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Thursday 10 September 2015

Seeking a fair GHG reduction target - Part 2:Current CC Measures are misleading

This is the second post in this series Seeking a fair Greenhouse Gas (GHG) reduction target. The first post ( Seeking a Fair GHG reduction target-Part 1:The problem)
outlined the main reasons why a consensus on GHG reduction targets is so elusive and also posed the challenge posed in this essay: How to set GHG reduction targets that will receive universal agreement. Quite an ambitious target indeed.

In this post I want to review the way GHG Reduction targets are currently specified, the common measures used when ranking countries' contribution to global CC, and to highlight any shortcomings in using these measures. Consensus on reduction targets can only be achieved if the measures we use to set a country's target are aligned with that country's contribution to CC.

GHG measures for setting reduction targets and ranking countries

Typically a GHG reduction target is stated as; -

By Target-Date (country) will reduce CO2-e emissions by (target ) % below the emission level at Baseline Date.

Two additional terms Emissions Per Capita and Emissions per $GDP are frequently used to rank countries as to their CC impact, so will be included in the following.

To understand reduction statements and country rankings based on these terms, we need to look under the covers.  I will avoid being too technical by providing only a brief summary here, however for a more in depth understanding of the many factors influencing these please read the references cited below.

  • CO2-e refers to Carbon Dioxide equivalents, generally stated as millions of tonnes of carbon dioxide per annum. 
  • GHG covers a range of gases which contribute to global warming,  including ; Carbon Dioxide, Methane, Nitrous Oxide, etc. (see https://en.wikipedia.org/wiki/Greenhouse_gas#Greenhouse_gases ). 
  • The relative contribution of each of these gases to global warming is different, based on a number of factors including its thermal radiation absorption rate, its longevity in the atmosphere and its interaction with other gases.  
  • Carbon Dioxide-equivalents is a measure of the overall impact of a given combination the various Greenhouse gases. The volume of each gas is converted to the mass of Carbon Dioxide which would have an equivalent impact on global warming, and these are summed to give an overall impact. There are several complexities behind the scenes which I will let interested readers follow up through the references.
  • Invariably references to a country's GHG 'emissions' refers to the CO2-e produced within a country. They should be qualified as production emissions, but this rarely happens. The problem with production emissions is that it does not account for the emissions in imported and exported products. The GHG emissions resulting from manufacturing a product which is subsequently exported should be assigned to the country which imported the product, since the exporting country would not have produced it were it not for their customer. Similarly the emissions generated in a product which is imported has to be added back to the country which imports the product. This adjusted figure is the consumption emissions of a country, ie the emissions due to product consumed within the country. Most references to 'Emissions' refer to production emissions and ignore the effect of imports and exports, and are therefore misleading. They overstate the emissions of producing countries (eg China) and understate the emissions of consuming countries (eg most of Europe).    (Note that sometimes the Emissions of a country are measured by the amount of energy 'consumed' or generated in the country. These are still production emissions as it refers to the emissions required to produce the energy used in the country.) 
  • Emissions targets are based on gross emissions of GHGs and ignore all absorption except for changes in land use. Greenhouse Gases in the atmosphere are the result of processes which increase emissions, both natural and anthropogenic, and absorption (decrease of emissions) by various carbon sinks, also natural and anthropogenic. While reduction targets use the total emissions of a country in any year they only account for the changes in absorption due to changes in land use, deforestation agriculture etc. The absorption by a country's existing forests is totally ignored, it is only the change in absorption that is taken into the calculation of emissions. Totally ignored are the vast forests of the continents that have always been the lungs of the world, including the significant contribution by physically large countries hich have retained much of their forests ie countries like Canada, Brazil, Russia, Australia. By looking at only changes in land use they totally ignore the role of some countries as net absorbers of GHG, cleaning up the emissions of the industrialized, deforested countries of Europe. Emission statistics which ignore total absorption are misleading. They overstate the emissions of countries with large forested areas (Canada, Russia, Australia) and greatly distort the ranking of countries as to their contribution to global warming. 
Target Date, Baseline Date
  • The Target and Baseline dates stated in reduction target statements vary.The Target/Baseline dates for the Kyoto protocol were 1990/2012 respectively. In more recent target statements by various countries Target (2025, 2026-2028, 2030) and Baseline (2000, 0205) vary. 
  • Setting a specific Target date is mandatory for any realistic target. 
  • However the Baseline Date establishes the baseline CO2-e to which the reduction target will be compared. So it is significant. As it is somewhat arbitrary a country can (admittedly modestly ) game the system by picking a baseline date where it had unusually high emissions.
  • More significantly any selected date misses the point. A country is responsible not for its contribution from just some arbitrary point in time, but its total net contribution to CC. This is its total Net Emissions (Gross Emissions less Absorption) since industrialization. European countries which industrialized and deforested a long time ago are treated kindly by a system which picks any recent date thereby ignoring their most significant emissions in the past. Developing countries are only now going through industrialization converting forests into agriculture and building factories, all contributing to their emissions. So emission targets cannot be fair unless they take into account each country's total contribution to global warming.
Emissions per person (E/p)
  • Emissions per person (E/p) are often used to compare & rank countries as to their relative contributions to CC. The idea is that by dividing a country's emissions by its population we have a fair way of comparing the CC contribution of countries of different size. 
  • However invariably the calculations use Gross Production Emissions which are misleading for the reasons cited above, so the resulting E/p will also be misleading.
  • The problem with Production vs Consumption emissions can be illustrated by looking at an example.
  • Consider two countries A and B, which start with; - 
    • identical population of 10 million
    • identical Production Emissions rates of 150mt/yr , made up from 50mt/yr generated in the manufacture of exported product and 100mt/yr locally consumed by its 10 million population at a Consumption Emission per person of 10t/p/yr.
    • The E/p for each country is 15 t/p/yr
  • After 100 years, for whatever reason half the population has migrated to B, however all the other variables are left unchanged, ie consumption E/p and Export emissions remain he same. However the E/p for A has increased 15 to 20t/yr and for B it has decreased from 15 to 13.3t/yr. (See Table below ) 
Country Measures Unit 1900 2000
Starting Equal Population of A to B
A Population million 10 5

