With one hurricane hitting Florida (USA) and one having just hit Texas (USA), several Caribbean Islands, and other countries along its path, the news media is all aflutter with stories about "climate change" making hurricanes bigger and stronger and faster and.....Let's slow down and look at what the science says.
NOAA, the IPCC and many other such agencies have repeatedly stated there is not a direct connection between global warming and hurricanes. Non-scientists and media people do not seem to have gotten the message. It's a free-for-all blaming Trump, global warming, and apparently anything that comes to the speaker's head. There is no science in any of these statements.
Irma was downgraded to a Cat 4 before hitting Florida (it was Cat 5 when it hit the Caribbean), and Hurricane Harvey was a Cat 4 at landfall. Neither was an "apocalyptic" storm. Both were major hurricanes, but both Florida and Texas were hit by hurricanes in the past. It's nothing new. There was a 12 year break in major hurricanes hitting the USA. That is important to remember. Hurricanes have been more frequent and much less frequent in the past compared to today. As for more powerful, not necessarily. According to reports, Hurricane Allen had winds 5 mph higher than Irma. Irma had the lowest barometric pressure on any cyclone in the Atlantic Basin. There have been other hurricanes with higher winds and lower pressures in other areas of the world. Irma is a record holder for a specific area only. That is important to remember.
Even if Irma was the strongest hurricane recorded worldwide, it would not show that CO2 causing changes in hurricanes. There will always be a "strongest" and a "weakest". That's how superlatives work. Breaking records is not a sign of impending doom. The 12 years without a hurricane was a record, too. The longest streak without major hurricanes since records began in 1851. Should some significance be assigned to this? Some have called it luck. If we call the lack of hurricanes luck, should we not call the return "bad luck" and not global warming?
Let's look at what the Category ratings mean:
Cat 1 74-95 mph wind (119-153 km/h)
Cat 2 96-110 mph wind (154-177 km/h)
Cat 3 111-129 mph wind (178-208 km/h)
Cat 4 130-156 mph wind (209-251 km/h)
Cat 5 157 or higher (252 km/h)
Some people have suggested a Cat 6 should be added. There really is no point to adding such a catagory other than to try and frighten people or make them think weather is getting worse. Winds of 157 or higher result in massive destruction. While the category is based on wind speeds, it's also based on damage and Cat 5 is basically total destruction. There really is no reason for further categories above 5. Once an area sustains massive damage, it really does not matter whether the wind was 160 or 195. It might even cause confusion as people "reason" that a Cat 5 is not the worst, so they would worry less about a Cat 5 than they did in the past. After all, it's not a Cat 6. It might not make sense to some, but people do tend to reason along those lines and mistakenly ignore the warnings. Stopping at Cat 5 says this is the most serious level of damage you are going to see and it's the most dangerous.
Some reporters and others are saying warming ocean waters made Irma worse and spawned multiple hurricanes within a short time span. IF water temperature were the only factor and the water temperature where these hurricanes were spawned was warmer (it does not appear to have been warmer, but rather a couple of degrees lower than what would be expected to develop a major hurricane), there might be some validity to saying global warming made these hurricanes stronger. However, there are many factors involved in hurricane formation, strength, paths, and duration. Weather fronts can slow the hurricane and increase the amount of rainfall, resulting in more flooding. Fronts may "reroute" the hurricane from its modeled path. We just don't know enough about hurricanes to make any judgements on whether or not planetary warming will make them more frequent, less frequent, stronger, weaker, etc.
Extreme weather has always been around. In the past, many more people died in hurricanes because there was no early warnings, no wind-resistant housing, no way to evacuate if need be. The modern world, with it's automobiles, helicopters, radar detection of weather phenomena and all the technologically advanced medicine, phones, and other things we in the US take for granted (and other parts of the world) make it possible to avoid many deaths, and to rebuild afterwards.
Our technology has made us safer and more capable of dealing with weather events. There's no reason to alter our lifestyles when we really don't know if it would make a difference or not. We can build more hurricane-resistant buildings, add sea walls and so forth to help deal, which is just prudent actions.
The science says the hurricanes may be less frequent but more powerful if the planet warms. Remember though, the 12 years the United States went without a major hurricane strike. All the while, science claimed the world was still warming. So warming may actually reduce the number and not affect intensity. We simply do not know what will happen.