crops and high-yielding, broad spectrum nutrition crops. Better mass transit systems may ease congestion, and better telecommunications may ease the need to travel.
This said, the chief issue is one of organisation. Political systems need to engage to create the conditions for sustainable choices to be made and investment to be attracted. The international institutions which will be needed for this to work are complex and demanding, and the issues associated with this development are explored elsewhere.
|to the top|
The Challenge Network supports the Trek Peru charity.