* Early Bronze Age. The climate was warm in Europe at altitudes now beyond cultivation, such as Dartmoor, Exmoor, the Lake district and the Pennines in Great Britain. The climate appears to have deteriorated towards the Late Bronze Age, with a period of unusually cold climate in the North Atlantic region 1800-1500 BC.
Source: BROWN Tony, The Bronze Age climate and environment of Britain, 2008
* Prehistoric Central North Africa. Climate cooler and wetter, some parts of the present Saharan desert may have been populated, judging by cave art and other signs of settlement in the area.
Source: Historical climatology, Wikipedia
* Roman Warm Empire. The first known global pandemic struck in 451 AD and recurred until 750 AD leading to the premature death of up to a quarter of the human population in the Eastern Mediterranean region. The plague of Justinian (536-750 AD) coincided with a period of major climate change in the Eastern Mediterranean. The largest dry to wet climatic shift of the last 11,000 years occurred in the 6th century AD. This was briefly interrupted (535-536) by a climatic reversal and failure of harvests which may have been caused by a major volcanic eruption. The climatic instability created the environmental condition to allow the plague to spread exceptionally quickly with devastating consequences for human mortality.
The Justinian plague era came to an end when the climate became drier once again. The wetter climate would have increased the number of rats and other rodents which carry fleas, which in turn carry the plague bacterium.
Source: Climate change and the Plague of Justinian, University of Plymouth
* Warm Period in Middle Ages. There was a warm period between about 800-1300 AD. During this period some parts of the globe may have been warmer than they are today, such as the North Atlantic. The effects of the warm period were particularly evident in Europe, where grain crops flourished, many new cities arose, and the population more than doubled. During this period, the Vikings colonised southern Greenland because the milder climates allowed favourable open-ocean conditions for navigating. The Greenland settlement lasted until 1300 AD when the little Ice Age ended the possibility of farming.
* 1046 Cold winter in the middle of the Warm Period. As it appears in the Anglo-Saxon Chronicle (1046): “And in this same year after the 2nd of February came the severe winter with frost and snow and with all kinds of bad weather, so that there was no man alive who could remember so severe winter as that, both through mortality of men and disease of cattle; both birds and fishes perished through the great cold and hunger.”
Source: The Little Ice Age Was Not So Little, Alternate history, ASB-Environmental
* Medieval Little Ice Age. In 1300, temperatures dropped dramatically in parts of Europe and North America. The Little Ice Age was not a time of continuous cold climate, but rather repeated periods of cooling and warming, each of which occurred during times of solar minima, that lasted until 1800.
With the colder climate, early snows, violent storms, and recurrent flooding massive crop failures occurred, resulting in famine and disease. Glaciers began advancing and pack ice extended southward in the North Atlantic, blocking ports and affecting fishing.
The change from the warm to the cold period was abrupt and devastating, leading to the Great Famine from 1310 to 1322. Continuous rain impeded the sowing of grain crops, and harvests failed once and again. Diseases increased, people died of starvation, and many farms were abandoned. 1316 was the worst year for cereal crops in the entire Middle Ages. Cattle could not be fed, hay wouldn’t dry and couldn’t be moved so it just rotted.
Sources: Medieval Warm Period, Science direct, EASTERBROOK, D, Evidence Based Climate Science, HUHTAMAA, H, Climate and the Crises of the Early Fourteenth Century in Northeastern Europe
* Europe’s ‘bleak midwinter’ of 1430-1440 made dramatic changes in response to food shortages and famine caused by exceptional cold. Crops failed, food and fuel prices rose. Malnutrition and famine struck many parts of Europe. Weakened populations fell prey to disease and pestilence, worsened by environmental and living conditions. Authorities responded by changing trade policy, banning food exports and introducing new approaches to protect people from hunger, such as communal granaries for storage. Norse colonies in Greenland starved and vanished as crops failed and livestock could not be maintained through increasingly harsh winters.
Source: What can a Medieval Climate crisis teach us about Modern day warming, The Guardian, 2016