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As the introduction of this paper stresses, concern about global warming is essentially a moral concern. There are two quite different ways in which a moral concern for future generations can be expressed. The first, which is the route taken by welfarism, is a concern with the well-being of the future generations, so that their welfare is incorporated along with that of the current generation in the social calculus. A welfarist concern suggests that the uncontrolled emission of greenhouse gases would reduce the (expected) welfare of future generations below acceptable limits. It asks us to place ourselves in a neutral position, to divorce ourselves from our position in the current generation, and to ask whether the distribution of welfare between us and our descendants is morally defensible. An alternative moral position concerns itself not with the welfare, but the rights, of future generations. From this point of view, the global environment is a common resource for us now and in the future. We can justifiably appropriate a part of it for our purposes only if there be, in Locke's words, 'enough and as good left in common for others'.

Let us begin by examining the implications of a welfarist position. There are, of course, several variants of welfarism. Utilitarianism gives us a choice between alternative social states so as to maximize the sum of individual utilities. Rawls' difference principle (1972) asks us to maximize the welfare of the worst-off person. Broome (1993) favours critical-level utilitarianism, which was first proposed by Blackorby and Donaldson (1984) - this states that we should seek to ensure that everyone has a critical minimum level of welfare, and having achieved this, we should be utilitarian. These welfarist principles, although very different, in the context of global warming and on the question of intra-generational distribution, may however give very similar conclusions.

How is this possible? After all, Rawls requires that we maximize the welfare of the least well off, whereas utilitarianism simply looks at the total sum of utility, irrespective of its distribution. These different theories may have similar practical implications because the distribution of welfare in the world today is so far removed from any utilitarian optimum. Given the widespread inequalities in the world today, it seems very likely that the marginal utility of one dollar to a poor Bangladeshi is substantially greater, and in fact of a different order of magnitude, than the marginal utility of one dollar to an average American. Utilitarianism would, in this context, require a redistribution of dollars towards the Bangladeshi until marginal utilities were equalized. Until that point, the practical difference between utilitarianism and the difference principle may be slight.

One may of course dispute the claim regarding the relative sizes of the marginal utility of one dollar. However, the only reasonable way to dispute this appears to be by denying that one can compare utilities across persons. If we do not allow for inter-personal comparisons of utility, we do not allow for the possibility of any utility-based moral theory. To the extent that we want to use any welfarist moral theory, we must allow for inter-personal comparisons of utility, and having allowed that, it seems unreasonable to dispute the conclusion regarding marginal utilities.

To conclude, any welfarist theory suggests that the burden of global warming should be put squarely upon the shoulders of the North. Of course, the qualititative conclusion is quite independent of the issue of global warming. The above argument would suggest a large transfer of wealth from the North to the South even if global warming was not a problem.

The welfarist theory of justice is disputed by rights based theories, such as those advanced by Locke, and more recently, by Nozick (1974). Nozick argues that the justice or otherwise of a social state cannot be evaluated by simply looking at the well-being of individuals in that state. Individuals have rights, including the right to appropriate what they have produced or acquired justly, and any redistribution on welfarist grounds would infringe those rights. Nozick's theory would argue that the difference in well-being between the American and the Bangladeshi is irrelevant, and may be consistent with justice. What matters is whether the resources which allowed the former to be well off are justly appropriated or not. If the condition of just appropriation is satisfied, redistribution is uncalled for. If the original appropriation is unjust, redistribution may be called for in order to ensure 'justice in rectification'.

There are two questions which arise in the context of the exploitation of global environmental resources. First, what does a rights based theory imply for the obligations of the current generation towards future generations? Second, if differences in well-being in the world today are
related to unjust past appropriation of global environmental resources, is redistribution called for on the grounds of 'justice in rectification'? We address the first question in the remainder of this section, and deal with the second question later in the chapter.

Locke suggested that private appropriation of a resource was just if there be 'enough and as good left in common for others'. In the context of a scarce resource (such as the global environment), it is clearly literally impossible to leave enough behind for others if one uses it at all. Nozick therefore reinterprets the proviso. my appropriation is just if 'the situation of others is not worsened' (Nozick: 1974,175). Nozick's proviso is very weak, as Cohen (1986) argues, since it allows the appropriator to retain all the benefits of acquisition. Nevertheless, even this weak proviso has some relevance. If we contribute to the greenhouse effect, thereby adversely affecting future generations, it is incumbent upon us to compensate them for this adverse effect. Our exploitation of the global environment allows us to enjoy a higher level of real income than would be possible in the absence of such exploitation. We should save a part of this real income, and transfer it to future generations, say as capital.

The future generation is however heterogeneous, and will be differentially affected by global warming - land-locked Switzerland may not suffer any adverse effects from global warming and may even benefit whereas a rise is the sea level could be disastrous for an island state such as Tahiti, or low-lying Bangladesh. Here the Nozickian proviso, that no one be worse off, requires us to make differential transfers - more to tomorrow's Tahitians and less to the Swiss. A given level of global emissions today entails a distribution (across countries or regions) of ill effects in the future. These adverse effects must be compensated for by transferring resources from today's generation to those affected in the future.

