Influences of climate change, climate variability, and drought on human communities and ecosystems in Hawaiʻi

Flames glow yellow and red behind a road-lining hedge.
Increasing wildfires are just one result of climate change and climate variability. (Photo: Hawaiʻi County Fire Dept.)

Over the past century, Hawaiʻi has experienced a pronounced decline in precipitation and stream flow and a number of severe droughts. These changes can have wide-reaching implications, affecting the water supply, native vegetation and wildlife, wildfire patterns, and the spread of invasive species. Several climate-related factors are influencing Hawaiˈi’s landscapes and contributing to these changes. These include climate change, climate variability, and drought (referred to collectively as CCVD). Climate variability describes how the climate fluctuates on a yearly basis around average values, while climate change describes patterns of long-term continuous change in the average.

While it is understood that CCVD will exert a growing influence on Hawaiʻi’s ecosystems and communities, there is currently little information on the historic impacts of CCVD in the region. Improving our understanding of past conditions will help Hawaiʻi’s natural resource managers better prepare for the future impacts of CCVD on ecosystems and communities. For example, invasive plant species in Hawaiˈi tend to be more fire-prone. If CCVD contributes to the spread of invasives, there may be more wildfires, and managers may need to revise current fire management strategies.

This project will use newly available datasets and tools to improve our understanding of the impacts of historic CCVD in Hawaiʻi. This information will then be used to assess the potential ecological and social impacts of CCVD, with an emphasis on fire risk. The results of this study will assist Hawaiʻi’s land managers in identifying which actions should be implemented to help prepare ecosystems and communities for future climate conditions.





Christian Giardina
Research Ecologist, Inst. of Pacific Islands Forestry, US Forest Service