I may just not be aware of a common trope. So set me right.
Suppose I keep a hive of bees in my garden for fun. By taking precautions when opening the hive, and handling individual bees at other times with skill, I can avoid getting stung. But my neighbours are less skilled and do get stung occasionally. Can they sue me successfully for tort? Suppose a neighbour´s child suffers from a bee-sting allergy (frequency say 1%), goes into anaphylactic shock and dies. Am I legally liable for her death? Many a lawyer would I think say that even at this frequency the death was reasonably foreseeable, and I have a good chance of losing in court.
(My bee-keeping is a hobby. I assume the professional, large scale industry protects itself from legal risks either by legislation or insurance. It also operates in the countryside, among a rural popularion with greater understanding of the hazards then suburbanites.)
Law doesn´t always reflect generally plausible ethical principles and intuitions, but in this case it does. I have a moral as well as a legal dury to avoid harm to my neighbours – Lord Atkin indeed referred explicitly to the Golden Rule in his judgement in the key English case on negligence, Donoghue v. Stevenson, 1932. (footnote)
The common law standard of proof for torts is that the harm be ¨reasonably foreseeable¨. This is the sort of squishy language that makes economists wince and trial lawyers rub their hands in glee. The social costs of settling individual disputes by direct reference to such an imprecise test are high, and I´m not arguing here in defence of the tort system as against clear quantitative regulations. But as a broad guide to ethics and policy, reasonable foresight makes ä lot of sense.
Ler´s try to put a percentage on it. For lawyers, it certainly covers risks much lower than ¨more likely than not¨, i.e. 50%. In radiological protection it extends to risks in a hundred thousand. My fatal bee-sting risk is two orders of magnitude greater. (Number of neighbours = 10; chance of a particular neighbour getting stung by my bees during the year = 10%; expected annual number of bee-stings = 1; allergy prevalence = 1%; allergy causing anaphylactic shock = 100%; percentage of fatal anaphylactic shocks = 25%; expected annual number of deaths, 0.0025). I think this is still a reasonably foreseeable harm.
Now here is my killer bee argument. Experts show me how I can reduce the quite small risk to my neighbours from my bees by a factor of 15 by keeping just 2% fewer of them. It doesn´t seem a difficult choice to make the change. Now suppose the risk of a fatal reaction every year from one hive was not 0.25% but 50%; so if I don´t change, my bees will kill one neighbour every two years. How would you describe my refusal to change: moral imbecile and scoundrel come to mind, possibly criminal and monster.
The way I´ve set up this thought experiment, my beekeeping is a trivial hobby, not essential to my or anybody else´s welfare. Is this element crucial to the intuitions I posit? It doesn´t look like it. Let´s change the frame to the commercial beekeeping industry, which provides vital pollination services to farmers and growers as well as directly producing honey. In the USA, there are ¨30-120¨ deaths annually from wasp and bee stings; I suppose these are more likely to be from bees, because the barbs on their stings prevent retraction when you swat the angry hymenopterite. There are 2.4 milion hives in the USA, run by 12,000 firms. Let´s say they cause 24 deaths, or 0.00001 per hive, or 0.001 per beekeeper. So keeping the parallel, the cut in bee numbers and presumably output of 2% would cut annual deaths from 24 to 2.5. This looks probably worthwhile, though it´s not quite so obvious as in my garden case, and would depend on the total value of the lost output. In the second sceanario, the risk is similarly 200 times greater: annual deaths are 4,800. The 2% cut in production reduces this by a factor of 15, to 320, saving 4,480 lives a year. The call here is not even close: the industry would be be required as a matter of course to make the change.
Now what is the difference with global heating? If you reject the analogy, kindly indicate in your response what percentage risk of global catastrophe makes not paying a 2% of GDP penalty the right thing to do: 50%? 10%? 1%? Now make a case that the real risk from business-as-usual is not higher than your limit.
I bet it can´t be done.
From Wikipedia on negligence in common law:
[In Donoghue v. Stevenson (1932)] Lord Atkin interpreted the biblical passages to ‘love thy neighbour,’ as the legal requirement to ‘not harm thy neighbour.’ He then went on to define neighbour as “persons who are so closely and directly affected by my act that I ought reasonably to have them in contemplation as being so affected when I am directing my mind to the acts or omissions that are called in question.” Reasonably foreseeable harm must be compensated. This is the first principle of negligence.
My source for the underlying propositions that (a) a 5º C increase in global mean temperature would be catastrophic and that (b) a feasible shift in technology and consumption costing 2% of global GDP would reduce the risk of this happening from 50% to 3%, is Nick Stern´s A Blueprint for a Safer Planet, 2009.