This web page considers the moral responsibility of climate change, and is extracted from the report by: Benito Müller, Niklas Höhne, and Christian Ellermann, October 2007, Differentiating (Historic) Responsibilities for Climate Change.

The Conceptual Framework

Contribution versus responsibility

Climate impacts – be they anthropogenic, due to natural variability or anything else – will inevitably have a large multitude of causes, each causally contributing to the impacts in question. The (moral) responsibility for climate impacts will also typically be shared by a number of actors. The key difference between being morally (partly) responsible for, and (causally) contributing to is that the former is a blameable matter which only makes sense if the impacts are anthropogenic, while the latter is not. The 1628BC eruption on the Aegean island of Thera (Santorini), it has been argued, led to an average global cooling of 1.5°C over the following one hundred years, which, in turn, has been put forward as one of the key contributing factors in the downfall of the Minoan civilization during the first half of the 16th Century BC, but it would be considered odd to hold the mountain morally responsible, let alone wishing to punish it accordingly.

The Report by Muller et al., recognises two distinct kinds of responsibility, namely strict (or unlimited) responsibility, and limited responsibility, which are based on, but different to, cumulative historic emissions of the greenhouse gases CO2, CH4 and N2O (incl. those from land use change and forestry).

Strict Responsibilities are in part determined by causal contributions as reflected in historic emissions since 1890, and in part by population size and the level of global greenhouse gas emissions that are seen to be harmless – here taken to be the current level of global ocean sinks (estimated at 7GtCO2eq/annum) – and allocated on a per capita basis. In other words, in order to determine a country’s share in the strict responsibility for the climate change problem, it is allocated a part of the harmless global emissions on a per capita basis. This ‘basic allowance’ is then subtracted from the country’s historic emissions, with the remainder (if any) determining its share in strict responsibility for the problem.

According to this methodology, industrialised countries (as listed in Annex I to the UNFCCC), are at present jointly strictly responsible for 64% of the climate change problem. As illustrated in the figure, the largest portion of strict historic responsibility has to be attributed to the US with 25.6%, followed by the EU15 (15.9%), OPEC (7.4%), Russia (7.3%), China (6.4%), Brazil (5.2%), the 76 countries of AOSIS and the LDC group (4.1%), Japan (2.8%), and finally India with next to no responsibility (0.3%). India’s very low share (compared to its causal contribution of 3.9%) is due to the large population of India and the fact that the basic allowances were allocated on a per capita based ‘lump sum’ thus, as it were, allowing the not so poor to benefit from the surplus basic allowances of the poor.

Limited Responsibilities. According to Aristotle, moral responsibility (‘blame’) can be limited because of ignorance or circumstances beyond ones control. For the purposes of the moral responsibility of climate change and this report, these conditions were applied as follows. First it was assumed that there was a time before which governments could not be blamed for not knowing about the problem, and second that very poor people have a morally justified need to emit a certain amount of greenhouse gases, over and above the harmless level (they have a right to overcome their poverty and, presently, can’t do so without these emissions).

There can be no doubt that after the start of the negotiations in 1990 that led to the UNFCCC, no government could reasonably plead ignorance of the climate change issue. While one might argue that they should have known even earlier, we have chosen to use this undisputable upper bound to implement Aristotle’s epistemic condition by restricting the limited responsibility calculations to post-1990 emissions. The justified need to grow, in turn, was implemented through the introduction of individual ‘subsistence allocations’ of 2tCO2eq. per poor inhabitant (the average per capita energy emissions of the developing world), which were allocated to every inhabitant surviving on less than $1 a day, replacing the above-mentioned basic allowance, if that was less (in this case less than 2tCO2eq.).

Subsistence allowances are for ‘subsistence emissions’ only. In contrast to the basic allowances, a surplus therefore cannot be transferred outside the eligible community, i.e. the inhabitants with less than $1 a day. Numerically, the epistemic constraint – i.e. disregarding what happened before 1990 – turns out to have by far the stronger impact, relative to the strict responsibility figures, than the introduction of subsistence emissions under these poverty parameter values. Their combined effect is a shift of responsibility of 9 percentage points away from Annex I to the developing world, chiefly absorbed by China (+5.1 percentage points). With the exception of AOSIS+LDC overtaking Japan, and China advancing to third place, the ranking remains the same as under the strict conception: US (20.3%), EU15 (12.4%), China (11.5%), OPEC (9.5%), Russia (6.8%), Brazil (5%), Japan (3.8%), AOSIS+LDC (4.7%%), and India (0.6%).

Concluding Remarks on the Moral Responsibility of Climate Change

The Muller et al paper put forward and discussed a methodology for the numerical differentiations of the moral responsibility of climate change as opposed to calculating causal contributions to climate change. For expository purposes, this was done on the basis of aggregate GWP [Global Warming Potential] weighted historic emissions as a proxy. Moving to fully fledged climate modelling techniques as used in MATCH [Modelling and Assessment of Contributions of Climate change ] could be done in the future, but would change the relative contributions and resulting responsibilities by at most 10% for most countries.

In the context of the Report, the authors did not wish to engage in a debate about which of the two conceptions of responsibility (‘strict’ or ‘limited’) with the chosen parameter values was more appropriate ( not least because the answer may well depend on what one wishes to do with the results). The authors believe that the order of magnitude difference in the responsibility of the two extremes of the scale under both conceptions gives pause for thought as to what sorts of burdens can justly be imposed, particularly given the discrepancy between the affluence and wealth of the exponents at either end of the spectrum of responsibilities considered in the Report.

The authors of the Report referred to here, believe that fair burden sharing needs to be based on a mixture of moral responsibility of climate change and some differentiated index of capability.