Ross Douthat considers the hoary question of which current practices we will someday condemn, linking also to Appiah, who raised it, and Will Wilkinson. Prisons, factory farming, immigration barriers, and abortion are among the nominations. I would suggest an alternate query, namely which practices currently considered to be outrageous will make a moral comeback in the court of public opinion. Torture and loss of privacy — in some of its forms at least — already seem to be on the rise, at least in terms of their acceptability in the United States.
What kind of moral status will "probabilistically causing natural disasters" have in the future? What status does it have now?
With rising health care costs and tight budgets in many countries, can we not expect euthanasia to rise in moral popularity? Will the principles for cutting off care force us to transparently embrace some ugly moral principle, or will the ugliness be our lack of transparency and arbitrariness on these matters?
Preemptive warfare feels unpopular, because Iraq and Afghanistan have gone poorly, and because there have no more major successful terrorist attacks on U.S. soil. I predict the idea will make a comeback. Robot and drone warfare may become even more commonplace, as will targeting at a distance and selective cyberwarfare. Those practices don't have to be wrong, but they could lead us to be morally cavalier about fighting a destructive war, even more than we are today. By the way, the French seem pretty happy about the recent U.S. intensification of drone warfare in Pakistan, which is directed at stopping an planned attack in Europe.
Tolerance of gay individuals and alternative lifestyles is at a historic high. I would not endorse a crude "regression toward the mean" hypothesis, but we should at least try it on for size. That tolerance is as likely to fall back as to progress.
Won't targeted genetic tests make abortion more popular and less sanctioned? Rural India is already full of ultrasound clinics. Won't the possibility of discrimination on the basis of genes (not many will refuse to do it, or make use of the information, if only implicitly) make discrimination more acceptable altogether?
On the bright side, totalitarianism and mass murder of one's civilian population have been out of style since the Nazis, the Soviets, and Mao. In that sense we still can expect the future to be morally superior to the past. But those gains were achieved some time ago. If we capitalize them, and take them for granted, at the other margins I am not convinced that we are going to see lots of moral improvement over the next fifty to one hundred years.