Jan 07 2016
It can be difficult to know what the optimal attitude is to have toward rare or unlikely events that would be catastrophic. How much should we worry about a large asteroid striking the earth? It could happen any time, but statistically is unlikely anytime soon (although is almost inevitable over the long term, meaning millions of years).
There are other rare but devastating natural phenomena. Phil Plait wrote about all the things that can bring Death from the Skies, including asteroids but also gamma ray bursts and other astronomical phenomena.
Today, however, we’re talking about death from below, specifically volcanic eruptions, more specifically supervolcanoes, and even more specifically the Yellowstone supervolcano. Recent news reports are breathlessly stating that scientists warn Yellowstone could blow in the next 70 years. Well, not so fast.
Yellowstone is a supervolcano. Its caldera is 34-45 miles in diameter. Beneath this caldera there is a large shallow magma chamber. Researchers also recently discovered a second deeper and much larger magma chamber. Yellowstone last erupted 640,000 years ago, and prior to that 1.2 and 2.1 million years ago.
Based upon these dates alone one might conclude that the supervolcano is “due” to blow again, but that could mean anytime in the next several hundred thousand years.
If any of them or other massive volcanic peaks suffered a major eruption the team said millions of people would die and earth’s atmosphere would be poisoned with ash and other toxins “beyond the imagination of anything man’s activity and global warming could do over 1,000 years.
The chance of such as eruption happening at one of the major volcanoes within 80 years is put at five to ten per cent by the experts.
The “5-10%,” however, is for a VEI (Volcanic Eruption Index) 7 event. This is a major eruption, but not the largest eruption, like a full Yellowstone supervolcano eruption. Scientists feel the chance of a major yellowstone eruption in the 21st century is less than 0.1%. The ESF reports:
The more frequent VEI 7 eruptions also are associated with high risk. With at least seven VEI 7 events during the last 10,000 years, there is a 5–10% chance of a VEI 7 eruption in the 21st Century. The impacts on our modern society could result in a global disaster, and it is timely to take measures to reduce this risk.
The essence of the report is that if we calculate the risks and the costs of major eruptions, given current and growing world populations, they warrant specific measures. We can’t do anything to prevent an eruption (unlike an asteroid impact, which we can theoretically prevent). We can, however, provide an early warning system and put into place systems of response to minimize the impact of the disaster.
Aside from the immediate loss of life in the vicinity of the eruption, the ash poured into the atmosphere could change weather patterns, exacerbate breathing conditions, and disrupt crops leading to mass starvation.
The ESF report seems reasonable – major eruptions are inevitable and not unlikely over the next century. When they do occur they have the potential of causing a major worldwide disaster.
They strongly advocate for taking steps to mitigate the effect of these less common but still devastating events, which sounds reasonable.
Along those same lines I feel it is reasonable to track Earth-crossing asteroids and develop the technology to divert them away from impact. These are threats faced by humanity as a whole, the entire planet, and therefore are perfect projects for the the UN and international cooperation.
It is more difficult to decide, however, how much we should worry or plan for much less likely but more devastating events, like a full eruption of Yellowstone. This may not happen for 100,000 years, and any preparations we take today will probably not help much and will be progressively obsolete as our technology advances.
Of course, this will always be true – whatever steps we take today will be nothing compared to what we can do in 100, 1,000, or even 10,000 years. This will still be true 1,000 years from now. At any given point in history we might as well take what steps we can with our given technology.
At the very least we should task relevant scientists to determine what steps we could take and their likely effectiveness. Perhaps there are some simple steps we can take that would help the world recover from such an eventuality.
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