Climate Change and Plague
I’ve talked before about one of the reasons that I worry about climate change: it’s the potential for it to unleash illnesses that have been rarely seen in recent centuries. In the Middle Ages, the Black Death, killed a third of the population of Europe, or more than 25-30 million people. The most widely held theory is that the Black Death was Plague: a disease caused by the bacterium Yersinia (Pasteurella) pestis that is most often carried by fleas. In recent years one scholar has suggested that the Black Death was actually caused by anthrax, and in 2001, two epidemiologists raised the possibility that the Black Death was caused by an Ebola-like virus rather than a bacterium.
A paper in today’s Proceedings of the National Academy of Sciences, was written by an international team of scientists, who focused their research on Kazakhstan. Why look in central Asia? This seems to be the original center of the illness. The desert regions of Central Asia are known to contain natural foci of plague where the great gerbil (Rhombomys opimus) is the primary host of the Yersinia-carrying fleas.
The first epidemic originated in Asia and was apparently transmitted to Europeans in 1347. A Turkish army besieging a Genoese trading post in the Crimea allegedly catapulted plague-infested corpses into the town. The Plague spread from the Mediterranean ports and ravaged all of Europe between 1347 and 1351. Those outbreaks coincided with both warmer and increasingly wet weather. There were renewed outbreaks in 1361–63, 1369–71, 1374–75, 1390, and 1400. For more than two centuries, everything remained quiet, but then there were further outbreaks in Italy in 1629-1631, London in 1665, and Vienna in 1679. There was another Pandemic in Asia from1855-1870 that claimed the lives of millions, and again coincided with wetter and increasingly warm weather.
Fleas become active when the temperature exceeded 10C (50F), so a warm, frost-free spring has led to an early start to breeding. Over the last two years, the flea population has continued to grow when the spring was followed by a wet, humid summer.
We don’t need to be unnecessarily alarmist, but the evidence indicates that climatic changes could lead to more outbreaks of bubonic plague among human populations. And who knows what other illnesses are waiting in the wings as our climate changes, we travel more and our physical resilience declines?
“Humankind has not woven the web of life. We are but one thread within it. Whatever we do to the web, we do to ourselves. All things are bound together. All things connect.”
–Chief Seattle (Native American Leader of the Suquamish and Duwamish Tribes who became a Roman Catholic and Cooperated in Creating Peaceful Relations with European Settlers, c. 1786-1866)
Dr. Richard G. Petty, MD is a world-renowned authority on the brain, and his revolutionary work on human energy systems has been acclaimed around the globe.
He is also an accredited specialist in internal and metabolic medicine, endocrinology, psychiatry, acupuncture and homeopathy. He has been an innovator and leader of the human potential movement for over thirty years and is also an active researcher, teacher, writer, professional speaker and broadcaster. He is the author of five books, including the groundbreaking and best selling CD series Healing, Meaning and Purpose. He has taught in over 45 countries and 48 states in the last ten years, but spends as much time as possible on his horse farm in Georgia.
