6. Decarbonize the World Economy

The intensity of energy and material use in the world economy is critical to a transition to sustainability. At present it is characterized by high levels of energy use and high material throughputs. This cannot last. Carbon emissions from fossil fuel burning are projected to double in the next 50 years, tripling the atmospheric (CO2) concentrations from their pre-industrial level.59 What needs to change?

The geography of consumption

Transition to sustainability is a direct challenge to existing patterns of consumption in wealthy countries. It requires nothing less than a restructuring of current patterns of global consumption through reduction in the amount of natural resources and energy used to generate wealth:

Ideas of ‘decarbonization’ (systematic reduction in society's reliance on carbon), ‘dematerialization’ (reducing the use of materials – or ‘doing more with less’)60 or ‘power down’ (reducing per capita resource usage) are established in environmentalism. Books like Richard Heinberg's Powerdown, or The Oil Depletion Protocol have set out both the problem and solutions.61 Decarbonization does not have to be invented: it simply needs to be tried.

Decarbonization of the world economy is the immediate critical challenge of a transition to sustainability, although it must be addressed in the context of the issues of biodiversity, water and poverty. Since the new millennium, recognition of the issue of climate change has grown, yet many people remain in denial about its severity. There is much talk of tackling Northern carbon bingeing, but we have not yet started to show how to de-link energy use and carbon consumption; or energy use and economic growth.

‘a shift to a low-carbon economy is essential’

A shift to a low-carbon economy is essential but deeply problematic. It bites hardest those who currently use most oil and other carbon fuels – rich countries. The reduction in greenhouse gas emissions in rich countries needed to prevent drastic climate change is hotly debated, but it is without doubt very large – probably about 90% by 2030,62 or about 200 billion tons of carbon over the next 50 years.63 This reduction will have to take place in the face of demand that continues to grow (not least in response to climate change itself, e.g., in demands for new heating or cooling).

Energy security beyond peak oil

The world consumes about 85 million barrels of oil per day. In 2007 we consumed on average about 4.71 barrels of crude oil per person per year, although the 4.8 billion people in low-income countries consume very little per person, while the 1.8 billion who live in high-income countries consume a great deal more.64 By 2050 there will be less energy available and more people: one billion will have more than average, seven billion will have less.65

We are in the era of ‘peak oil’ – the point at which the maximum rate of global oil production is reached. The era of cheap hydrocarbons is coming to an end.66 High energy prices will be a major driver of change in the twenty-first century.

Adjustments to life beyond peak oil will have knock-on effects for all aspects of everyday life: how food and everyday goods are produced and transported, patterns of employment, the performance of stock markets and economies, and hence on security and geo-politics.

High energy prices will have particular implications for the world's poor who currently do not have access to modern energy services and depend heavily on biomass such as wood, charcoal or costly kerosene and oil. New boundaries of energy availability will create huge challenges in providing affordable heating, lighting and cooking as well as sustainable mobility, transport of goods, and housing.

Consumption of gas is growing but it is expected to shrink from 2020. Coal use will continue to expand (especially in China, India and USA), and it is likely to continue to be used extensively for the next 150 years. New technologies, especially carbon capture and storage, and ‘clean burn’ combustion will improve efficiency and reduce CO2 production.

Rapid rises in energy prices will generate huge pressure for alternative sources of energy. Carbon taxes (which seek to make energy generation pay the costs of CO2 production) would accelerate this shift to alternative power sources.

Biofuels are receiving increasing attention. First generation biofuels (bioethanol from corn, wheat or sugar; biodiesel from palm oil or Jatropha) are already in commercial production (notably in Brazil), and policies in many countries are beginning to support rapid expansion in planting of feedstocks to produce biofuels. There is increasing interest in mass power generation using organic waste products which, when combined with other renewable sources of electricity, may provide a necessary sustainable transition for the transport sector.

