Fahrenheit 536

Mister Grey Sky:  Ash cloud over Hammerwich?

Canada’s Anglo-Celtic Connections blogged about The Year Without A Summer in 1816, which had serious consequences for much of the northern hemisphere, including the UK, and particularly in the English East Midlands. On 10 April 1815 Tambora, a three mile high volcano on the island of Sumbawa in the East Indies, erupted violently and propelled its top third high into the sky. The sound of the explosion could be heard more than 2,000 miles away and there were devastating tsunamis in the far east, but its legacy in Europe was more subtle. The finer particles from the ash cloud travelled round the stratosphere, reducing sunlight, leading to cold weather and crop failure across Europe and northern America.

It may not be possible to assess the impacts of such events on specific individuals, families or towns, but they affected all of Andrew’s Kindred one way or another.

But there have been more severe natural disasters one of which was the global cooling event and the Mayan Hiatus that occurred about 536 AD. A recent showing of a documentary on Yesterday, the UKTV Channel, explored the causes and impacts (from the series Perfect Storms:  Disasters That Changed The World). These events have been attributed to the extremely powerful eruption of Ilopango in El Salvador. There were obvious consequences for those in the vicinity: burning ash deposits, crop failure, destruction of thatched buildings, etc. The effects on climate were widespread as low temperatures and sunlight affected crop production.

The cooler temperature triggered into action a bacterium that had lain dormant for thousands of years and this would lead to the end of the Roman Empire, then centred on Constantinople (now Istanbul, Turkey). The bacterium was yersina pestis or y pestis. Through sea-going trade y pestis was spread by rats and great human populations were infected with bubonic plague and then pneumonic plague. The Emperor Justinian caught the fever, but, even though he survived, the disastrous effects on the populace and the economy meant that his hopes of reuniting the Roman Empire were dashed. Europe was plunged into a new dark age.

Lessons for our time?

We may be better at forecasting volcanic eruptions and their impacts, but we may not be any better at dealing with the effects. Even the small eruption on Iceland a few years ago caused considerable interference in aircraft movements across the Atlantic and in Europe. It was suggested in the TV programme that an eruption similar to Ilopango today would cause the complete breakdown of the global economy and return us to the 6th century.

We also have the knowledge and technology to treat the plague, but would we have the facilities or sufficient drugs in sufficient quantity and in the right places? I appreciate there are differences, but the outbreaks of ebola in western Africa and the current issues with zika virus in Brazil, which has now spread to Florida and the UK, have proved challenging for us to overcome.

Perhaps more alarming would be a sort of reverse scenario 536. It is known that some micro-organisms survive in water trapped in the Antarctic ice cap. What if the continued melting released a virulent organism into the ocean currents? What if it was fatal to fish or humans? Would we have time to develop vaccines? Could we clean up the oceans?

That collective action by homo sapiens can work is evidenced by recent reports that, following the global ban on chlorofluorocarbons (CFCs) in aerosols, the ozone hole is significantly reduced. It is suggested, however, that although there are clear benefits in relation to the effects of ultraviolet radiation, for example skin cancer and cataracts, as ozone is a greenhouse gas, repairing the ozone layer could exacerbate global warming. There is an interesting piece about this in National Geographic, here.

Apologies to Jeff Lynne’s ELO for the picture caption.