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carbon footprint

‘Carbon footprint’ can be useful shorthand to describe the amount of carbon dioxide we generate – individually, in our cities, nationally, or from the products we use. The term ‘footprint’ is also used to describe the impact of emissions, by providing a measure based on the area of things like forests, oceans and grassland that are required to absorb the carbon dioxide.

Later in this chapter, we’ll use this measure of impact to look at the carbon footprints of different countries. Elsewhere in the book we’ll be focusing on carbon dioxide emissions, particularly in the UK, where government figures for emissions are given in weight.

the 2°c target

The UK government, together with the rest of the European Union, has pledged to stabilise greenhouse gases to prevent average global temperatures rising more than 2°C above pre-industrial levels. Allow greater temperature change, climate scientists say, and we start to play havoc with agriculture, the economy and the natural environment – committing millions of people to hardship and millions of species to extinction. Perhaps even more worrying is the prediction that a higher rise than 2°C would increase the risk of spiralling and irreversible climate change.

UK path to a safer future

Steady but steep - the UK needs to make serious cuts in carbon dioxide emissions over the next 40 years to play its part in avoiding runaway climate change. Based on research by the Tyndall Centre for Climate Change Research at the University of Manchester, the chart assumes the need to stabilise atmospheric carbon dioxide at 450 ppm.

To stay within a 2°C rise the science tells us we would need to keep greenhouse gases (and other pollutants) at no more than 450 parts per million carbon dioxide equivalent. But we’re already racing towards that threshold: carbon dioxide alone had already reached 380 ppm in 2006, and emissions are rising by nearly 2 ppm per year.

And there’s more. As a result of the carbon dioxide already in the atmosphere scientists warn that 2°C could be the lowest increase we can hope for.

So how much time do we have to turn things around? Because carbon dioxide stays in the atmosphere for so long, and because it takes a while for it to affect the climate, the fossil fuel we burn in power stations today will still be affecting the climate at the start of the next century. That means we have to reduce emissions as quickly as possible, rather than hoping to make big cuts five years from now. The sooner we make cuts, the better.

Two facts illustrate the urgency of the task that faces us if we want to stay within a 2°C rise:

1 Greenhouse gas emissions have to start falling by 2015. They must then continue to decline.

2 Industrialised countries need to cut emissions by about 90 per cent by the middle of this century.

So can it be done? Some argue that it is unrealistic to expect to cut carbon emissions quickly and deeply enough to stay within 2°C. But the scientific consensus is that we must.

where in the world do the emissions come from?

Most carbon emissions from human activity come from industrialised countries, whose economies rely on manufacturing and transport powered largely by fossil fuels.

The United States, home to fewer than 1 in every 20 people in the world, is responsible for about a fifth of global carbon dioxide emissions.

Europe accounts for 15 per cent of global carbon dioxide emissions, working out at around 9.3 tonnes per person per year. That’s enough to fill two Olympic swimming pools for every person in Europe.

China became the biggest emitter of carbon dioxide in 2006. But China’s emissions per person are less than those of the United States: in 2003 the average American emitted nearly six times as much carbon dioxide as the average person in China.

Across the world average emissions were 3.7 tonnes per person in 2003. But in some African countries, such as Mali and Burundi, they were less than 0.1 tonnes per person.

Comparative worldwide emissions (2003)

NB: Includes international aviation and shipping, excludes land use change. Source: World Resources Institute

A country’s greenhouse gas emissions depend on the size of its economy, the types of industry it has and the kinds of energy it uses. Demand for heating and air conditioning are also key factors: rich countries with hot summers use lots of energy for air-conditioning; cold countries use more for heating.