The above discussion makes clear that current emission entitlements also entail a corresponding liability, for compensating future generations. How are the emission entitlements to be distributed within the current generation? The Lockean proviso suggests that each individual in the current generation has an equal share in this global resource. It suggests that countries should be distributed emission entitlements on the basis of their populations. Further, the liability to compensate future generations should be based upon the emission entitlement.


A number of criteria have been proposed as bases for distributing emission entitlements, which we can examine in the light of the preceding discussion

Entitlements Based on 'Grand fathering'

Grand fathering refers to the establishment of a property right through use. In the context of the global environment, this criterion implies that entitlements to emit in the future will be equal to current emissions. In other words, those who are currently polluting excessively have thereby established a right to continue polluting in the future. If total emissions are to be reduced, this principle implies that emission entitlements will be proportionately reduced, so that each country will be called upon to make equal percentage reductions in emissions. In either case, this criterion favours the developed countries, which have a high level of current emissions, and adversely affects developing countries. On this basis, Table 6.2 suggests that developed countries with 23 per cent of the world's population will be allotted 58 per cent of the world's emission entitlements, whereas developing countries with 77 per cent of the world's population will be allotted 42 per cent of entitlements. Per capita entitlements in the North will be, on average, 4.6 times as large as those in the South. Since this doctrine is unfavourable to the South, it is sometimes sought to be tempered by requiring deeper cuts for countries which have had a greater historical contribution to emissions. Extending this, it may also be possible to allow for negative cuts, ie to allow developing countries to increase emissions. However, the underlying basis on which rights to the global commons are sought to be defined is the same in all these variants - the right is established through usage.

Grandfathering is based upon the status quo doctrine: the current rate of emissions confers a status quo property right that is established by the use of the right in the past. Consequently, if reductions are to be made, each country must be dispossessed from its status quo right equally. This is grossly inequitable, since developing countries, whose emissions will surely rise from their extremely low levels at present, are penalized. Even among developed countries, it punishes those countries which have made the greatest efforts at energy efficiency such as Japan. Such countries have lower levels of emissions as compared to the US, and the costs of additional emission reductions are substantially greater for them.

Recall our earlier discussion, where we argued that a rich country could use the global environment as a way of transferring welfare to its descendants. Grandfathering is doubly dubious: not only is this transfer not addressed, a further benefit is conferred upon those who over-exploit the environment.

Emission Quotas Proportional to GDP

The logic of this allocation is that all production should be required to be equally clean. This may seem an efficient way of achieving any global target, but this is not the case if quotas are not traceable. The scheme without traceable quotas requires countries to achieve the same average level of GDP to emissions. This is not the same as equating the marginal cost of emissions in terms of international currency. The latter can be shown to be the appropriate criterion for an efficient allocation of emission reductions. Distributionally, this scheme would be most favourable to Japan and Western Europe, and least favourable to Eastern Europe/former USSR and the developing countries. Given that there is no efficiency requirement for operating this scheme, the distributional criteria are based on the idea that the richer countries should have more of the world's common resource.

Equal Per Capita Emission Quotas

The basis for this principle is that the world's environment belongs equally to all human beings, and each one is entitled to an equal share. In other words, whatever the target level of emissions, permits should be shared out between countries on the basis of their share in world population. This principle entails a distribution of emission entitlements which is very different from the distribution of actual emissions, since the LDCs have a greater share of world population than of emissions. Opposition to this principle is essentially on 'pragmatic' grounds, that this would be unacceptable to developed countries.

With equal per capita entitlements, each country would have an aggregate entitlement proportional to its population. The question arises, should the aggregate entitlement in a particular year be based on the population in that year, or should it be based on population in some base year, say 1994? Several writers (Grubb 1989, for example) have argued in favour of the Latter. They suggest that if entitlements were based on current population, poor countries, which would trade some of their entitlements for foreign exchange, would have a positive incentive to increase population so as to increase their foreign exchange earnings. The emission entitlements scheme would therefore have the undesirable effect of increasing population. However, on the assumption that governments are concerned with per capita income (or per capita welfare), this argument seems incorrect. An increase in population which raises total entitlements may increase the total foreign exchange earned by selling entitlements. It will not increase per capita foreign exchange earnings, and will therefore not raise per capita income. Per capita income is likely to fall due to the rise in population, given the scarcity of other factors such as land and capital. Consequently, a traceable entitlements scheme based on current population will be neutral in its effect on population - it creates no additional incentive for higher or lower population size. Of course, if entitlements are based on population in the base year, this creates an additional incentive to reduce population growth.

If we start from the position that each individual has an equal right to global environment, the allocation of emission quotas is straightforward. Given the global emission target, this is simply divided by the global population, and each country is allocated quotas in proportion to its share of the world population. It is immediately obvious that most developed countries would then have a deficit of allocated emission quotas relative to their desired level of emissions, whereas developing countries would have a surplus. Consequently, trade in quotas would bring about transfers between countries. An equivalent allocation can be brought about by an international carbon tax; a specific tax which would be levied on each ton of equivalent carbon.


