California recently released its Fourth Climate Change Assessment. This set of reports is an incredibly important read for any sustainability professional serving California tribal communities. Below are key some highlights from the Statewide Summary.

Highlights of the Report

Extreme wildfires will be more frequent, larger and costlier. A study concluded that the frequency of CA wildfires burning over 25,000 acres will increase by 50% by 2100, and that the average area burned statewide will increase by 77%. High risk fire areas are estimated to see insurance costs rise by 18% by 2055.

Sea levels will erode beaches and destroy homes and businesses. As much as 31-67% of Southern California beaches may completely erode by 2100. Saltwater inundation of residential and commercial buildings could total nearly $18B. The report’s complete summary of climate impacts is provided below.

Tribes are locked in place. While some individuals can migrate from danger, Tribes with reservations are essentially locked into fixed geographical locations and risk loss of cultural traditions and livelihoods. A comprehensive summary of specific impacts and recommendations for tribal communities can be found in this report.

Increasing the resilience and engagement of disadvantaged communities matters.

Climate change hurts people. From air pollution-related respiratory illness to heat-related hospitalizations, public health will be increasingly at risk, particularly for most vulnerable populations.

Climate changes nature. California’s coastal, marine and land-based environments are impacted by changing temperature and water patterns. Impacts range from changes to agricultural crop yields, to harmful algal blooms, fishery closures, and a significant loss of northern kelp forests.

Built systems, and human interactions with them, need to be adapted.  Increased temperatures will increase demand for air conditioning and electricity (especially at peak times), while lower snowpack will increase the urgency in upgrading man-made water storage capacity (e.g. groundwater) and changing how humans use water.

Climate change is expensive. I think about this every time I complete a vulnerability assessment and start looking at adaptation strategy options. The report suggests we can make up for the cost of deep GHG emission reductions in CA by just avoiding increased costs associated with public health. Below is a table the report provides summarizing estimated economic impacts.

The Assessment’s emphasizes additional monitoring and research, protection of vulnerability communities, coordination with local and regional governments, and natural infrastructure solutions. For example, land conservation and soil management are increasingly can improve soil water-holding capacity, increase base flows and aquifer recharge, reduce flooding and erosion, and reduce climate related water deficits. Additionally, this report is unique in its recognition of the important intersection between land use and climate change. It also uniquely presents both adaptation and mitigation needs, since they are interrelated (more mitigation means better projections and less impacts to adapt to).

The reports do not detail mental health impacts or psycho-social adaptation strategies, which can be extremely effective in building human resilience to climate change and associated stresses and traumas. To learn more about that topic, please check Prosper Sustainably’s recent blog and interview with Bob Doppelt, author of Transformational Resilience. Communities in California, like those participating in the Capital Region Climate Readiness Collaborative in Sacramento, are considering psycho-social resilience as part of their adaptation efforts.

Finally, but importantly, this Assessment helps local and regional communities evaluate their own climate change risks and opportunities. You can view regional reports for nine areas of the State here. Reports like these can be key to bringing credible and accessible data and talking  points to decision-makers who were considering how to best avoid costly and devastating impacts to tribal residents and businesses.