Climate change could be causing these storms – how bad can tornadoes, hurricanes, and tsunamis get? Image courtesy of NASA.

Severe storms are everywhere these days, it seems – from Super-Typhoon Haiyan to the tornadoes whipping around the central U.S. right now. What’s next, and how bad could these storms get?

## Big John’s A-Comin’

Man walks into a bar and breathlessly exclaims “Big John’s a-comin’.” The patrons head for the door but before they can exit a giant of a man bursts through, approaches the bar and says “Quart o’ bourbon.” He chugs the quart as the patrons cower in the corners and the huge man orders another bottle. Serving him quickly, the bartender gets up his nerve and asks “What’s yer rush, fella?”

Ain’t ya heard,” replies the large man, “Big John’s a-comin.”

The story could be a metaphor for recent cyclones, typhoons, hurricanes, tornadoes, floods, tsunamis, and earthquakes. It’s instructive to ask “How bad can it get?”

## Hurricanes (Including Typhoons)

The recent typhoon that hit the Philippines is pretty close to the maximum strength possible. Historical records and computer modeling indicate that winds in a hurricane can approach 220 miles per hour. How destructive could it be here? If a tropical system as strong as Typhoon Haiyan were to hit a populated area in the United States, the damage would be in the hundreds of billions of dollars. Loss of life would depend on preparations and building codes.

## Tornadoes: Bigger Than a Dust Storm

The most powerful tornado would bring winds over 315 miles per hour. Very little could withstand this, and it is fortunate that tornadoes are small. An EF5 tornado in a major city would be catastrophic for both life and property along its path. But the aerial coverage of a tornado is tiny compared to that of a hurricane.

## Flooding: The Basics

Theoretically it could rain for 40 days and 40 nights, and in fact the weather is becoming more persistent — it remains the same for a longer period of time than in the past. Flooding is more a result of man’s interference with natural systems than anything else. If a city like New Orleans is armored and then the dam breaks — we saw how that worked with Katrina.

## Global Warming or Climate Change?

Global climate change, commonly referred to as global warming, changes the equations. Stronger hurricanes, stronger tornadoes, bigger floods, and more serious droughts may be in the cards. We know that the climate has changed drastically within decades in the past. A runaway effect is not out of the question for rain, wind, heat, or cold. We can’t predict the maximum and minimum values possible for these quantities with any accuracy.

The largest tsunami that a magnitude 9 earthquake would cause can be calculated in feet or at most a few tens of feet. However, there is a scenario that can create a tsunami many tens, hundreds, even over a thousand feet high; that is the collapse of the wall of a volcano. A volcano that could cause such a massive tsunami exists on the Canary Island of La Palma.

If the west wall of Cumbre Vieja were to crumble, the debris would tumble into the deep waters of the Atlantic Ocean, displacing millions of tons of water. We estimate that the resulting tsunami could be over 60 feet along the east coast of the United States, hundreds of feet on the coast of Africa, and more than a thousand feet in nearby islands.

The results would be unimaginable.

#### Resources:

Sohn, Emily. Will Hurricanes Ever Reach Category 6. Discovery. Accessed November 18, 2013.

Ward, Steven N. &  Day, Simon. Cumbre Vieja Volcano — Potential collapse and tsunami at
La Palma, Canary Islands
. University of California, Santa Cruz. Accessed November 18, 2013.

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