What are your plans for the evening of the apocalypse?

The consensus would converge on it being fake news. No downside to being wrong, so prediction makes would agree with this consensus.

People with professional skills relevant to evaluating the claims who denied the data would rapidly rise to the top of their professions.

This depends on the exact situation, how certain it is, how certain the date is, and how big are any tiny possibilities of survival.

First, realize that many groups will have already gamed the scenario and will have put their reactions in motion long before it's public knowledge. Us mehums probably start to see effects (stock and long-term futures disruptions) before we know why. Even if there's almost zero chance of survival, a good fraction won't believe it's actually zero, and will divert a LOT of resources into preparing for it, and out of maintaining the status quo for the next 5 years.

Second, realize how fragile modern civilization is. Sure, a lot will want to keep doing their jobs and getting paid, but if ANYONE in the long supply chain is one of the ones who quits, there's no food to serve, so the waiter has no job anyway.

My prediction: with credible evidence of near-term unstoppable extinction, riots and starvation kill maybe 60% in the first 6 months, probably another 35% before the event actually occurs.

Many parameters can be changed to lead to different reactions. It doesn't take much uncertainty to let people live in denial and stick with the status quo (but note that if the elites take it seriously, this lets them plan but makes the masses more likely to give up). It doesn't take much hope of stopping it to get enough people to band together WW2-style to both carry on and conserve, and to contribute to the survival effort.

The financial effects would be immediate and extreme. All sorts of mad things would happen to stock prices, inflation, interest rates, etc. The people who quit their jobs to live off their savings might well find that their savings don't stretch as far as they thought, which is probably a good thing since the whole system would collapse much faster than five years if a significant proportion of people were to quit their jobs.

I think the changes would be huge and happen right away. At first a lot of people might not know exactly what to do, but some would. As Oscar_Cunningham predicts, I think the financial effects would be the first extreme change. The stock markets would crash, and bank runs and people abusing their credit or withholding loan/ccard payments would cause banks to go under immediately. This would all be in the news the very next day, causing big reactions from everyone.

I'm not sure what the world would look like a few weeks/months after that, but I think it would be pretty extreme. So many sectors (or big parts of them) won't make sense anymore (research, education, construction, policy-making, are a few that come to mind). Many people would try to quit their jobs, even though it would be hard to predict what their savings would turn out to be worth.

I would probably start thinking really hard about how to profit/protect myself, reading online everything I could find about what the most informed people are saying, trying to figure out what I should be doing right away that I wouldn't be able to do later.

This is the premise of the chapter "8 May 1905" of Einstein's Dreams ("The world will end on 26 September 1907. Everyone knows it.")

In the PDF that shows up in google results, it starts on page 65. The chapter can be read on its own without context.

I suspect a lot more people would start attending church.

In a situation like that you face the human irrationality. The most common reaction would be denial. Always is. Then there will be attempts to avoid the apocalypse, some declared successful, regardless of the actual results. There will be a revival of religions, new and old. Increasingly risky behavior. Mass murders/suicides. A sharp decline in childbirth except in the groups that are not aware of the impending doom or do not believe "Western propaganda."

I assume "every one finds out for sure" means something like everyone being about as convinced as they are about global warming, Any stronger conviction means something really weird is going on so I have no idea what would happen.

I'd expect something similar to what happens to people in doomsday cults (probably with less cultishness, because people in those cults did join a cult unlike most humans).

I'm not an expert on those but my impression is that the upcoming apocalypse has very little effect on their lives.

So... a couple news cycles about the revelation, another round before the event. Maybe a movie. I wouldn't expect much more than we got for 2012 apocalypse. Maybe some small groups doing good/ evil/ extreme hedonism/ trying to avert it but I think almost everyone would basically ignore it.

And given how such revelations tend to pan out they'd be right to.

I first wanted to write a poste about the fact that all depends on the type of apocalypse, but the more I was writting, the more I realised that the outcome and the process would be the same in pretty much every case.

A biological desaster would force us to stay in safe zones, the financial sectors would break down and the army could abuse of it's power, because some weeks after the beginning of the apocalypes, the rule of the strongest would lead again.

An enormous financial crisis would make every infrastructure collapse, driving us to form small groups of 10-15 people that would help each other to survive. In this scenario the army is -again- the strongest and the ruler.

However, I think that in this case there would be soon new states and organisations growing on the ruins of our past civilisation.

A natural desaster could wipe out human kind and if not, it would be like in the biological scenario and force us to stay in safe zones under the watch of the ones who have the weapons.

What could be a leading factor is the severity of the desaster, but we are talking of an apocalyps here, so I gonna assum it would be extrem sever.

Having members of my family that rely on some pharmaceuticals to live, I would first steal all I can grab in the pharmacy before joining a small group to live as best as we can.