global disaster mean this is happened to almost all of the countries in the world and i think yes possibly it will decrease the value of cryptocurrency because when global disaster happened most of people only concern how to save their own life without care for their wealth and if it is so then bitcoin will being worthless and lack of interest also the damage effect is there's no internet connections which being the main thing to use bitcoin
Global disaster would eventually lead to a decrease in the value of bitcoins. This is because the value is entirely dependent upon the rate of investment and buying and selling of shares in the international market in terms of cryptocurrency.
And if there would be some kind of war between the countries or the whole world afflicted with the Btcs then obviously the market would crash leading to a decrease in the value of this digital asset.
Bitcoin has proved itself unstoppable and no disaster can affect its value because btc investor are spread all across the world and more to it they will never let it down and as its start dumping people rush toward it and give it a strength again and that will also happen if its prices go down by some incident the investors will play their role and they will surely buy bitcoin to give strength again and in past they did it many time.