WC is not a climatologist. You already knew that. But WC has read pretty widely in anthropogenic climate change. And it seems pretty clear that humankind is making tropical cyclones – hurricanes, cyclones and typhoons – worse, in at least four different ways.
- More Heat for a Heat Engine. Cyclones are heat engines. The mechanism is pretty well understood: ocean heat energy fuels cyclones, in the same way that gasoline fuels an internal combustion engine. The warmer the ocean water, the more powerful the cyclone, other things being equal. One of the consequences of anthropogenic global warming is that the oceans are being warmed. Whether it is the Arctic Ocean ice melting of the Gulf of Mexico setting record high temperatures, the heating of oceans is an objective, measurable fact. That additional heat is additional fuel for the Carnot Engine that is a cyclone.
- Warmer Air Carries More Moisture. Warmer air simply carries more water vapor than does colder air.It’s not linear, either; as the graph shows, air at 30°C carries almost twice as much moisture as air at 20°C. As anthropogenic global warming heats the planet, the amount of water in the atmosphere is increased. Rainstorms are more intense. Cyclones carry and dump even more rain. That’s part of what happened to Houston.
- Building in Flood Plains. Flood plains are there for a reason. If you’ve been to coastal Texas, you know that the coastal areas are flat as a pancake for miles inland. There are barrier islands, swampy channels and thinly vegetated mucky land for miles inland. Places like Houston are built on that stuff. Worse, much of it has been paved over, eliminating the ability of that land to do what nature has designed it for: to absorb water. Houston, like much of coastal Texas, is built on land designed by nature to take floodwaters. And then humankind has aggravated the problem by impairing the land’s ability to deal with floodwaters.
- Removing the Economic Risk of Flooding. This is related to the problem of building in flood plains. A sensible government would discourage development of flood zones. A sensible government would make those areas parks, or simply leave them wild. But the United States instead subsidizes flood insurance for development in flood zones, decreasing the risk and thereby encouraging development. And that, in turn, magnifies the extent and cost of flood damage when cyclones occur.
Republicans, including both Florida Governor Rick Scott and EPA Director Scott Pruitt, say it would be “insensitive” to talk about the role of humans and climate change and cyclones right now. WC thinks that’s a pretty lame excuse for a stall. There’s no better time. Especially as the Houston area rebuilds in exactly the same place, facing exactly the same problem. Or one that’s even worse.