China has become a major emitter of greenhouse gases only in the past 20 years while the United States and the UK have been pumping out carbon dioxide throughout the past century. And it is the total quantity of carbon dioxide in the atmosphere that is driving global warming, not just the annual amount added to this total. So it’s the developed countries that are mostly responsible for the problem.

seven people who can make a difference

1 The President of the United States

2 The President of China

3 The British Prime Minister

4 The Mayor of London

5 Your boss

6 Your council leader

7 You

comparing carbon footprints

A country’s real contribution to the total amount of greenhouse gases in the atmosphere depends not just on the energy it uses, but also on the way it uses land and the stuff it consumes. The amount of land being farmed will affect emissions of methane and nitrous oxide as well as the amount of carbon dioxide held by the soil. (Forests help remove carbon dioxide from the atmosphere.) Goods imported from overseas also have their own carbon footprint and use up natural resources.

To get a clear picture of a country’s overall footprint, then, we need to look at what it is consuming, including imports. The Global Footprint Network uses information on all of these areas to estimate each country’s total impact on the planet in terms of environmental cost, and has come up with a measure it calls global hectares. Using this measure, humanity’s global footprint is put at 13.9 billion global hectares. That’s 24 per cent more than the natural resources available on Earth. This is a problem: we are exceeding the planet’s ability to absorb our impact.

Global footprints (global hectares/person, 2003)

UK emissions

Half a billion tonnes. That’s how much carbon dioxide the UK emits each year. Some 60.2 million people live in the UK – that’s just less than one in every 100 people in the world; but in 2005 our emissions were around 2 per cent of the global total – double our fair share.

In fact the true total is even higher: 556 million tonnes is the official figure, but that doesn’t include our share of emissions from international aviation and shipping; nor the emissions created by all the products we buy from overseas.

Add to that the UK’s history and the footprint gets heavier still. We have been pumping out carbon dioxide since the Industrial Revolution. It is this historical record that leads many to argue that greenhouse gas emissions are a problem created by the developed countries, including the UK, and to insist that it is the old industrial world’s responsibility to reduce its emissions first. Richer countries, particularly the United States, have been reluctant to cut emissions before developing nations do, claiming it will damage their economies. This has been a major barrier to international agreements to tackle climate change.

the need to cut

Politicians may argue about who is responsible for cutting just how much carbon dioxide; but to keep within the 2°C threshold, globally we need to reduce emissions of carbon dioxide massively by 2050. This looks like a tall order – but it is possible.

Where can the cuts come from? And what difference will they make to the way we live?

is it all about population growth?

Some people argue that tackling climate change means doing something about the world’s growing population: the Earth’s resources are limited and there simply is no longer enough to go around if we go on consuming at this rate; our survival, some say, depends on keeping our numbers down.

The global population has grown more than six-fold just over 200 years to around 6.6 billion in 2007. It is expected to stabilise at around 9.2 billion by mid-century. But the countries with the fastest growing populations are among those who have done the least to affect climate change

Carbon dioxide emissions per person are far higher in the richest countries of the world such as the United States, Canada, Japan, Australia and the UK. By contrast, many countries in Africa have per capita emissions that are negligible in comparison – less than one-hundredth the level. Many countries in Latin America have per capita emissions that are only around one-tenth those of the richest countries.

Global population is not the root of the problem: it is the rapid use of energy and natural resources by the richer and fossil-fuel dependent economies that is putting pressure on the planet.

Carbon-dating climate change – a timeline

End of the Permian period (251 million years ago). Geological evidence suggests carbon dioxide concentrations were four times higher than today. Much of Central Europe and the southern United States was desert, and seas were 20 metres higher. Methane releases from the sea beds are thought to have wiped out many living things. Some estimates suggest that 95 per cent of life on Earth was eradicated.

Start of the Holocene (10,000 years ago). End of the last ice age and the beginning of a relatively stable climate.

Medieval Warm Period (900-1200 AD). Relative warming in the Northern Hemisphere, with wine grown in the UK and droughts in North America. Temperatures in Europe are thought to have been 1°C -2°C warmer than at the start of the 20th century, but little evidence exists of warming on a global scale.

1750-1800 Start of the Industrial Revolution and the use of coal to drive industry.

1800 Start of the Anthropocene. According to some climate scientists, the stable period of the Holocene is coming to an end: humanity’s influence over the world’s climate is so great that the current age should be known as the Anthropocene.