Belatedly, the potentially negative impacts of first generation biofuel crops on land rights, water requirements, food production, and biodiversity (particularly in remaining areas of tropical forest) are being recognised.67 Second generation fuels from algae, grass, agricultural waste or wood cellulose are more hopeful, although woody biofuel crops are still likely to place significant demands on agricultural land and biodiverse ecosystems.

In both Europe and North America, the political response to spiralling oil prices and the links between CO2 and climate change, led to a policy cascade in favour of biofuels as a substitute for oil. In his 2006 State of the Union Address, President Bush announced an ‘Advanced Energy Initiative’, to reduce US reliance on foreign sources of energy by changing the way vehicles, homes and businesses were powered. Proposals included advanced battery technologies, hydrogen fuel cells and, critically, technologies to manufacture cellulosic ethanol cheaply.

‘the era of cheap hydrocarbons is coming to an end’

Where biofuels can be produced and consumed locally, they may have a significant role to play in global decarbonization. Yet many problems remain. As a global strategy to substitute for crude oil, biofuels offer a dubious environmental trade-off. Many biofuels capture less energy than they cost to make: growing and processing biofuel crops is highly energy-intensive. Land demand for such crops would be significant. Any sense that the shift from crude oil to biofuels involves sacrificing the food or forests of the poor so the rich can continue to drive their cars, is unlikely to be widely acceptable because it would raise significant justice issues. Biofuels offer no magic solution to the decarbonization challenge.

Technologies for a low carbon economy

Technology development is critical to decarbonization. Research on renewable energy is expanding rapidly and productively, despite a continuing bias in favour of nuclear power in countries like the UK.68 The market for photovoltaics is growing rapidly, and costs are declining, as are material demands in manufacturing. Thin film photovoltaics are more efficient and less energy-intensive in manufacture.69 Vast investments are being made in wind power, especially by the private sector (for example in Denmark). Geothermal energy has more potential than is often assumed.

A switch from incandescent light bulbs to compact fluorescent bulbs yields huge improvements in efficiency. A shift to LEDs (light-emitting diodes) offers further gains. In buildings, better insulation and glazing, systems of grey water use and un-powered cooling hold promise. New ‘eco-cities’ are being built in Shanghai and Abu Dhabi, and on a smaller scale there are experiments with energy-efficient housing, in both industrialized countries (e.g., the German passivhaus),70 and in developing countries (e.g., India),71 and increasing interest in the innovative use of shade, natural ventilation and materials. The need for low-energy low-cost but comfortable dwellings for the world's urban poor is a critical sustainability challenge. Improvements in building design need to be allied to their use (e.g., controlling plug-loads from electrical appliances), and the wider patterns of use of cities and their regions (e.g., commuting and other travel).

Fuels like hydrogen offer a means to maintain existing transport systems, but only at a huge energy cost. Hydrogen is likely to be derived from the sun and wind by 2050, but it is a carrier and not a source of energy. Electric or compressed air engines (especially in trains and buses rather than cars) offer alternative ways to store and move energy, but not to create it. There is no easy technological route to low-energy aviation, even as a temporary strategy – not only does international governance of aviation fuel preclude taxation to promote efficient use, but few fuels have the same embodied energy as aviation fuel. Airships may once again be used, although they are slow, but there is currently limited interest from airplane manufacturers: indeed much more funding is going into supersonic upper atmosphere aircraft whose prospective environmental performance is lamentable.72 There are also technologies to improve the energy efficiency of ships (e.g., kites, novel sails and hull bubble layers), but again, these are currently only at the level of experimentation.73

Carbon emissions can be reduced by a range of technologies, and by changing the way people move around and live. Shifts from private cars to buses or trains, or from powered heating and cooling to house insulation, have huge potential.

‘biofuels offer no magic solution’

Strategies for stabilising carbon emissions

The Princeton University Carbon Mitigation Initiative (CMI), for example, claims that many strategies available today can be scaled up to reduce emissions by at least one billion tons of carbon per year by 2054. These one billion ton reductions are referred to as ‘stabilization wedges’ (Box 6.1).74

Box 6.1 Princeton University Carbon Mitigation Initiative

The Princeton University Carbon Mitigation Initiative (CMI) identifies 15 strategies to keep carbon emissions level over the next 50 years (reducing projected carbon output by seven billion tons per year by 2054, keeping about 175 billion tons of carbon from entering the atmosphere).


