There are different ways of calculating national and local carbon emissions. Different measurements create different impressions about the success (or not) of climate change policies, and lead to different ideas about the most effective ways of reducing carbon emissions.

The main measurements of carbon emissions

These are:

• total emissions over a specific area (eg a country)
• per capita emissions – average emissions per person within a specific area
• personal/household/business/school carbon footprint – a calculation of all the carbon emissions from every material activity a particular person/household/business/school carries out
• historical emissions – these are emissions from the past, eg since the start of the industrial revolution
• emissions from consumption, or emissions from production

You can measure CO2 from burning fossil fuels; or you can also include other greenhouse gases and non-fossil-fuel sources of CO2.

Here is an interesting comparison of different countries’ carbon emissions,  according to different ways of measuring carbon emissions.

Which measurement of carbon emissions is most accurate and fair?

Things being what they are, politicians and others often use the measurement that makes it look as if their policies are working, and that may also serve to place responsibility for emissions on others.

For example, the official UN way of measuring national carbon emissions, used in the Kyoto protocol, is based on measuring a country’s production emissions. This means all the emissions created by production activities; these can be manufacturing, transport, energy generation, farming, services and so on.

In the UK, using this production emissions measurement also lets politicians ignore the fact that the decline in UK production emissions is largely the result of the UK outsourcing a lot of its production to China, India and other countries. The production emissions measurement makes it look as if its post-Kyoto climate change policies have been working. But the UK is responsible for the share of China’s carbon emissions that are created during the manufacture of goods for consumption in the UK. The production emissions figures omit these.

UK Production carbon emissions have fallen since 1990

This graph from DECC shows the UK production carbon emissions. The top (green) line is all six greenhouse gases measured under the Kyoto Protocol. The bottom (blue) line is carbon dioxide.

A more accurate picture includes consumption emissions

Recently, the Department of Energy, Food and Rural Affairs (Defra) has produced UK consumption carbon emissions figures, which are a more accurate account of the carbon emissions the UK is really responsible for. They include carbon emissions from the production of goods abroad, that are imported and consumed in the UK. They show that UK carbon emissions have been rising since 1990 – so the climate change policies haven’t achieved their targets.

Many people say it would be more accurate for UK carbon emissions measurements to also include aviation and shipping carbon emissions, from transporting imports to the UK.

This gives a much higher per capita carbon footprint than production emissions. The UK consumption carbon footprint has been rising steadily since the UK signed the Kyoto Protocol. The UK per capita consumption carbon footprint is now nearly 17 tonnes.

This graph shows the difference between production emissions (which the graph calls direct emissions) and consumption emissions (the red line, which the graph calls Domestic emissions minus exports plus imports)

UK consumption carbon emissions have risen since 1990

Figures from the Department for the Environment, Farming and Rural Affairs (Defra) also show that UK consumption carbon emissions were about 20 percent higher in 2009 than they were in 1990. Between 1995 and 2005, UK consumption carbon emissions rose by about 35 percent, but the recession reduced the the UK consumption carbon footprint  by 9 percent between 2008-2009.

Production carbon emissions figures mask the rebound effect

Another problem with using production carbon emissions is that they give a false picture of the effectiveness of carbon reduction measures.

For instance, Calderdale’s Energy Future aims to bring in over £320 million of investment into the area by 2020, and grow the local economy. However, if people have more money, they will either save it or spend it. Either way, unless they save it in green savings schemes or spend it on carbon neutral goods or services, this extra money will cause more greenhouse gases to be emitted. This is called the rebound effect. If it more than cancels out carbon emissions reductions, it’s called the backfire effect.

Only consumption carbon emissions measurements will show the rebound effect, and make it possible to see how it balances out against the reductions in carbon emissions that come from increased energy efficiency and energy savings. This is why the carbon calculators Energy Royd links to all measure consumption carbon emissions.

Many countries in the global south believe that when countries in the post-industrial north use production carbon emissions, it’s way for them to avoid taking responsibility for the carbon emissions they’ve outsourced to the low wage economies. This is obviously unfair since it puts pressure on countries like China and India to pay for those carbon emissions.

Including other greenhouse gases

Farming is a source of other greenhouse gases like methane and nitrous oxide. Changes to land use, like deforestation,  are an important non-fossil-fuel source of CO2, as peaty soils that held a lot of carbon dry out and release a lot of CO2 into the atmosphere. Both farming and land use changes  contribute significantly to greenhouse gas emissions and climate change.

Deforestation in Malaysia_Food & Agriculture Organisation photo

CO2 from burning fossil fuels

This diagram from the Guardian website represents the US Energy Information Administration figures for CO2 from burning fossil fuels, 2009.

Calderdale’s carbon emissions

Calderdale’s Energy Future (CEF)  states that Calderdale’s per capita carbon emissions were 8.1 tonnes in 2005, and by 2010 they had reduced to 6.9 tonnes – lower than the UK national figure of 8.2 tonnes/person in 2005 and 7.4 tonnes/person in 2010. Since personal carbon footprints correlate with income, the reason for Calderdale’s lower than national per capita carbon emissions may be because incomes in the area are lower than the national average. This is just a guess.

Update: Calderdale’s carbon emissions per person rose in 2010

Calderdale’s carbon emissions per person rose from 6.1 tonnes in 2009 to 6.4 tonnes in 2010, according to statistics released by the Department of Energy and Climate Change in August 2012. Industrial and commercial carbon emissions and domestic carbon emissions both rose in 2010, compared to 2009 figures, although transport carbon emissions declined. The per person carbon emissions are worked out by dividing Calderdale’s total carbon emissions by the number of people living in Calderdale.

These figures compare with DECC’s figure for 2005 Calderdale per capita emissions of 7.2 tonnes. They are obviously production carbon emissions, not consumption carbon emissions and so under-represent the true figure.

I’m not sure why there is a bit of a discrepancy between the CEF figures and the DECC figures.

Personal carbon emissions correlate directly with income

This infographic is from the Joseph Rowntree Foundation.

CEF points out that two thirds of the decline in Calderdale’s carbon emissions  occurred in 2009 because of the recession.

The CEF figures are obviously production carbon emissions, not consumption carbon emissions. Using production carbon emissions underestimates the amount of carbon emissions that the UK and Calderdale are responsible for, and masks the fact that UK and Calderdale consumption carbon emissions have risen since Kyoto.

This page was updated on 30 August to include latest DECC figures for Calderdale carbon emissions in 2010.