1896 Svante Arrhenius, a Swedish chemist, identifies the global warming properties of greenhouse gases, predicting that a doubling of carbon dioxide levels could raise temperatures by 5°C.

1979 First World Climate Conference highlights concerns about levels of carbon dioxide in the atmosphere. The Intergovernmental Panel on Climate Change (IPCC) (see p.54) is established.

1987 The Brundtland Report, Our Common Future, makes the case for, and provides a definition of, sustainable development.

1990 The Intergovernmental Panel on Climate Change (IPCC) publishes its first assessment; it says climate change is a concern and human activities are likely to be contributing.

1992 Rio Earth Summit. World leaders meet in Rio de Janeiro, Brazil, to discuss the state of the planet, signing up to the United Nations Framework Convention on Climate Change.

1997 Kyoto Protocol. The first legally enforceable international treaty designed to cut greenhouse gas emissions. Signed by 141 countries, the Kyoto Protocol eventually comes into force in 2005.

2001 Newly-elected US President George Bush refuses to ratify the Kyoto Protocol. ‘I oppose the Kyoto Protocol because it exempts 80 per cent of the world, including major population centres such as China and India, from compliance, and would cause serious harm to the US economy.’

2002 Larsen B ice shelf breaks up. A piece of ice a quarter the size of Northern Ireland falls into the sea in the Antarctic.

2003 European heat wave. Some 35,000 Europeans die as a result of extreme temperatures.

2004 UK Prime Minister Tony Blair is ‘shocked’ by scientists’ warnings on climate change. He tells reporters that ‘unchecked climate change has the potential to be catastrophic in both human and economic terms’.

2005 UK Prime Minister Tony Blair makes climate change a priority for the G8 rich countries summit at Gleneagles. UK emissions continue to rise.

2006 UK Government agrees to introduce new legislation designed to tackle climate change. UK emissions continue to rise.

2007 The IPCC and former US Vice President Al Gore share the Nobel Peace prize. Gore’s film An Inconvenient Truth, highlighting the threat posed by climate change, wins an Oscar. Japan announces that climate change will be a priority at meeting of the G8 industrialised countries.

breaking down the UK’s carbon footprint

When looking at where our carbon dioxide emissions come from we can slice the cake a number of ways. The flow chart shows one breakdown by end-user. But a common way to think about emissions is in terms of three key end-uses – electricity, heat and transport.

electricity

Demand for electricity is responsible for roughly a third of the country’s carbon dioxide emissions. That’s because we rely on fossil fuel: large, centralised power stations burn coal and gas to generate most of our electricity. The UK does produce some electricity using renewable sources such as wind and hydropower, but at the moment this provides only around 4 per cent of our electricity.

Demand for electricity in the UK has doubled since the 1970s – partly as a result of the growing number of smaller households, most with their own fridge, freezer and microwave. Over this period power stations have become more efficient, but a diminishing supply of North Sea gas, combined with high oil and gas prices, have led generating companies to turn to coal. Coal produces higher levels of carbon dioxide emissions than gas does and can cause other pollution problems as well.

heat

If we’re looking at our footprint in terms of the end use of the energy, heating homes, offices and public buildings plus the heat used in industry actually account for the biggest slice of

a snapshot of the UK’s CO2 emissions in 2005

The areas of the boxes show how each sector contributes to the UK’s total of 595 MtCO2 in 2005. We’ve included international aviation and shipping. Source: BERR/Friends of the Earth.

the UK’s emissions. Industry and domestic consumers alike How we heat our rely mainly on oil and gas. Total demand for heat energy is homes falling slightly, partly thanks to improvements in efficiency. And despite the recent trend towards coal, the switch to gas that has been happening since the 1970s means that carbon emissions from heat generation have been falling. In our homes, gas is the main source of energy – and domestic use is rising slowly.

