Lost in the drama of what is happening in south Texas and the President's predictably weird, tone deaf, self-congratulatory response to it is the fact that in the past 12 years the Gulf Coast has been hit by two "100 Year" storms and now a "500 Year" storm.
Those names are somewhat misleading, of course, because they are derived from the odds of a storm of that severity happening in any given year. So, a 100 Year storm is just an extrapolation of a storm that has a 1% chance of occurring each hurricane season. Something that has a 1% chance of happening could very well happen three times in twelve observations, but it certainly isn't likely. That said, even before 2005 these storms clearly were much more frequent than once every century. A more accurate way to describe them might be "More powerful than 99% of storms" or simply to update the odds to incorporate the last 100 years of data. It's likely that a more accurate term might be something like "Ten year storm," as that seems to reflect what we've experienced.
In other words, don't get too caught up on phrases like "100 year storm." It's inaccurate any way you look at it.
Instead, let's stop and consider the fact that warming and rising oceans are going to continue to increase the clip at which these storms strike the United States (and elsewhere, obviously). The Gulf Coast and Atlantic Coast are such densely populated areas that when these storms do hit, they will inevitably cause nearly catastrophic damage. Frankly it's amazing that the death toll in Texas is not higher, but even so it is clear that there will be billions upon billions of dollars in damage. ProPublica has a great rundown of just how vulnerable a low-lying city like New Orleans or Houston is to severe weather off the open ocean.
The stark reality is that it is probably too late for this or any other country to truly roll back the effects of human degradation of the environment. We are down to simply trying not to make it any worse than it already is. What is certain, though, is that the future of the Gulf Coast is not as promising as the numbers of Americans flocking to the Sun Belt since 1990s might suggest. Jack the temperatures up another degree or three, bring more frequent (and more severe) weather off the oceans, and let these unsustainably enormous populations continue to work away at the water resources of the area and it's going to add up to a nightmare for government at every level. The cost of a system to protect the Texas coast would no doubt be staggering and I have no doubt that the kind of statewide officials Texans elect will produce nothing but "Global warming is a hoax" rhetoric.
We have, in other words, unprecedented challenges coming our way at the exact point at which our elected officials have the least vision and foresight. Good luck.