Indicators of Climate Change in California

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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.