Climate Change Impacts Across California

Executive Summary

The Impacts of Climate Change Are Widespread

California Is Already Experiencing the Impacts of Climate Change. While some of the most severe signs of a changing climate are not predicted to affect California until the coming decades, certain impacts are already occurring. At the statewide level, in 2021, California experienced its hottest average summer temperatures, its second largest wildfire, and its third driest year (based on precipitation) on record. Scientists tell us these types of extreme events and weather will become increasingly prevalent in the coming years as the climate continues to change.

Climate Change Impacts Cut Across Different Sectors. Because it involves changes to natural processes, climate change often is thought of as an “environmental” issue by the media and public. In many ways thus far, California’s state government also has used this lens to address climate change issues. For example, many of the climate change response activities that the state has undertaken have been led by and administered through departments within the California Natural Resources and Environmental Protection agencies. Similarly, most of the climate adaptation legislation and funding that the Legislature has debated and approved have been discussed primarily by environmental budget and policy committees. However, while a changing climate does impact the environment, its effects are significantly more widespread. Climate stressors present California with five key climate hazards: (1) extreme heat events, (2) more severe wildfires, (3) more frequent and intense droughts, (4) flooding due to extreme precipitation events, and (5) coastal flooding and erosion resulting from sea‑level rise. Besides affecting natural resources, these hazards have major impacts on public health and safety, as well as property and infrastructure. As such, climate change affects all of California’s residents, employers, and workers, along with the state’s economy, budget, healthcare systems, transportation and water infrastructure, agricultural operations, housing market, and educational services.

About This Series of Reports

This series of six reports, which grew out of an initial project conducted for the Speaker of the California Assembly, is intended to help policymakers think about how climate change will impact various sectors and, consequently, what key corresponding policy and fiscal issues the Legislature will face in the coming years. Given the complexity of the issues, these reports do not contain explicit recommendations or a specific path forward; rather, they are intended as framing documents to help the Legislature adopt a “climate lens” across policy areas.

Because some degree of climate change already is occurring and more alterations are inevitable, these reports focus on the response to resulting impacts—referred to as climate adaptation—rather than efforts to lessen the magnitude of climate change through reducing greenhouse gas emissions—referred to as climate mitigation. (The state also has numerous programs and policies underway in the climate mitigation space, including its cap‑and‑trade program and vehicle emissions standards.)

This series contains five reports that discuss how climate change will impact specific sectors, along with a report that highlights issues and themes that cut across all policy areas. While this list is not comprehensive of all the sectors affected by a changing climate, it represents many of the key areas in which the Legislature is beginning to grapple with the wide reach of climate impacts. Each report contains: (1) a summary of the climate hazards affecting California, (2) how those hazards impact the specific sector, (3) a discussion of pertinent existing state‑level efforts that are underway, and (4) resulting key relevant issues and questions facing the Legislature. The series includes the following reports:

Crosscutting Issues. Given the magnitude of the climate change impacts that California already is beginning to experience, the Legislature will confront persistent questions about how the state should respond, including the need for: coordination, additional information, prioritization of efforts, state‑level technical and financial assistance, and a focus on the most vulnerable Californians.

Health. Climate change has a wide variety of direct and indirect health effects on Californians, with rising temperatures, extreme heat events, and wildfire smoke posing particular threats. Certain populations—particularly lower‑income, older, and medically compromised individuals, as well as outdoor workers—will disproportionately bear the adverse health burdens of climate change.

Housing. The risks posed by a changing climate will need to be considered as a more significant factor when building new housing, as well as necessitate changes to existing homes and communities to ensure they are adequately protected from growing climate‑driven hazards. Encouraging community‑level mitigations, keeping the insurance market healthy, and mitigating the disproportionate risks faced by low‑income residents are areas where the Legislature could consider taking actions. The state also will want to ensure that impacts on housing supply and affordability are considered as part of any actions.

K‑12 Education. More extreme weather and climate‑driven events will result in more frequent emergencies and school closures, negatively affecting student learning, school facilities, and school district budgets. The Legislature will want to consider how the state can support schools in preparing for and responding to more frequent emergencies and public health issues.

Transportation. Some existing transportation infrastructure will need to be modified or relocated to remain useable under a changing climate, and planning, construction, and maintenance will increasingly need to account for the effects of climate change to maintain the current longevity of transportation infrastructure.

Workers and Employers. Changing conditions—including more days of extreme heat and widespread wildfire smoke—increase the likelihood of injuries, illnesses, and fatalities for exposed workers, particularly those that primarily work outdoors or indoors without adequate air conditioning or ventilation. Certain workers likely also will face greater work instability, both in the short term due to extreme weather events, but also in the longer term, as affected industries shift operations or locations in response to climate change impacts.