A change in the state of the climate that can be identified (e.g. using statistical tests) by changes in the mean and/or the variability of its properties that persist for an extended period, typically decades or longer (1).
The variations in the mean state and other statistics (e.g., standard deviations, the occurrence of extremes) of the climate on all spatial and temporal scales beyond that of individual weather events. Examples of climate variability include interannual El Niño and La Niña events that occur every two to seven years and influence weather patterns over vast regions of the globe (1).
Climate change is anticipated to have profound effects in the Hawaiian Islands. Key indicators of the changing climate include rising carbon dioxide in the atmosphere, rising air and sea temperatures, rising sea levels and upper-ocean heat content, changing ocean chemistry and increasing ocean acidity, changing rainfall patterns, decreasing base flow in streams, changing wind and wave patterns, changing extremes, and changing habitats and species distributions. This is shown below in Figure 1:
Atmospheric concentrations of carbon dioxide and other greenhouse gases, including methane and nitrous oxide, are increasing due to human activity. Hawaii’s Mauna Loa Observatory is one of the world’s leading scientific stations for monitoring the atmosphere. For more than fifty years, beginning with atmospheric chemist Charles Keeling’s readings of carbon dioxide levels in the atmosphere, the Mauna Loa Observatory has provided climate scientists a continuous record of the atmosphere’s increasing concentration of carbon dioxide—and sparked the international debate over global warming. The Keeling Curve is a measurement of the concentration of carbon dioxide in the atmosphere made atop Hawaii’s Mauna Loa since 1958 (3). It is the longest-running such measurement in the world. Live readings can be accessed via the Scripps Institution of Oceanography.
- IPCC, IPCC Fourth Assessment Report: Climate Change 2007: Working Group II: Impacts, Adaptation and Vulnerability. 2007.
- Keener, V.W., Marra, J. J., Finucane, M. L., Spooner, D., & Smith, M. H. (Eds.). Climate Change and Pacific Islands: Indicators and Impacts. Report for The 2012 Pacific Islands Regional Climate Assessment. 2012: Washington, DC.
- Scripps Institution of Oceanography. The Keeling Curve. 2015.