Two factors are held accountable for the incongruity of predicted occurrence of this storm and particularly of its intensity. One is climate related and thereby, the indirect result, in this case, of human behavior.
The waters in the nearby Gulf of Mexico, starting point for storms, are registering 30 C. That increase and associated increased water vapor in the atmosphere ready to condense to storm rains, make those 500 year estimates look hapless.
The second factor is directly related to human behavior. Houston is known for its lack of regulatory protections in terms of development and city planning. It's made Houston the fourth largest US city.
But developers have covered over large swaths of wetlands with concrete and thus eliminated the natural run-offs that would have carried rain water away and mitigated any flooding.
Harvey has resulted in 60 deaths thus far, a terrible price. While we can sympathize we should not ignore the fact that South Asia monsoons have taken 1200 lives this year.
It's usually the poor and vulnerable elderly and children who die. The financial burden--in Harvey's case it's upwards of $160 billion (USD)--becomes the burden of taxpayers countrywide.
What can we take away from disasters like this, which, if less predictable, are potentially able to be mitigated in their effects?
Houston has an area of 1700 km(2) and 2.5 million people. It is an inland city, with no coastline but is exposed to hurricanes simply by its proximity to storms originating in the Gulf of Mexico. Unrestrained overdevelopment played a major role in Harvey's outcome.
Auckland's area is 1086 Km (2) with a population of 1.3 million. It has a coastline of 3700 km.
While the entire country has not been hit by severe storms due to relatively cool waters (less than 26 C.) that may be changing as last year's storms, Cook and especially Donna foretell.
We can't predict the coming storms but those older statistics of 500 years' storms are flawed. Storms will be more frequent and more intense, producing flooding and stormwater surges in low-lying coastal areas.
What's needed is preparedness locally and nationally. Warming and rising seas make 500 year floods more likely to be 100 year floods or ten year floods. Complacency invites unhappy surprises. Humans should have learned that at Pompei.
Houston, demonstrates that heedless development can increase vulnerability to Nature's counterforce. Auckland's over-development is dramatically demonstrated in its daily automotive gridlock, its slow self-strangulation, even in good weather, making evacuation in bad weather a bridge too far. Size does matter.
But not always for our mutual benefit.
It's time for a rethink of policy that elevates development with a siren song of jobs above all values, values like respect for the natural structure and function of the planet.
While we have , with good reason extended ourselves to explore and understand space and the Cosmos, we ought to work to understand better, to preserve more actively and to protect the habitat of this planet that nurtures us and gives us the means for meaningful life.
*Jay Kuten is an American-trained forensic psychiatrist who emigrated to New Zealand for the fly fishing. He spent 40 years comforting the afflicted and intends to spend the rest afflicting the comfortable.
