Global Warming is *Not* Causing More Hurricanes

There is no doubt that global warming is happening. Denying that global warming is occurring is simply a refusal to accept statistics. It’s really more of an issue of whether humans are causing global warming. That’s the more acceptable question.

In any case, many sources say that global warming is responsible for the recent surge of hurricanes. There are suddenly more hurricanes, what could it be, hmmm warm water is needed for hurricanes, what warms, oh yes it’s global warming, etc. Okay, valid point so far. It makes logical sense that when the Earth warms, the water part warms as well; after all, the majority of the surface of the Earth is water. That makes sense.

But there is actually a major problem with this theory.

There aren’t more hurricanes.

If p then q, p, therefore q. We have p; global warming is indeed happening; we also, however, have not q. Over the past few decades, the number of hurricanes has actually stayed more or less consistent.

It’s frequently been said that we’ve been having more hurricanes, but that’s actually not true. Such claims are supported by graphs like these, where there is an upward trend occurring, but the problem with this is that global warming is a global issue, and those are statistics for the Atlantic Basin.

I decided to make a graph showing Accumulated Cyclone Energy statistics for both the Atlantic Basin and the Eastern Pacific Basin.

The total amount of tropical cyclone activity around North America has not really changed much over the long run, with only short-term fluctuations. Unfortunately, I could only find Accumulated Cyclone Energy statistics for these two basins. Now, I could just leave this issue with a semantics argument that tropical cyclones are only called hurricanes around North America, but looking elsewhere in the world, the Western Pacific Basin, the most active season in the timespan of the above graph is 1997, two other highly active seasons are 1979 and 2002, and both of these are dips in activity around North America. (There is one thing to note, though: 1977 was also a year of particularly low activity in the Western Pacific. Something interesting was happening that year.) The Western Pacific Basin also is currently in lesser activity mode, so cyclone activity is definitely not really increasing recently.

So why does it sound like there are more hurricanes? Part of it could be blamed on media craze, especially post-Katrina, but really it is the fact that due to wind patterns, hurricanes tend to travel west. In the middle of the pacific, there is a sort of a trough that is unfriendly to hurricanes  and thus make it so that many hurricanes in the Eastern Pacific never hit any sort of land, and no matter how strong Eastern Pacific hurricanes get, if they don’t hit land, they don’t cause much damage, and it is not very newsworthy. On the other hand, Atlantic hurricanes do have land to hit in the west, and thus have a high potential for damage. And thus, in North America, the amount that we hear about hurricanes is roughly proportional to Atlantic hurricane activity, and thus it seems that there are more hurricanes recently, when in reality, it is not a new era of hurricanes, it is a new shift of hurricanes.


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