BETA
This is a BETA experience. You may opt-out by clicking here

More From Forbes

Edit Story

Why Hurricanes Like Lane May Become More Common In Hawaii

Following
This article is more than 5 years old.

Hurricane Lane continues to capture the attention of the world. It has weakened but continues to pose a serious threat to the Hawaiian islands. It is already one of the most prolific rain-producing hurricanes in U.S. history (and its still raining at the time of writing. Even though Hawaii is situated in the tropical Pacific Ocean, it does not take many direct hits from hurricanes. However, a recent study suggests that this might change in the future. I wanted to find out more, so I reached out to one of the authors of the study.

NASA

I want to caveat this article with three cautionary notes. First, I am not a big fan of "1-study mania." This notion that one study comes out and becomes the "law of the land" in the eyes of some people. It is important for multiple studies to build a consensus on a finding in science. Second, the attribution science on tropical cyclones and climate change falls in the middle of the "understanding spectrum" according to a recent report from the National Academies of Sciences, Engineering and Mathematics. It noted that we have good physical understanding of tropical cyclones within the context of warming climate. However, confidence in attribution was lower than for heatwaves, rainfall intensity, and drought because the satellite observation record is truncated and climate models do not represent tropical cyclones very well. The NOAA website at this link is the first place that you should go for understanding of the current status of linkages between tropical cyclones and climate change.  Third, I think that it is speculative and irresponsible to make statements like "Hurricane Lane" was caused by climate change, and it is unwise to divert the focus from a dangerous situation that is evolving.

Before discussing the new findings, it is important to remind you of why hurricanes are rarer in Hawaii than you might think. In the days before Hurricane Lane I wrote in Forbes,

Hawaii is typically somewhat shielded from hurricanes because of strong upper level winds (remember the wind shear I talked about earlier) and relatively cooler waters. Colder waters from deep ocean are often moving to the surface near and around Hawaiian waters. This process of upwelling often keeps waters in the upper 70's near Hawaii. Hurricanes typically thrive in waters at least 80 deg F. For these reasons, hurricanes that approach Hawaii from the east are typically going to struggle to organize. However, storms that approach from the south, like Lane have a chance.

As I write this, Hurricane Lane is has been "wind sheared" to Tropical Storm status. The graphic below shows the storm and the strong wind-sheared environment (red) that the hurricane drifted into over the past few days.

CIMSS/NOAA

A joint 2017 study by researchers at the University of Colorado, Massachusetts Institute of Technology (MIT), and Woods Hole Oceanographic Institution was published in the American Meteorological Society Journal of Climate  I spoke to one of the authors of the study, Dr. , about the implications of their findings once Hurricane Lane cleared. I did not want to publish this article and convolute the more immediate natural hazard threat with "twitter tennis (back and forth)" on the climate change linkages.

I asked Dr. Karnauskas, an Associate Professor with the Cooperative Institute for Research in Environmental Sciences at the University of Colorado-Boulder, what the key implications of their study were. He wrote,

Tropical storms near Hawaii are predicted to increase in frequency by about 15% per decade, assuming business-as-usual fossil fuel emissions. We can cut that increase roughly in half by reducing our fossil fuel emissions. The increase in hurricane activity near Hawaii is due to two factors: warming seawater and less wind shear. Unfortunately, the increase in tropical storms will be in the form of storms with maximum winds faster than 125 mph.

This study used the methodology that renowned tropical meteorologist Dr. Kerry Emanuel (MIT) has applied to climate models. The study also found that a term called the Power Dissipation Index also increases. This suggests that overall hurricane intensity will also increase, not just the number of them. Some scientists would counter that the business-as-usual or "worst-case" scenarios are not likely to happen so presenting results from that perspective are misleading. While perhaps a fair point in isolation, it is important to understand the full range of risks on the table. At the scale of weather threats, emergency managers and insurers have told me that they want to the full range of possibilities so I do not have an issue with this approach within a climate context. Further, other recent studies have also found evidence of increased intensity, changes in frequency, or poleward storm track migration in the Pacific Ocean.

One last point that was fascinating about the study I referenced herein, Professor Karnauskas let me know,

the research was effectively funded by the U.S. Department of Defense via a contract from a program called SERDP. Clearly the United States government is just as concerned about impacts on their Pacific-based defense installations and assets as the rest of us civilians are.

This is certainly correct since U.S. military reports have repeatedly worried that military assets and bases are vulnerable to sea level or storms. They also are first-responders for humanitarian aid to many global hurricane or typhoon disasters.

NOAA

Follow me on TwitterCheck out my website