You're right that it's often hard to pin down long term impacts, but I don't think this is a debate with quite as wide a field of credible estimates as you sugg

You're right that it's often hard to pin down long term impacts, but I don't think this is a debate with quite as wide a field of credible estimates as you suggest. The 985,000 figure comes from an interesting source. It originated in a book that peer reviewers savaged, for, among other things, making up numbers without providing any justification whatsoever and ignoring the scientific method. M. I. Balonov decried the book, claiming "it has very little scientific merit while being highly misleading to the lay reader." He called it science fiction. https://en.wikipedia.org/wiki/Chernobyl:_Consequences_of_the_Catastrophe_for_People_and_the_Environment#Reviews https://en.wikipedia.org/wiki/Chernobyl:_Consequences_of_the... While you're right that there are hard problems in long term forecasts, but there are entire fields of study, dosimetry and epidemiology, that have had smart people toiling away on those problems for their entire career, and this is maybe the most widely studied industrial disaster in history. We have made enormous strides in how to measure environmental radiation, doses received, and the correlation between those and increases in mortality. Individuals are hard, but population estimates are actually easier to calibrate over time. So if you write a book containing a sensationalist number to get some headlines, researchers will be able to tell you're pulling their leg. As rtpg says though, this is a bit of a moot point, because, sure, let's call it 985,000, then nuclear remains still the safest form of power by an enormous margin.