According to an overwhelming body of science, the Earth is warming at significant rates resulting in a myriad of climatic changes. According to the Intergovernmental Panel on Climate Change (IPCC) 5th Assessment Report: Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased.
These changes are already impacting Hawai‘i and the Pacific Islands through rising sea levels, increasing ocean acidity, changing rainfall patterns, decreasing base flow in streams, changing wind and wave patterns, changing extremes, and changing habitats and species distribution.
The island of Kaua‘i is subject to a variety of coastal hazards, including marine inundation and terrestrial flooding, coastal erosion, hurricanes, and tsunamis. Coastal flooding, marine inundation, and coastal erosion in particular are predicted to be exacerbated by climate change related sea-level rise (SLR). Although the Kaua‘i General Plan (GP) does address coastal hazards such as coastal erosion, it does not specifically recognize climate change and SLR and its potential to exacerbate existing coastal hazards. The Kaua‘i County Planning Department requested this technical study with the update of the GP as a catalyst for beginning to address climate change and SLR.
Through the Kaua‘i Climate Change and Coastal Hazards Assessment (KC3HA), we focus in on the coastal hazards present on Kaua‘i (erosion, flooding, wave inundation, and wind), and the how these hazards are affected by climate change and SLR. A large part of the assessment focuses on SLR due to potential for changing erosion, flooding, and wave inundation hazards.