Wacky weather? General warming can lead to hotter and more frequent heat waves, so that this past winter’s record breaking high temperatures could become much more common. It will also change the frequency and heaviness of rainfall, though it’s difficult to say whether this will mean more rain or less for Hawaii.
The trickiest part of global warming science is trying to predict weather changes for small regions. As the IPCC points out, there haven’t been any global trends for any particular kind of weather catastrophe, but there certainly have been regional trends toward weather chaos. To many climatologists, the fact that Oregon had its worst flooding in 32 years, after the East Coast endured the blizzard of the century, while Honolulu broiled in its hottest December ever recorded, is exactly the face of global warming.
“The models show both increasing and decreasing precipitation for this region,” says Mackenzie. “We could get more El Nino, resulting in a drier climate.” Or, a warmer climate could lead to more evaporation, therefore more cloud-building and presumably more rain.
Mackenzie and other scientists also suggest that global warming will bring stronger and more frequent hurricanes to Hawaii by warming the surface of the seas. The book is not closed on this subject, though. According to Oahu Civil Defense data, there hasn’t been any consistent increase in the number of hurricanes in the Central Pacific, and Tom Schroeder, of the UH Department of Meteorology, says the 1979 record for intensity in hurricanes has yet to be beaten.
“People predicting more or stronger hurricanes as a result of global warming are only looking at increased sea temperatures,” says Schroeder. “But it takes six different requirements for a tropical storm to occur, and warm water is only one of them. It’s not clear what effect global warming would have on the other five.”
Warming would also endanger native plant species, especially those at high altitudes. The silversword, for instance, is perfectly suited to the chilly peak of Haleakala, but there’s nowhere for it to grow if that climate warms. Coral reefs, coral atolls and reef islands are especially vulnerable to even slight warming, resulting in coral bleaching, coral death and increased coastal erosion.
Other effects of global warming are less of a direct threat to Hawaii. For instance, there are the bugs. Termites and roaches ran amok in New Orleans over the past few years as that city went without a killing winter freeze. There is evidence that malaria and yellow fever are already spreading further north and to higher altitudes as warming allows disease-carrying insects to go beyond their usual ranges.
“My concern is not for the developed, industrialized world,” says Mackenzie, “but for the developing world. We can do a lot to adjust here in Hawaii. We have First World-quality healthcare and engineering to deal with sea-level rise, disease or increased storm activity. But the Pacific region is very vulnerable. Flooding, the spread of disease—we could be seeing the mass migration of people trying to escape these problems.”
It’s not at all impossible that Hawaii could receive a surge of immigration over the coming century, a social cost of global warming that few have anticipated.
By now, you’re probably wondering how much worse things could get. In fact, you look like you could use some good news. Now is a great time to ask—