You might recall that when we covered the topic of global warming earlier this year, we learned that one of the effects of global warming is more violent storms. Well, in terms of hurricanes, this would mean stronger, more violent hurricanes, right? Such as Hurricane Katrina? Hmm…maybe not.
Apparently there is currently a debate about whether global warming affects hurricane intensity, or even the mere formation of them. Many researchers strongly believe that global warming is linked to hurricanes, while others do not. A new study that’s come out shows that it’s possible that global warming actually makes it more difficult for hurricanes to form!
Gabriel A. Vecchi of the National Oceanic and Atmospheric Administration and Brian J. Soden of the University of Miami utilized 18 complex computer climate models to predict the impacts of global warming for the time spans 2001-2020 and 2018-2100. Part of their results was an increase in vertical wind shear over the tropical Atlantic and eastern Pacific oceans. Vertical wind shear = a difference in wind speed or direction at different altitudes. Normally, when hurricanes encounter these they can weaken because the heat of the rising air spreads over a bigger area.
BUT…as we learned in class, warm water is what drives storms such as hurricanes, so it should seem that warmer conditions should make storms stronger, not weaker.
A tropical cyclone is shown above. This is a type of hurricane.
Vecchi and Soden don’t know if this change in wind shear will negate the increased potential from warmer oceans, but they do believe that it will make the Atlantic Ocean and Eastern Pacific ocean not as favorable to hurricane formation. On this issue, Vecchi states, “Which one of the two — warming oceans or increasing shear — will be the dominant factor? Will they cancel out? We and others are currently exploring those very questions, and we hope to have a better grasp on that answer in the near future.”
All they know is that the change in vertical wind shear will be large enough so that it cannot and should not go unnoticed. It should also be kept in mind that this recent study does not in any way intend to undermine the realities of global warming – they are out there, beginning to affect the world and scientists want everyone to constantly be aware of this.
So, on what do we base our own opinions? Well, there’s Hurricane Katrina that struck in 2005, which was highly devastating and would lead us to believe that global warming is producing stronger storms than ever. Now we’re just weeks away from the start of hurricane season – June 1. Forecasters, scientists, residents, and probably many others are anxiously waiting to see what will happen this summer as far as hurricanes. William Gray of Colorado State University, who is a top researcher, believes that there will be at least 9 hurricanes this year, with one of them likely striking the United States.
Even though Vecchi and Soden’s research predicts that hurricanes might be less intense because of increased wind shear, they did not get the same results for the west and central Pacific Ocean – rather, these areas will see better storm development.
Hurricane expert Kerry Emanuel of the Massachusetts Institute of Technology believes, in contradiction with the findings of Vecchi and Soden, that storms’ vulnerabilities to wind shear is exaggerated. Emanuel published information last year that calculated that increasing the intensity of a storm via warming by 10% increases hurricane strength by 65%, but increasing shear by 10% only reduces hurricane strength by about 12%.
If the experts are split in their beliefs on this issue, then we can be sure that there is definite uncertainty regarding global warming and hurricanes. It seems to me that the only solution to this debate is time.
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