Documentation > Greenhouse effect > Greenhouse gases and us > How do greenhouse gas emissions presently evolve ?
A a consequence of a neverending fossil energy consumption (coal, oil, gas), CO2 emissions increase, and not only do they increase, but until recently they increased faster each year. The average annual increase, that what very high after the Second World War, started to diminish after the fisrt oil shock, but still these CO2 emissions go on rising, as it is easy to see below.
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Incidentally there is an interesting remark that can be made out of the graph above : the only events that induced a decrease of the emissions are "unpleasant" ones : wars, oil shocks, recessions (the latter is particularly visible for the former USSR after 1990, when the fall of the Berlin Wall led to a recession of all the former communist countries). A simple consequence of this observation is that, in a finite world (where emissions hence can't rise indefinitely), if we do not implement a voluntarily dcrease of the emissions, it is the finite aspect of the world that will do it for us, with the help of one or several more or less painfull events.
If we breakdown the CO2 emissions by country category as referred to in the Kyoto protocol, we get the below figure.
 CO2 world emissions, in millions tons of carbon equivalent. From Mission Interministérielle de l'Effet de serre Annex I designates all the countries that have committed themselves to a reduction of the greenhouse gases emissions under the terms of the Kyoto protocol ; this category essentially comprises developped countries and countries "in transition" (Eastern Europe countries, mostly). Annex II designates the countries that signed the Kyoto protocol but that did not commit to any reduction (essentially developping countries, including China and India). |
But it is essential to remind that CO2 coming from the use of fossil fuels accounts for only half of the problem.
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Breakdown of world greenhouse gas emissions in 2004 by gas (except ozone), in billion tonnes CO2 equivalent. From IPCC, 2007 |
The emissions of other gases include :
CO2 linked to deforestation, often referred to as coming from "land use and land use change", because practically the land use change that leads to significant CO2 emissions is deforestation : most of the wood cut is burnt (forestry represents a small part of the wood cut, even though it often creates paths that allow the cutting of the rest of the wood by locals peasants seeking arable land), what generates CO2 emissions, and then the soil frees adds some CO2 emissions when it is`plowed (plowing exposes the humus to the air and lead to accelerated oxydation of the soil carbon),
How do contries compare for this problem ? We can of course breakdown the emissions by country, what immediately allows to see that a couple of major countries account for a large fraction of the world emissions.
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But the ranking of the emissions per inhabitant is rather different, and in addition to something expected, which is that emissions are more or less proportionnal to economic development, this ranking reveals a surprising fact : among the G7 countries, emissions per capita vary from 1 to 3 between the most "virtuous" countries and those who are not.
 Greenhouse gas emissions per person and per year, in kg carbon equivalent, for annex I countries plus China (China : CO2 only), for 1990 and 1998 (ranked by 1998 level). It can be noticed that among the countries that have an important GNP per inhabitant, the most "virtuous" are France, Sweeden and Switzerland, three countries that produce their electricity with "carbon free" means : nuclear and hydroeletricity. In the case of Switzerland the high proportion of services in the economy probably also plays a role. Emissions per inhabitant in China are close to one tenth of what they are in the US. This figure also shows clearly the important decrease of the emissions per inhabitant of the former communist countries. Source : United Nations Framework Convention on Climate Change (except China : french minitry on industry) - UNFCCC ; Institut National d'Etudes Démographiques - INED for populations ; divisions have been made by your humble servant. |
The "big bad boys" regarding greenhouse gases are without any doubt the Americans : not only their country is the first emitter in the world, but they are also on the podium for the emissions per person, and the latter is still rising !
The "under-developped" countries are definitely lower emitters : in average, the CO2 emission per inhabitant (energy use only) is around 0,4 tonne carbon equivalent per year (that is one fifth of what a French "does", and 7% of what an American "does"), but all non-Annex I countries (those who did not commit to any reduction of their emissions so far) are not that low !
 Net CO2 emissions per person and per year, in tonnes of carbon equivalent, for a large selection of non-Annex I countries (those who did not commit to emission reductions). To give a reference, A Swiss citizen emits 1,7 tec/pers./year, and USA citizen over 5, for this sole gas. Note the modest emission per capita of India (0,3 in rough figures) and the very low emission per capita of major black african countries (Nigeria is the most populated african country, with over 120 million people). Note at last that Israel, South Korea and Singapore, not to mention oil producing countries, though having emissions per capita and/or developping status close to that of OECD countries, did not commit to any reduction. From United Nations Framework Convention on Climate Change - UNFCCC. |
And at last the breakdown by activity of greenhouse gases is very different from one country to another. It depends on the global economic wealth, the dominant electricity production mode(s), the eating habits.... In order to give an idea anyway, here is what it is for the whole planet and for the sole CO2 seul (as emissions are known with an 50% error margin for methane and nitrous protoxyde, a beautiful pie chart would not be easy to draw....).
 Breakdown by activity of the CO2 emissions in the world in 1999 (from International Energy Agency). It can be noted that the first source is electricity production. It can then be easily understood that, given the reduction effort that it is necessary to achieve if we want to seriously adress the problem, the fight will be more easily won if we do not refuse the help of nuclear electricity. |
Due to the fact that we produce almost all our electricity with "CO2 free" processes (nuclear accounts for 80%, and hydroelectricity for 15%), the breakdown in our country is not the same : for CO2 emissions it is transportation that comes first, with "buildings" coming second (use of fossil fuels for heating or sanitary hot water, but air conditionning, if it operates on electricity, is not included, because using electricity does not free any CO2, it's producing it that possibly does).
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In France the "energy sector" is composed for half of emissions coming from the coal and gas fired power plants that we also have (but in little quantities), and for the other half of emissions coming from refineries (refining oil consumes about 8% of the initial oil, the heating energy being often provided by oil coke). Incidentally it is interesting to note that "clean" fuels (no sulfur, for example) require an additional energy consumption in refineries to be produced, therefore generating more CO2 emissions.
If we take all the greenhouse gases into account, surprise ! It's the agriculture that comes first ! (chart below).
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Indeed, agriculture is the principal emitter of "non CO2" gases : 2/3 of methane - CH4 - and of nitrous protoxyde - N2O - come from agricultural activities, respectively from cattle raising and fertilizer use. These "minor" gases represent a little bit more or a littyle bit less than a quater of the emissions depending on the way to calculate (charts below).
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The respective proportions of CO2, methane and nitrous protoxyde may vary (a lot sometimes) depending on the country : those with an important share of agriculture in the activity generally have methane emissions proportionnally higher, while heavily industrialized countries that, in addition, use a lot of coal fired power plants have CO2 emissions even more dominant than in France.
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| A couple of examples of breakdown by gaz for some Annexe I countries (see Kyoto Protocol). Source : United Nations Framework Convention on Climate Change - UNFCCC. | |
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No, that's not the case : respective evolutions are rather different depending on the activity/sector. This analysis, though restricted to France for the precise figures, is more or less valid in many other places.
 Breakdown by activity of the CO2 emissions in France since 1960, in millions tonnes of carbon equivalent. International air transport is not included. Three epochs are visible on this graph :
From CITEPA, 2002 |
before the first oil shock (1974), all the emissions are rapidely
rising. The strong economic growth that accompanied reconstruction
in France after the Second World War went with an equally strong
growth of the emissions, with a final phase obvious in 1973.