Climate Change & Regional Planning

How is Our Climate Changing?

The San Diego region's climate, like all others, is changing and threatening our quality of life and economic prosperity. 

By the end of the 21st century, the temperature is predicted to increase in San Diego County by more than 5˚F to as much as 10˚F. The magnitude of the increase will depend on how much greenhouse gas emissions are emitted in the future. In California, polluting emissions have generally decreased during the 2000-2016 period due to state mandates focused on reducing greenhouse gas emissions.

In addition to more extreme weather, our region will experience more frequent coastal flooding, increased risk of wildfires, potential declines in native plant and animal populations, and threats to human health, particularly among our most vulnerable communities.

To reduce polluting emissions and local vulnerabilities to climate change, an unprecedented number of local governments and public agencies in the region are working together with nonprofits, businesses, communities and philanthropic institutions to ensure the ongoing vitality of the economy and environment for all communities and future generations. Want to know more about what we're measuring?

Human Contributions: Greenhouse Gas Emissions

Accelerating GHG emissions from human activities contribute to climate change impacts. The main greenhouse gases (GHGs) included in community-wide GHG analysis are carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O).

In California, the transportation sector is the largest contributor of greenhouse gas (GHG) emissions. In 2017, direct emissions from vehicle tailpipe, off-road transportation mobile sources, aviation, rail, and watercraft accounted for 40% of statewide emissions. The pattern is similar in the San Diego region. From 2015 to 2018, emissions from vehicle tailpipe alone contributed about 54% to 56% of total emissions every year in the City of San Diego, even as the total emissions decreased 5% since 2015. Building energy use, such as lighting and appliances electricity use, heating and cooling natural gas use, contributes the second largest GHG emissions, with over 40% annually. Other GHG emissions arise from solid waste disposal, wastewater processing and from energy to convey, treat and distribute water to drinking levels.

Regional Concern

In a recent public opinion survey from 2020, results show an overwhelming majority – 86% – of a sample of San Diego County residents have high to moderate levels of concern regarding climate change impacts. Results indicate higher levels of concern compared to national results. Concern is measured utilizing the polling format from the Yale Center from Climate Change Communication that measures concern on a six part scale from alarmed to dismissive.

Alarmed: I am very concerned about climate change and think the government and individuals need to act now.

Concerned: I am concerned and think we need to take action but we have time to decide what the appropriate responses should be.

Cautious: I suspect that climate change is happening but I am not certain. We have time to make careful decisions about when and whether to respond.

Disengaged: I have not really thought much about climate change.

Doubtful: I suspect that climate change is NOT happening but I am not certain. I am concerned more about overreacting to climate change.

Dismissive: I do not believe climate change is occurring and certainly do not think humans have caused it. So, I’m not motivated to take or support action to address it.

Regional Planning

The San Diego region is collectively moving towards greater climate resilience and enhancing the region’s resilience to these impacts takes detailed, holistic and collaborative planning. Climate planning in the San Diego region takes place in many ways and on many levels. Cities in the San Diego region were some of the first in the nation to adopt efforts aimed towards mitigating GHG emissions and this took the form of establishing Climate Action Plans. In addition to individual city plans, The San Diego Association of Governments (SANDAG) prepares and updates a Regional Plan every four years, which contains several elements that intersect with climate planning. The Sustainable Communities Strategy is one such element, required by state law, to show how development patterns and our transportation system will work together to reduce GHG emissions from passenger vehicles. San Diego Forward: The Regional Plan (2021) is a long-term blueprint for a sustainable future for the San Diego region.

While many Climate Action Plans focus on reducing an entity's GHG emissions, in recent years many regional and local agencies have increased their planning efforts to address climate adaptation, as well as consider additional resiliency strategies such as preparedness of essential infrastructure in the case of extreme weather events and natural disasters. This focus helps enable cities and agencies to address climate resilience planning more holistically and can enable climate to be integrated across multiple planning efforts to streamline success. The California Office of Research and Planning defines resilience as the capacity of any entity – an individual, a community, an organization, or a natural system – to prepare for disruptions, to recover from shocks and stresses, and to adapt and grow from a disruptive experience. 

In the San Diego region, this resilience planning is being fueled as local and regional government bodies as well as special jurisdictions such as, the San Diego Association of Governments (SANDAG), San Diego Gas & Electric (SDG&E), the San Diego Regional Climate Collaborative (Climate Collaborative), the Tijuana River National Estuarine Research Reserve (TRNERR) and Scripps Institution of Oceanography (SIO), are constructing plans, implementing projects and scaling research on climate mitigation, adaptation and hazard mitigation planning.


