This monthâ€™s decision by 21 young American citizens, mostly teenagers, to sue President Barack Obama and various branches of the US government over climate change has highlighted a crucial issue that is all too often overlooked: the tendency to value current generations' well-being much more highly than that of future generations.
The â€śyouth plaintiffsâ€ť, aged between 8 and 19, argue that the US government has known for more than 50 years that carbon dioxide from fossil fuels is causing dangerous climate change, and yet has not prevented emissions from rising.
Their lawsuit â€“ filed in an Oregon district court and directed at Obama, the Department of Energy, the Department of State, the Environmental Protection Authority and others â€“ argues that future US generations will disproportionately bear the cost of a destabilized climate, despite having the same constitutional right to freedom from harm as current generations.
They are aiming to obtain a federal court order that would require the government to develop a plan to protect the atmosphere and climate system. Lead counsel Julia Olson said that the US federal government:
â€¦has a constitutional responsibility to leave a viable climate system for future generations. The Government has consciously chosen to endanger young peopleâ€™s right to a stable climate system for the short-term economic interests of a fewâ€¦ This administration must no longer consign future generations to an uninhabitable planet.
Current science, future impacts
The likely impact of climate change on future generations was set out by the 2014 US National Climate Assessment, which said that the overall weight of evidence â€śconfirms that climate change is affecting the American people now, and that choices we make will affect our future and that of future generationsâ€ť.
The plaintiffs argue that:
â€¦a substantial portion of every ton of CO2 emitted by humans persists in the atmosphere for as long as a millennium or more. Therefore, the impacts associated with past and current CO2 emissions will be borne by our children and future generations. Our nation will continue to warm in response to concentrations of CO2 from past emissions, as well as future emissions.
The wider point is that the impacts are likely to be worse for future generations, but in deciding what to do about it now, their interests tend to be discounted in favour of current generations.
Putting a price on the future
In the popular discourse about climate change, it is rare to hear anyone talk about â€śdiscountingâ€ť. But it is a crucial concept in considering what climate action our society should take.
Current generations bear a responsibility for the well-being of future generations â€“ a point firmly made by the young plaintiffs in their legal action against the US government. But how do we weigh up the size of this future debt?
The â€śdiscount rateâ€ť weighs future peopleâ€™s benefits against costs borne by people in the present. Thus it is a measure of how highly societies value their future.
If a cost-benefit analysis uses a high discount rate, it discounts future benefits to a high degree, giving little weight to the interests of future people â€“ perhaps on the basis that those future people will be cleverer and/or richer than us and can presumably look after themselves. This is broadly the approach set out by Yale economist William Nordhaus in his books A Question of Balance and The Climate Casino.
In contrast, the British climate economist Nicholas Stern, in his 2006 review of climate economics and in his 2015 book Why Are We Waiting?, uses a low discount rate, effectively asking the present generation to make urgent sacrifices for the sake of future people.
The US economist and Court of Appeals Judge Richard Posner agrees that there is a strong case for taking costly measures now. But he also notes that there is no objective guide to the weight that should be given to the welfare of future generations.
The costs of caring for the future
The fiendish issue here is that even if we can reach a deal to reduce greenhouse emissions now, people living in the future will benefit, not those living today. But we, today, will bear the costs of reducing those emissions. Thus there is a temptation to apply a high discount rate to protect current interests, rather than a lower one that might protect those in the future.
University of Oxford philosopher John Broome sees it like this:
(The current generation) will be sacrificing some of its own well-being for the sake of greater well-being that will come to people far in the future. Is the sacrifice worthwhile? Does it improve the world on balance? This is a question of weighing: How do increases in future well-being weigh against sacrifices of present well-being?
The US plaintiffs, who will be middle-aged by mid-century, want those future interests protected. That is why they are calling for â€śan enforceable national remedial plan to phase out fossil fuel emissions â€¦ so as to stabilize the climate system and protect the vital resourcesâ€™ on which the young Americans now and will dependâ€ť.
These 21 young Americans have thrown the issue of pricing the planetâ€™s future into stark relief. It is a question that truly resonates through the generations.