Demographic Crises
Effects of the Great Famine
The harsh winters were hard on buildings, on people, on bridges (ice floes battered at the foundations), on trees, and on animals. When the Baltic Sea froze, it meant not only that there were no trade ships sailing, it also meant no fishing could be done.
The effects of the rain were worse. Crops were ruined, leading to starvation and driving up prices. The flooding broke scores of bridges and broke down dikes and dams. Constant rain stripped away topsoil, especially in uplands where trees had been cleared away to make room for that marginal farming I mentioned earlier. In some places, the soil was eroded right down to bedrock and gravel, and farming was permanently abandoned. Even where the effects were not so drastic, the rains leeched away nitrates and left the soil poorer.
In other places, a layer of clay was underneath the topsoil. The water simply sat on top of it, making it impossible to farm for two to five years after the rains had moderated. In many places across northern Europe our sources speak not only of the calamitous weather but also report poor harvests well into the 1320s.
Besides direct crop damage there were other effects of the heavy rains. Foundations were undermined, including things like castles and city walls. Turf couldn't be cut for roofs. Quarries flooded and stone could not be cut. Fish traps were wrecked, as were watermills (which included many mills for grinding grain). The rain made mud, of course, and roads that were closed due to heavy snows in the winter were also closed in the summer because of mud up to the cart axle.
The rain affected animals, too, breeding disease. Ruminants were hit hardest, including such vital animals as oxen and sheep. It's extremely difficult to know exactly which diseases, but possible candidates include rinderpest for the oxen and liverfluke for the sheep and goats. Besides direct diseases, food for animals was likewise in short supply and they too starved.
Effects were worse in the towns than in the countryside. In the towns, alternative sources of food were scarcer. In the countryside, a starving man could eat rotting food, bark, grasses, carcasses. The urban dweller had little more than what was in a kitchen garden. Cities tended to have a large population of indigent, who were especially vulnerable. Moreover, town resources were further stretched by large numbers of vagabonds coming in from the rural areas.
Finally, a word about starvation. It's actually rather difficult to starve to death. More commonly, the person will succumb to disease or to exposure. Literal starvation happened mainly in areas of dense population that were additionally afflicted by warfare.
The worst weather was over by 1318, but as noted previously bad weather persisted into the early 1320s. Only by 1325 or so had the crisis truly passed. Northern Europe was not afflicted by demographic disaster for another twenty years, but then it was the turn of southern Europe, which experienced evil weather and crop failures in the 1320s and 1330s.