I think the Atlantic may see less storms overall perhaps due to wind shear, but due to the warming oceans the hurricanes that do form, which are able to take advantage of periods of lower shear at times, will be able to become more intense due to higher heat content. That's a theory that's been around for awhile too. I don't recall specifically how that theory impacts the East Pacific. I don't think it involves less storms there though, but I'm not sure. It takes a long time though to see how things go, to see a pattern that could be very attributable to a specific theory. Over the short term anything could explain anything. You will have seasons that see little activity and some that have lots. Seasons that have a lot of powerful storms and others with little. Over the short term anything could explain that. But over time you have more years of data to make conclusions.

Although, I would have thought that over about the last decade there would have been some stronger Atlantic storms. There were storms like Ike and Sandy which had major impacts, but that was exacerbated by size. High heat content helped with that in Ike probably and Sandy was its own conundrum that I couldn't begin to explain, but there has been a lack of powerful storms in terms of wind. Will hurricanes be more powerful in our basin due to climate change? Larger perhaps too? I don't think there is enough data from the satellite era to make conclusions yet. Perhaps the period we are in is just luck and we're going to see a lot of powerful storms soon. Or maybe not. But I think it will take many decades to determine.

The impact might be very minimal too, either way, perhaps imperceptible except for long term statistics. If there are less storms in the Atlantic due to climate change, how much less? A few storms per year? 1? 0.1? Perhaps overall the storms that do form are more powerful on average. But is that averaged over many or will there be a few that are so powerful they bring up the average? Then there is storm size. Then there is the actual damage that is caused too, which is something different, but important. Rising sea level will make it easier for some areas to flood. (and some areas are really susceptible to damage, such as due to being low already, and getting lower) But that is different because we are talking about purely the number, strength and size.

I don't think we can really know why approximately the past decade has been relatively quiet in terms of strong storms in regards to wind. Will future storms be less powerful in terms of wind speed, but due to high oceanic heat content use the energy to instead be monstrous in size, like Ike or Sandy? Maybe less category 5's and more category two's that have the surge equivalent of what most people might think of a 4 as having for example. (not that storm surge should be tied to the wind scale, but there are perceptions that people I'm sure still have from when it was rather tied together)

Each basin is different though. The Pacific seems to be its own beast. I don't follow that as much, but I would say there is probably not a decrease there. For the east, 2010 had a very low number of storms, though it happened to be a particularly deadly season. The West Pacific has so much activity. I'm not sure what the averages are there. (they mention the east though for their paper)

Other questions. Some areas may have higher shear, but perhaps some areas will not. Warmer waters could allow hurricanes to form farther north, perhaps more frequently in those areas. So will that mean overall more or less storms for the basin? Also, note the Gulf in even their predictions. Why has that region not seen storms with high wind recently? (Most of Ike's damage was due to surge caused by lesser winds, though over a large area due to its size. The surface wind speed was that of a category 2.)

The study seems to show only very small increases in shear. I'm not sure that would have that much of an impact. (until things really, really started warming) I had thought the changes might be a lot more substantial than that. Would be talking about just a few knots at most so far? Even if things were exactly as they have in there modeling, I'm not sure that storms would in fact be less intense overall in terms of wind speed or less storms. I would argue that the minimal increase in shear impacts in those particular regions could be negated in overall averages thanks to other areas. (And for the U.S., areas much closer to home by the way. And yet the U.S. continues to be lucky with its streak of no major hurricane landfalls, in terms of surface wind speed.)

But the problem is we don't know for sure. Even this paper talks about other variables. Until you have a lot of decades to look at, it's hard to try to make any conclusions on whether something is a trend or just a temporary anomaly. Fifty years from now we would probably know. (I think.) The various charts should have some kind of change, but even then it might not be very large yet. The warmer things get though, the more changes, whatever they might be, we'll probably see. So by then it could possibly be more than blips on a chart. (but it might still be hard to pinpoint the specific cause of changes)

I guess some climate science is hard. The scientists want to know the answer to questions and ideas they propose, but you may have to wait a long time to get the answer, such as the next generation. It makes me think about a joke Neil deGrasse Tyson made about the trip to Pluto. He was talking about how the spacecraft needed to get there while the lead scientists were still alive. He had said that's kind of the number one requirement for a scientific experiment, "it has to finish before you die". Some conclusions on climate science take so long, I guess you just have to come to terms with the fact that it may be future generations that have to answer the questions proposed.