A bit old, but if somebody shouldn't have seen it, here's something on the lighter side:
Wednesday, December 24, 2008
Thursday, December 18, 2008
Externalities on future generations?!
It is often said that the GHG emissions of the present generation have negative externalities for future generations, or also, that they involve costs for future generations. That is: While the present generation reaps the benefits associated with emissions, it externalizes the costs of these emissions to the future.
I want to argue that there is something problematic about the idea of "externalities" or "costs" to future generations. I assume that the concepts of "cost" and "externality" are understood in the sense that an action of A counts as imposing an externality/cost on B in case B is made worse off than it would otherwise be, i.e. had the action not occurred. So, if A listens to loud music this imposes an externality/cost on B because B is made worse off than if A had not listened to loud music. In such simple cases, it is clear which two situations are compared: The baseline case is the situation where A does not listen to loud music and the deviating case which is said to involve costs/externalities is the situation where A does listen to loud music. A's not acting (i.e. not listening to loud music) is the case relative to which we compare other cases and which helps us separate costs from benefits (or, respectively, negative from positive externalities).
The problem in the intergenerational case is that we do not have an obvious baseline scenario which would allow us to separate positive from negative externalities (or, respectively, costs from benefits). If someone claimed that global emissions of 30 billion tons involve negative externalities on future generations, we can always ask: Relative to what baseline is the future generation made worse off by these 30 billion tons? And why is this the obvious baseline? Would you count global emissions of 5 billion tons or of 0 billion tons (or of -2 billion tons) as positive externalities or would you still count them as negative externalities?
Similarly, we can ask how much the present generation has to save for those savings to count as a positive externality. Does any addition to what the present generation has inherited from past generations count as a positive externality? And, if so, why? Why should zero savings be the natural baseline relative to which saving more counts as a positive externality and saving less counts as a negative externality?
In the non-intergenerational case, we are in possession of an obvious baseline: "Not listening to music" - or more generally: not doing something, not affecting the world, leaving the world as it is, in its status quo position. In the intergenerational case, we are not in possession of some "status quo" of future generations (associated with not acting on our part, i.e. not affecting future generations) relative to which we could count worsenings as costs and improvements as benefits.
So, there is something problematic about the claim that GHG emissions involve externalities or costs for future generations.
(P.S.: Some more things would have to be said, e.g.: (i) that I left the Non-Identity Problem out of the picture or (ii) that in some cases context makes it obvious what counts as the baseline or (iii) that there actually is at least one salient baseline: the baseline of what we owe to future generations).
I want to argue that there is something problematic about the idea of "externalities" or "costs" to future generations. I assume that the concepts of "cost" and "externality" are understood in the sense that an action of A counts as imposing an externality/cost on B in case B is made worse off than it would otherwise be, i.e. had the action not occurred. So, if A listens to loud music this imposes an externality/cost on B because B is made worse off than if A had not listened to loud music. In such simple cases, it is clear which two situations are compared: The baseline case is the situation where A does not listen to loud music and the deviating case which is said to involve costs/externalities is the situation where A does listen to loud music. A's not acting (i.e. not listening to loud music) is the case relative to which we compare other cases and which helps us separate costs from benefits (or, respectively, negative from positive externalities).
The problem in the intergenerational case is that we do not have an obvious baseline scenario which would allow us to separate positive from negative externalities (or, respectively, costs from benefits). If someone claimed that global emissions of 30 billion tons involve negative externalities on future generations, we can always ask: Relative to what baseline is the future generation made worse off by these 30 billion tons? And why is this the obvious baseline? Would you count global emissions of 5 billion tons or of 0 billion tons (or of -2 billion tons) as positive externalities or would you still count them as negative externalities?
Similarly, we can ask how much the present generation has to save for those savings to count as a positive externality. Does any addition to what the present generation has inherited from past generations count as a positive externality? And, if so, why? Why should zero savings be the natural baseline relative to which saving more counts as a positive externality and saving less counts as a negative externality?
In the non-intergenerational case, we are in possession of an obvious baseline: "Not listening to music" - or more generally: not doing something, not affecting the world, leaving the world as it is, in its status quo position. In the intergenerational case, we are not in possession of some "status quo" of future generations (associated with not acting on our part, i.e. not affecting future generations) relative to which we could count worsenings as costs and improvements as benefits.
So, there is something problematic about the claim that GHG emissions involve externalities or costs for future generations.