The discussion hitherto has been based an allocating entitlements to current emissions, without reference to the historical record of contribution to current concentrations of greenhouse gases in the atmosphere. But the greenhouse effect must take into account the contribution of past generations for reasons already stated; those of the cumulative build up of CO2 in the atmosphere and its long-term effects. Fujii (1990) and Smith (1991) have attempted to calculate the overall responsibility of different countries for current CO2 concentrations. This involves calculating the cumulative effect of emissions since 1800 (emissions at an earlier date are discounted by the rate of CO2 decay). In the case of methane, the residence time in the atmosphere is short, so that the difference between current emissions and cumulative emissions is not very large. Table 6.1 shows current emission shares and the overall contribution to concentration, region-wise. The contribution of Western Europe and North America to the concentration was much greater than their share of current emissions. Historical emissions from LDCs have been extremely low, and hence their low share in contributing to overall CO2 concentration.

Fujii (1990) argues that each individual in each generation has the same emission entitlement. He divides each region's contribution to current GHG concentration by the total population of the region, past and present, in order to derive the contribution per capita. This is even more unequal across countries than the distribution of current emissions per capita. Fujii argues that developed countries owe LDCs a debt because of their excessive emissions in the past. This point is also made by Smith (1991, 1993), who calculates a natural debt index - an index of how much each country has 'borrowed' from the natural environment. Both Fujii and Smith argue that this debt should be repaid, and that emission entitlements should be adjusted to correct this imbalance. Consequently, equitable allocation would require that LDCs have greater emissions per capita as compared to developed countries, reflecting the difference in natural debt.

What is the validity of this argument, which holds current generations in the North responsible for the emissions of their ancestors? Are Fujii and Smith right to argue that the North must today repay those natural historical debts? Or can one take an individualist stance, and argue that the natural debts incurred by past generations in the North have perished along with those who incurred them?

To take a welfarist moral position, one can argue that history is irrelevant. One can argue for a redistribution between North and South on welfarist criteria, given the enormous inequalities that exist in the world today. However, the question of precisely how these inequalities came about is irrelevant for a welfarist, and the fact of past exploitation of the environment by the North makes no difference to the argument. However, for a rights based moral position, the question of the historical responsibility is indeed critical. Can one then take a purely individualist position, and argue that nations as such bear no responsibility, and it is merely the individuals who lived in the past who bear responsibility? If current generations in any country are not responsible for the acts of their predecessors, why should they have to repay a debt which they played no part in incurring? On this reckoning, developed countries may have indulged in excessive emissions of greenhouse gases in the past, but there is no way they can be held responsible for this, since the individuals who were responsible no longer exist.

This argument does not stand for several reasons. The first, and rather obvious, reason is that much of the carbon dioxide currently in the atmosphere has been emitted in the lifetime of the current generation. However, more importantly, it can be argued that the current generation may also have to take responsibility for past emissions, even if we do not want to attach any moral opprobrium upon them for this. The current generation is the beneficiary of resource transfers from previous generations. These resource transfers take various forms, including physical capital, human capital investments, and knowledge, as well as natural and environmental resources within developed countries. They have been possible only because of past exploitation of global environmental resources. If the earlier generations in the developed world had been constrained from degrading the global environment to the extent they have actually done, they would have suffered through lower level of per capita income. In consequence, they would have been less able to save and invest in productive capital, and less able to transfer productive assets to the current generation. Developing countries have a claim to a part of these transfers, simply because they were made possible by the excessive use of global environmental resources by previous generations in the developed countries. Put somewhat differently, if current generations in the North accept assets from their parents, then it is incumbent upon them to also accept the corresponding liabilities.

There are two caveats in applying this argument. First, if the past generation has transferred more liabilities than assets, the current generation in the North could well be justified in accepting neither although however, this is in fact not the case. Second, excessive Northern exploitation of environmental resources may have also enabled a greater stock of global public goods to be transferred. Scientific knowledge is one example. These public goods may benefit all countries today, albeit to different degrees, and to the extent that they benefit the South, the North today has to compensate the South less.

What about the argument that the natural debt idea is invalid since the North was unaware of the possible harmful effects of emissions of greenhouse gases? It seems to us that this argument is misplaced. Ignorance of the harmful effects simply means that we cannot attach any moral blame on previous generations. However, no matter what motivated them, the effect was to benefit their children by permitting a larger extent of transfers of assets, and to the detriment of the global stock of environmental resources. Ignorance does not undo the case for corrective action today. An analogy would be if I take an object, not knowing that it belongs to you, and give it to my daughter, you are surely entitled to reclaim it, even though neither my daughter nor I may be a thief.


We have argued that questions of inter-generational as well as intra generational equity must necessarily be confronted if we are to have a meaningful discussion of global warming. These questions of distribution can be addressed from a number of divergent view points. Nevertheless, we find all these viewpoints seem to give qualititatively similar conclusions - that current generations have a responsibility to the future, and the burden of this responsibility must be borne largely by the North.


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