Indicators of Climate Change in California

Environmental indicator icons

The Office of Environmental Health Hazard Assessment (OEHHA) researches and presents indicators in periodic reports describing how California’s climate is changing and how these changes are affecting the state. Indicators are scientifically-based measurements that track trends in various aspects of climate change. The 2018 report compiles 36 indicators grouped into four categories: human-influenced drivers of climate change, such as greenhouse gas emissions; changes in the state’s climate; impacts of climate change on physical systems, such as oceans and snowpack; and impacts of climate change on biological systems – humans, vegetation and wildlife.


 Indicators of Climate Change in California

The world’s climate is warming. Both globally and in California, this conclusion is supported by observations showing increasing air and ocean temperatures. Likewise, observed changes to hydrological systems, the oceans, and many plant and animal species have been attributed to climate change. The trends presented in the third edition of the report, Indicators of Climate Change in California, serve as evidence that climate change is continuing to occur in California and is having significant, measurable impacts on the state and its people. This report portrays an increasingly troubling story of accelerating rates of warming, record-breaking events, and species responses that have the potential to cause ecosystem disruptions.

The report presents 36 indicators that, both individually and collectively, show how climate change is affecting California. These scientifically-based measurements track trends in various aspects of climate change and are useful for communicating information about the climate change issues confronting the state. The report is intended to promote scientific analysis to inform decision-making on mitigating and adapting to climate change, and to serve as a resource for decision makers, scientists, educators, and the public.


2015 Workshop:  Indicators of Climate Change in California

On June 16 and 17, 2015, OEHHA convened a workshop to improve upon and explore new metrics for tracking climate change and its impacts on California’s water resources, oceans, fish and wildlife, forests, agriculture, and the health and well-being of the state’s residents.  OEHHA used information from the workshop to help develop the 2018 climate change indicators report.


2013 Report: Indicators of Climate Change in California

In 2013 OEHHA released "Indicators of Climate Change in California," a report presenting 36 indicators tracking trends in atmospheric gases that influence climate, changes in the state's climate, and the impacts of climate change on California's environment and people. This report updated a 2009 report.


2010 Environmental Justice Impacts of Climate Change

Evidence is emerging that 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.  These concerns were highlighted in the Indicators of Climate Change in California: Environmental Justice Impacts Report.