(P.S.: Some more things would have to be said, e.g.: (i) that I left the Non-Identity Problem out of the picture or (ii) that in some cases context makes it obvious what counts as the baseline or (iii) that there actually is at least one salient baseline: the baseline of what we owe to future generations).
Tuesday, December 9, 2008
Are Historical Emissions Harmful? Postscript
And then, there is of course a fourth reason why it is debatable whether historical emissions count as harmful: The Non-Identity-Problem.
The Problem in a nutshell is this: If in 1970 a people decided to pursue a policy of rapid economic growth which at the same time has a big impact on climate, this decision not only worsens the condition of persons living in 2070 but it also influences the whole course of history, including which persons exist at all in 2070. A given person in 2070 who would not exist but for the policy chosen in 1970 cannot claim to be worse off had a greener policy been pursued in 1970 because with such a policy the person would not be better off but rather not exist at all.
Quite a mindboggling problem.
A lot of the solution turns on, roughly, whether one can understand "harm" in other ways than "making worse off". For a discussion, see Lukas Meyer's entry in the Stanford Encyclopedia of Philosophy on intergenerational justice.
The Problem in a nutshell is this: If in 1970 a people decided to pursue a policy of rapid economic growth which at the same time has a big impact on climate, this decision not only worsens the condition of persons living in 2070 but it also influences the whole course of history, including which persons exist at all in 2070. A given person in 2070 who would not exist but for the policy chosen in 1970 cannot claim to be worse off had a greener policy been pursued in 1970 because with such a policy the person would not be better off but rather not exist at all.
Quite a mindboggling problem.
A lot of the solution turns on, roughly, whether one can understand "harm" in other ways than "making worse off". For a discussion, see Lukas Meyer's entry in the Stanford Encyclopedia of Philosophy on intergenerational justice.
Tuesday, December 2, 2008
Are Historical Emissions Harmful? Part III
Here is a third reason why it is unclear in what sense historical emissions are harmful. This third reason has less to do with how much costs past emissions impose on future generations but rather in what way they impose such costs.
Imagine first that the amount of emissions of the present generation is completely independent of how much past generations emitted. In this case the harm of historical emissions consists in the harm they do to the environment and the burdens for humanity that follow.
Imagine second that the amount of emissions of the present generation is completely dependent on how much past generations emitted. Imagine, for example, that the present generation imposes on itself the constraint not to let CO2 concentrations exceed 550 ppm and does whatever is necessary to just reach that goal (i.e. if the past emitted much, the present emits little and if the past emitted little, the present emits much). In that case the costs of past emissions do not consist in damage to the environment (since the present generation completely counterbalances excessive emissions of the past with its own behavior) but the costs of past emissions rather consist in the burdens to the present generation of having to limit its own emissions. The "harmfulness" of past emissions consists in making the present generation forego benefits (such as flights into vacation or the money saved by building a cheaper but dirtier power plant) in order to keep concentrations below 550 ppm.
Reality will be somewhere between the first and the second scenario, i.e. the present generation's emission level will be somewhat dependent on the level of past emission levels. And therefore the costs imposed by historical emissions will also be both: Damage to the environment and sacrifices of the present generation in order to limit its own emissions in response to past excessive emissions.
Imagine first that the amount of emissions of the present generation is completely independent of how much past generations emitted. In this case the harm of historical emissions consists in the harm they do to the environment and the burdens for humanity that follow.
Imagine second that the amount of emissions of the present generation is completely dependent on how much past generations emitted. Imagine, for example, that the present generation imposes on itself the constraint not to let CO2 concentrations exceed 550 ppm and does whatever is necessary to just reach that goal (i.e. if the past emitted much, the present emits little and if the past emitted little, the present emits much). In that case the costs of past emissions do not consist in damage to the environment (since the present generation completely counterbalances excessive emissions of the past with its own behavior) but the costs of past emissions rather consist in the burdens to the present generation of having to limit its own emissions. The "harmfulness" of past emissions consists in making the present generation forego benefits (such as flights into vacation or the money saved by building a cheaper but dirtier power plant) in order to keep concentrations below 550 ppm.
Reality will be somewhere between the first and the second scenario, i.e. the present generation's emission level will be somewhat dependent on the level of past emission levels. And therefore the costs imposed by historical emissions will also be both: Damage to the environment and sacrifices of the present generation in order to limit its own emissions in response to past excessive emissions.
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