1. Double fuel efficiency of 2 billion cars from 30 to 60 mpg

2. Decrease the number of car miles traveled by half

3. Use best efficiency practices in all residential and commercial buildings

4. Produce current coal-based electricity with twice today's efficiency

Fuel switching

5. Replace 1400 coal electric plants with natural gas-powered facilities

Carbon capture and storage

6. Capture and store emissions from 800 coal electric plants

7. Produce hydrogen from coal at six times today's rate and store the captured CO2

8. Capture carbon from 180 coal-to-synfuels plants and store the CO2


9. Double current global nuclear capacity to replace coal-based electricity


10. Increase wind electricity capacity by 50 times relative to today, to a total of two million large windmills


11. Install 700 times the current capacity of solar electricity

12. Use 40,000km2 of solar panels (or four million windmills) to produce hydrogen for fuel cell cars

Biomass Fuels

13. Increase ethanol production 50 times by creating biomass plantations with area equal to one sixth of world cropland

Natural Sinks

14. Eliminate tropical deforestation and double the current rate of new forest planting

15. Adopt conservation tillage in all agricultural soils worldwide

If all these technologies offer opportunities to reduce carbon emissions, other developments are driving in the opposite direction. Recent expansion of hydrocarbons from tar sands in Canada is deeply negative in terms of carbon and water, because of dependence on steam to liquefy the tar.75 The conversion of coal to liquid is also highly energy-inefficient (half the energy in the coal is lost in producing liquid fuel). High energy prices in the coming decades will drive policy, but it would be a mistake to assume that they will drive sustainability.

A decarbonized global economy cannot come from technology and the urban industrial sector alone. Approximately a third of greenhouse gas emissions come from deforestation, agriculture and forestry. Patterns of future rural land-use change have profound implications for attempts to decarbonize the economy. A decarbonized world must therefore also be one that addresses rural production and poverty, and takes account of the impacts of global environmental change and their impacts on forests, peatlands and other carbon stores and sinks.

‘expensive energy presents huge political challenges’

The unstable politics of transition

The challenge of decarbonization is increased by the fact that as the energy that drives it becomes scarcer and more expensive, the more likely it is to increase global political instability. Technologies once deeply unpopular because of their risks, such as nuclear power, will come to be judged differently.76 As energy scarcity bites in rich countries, politicians are likely to judge energy security more highly than climate change, or world peace. Like climate change, expensive energy presents huge political challenges. Major climate events (extreme temperatures, hurricanes, floods, storms etc.) can be expected to provide shocks capable of disrupting national planning (e.g., on the scale of the flooding of New Orleans from Hurricane Katrina in 2005, or the cyclone impacts on the Irrawaddy Delta in 2008), and through them to impact on the global economy.

Thus difficult decarbonization transitions need to be made under less than ideal political and economic conditions.

The market and consumers can drive rapid change in economic activities in ways that are compatible with sustainability (e.g., growth in non-fossil energy, hybrid vehicles, organic food or fair-trade products). Can they also drive dematerialization? The business challenge is considerable. Endless innovation will be needed to generate a ‘race for the top’ in terms of low-energy industrialism and low-impact living, and away from the more usual downward spiral of polluting, resource-heavy and energy-heavy production.

Belief systems underpin patterns of production and consumption. The growth of the environmental movement shows the power of beliefs over immediate material self-interest. The factors determining when people act as citizens and as consumers are complex, but clearly beliefs matter as much as markets.

A greater challenge is whether the market can drive dematerialization and materialization at the same time. Can it drive dematerialization in the economies that serve the wealthy, while allowing materialization of the economies that serve the poor? Can it deal with the challenge of global justice?

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