Hurricanes:
Physical processes suggest, and numerical modeling simulations generally confirm, an increase
in tropical cyclone intensity in a warmer world, and Earth system models generally show an
increase in the number of very intense tropical cyclones. For Atlantic and eastern North Pacific
hurricanes, increases are projected in precipitation rates and intensity. The frequency of the
most intense of these storms is projected to increase in the Atlantic and western North Pacific
and in the eastern North Pacific.
Alaska:
Much of Alaska’s infrastructure is built on a thick layer of permafrost, which is now melting. In
addition to causing houses and roads to sink and putting local communities at risk, thawing
permafrost is forcing military bases to contend with uneven roads and runways.
Hawaii:
Since 1960, sea level has risen between two and eight inches on Hawaii’s shoreline, exacerbating
threats like hurricanes, tsunamis and extreme tides. Over the last century, 70 percent of
beaches on Kauai and Maui have chronically eroded by the shore, causing wetlands to migrate
and cliffs to collapse. Sea level rise threatens native communities and may force them to
relocate. Many of the natural and built environments in Hawaii, including land, coastal artifacts
and cultural structures, are also vulnerable.