Shahab Sabahi
Energy and Environment for Development – Policy Analysis Research Group
Climate change has been scientifically proven to be the ultimate cause of significant human crises in pre-industrial Europe and the Northern Hemisphere by Professor David D. Zhang from the Department of Geography of the University of Hong Kong (HKU).The research finding is the first scientific verification about climate-crisis causal linkages. ( the Proceedings of the National Academy of Sciences of the United States of America, the most prestigious journal in social sciences, on October 4th, 2011, Hong Kong time)Zhang collected required data about climate, demography, agro-ecology, and the economy from the years 1500 to 1800 in Europe and found that these variables up and down along with the weather. They used a number of criteria to confirm that the relationship was causative and not merely associative: there had to be a strong and, importantly, consistent relationship between variable and effect; the cause had to precede the outcome; and the researchers had to be able to predict the effect based on the cause.
And as is the case with everything in the environment, a change in one area often triggered a cascade of changes in others. Take for example the cooling that occurred from 1560 to 1660—a century within the 300-year era known as the Little Ice Age: plants couldn't grow as much or for as long, so grain prices soared, famine broke out, and nutrition sank. Poor diet means poor growth even for survivors, and the late 16th century saw a decline in average human body height by 0.8 inches. As temperatures rose again after 1650, human height crawled back up too. Before it did, however, sky-high grain prices and accompanying real wage declines brought social problems more pressing than height.Peaks of social disturbance such as rebellions, revolutions, and political reforms followed every decline of temperature, with a one- to 15-year time lag adding that many such disturbances escalated into armed conflicts. The number of wars increased by 41% in the cold phase.
There were more peaceable responses too. Poorly fed or otherwise deprived people tend to decamp from where they're living and move somewhere else, and migration rates increased in this era along with social disturbance. The problem was, in these cases the relocation wasn't the hearty westward-ho kind of 19th century America, when well-fed settlers could live off the land (and the buffalo) while they sought new homesteads on the frontiers. Rather, migration among the hungry or unwell often leads to epidemics. It may be too much to lay the great European plagues of 1550 to 1670 entirely at the door of global cooling, but dramatic climate shift and resultant poor health surely played a role. It was around 1650 as well that European population collapsed, bottoming out at just 105 million people across the entire continent. Wetter countries with more fertile land or those with stable trading economies tended to do better in this eras of hardship, but no one was spared.
So the results show that climate change has affected human life and also no single event can be attributed entirely to global warming. Our own time follows the same pattern and will experience the same natural pressures and cultural changes as before.
Energy and Environment for Development – Policy Analysis Research Group
Climate change has been scientifically proven to be the ultimate cause of significant human crises in pre-industrial Europe and the Northern Hemisphere by Professor David D. Zhang from the Department of Geography of the University of Hong Kong (HKU).The research finding is the first scientific verification about climate-crisis causal linkages. ( the Proceedings of the National Academy of Sciences of the United States of America, the most prestigious journal in social sciences, on October 4th, 2011, Hong Kong time)Zhang collected required data about climate, demography, agro-ecology, and the economy from the years 1500 to 1800 in Europe and found that these variables up and down along with the weather. They used a number of criteria to confirm that the relationship was causative and not merely associative: there had to be a strong and, importantly, consistent relationship between variable and effect; the cause had to precede the outcome; and the researchers had to be able to predict the effect based on the cause.
And as is the case with everything in the environment, a change in one area often triggered a cascade of changes in others. Take for example the cooling that occurred from 1560 to 1660—a century within the 300-year era known as the Little Ice Age: plants couldn't grow as much or for as long, so grain prices soared, famine broke out, and nutrition sank. Poor diet means poor growth even for survivors, and the late 16th century saw a decline in average human body height by 0.8 inches. As temperatures rose again after 1650, human height crawled back up too. Before it did, however, sky-high grain prices and accompanying real wage declines brought social problems more pressing than height.Peaks of social disturbance such as rebellions, revolutions, and political reforms followed every decline of temperature, with a one- to 15-year time lag adding that many such disturbances escalated into armed conflicts. The number of wars increased by 41% in the cold phase.
There were more peaceable responses too. Poorly fed or otherwise deprived people tend to decamp from where they're living and move somewhere else, and migration rates increased in this era along with social disturbance. The problem was, in these cases the relocation wasn't the hearty westward-ho kind of 19th century America, when well-fed settlers could live off the land (and the buffalo) while they sought new homesteads on the frontiers. Rather, migration among the hungry or unwell often leads to epidemics. It may be too much to lay the great European plagues of 1550 to 1670 entirely at the door of global cooling, but dramatic climate shift and resultant poor health surely played a role. It was around 1650 as well that European population collapsed, bottoming out at just 105 million people across the entire continent. Wetter countries with more fertile land or those with stable trading economies tended to do better in this eras of hardship, but no one was spared.
So the results show that climate change has affected human life and also no single event can be attributed entirely to global warming. Our own time follows the same pattern and will experience the same natural pressures and cultural changes as before.
No comments:
Post a Comment