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Ranking Countries by CO2 Emmisions per km2 of Land Surface Area

Data on CO2 emissions can be presented in many formats, each projecting a certain point of view. Ranking countries according to Total CO2 Emissions identifies the countries that emits the largest quantity CO2. Ranking countries according to Total CO2 Emisions per capita identifies the countries which emits the most CO2 per individuals. Neither of these data sets offer any insight into whether any specific country would be emitting above its own natural sustainable emission limit. As humans mostly live on land, it could be reasoned that the emissions due to human activity should be related back to the land surface area.

Ranking countries by their CO2 emissions per km2 of land surface area decouples the interpretation of the data from population density or individual consumption. It effectively lists countries according to total emission density. It will clearly identify the countries where the emission density into the atmosphere above it is above the world average. It places the focus back on the land and the emissions being released into the air from it. Such a ranking remains independent of population growth.

The table below was compiled using other information available from Wikipedia. One dataset used is that Countries by carbon dioxide emissions (2006) As quoted from that Wikipedia page, it is a list of sovereign states by carbon dioxide emissions due to human activity. The data presented below corresponds to emissions in 2006. The data itself were collected in 2007 by the CDIAC for United Nations. The data consider only carbon dioxide emissions from the burning of fossil fuels, but not emissions from deforestation, and fossil fuel exporters, etc. According to that list, the top 10 countries in the world emits 67.2% of the world total.

Land surface areas were also obtained from Wikipedia List of countries and outlying territories by total area. For statistical purposes, dependent territories are listed separately from their sovereign states and are set off in italics. The figures represent total areas, covering land and inland water bodies (lakes, reservoirs, rivers). Marine internal waters (coastal waters), territorial waters and Exclusive Economic Zones are not included. Also not included in the list are uninhabited dependent territories – including various countries' claims to parts of the continent of Antarctica (14,400,000 km2/5,600,000 sq mi) – and entities such as the European Union (4,324,782 km2/1,669,808 sq mi total area) that have some degree of sovereignty but do not consider themselves to be sovereign countries or dependent territories. The total land area of the world is 148,940,000 km2 (57,510,000 sq mi)[1] (about 29.1% of the Earth's surface area).

The data above was used to calculate the emission per km2 for the list of countries. The table below ranks countries according to their annual CO2 emissions (in thousands of metric tons) per km2 of the country's land surface area.

This table clearly identifies how each country's greenhouse gas emission density compares against the world average. For example, based on the Wikipedia data used for CO2 emissions and land surface areas for different countries, it identifies Singapore as the worst polluter at a CO2 emission density of 79.74 thousand metric tons CO2 per km2, and Ireland just makes the top 50 at 0.623 thousand metric tons per km2. This can be compared against a world land surface emission density of 0.191 thousand metric tons CO2 per km2.

Intuitively this ranking makes sense. A small, primitive tribe of 20 people cooking on wood fires, occupying an area of 2500km2, can produce less CO2 than a industrialized neighbourhood of 2500 people living in 20km2. Expressing emissions in terms of per capita implies that every human being has the right to pollute the same amount as the average person in the world. This however, ignores the effect of concentration of emissions- or aggregate emissions - on a country level. The inherent flaw in expressing emissions on a per capita basis is that it ignores population growth. As soon as the population of a country changes, the per capita values must be recalculated. It is also not clear how it is sensible to compare the values from one decade to another.

This ranking provides an alternative approach which may assist towards obtaining agreement on global greenhouse gas emmisions. The ranking is independent of population density or the type of economy. It does not favour poor or rich countries, nor does it discriminate between developed, developing and under develop countries. An international agreement on a target value greenhouse gas emission density from the land surface will in effect aim towards a green house concentration in the atmosphere that is fixed and independent of population level or pouplation growth.

The list can be expanded to include more countries. Other factors which determines the ability of a country to absorb CO2 should be considered as well. The obvious factors are: (1) Annual rainfall, (2) Average height above sea level, (3) Average annual temperatures, (4) length of coastal perimeter.

Evaluating every country along these lines are somewhat akin to determine the cattle carrying capacity of a farm. Perhaps a more down-to-earth analysis is required.

Living plants are one of the known sinks of carbon dioxide. It is therefore logical that the ability of a country to provide a sink for the CO2 generated inside the countries borders would be proportional to the extent that it sustains plants. The total amount of living plants that can be sustained by a piece of land (or a country) is mainly a function of the following variables: CO2 Sink Capability - An indication of the total plant life that can be sustained A - proportional to the size of the country; P - proportional to the annual precipitation in the country; T - dependent on the minimum, maximum and average annual temperature of the air; H - inversely proportional to the height above sea level;

The most simplistic representation of this would be:

CO2 Sink Capability = f(A, P, T, 1/H)

Perhaps a better refinement would be to base it on the climate classification of every country, such as the Koppen classification. Although it requires the specialist input of geographer or climatologists, it is based on the natural sciences and not on artificially generated accounting practises, such CO2/capita.

The most difficult part of this presentation is how to convey the concept to people.

To think about its phrasing, think why is rainfall expressed as total rainfall for a country, not rainfall per capita? Why is food production expressed as total production for a country, not tons/capita?

[1] ^ CIA - The World Factbook

Henks (talk) 00:37, 2 February 2010 (UTC)henks