Planet808: Examining Climate Change In The Islands

Jun 21, 2019

It's not your imagination, it really has been hotter than usual since mid-May. Dozens of heat records have been tied or set, with the hottest months still ahead in August and September.
Credit Noe Tanigawa

Today, on the summer solstice, HPR starts a closer look at how climate change is playing out in Hawai‘i.  We’re calling these reports “Planet808: Climate change in the islands.” And we begin with UH Professor, Chip Fletcher, author of Climate Change: What the Science Tells Us.

Charles “Chip” Fletcher is Associate Dean for Academic Affairs and Professor, Department of Earth Sciences, at the School of Ocean and Earth Science and Technology (SOEST), University of Hawai'i at Manoa. He is also Vice-Chair of the Honolulu Climate Change Commission.
Credit Chip Fletcher

Chip Fletcher, vice chair of the Honolulu Climate Change Commission, studies its particular effects in Hawai‘i.  Recently, the national weather service announced dozens of high temperature records set or tied here since the middle of May.  Honolulu experienced daily record highs 9 out of the first 18 days of June.  

Fletcher says records have been kept for many decades and in several cases over a hundred years, so the sample is quite deep, and there seem to be two basic reasons for the high temperatures. “The thinking is that these records highs have been set because there have been very low tradewinds which tend to have a cooling effect, and we’re in an El Nino phase.”

The El Nino phase is not a strong one, Fletcher says, but higher sea surface temperatures lead to warmer air. “The combination, then, has led to many record breaking hot days over the course of the last month.”

Fletcher says Hawai‘i’s famous tradewinds have been shifting over time, from a northeast direction to a more easterly direction. 

“The winds from the east are weaker,” says Fletcher, “They are producing less rain, we get less trade showers, and why this is happening is still the subject of research.” Changes in the tradewinds affect the natural cooling systems in many local buildings.  These changes may already be resulitng in more air conditioning, which requires energy, and adds warm air to surroundings.

In the extended interview, Fletcher describes changes in Pacific-wide air circulation patterns, and observations show changes in the zone of maximum winds.

Fletcher says, “The band around earth where maximum winds are seen to occur is actually migrating toward the poles.  Really what that means is, tropical cyclones are finding new pathways." 

Whereas tropical cyclones until recently have largely passed to the south of the Big island, causing perhaps, large waves across the island chain, that could be changing.

“Now more of those tropical cyclones which have the potential to become hurricanes are shifted to the north so they might be intersecting the Hawaiian Islands,” according to Fletcher. “Hawai‘i can expect to see more tropical cyclones landfalling on the islands just as last year we interacted with some very powerful storms and we barely missed Hurricane Lane."

Find Oahu's Resilience Strategy here.  Note, job one is to increase affordable housing in order to shelter more residents.