How we heat our homes

Source: BERR

Carbon emissions from industry (2002)

power hotspots

If we look at our emissions in terms of broad economic sectors, the biggest sources are business and transport and our homes.

About 40 per cent of the UK’s carbon emissions come from businesses, with industry accounting for about half of that. The chemicals industry accounts for a fifth of all the energy used in industry, with food, drink and tobacco the second biggest industrial consumer. The UK’s service economy – i.e. banking, insurance and shops – is less energy-intensive, but as the dominant sector still uses lots of heat and power. In fact services account for a fifth of our greenhouse gas emissions.

As individuals our main energy-consuming activity is heating our homes. Private transport comes second – followed by food and drink, health and hygiene and heating water. Holidays, clothing, cooking and books and newspapers come low down on the list.

transport

Transport is often referred to as the problem sector: since 1990 transport emissions have risen by a fifth. Some 22 per cent of UK greenhouse gases come from road vehicles – perhaps not surprising since running a car today is cheaper in real terms than it was ten years ago. But aviation is a fast-growing problem.

Emissions for a journey from London to Edinburgh	kg CO2 per passenger
1 Plane	96.4
2 Car	71
3 Rail (high speed electric)	11.9
4 Coach	9.2

According to the Department for Transport, aviation emitted 2.5 million tonnes in 2005. But this figure only includes domestic civil aviation. If the UK’s share of international aviation is included (calculated as half of all flights taking off or landing in the UK), then emissions for aviation were more than ten times that. Even then a crude measure of carbon dioxide emissions from aviation does not reveal the true extent of the impact that flying has on the climate. Because aeroplanes create pollution high in the upper atmosphere, the impact of the emissions is magnified. How much of a difference this makes is still being studied, but conservative estimates suggest UK emissions from aviation account for 13 per cent of the UK’s climate change impacts. Emissions from shipping are also on the rise, as more and more goods are traded around the world.

Transport emissions (2006)

Excluding international flights and shipping

Including international flights and shipping

UK transport emissions are big and getting bigger. Watch out for the way they’re reported: emissions from international aviation and shipping have not generally been included. But when they are it’s clear how serious a problem air travel presents.

our carbon exports

None of the above takes account of the greenhouse gases the UK is responsible for elsewhere in the world. British companies play a huge role in international trade and many of the goods they sell and that UK consumers buy are manufactured overseas. Yet the energy used to produce them does not show up on the UK greenhouse gas inventory.

Take one of the UK’s most successful companies, British Petroleum (BP). Its direct activities, such as exploration, drilling and refining, combined with the sale of its products, are estimated to have resulted in emissions of nearly 1.5 billion tonnes of carbon dioxide in 2004. That’s more than double the carbon dioxide produced by the UK. According to one financial company, emissions from all the oil, gas and coal sold by FTSE 100 companies is likely to be close to fifteen per cent of the global total from all fossil fuels.

farmland

According to government figures, agriculture is responsible for 8 per cent of the UK’s greenhouse gas emissions. This is largely from methane and nitrous oxide rather than energy use.

Intensive farming relies on chemical fertilisers, which increase the amount of the greenhouse gas nitrous oxide in the atmosphere. Fertiliser production is the largest source of nitrous oxide emissions in the world and producing fertiliser itself relies heavily on fossil fuels. Making and transporting fertilisers is the largest source of carbon dioxide emissions in the farm sector, but these emissions are not included in the government’s figures for agricultural emissions. Sheep and cows emit methane as a result of the digestive process, resulting in high levels of emissions from livestock and dairy farming.

Meat farming is responsible for two thirds of the nitrous oxide and more than a third of the methane associated with human activity. One study found that every 1 kg of beef produced results in emissions of more than 36 kg of carbon dioxide equivalent: two-thirds of the energy used goes to produce and transport cattle feed. Producing food for livestock and clearing land for grazing is having a huge impact on valuable forests. Greenhouse gas emissions from livestock have been put at around 18 per cent of the global total. And demand for meat is rising, especially in the developing world: meat production is predicted to double between 2000 and 2050.