Indicators of Climate Change in California: Environmental Justice Impacts Report

In 2009, the California Environmental Protection Agency’s (Cal/EPA) Office of the Secretary requested the Office of Environmental Health Hazard Assessment (OEHHA) to develop indicators describing the disproportionate impacts of climate change on environmental justice communities.  These indicators will help Cal/EPA examine potential environmental justice concerns associated with climate change. 

Evidence is emerging that some of the projected impacts of climate change on human health and well-being are already occurring.  Some of these impacts may disproportionately affect those who are socially or economically disadvantaged, and hence represent environmental justice concerns. 

This report presents four indicators that help track trends relating to the disproportionate impacts of climate change on these communities.  The indicators chosen were selected based on evidence that: (1)  the impacts of climate change are already occurring (rather than projected to occur based on future climate scenarios); and (2)  disparities exist among socioeconomic or racial groups in either the degree of exposure to a hazard, or the capacity to take action to reduce exposures or minimize adverse outcomes.  The indicators are summarized in the text box below.

The Indicators

Air conditioner ownership and cost
Low-income individuals and families are less likely to live in homes with air conditioning.  Moreover, electricity costs for cooling are a greater proportion of their household income compared to more affluent households. 

Farm worker exposure to extreme heat
Farm workers are a low-income, predominantly Hispanic population.  They experience disproportionately greater exposures to extreme heat.  Summertime extreme heat in certain agricultural stations declined from 1950 to the mid-1980s, but appears to be trending upward.

Exposure to urban heat
Low-income residents and people of color are more likely to live in urban neighborhoods with large impervious areas and with minimal tree canopy—conditions that intensify summertime heat.  Indicators to track these conditions need to be developed.

Vulnerability to wildfires
The rural poor living at the wildland-urban interface may have less capacity and resources to take measures to prevent and fight wildfires and to recover following a fire.  Indicators that integrate information about fire threat and about community capacity will help track vulnerability to wildfires.


The lack of California-specific data - in particular, community-level data - needed to examine disparities among income or racial groups precluded the development of more indicators. The present work also does not address projected impacts where the influence of climate change cannot be distinguished from the effects of other factors. Lastly, potential disparities resulting from climate change mitigation policies, strategies or regulations are beyond the scope of this report.