I believe that with a high degree of probability, people will sell off their bitcoins in the event of any really strong cataclysm that threatens their life.
If it's a cataclysm where people don't have food and water - sure, they'll sell their bitcoins to buy essentials.
But if it's just a global recession - big investors like to protect their money and gold and digital gold (bitcoin) then become more attractive as they hold their value.
- Well, a global disaster related to food and water, that will certainly make the value of bitcoin decrease when people continue to sell their bitcoin to use for food and drink accumulation, and even if the disaster is a global recession, I still think that the value of bitcoin will still fall, instead of increasing as you say. Because investors and people need to store their money in a safe and less volatile place, that's gold, they can't choose bitcoin when it's just a virtual currency, everyone's reputation and trust with bitcoin is still too low, they will not accept the risk, they will sell bitcoin and move to gold as soon as possible.
I dont agree with you, India had demonetization that time most of them were investing in Bitcoin and the difference of price between international market and indian market was more then 30% up. So i think when their will be global recession then Bitcoin price will surely jump up and how much up it will go dont know but surely it will be double then what price it was .