There might not have been a Scientific or later Industrial Revolution. A good example of a slice of Europe without the Black Death (because any infection on board a ship would kill the crew off before the ship could get there) was Greenland. The Greenlanders had a social structure that kept them attempting to farm and fish and starve and avoiding the heathen Innuit when the Innuit had the key to their adaptation to a hunting life under new conditions. The social structure kept them playing by the rules even after that became counterproductive.
So maybe something like the Black Death (which laid the Muslims low too). prevented the Little Ice Age from causing the kind of ecological collapse in Europe that had doomed previous Central European civilizationssuch as the Middle European Celts when the climate turned too cold to support the population. Because of the Black Death's repeated hamer blows, not only were Europeans brought into a condition of labor shortage that stressed feudalism and increased the value of the individual, the repeated trauma of the Black Death engendered skepticism about the Catholic and Orthodox world view, particularly the Great Chain of Being, but also including any religious explanation for phenonenaToo many people were too traumatized from losing loved ones for survivors of the pestilence to believe in the Church the same way that they did before. So, as Ioan Couliano said, Science could evolve out of the magical tradition the same way a wingless fly can evolve living beneath a waterfall where flight is impossible.
Moreover, the Death affected everyone and kept nations from having surpluses of fighting men. One of the reasons for the Crusades was that there were so many knights that knights were killing each other over trivialities, without a war to make "wall fodder" of some of them. What the Death did was basically freeze most nationalities in place. With the singular exception of Ottoman Turkey, no one West of Russia was successfully doing any conquering during the 15th Century. The Death prevented desperate Scandinavian states from launching attacks southward against Germany and France but it also restrained the Almohads from pressing advantages against Christian Castille OTTL. Had the Death not happened, we might have seen another Wanderenvogel as Northern Europeand aattempted to migrate southwards. But we also would not see the Almohads and Ottomans moving more aggressively into Europe and Islamiciszing European nations weakened by famine--something we would be living with today.