Emissions in exports mt/yr 50 50

Consumption Emissions/p t/yr 10 10

Production Emissions mt/yr 150 100

E/p t/yr 15.00 20.00

B Population million 10 15

Emissions in exports mt/yr 50 50

Consumption Emissions/p t/yr 10 10

Production Emissions mt/yr 150 200

E/p t/yr 15.00 13.33

  • Although the actual emissions due to personal consumption remain the same the E/p figures are different. Clearly any comparison or ranking of countries using Emissions per person is misleading.
  • While this illustration focused on the problem with Consumption vs Production emissions, E/p is simlarly misleading due to Emissions definitions ignoring Absorption rates. 
Emisions per $GDP(E/$)
  • E/$ emissions per unit of GDP are often used to compare the carbon intensity or efficiency of countries ie how much CO2-e is emitted per $ of GDP. The idea is that by dividing the emission rate by the GDP, we can gauge how much, or ideally how little CO2e a country emits for each $ they generate.
  • Given that these measures also rely on fallacious definitions of Emissions they suffer the same problems as covered above. 
  • In this case the E/$ is understated for countries which tend to import goods and overstated for those which export goods.


Summarizing we can see that the measures used in Reduction Target statements do not reflect a country's contribution to climate change. The measures are misleading in several ways;

  • By using Production Emissions they overstate the contribution to global warming of producing countries while understating the contributions of consuming countries.
  • By using Gross emissions instead of Net emissions they overstate the contribution to countries which have extensive forested areas and understate the contribution of smaller industrialized which have deforested.
  • By setting a Baseline date they understate the very significant contribution to global warming of countries which industrialized countries well before the artificial baseline date and penalize developing countries which are now or only recently going through industrialization.
Reduction targets established in this way will always be a source of argument as they do not reflect each country's contribution to the problem.

So how do these misleading measures generate misleading rankings?

I will try to address this in my next post.


1. Wikipedia - Greenhouse Gases
2. Climate Change Authority, Feb 2014, "Reducing Australia's Greenhousegas Emissions - Target and progress review"
3. United Nations Framework Convention for Climate Change website, "Glossary of Climate Change Acronyms

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