It has often been claimed that Australian annual CO2 emissions are such a tiny fraction of the world’s total, around 1.5%, that there is no need for us to take action. If we are only responsible for such a small proportion, why should we bother with a carbon tax or emissions trading scheme?

This argument may seem plausible at first glance, especially because it seems to let us off the hook so readily.

However, even after limited analysis this argument turns out to be deeply flawed and misleading at many levels. The argument is flawed and misleading because it is ignoring the full context.

To provide context, we must first remember that there are about 200 countries in the world. If they shared emissions equally, no single country would emit more than ½ a percent of the total. So without going any further, our 1.5% is already three times more than would be expected if we had an equal share in the world’s total—clearly we do not. This reinforces the fact that looking at a single number, whether it’s 1.5% or 8% or 4.39875% is often meaningless; we must look at the full context. And this begins with a comparison of any given country’s emissions against those of other countries.

There is an additional context we must consider in the case of CO2 emissions: We must recognize the importance of the sum total of emissions across the last two or three centuries. Why? Because CO2 accumulates in the atmosphere, and hence what matters to a country’s responsibility for climate change are its historical emissions—in the same way that if 5 housemates run up a debt, each person’s responsibility extends to their entire expenditures, not just last week’s excessive bar tab. Unfortunately, people’s cognitive apparatus is not well equipped to deal with quantities that accumulate, and so it is worth expanding on this point.

Historical emissions data are provided by the Carbon Dioxide Information Analysis Center (CDIAC), which we link to from this website. These data go back as far as 1750 (for some countries) and they are the best available record of global annual emissions over time. (These particular data extend to 2007 and they are from burning of fossil fuels.) When emissions are summed across the available record, the top 25 all-time emitters are as follows:

(*For this analysis, the Russian Federation and the Czech Republic inherited all the emissions of the Soviet Union and Czechoslovakia, respectively. This should be apportioned differently, e.g., based on the share of historical emissions by that part of the former, bigger, country. For simplicity I omitted that step here because it makes little difference for present purposes.)

You will note that Australia is 14^th—out of 200—in terms of cumulative emissions. This should clarify how misleading it is to talk about “only 1.5% of emissions are ours”. In fact, over history, we are responsible for a lot of CO2 in the atmosphere. This can be clarified further by plotting the (logarithm of) historical emissions of all countries against the rank position of each country (in other words, we order the countries from most-emitting on the left to least-emitting on the right). This is shown in the figure below:

(In these data, some administrative entities such as the Falkland Islands are considered independent “countries”, which inflates the total number of observations but that has no bearing on the rank position of Australia).

The figure clarifies that Australia has more historical responsibility for CO2 in the atmosphere than 228 other countries. In other words, we are more responsible for climate change than about 94% of all countries in the world.

There is one additional important point to be made: The data presented thus far are total cumulative emissions, not adjusted for population. The figure above and the earlier table are not per capita but they are the sum total of emissions. Despite that, we are ahead of Brazil, for example, which has roughly 10 times the population of Australia.

Australia has 1/3 of a percent (or .0031) of the world’s population—and yet we are number 14 on the list of total emitters and have more responsibility for global warming than about 94% of all other countries.

To provide full context, let’s examine what happens when we convert total historical emissions to per capita emissions. How much of a responsibility does each one of us in Australia have for the carbon emitted during the last 100-200 years? Like it or not, Australians have emitted 3,638,504,000 tons of carbon to date, and as you can see in the table below, each and every one of us carries a share of this historical burden that’s equivalent to roughly 172 tons.

Let’s place that burden into further context:

(Countries with a population below 2 million were omitted from this analysis because their per capita emissions often fluctuate considerably across time, suggesting that those estimates may not be terribly stable. For example, Luxembourg’s population is less than ½ million but their per capita emissions are very high. At least in part, this turns out to be due to the fact that German and French drivers fill up their cars in Luxembourg because petrol is less heavily taxed there, and the emissions then count towards Luxembourg’s. This is one of the reasons why per-capita statistics from small countries are easily distorted. *The Czech Republic and Russian Federation are again inheriting all historical emissions of their former countries for simplicity.)

We are within the top 10 emitters if we account for the size of our relatively small population relative to that of some other countries—for example China, which is in position 61 on this list. In other words, the country that is the favourite bugaboo of those who want to forestall climate action in Australia, is way down the list when it comes to the historical responsibility of each of its citizens.

Australians, by contrast are among the top 10.

There is no shirking that responsibility.

Sooner or later we must cut emissions. And of course we will, because the laws of physics do not negotiate. The only question is when we will finally begin climate action.

In the next post, we will explore that “when” and place it into its proper context, by considering what other countries have been doing already.