A recent research article made the news, telling of the worst year to be alive: 536 AD. This was surely the darkest moment of a dark age, and scientists have tracked its source to volcano(s) in Iceland. It darkened skies around the world, led to a ~4ºF drop in temperature, and crop failures throughout Europe and the near east, and crop delays in China. There seem to have been repeated eruptions over the ensuing years, though perhaps volcanos elsewhere contributed. The result was the coldest decade in at least 2,000 years, and a plague in 541-3 that wiped out at least 1/3 of the Byzantine population, among others. It took decades for Europe to recover, notably shown by ice cores with high lead pollution about 640 AD, showing that silver mining in France had recovered, presumably being pursued for minting coins.
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| Turner's "Chichester Canal", of 1828, thought to reflect some of the atmospheric effects of the 1816 global volcanic pall. |
There have been several similar, though less extreme, events, like the "year without a summer" in 1816, due to the eruption of Tambora in Indonesia. This vocano is estimated to have ejected 40 cubic miles of material, but only lowered temperatures in Europe by about 3ºF, yet caused substantial famine, snowfalls in June, frost in August. A much smaller eruption, of Krakatoa in 1883 also caused dramatic sunsets and world-wide cooling, but had far less devastating effects, being smaller, and because it happened in August, and did not affect the following summer as severely.
Are our agricultural systems robust enough to withstand such an event today? I doubt it. We have optimized and stretched in every direction, supporting vast urban populations, without a thought given to adverse events of global scope. The only significant failsafe is that most agricultural production goes to supporting livestock, which under duress could be used directly for human consumption.
Conversely, we are engineering a permanent climate disruption of equal proportion but in a warming direction, by our emissions of CO2. Will temperatures go up by 3ºF? 4ºF? 5ºF? We are already at 2ºF, (vs temperatures at 1900), with much more baked in from our past emissions, and from their relentless continuance and growth. Will we survive if agriculture has to move to Canada and Siberia? If Florida and New York are under water? Sure, but at what cost to ourselves and more importantly, to the natural world?