Climate Action Plans are an important tool for local jurisdictions to quantify local level emissions and mitigate climate change. Climate Action Plans also streamline GHG reporting requirements for local governments. In San Diego, 18 out of 19 jurisdictions have a Climate Action Plan. 

In 2020, the Climate Collaborative released a ESRI Storymap synthesizing data and information from Climate Collaborative member entities and the Storymap provides an online tool to develop capacity and recognize and highlight regional climate leadership: Climate Leadership in the San Diego Region: Telling the story of local climate planning and highlighting the power of energy efficiency to reduce greenhouse gas emissions


Climate Adaptation can be defined as the adjustment in natural or human systems in response to actual or expected climatic stimuli or their effects, which moderates harm or exploits beneficial opportunities. In 2018, SANDAG was awarded funding from the Caltrans SB 1 Adaptation Planning Grant Program, with Climate Collaborative as a sub-recipient, these funds were allocated to prepare The Regional Adaptation Needs Assessment. Many regional agencies, cities and organizations are currently addressing climate adaptation by either integrating into existing plans, such as General Plans or Hazard Mitigation Plans, or by developing separate Adaptation Plans. 

Resiliency Planning  - Hazard Mitigation

The County of San Diego has been extremely active in planning for future disasters and hazard mitigation. The County of San Diego (County) has developed and implemented The County Resilience Program, including the Wildland Fires Resilience Review Report, which outlines strategic initiatives to best prepare, respond to, and recover from wildland fires. In addition to this program, the County of San Diego is currently seeking stakeholder input to update the Multi Jurisdictional Hazard Mitigation Plan to include impacts from climate change. 

San Diego Gas & Electric released the Wildfire Mitigation Plan in early 2020. This Wildfire Mitigation Plan outlines a safe and fire‐hardened electrical system that is rigorously inspected and maintained. It also utilizes the latest science and technology to create situational awareness tools that enables the utility to anticipate, prepare for, react to, and recover from extreme conditions.

What Policies Are Behind Regional Planning Efforts?

The following policies inform the regional planning responses to issues of natural resource management and protection:

California Urban Water Management Planning Act (1983) requires urban water supplies serving more than 3,000 acre-feet annually to prepare an urban water management plan every 5 years to plan for adequate supplies for the future.

California Porter-Cologne Water Quality Control Act (1969) is the basis of water protection and pollution control efforts and was used to develop the national Water Pollution Control Act Amendments of 1972 (the Clean Water Act 1972). California enforces the Clean Water Act, setting water quality standards and issuing discharge permits through Water Boards to restore and maintain the quality and integrity of waters.

California Global Warming Solutions Act (AB32, 2006) and Executive Order S-03-05 provide the basis of all climate and energy policies in California today. AB32 has a target to cut greenhouse gas emissions to 1990 levels by 2020; EO S-03-05 has a goal of reducing GHGs to 80% below 1990 levels by 2050, in line with internationally agreed scientifically developed targets. SB32 (2015) sets a mid-term target of 40% below 1990 levels by 2030. Through EO B-55-18, California has established a new statewide goal to achieve carbon neutrality no later than 205, and achieve and maintain net negative emissions thereafter. Multiple other climate and energy regulations have followed, such as:

  • The Sustainable Communities and Climate Protection Act (2008), also known as Senate Bill 375, ties together the regional allocation of housing needs and regional transportation planning in an effort to reduce greenhouse gas (GHG) emissions from motor vehicle trips and develop a Sustainable Communities Strategy within the Regional Transportation Plan.
  • Updates to the California Environmental Quality Act (2010) require all new discretionary projects to include GHG analysis and mitigation, leading to the requirement for community-level GHG mitigation plans and climate action plans.

California Coastal Act (1976) is aimed at protecting, maintaining, and enhancing the overall quality of the coastal zone environment and its natural and artificial resources through the work of the California Coastal Commission which also administers the federal Coastal Zone Management Act in California. The Coastal Act mandates standards to be applied to planning and regulatory decisions made by the Commission and by local governments.

Disaster Mitigation Act (2000) is a federal act that requires all local governments to develop a hazard mitigation plan to qualify for federal funding.

California Endangered Species Act (1970) preceded the national Endangered Species Act (1973) - This Act aims to protect endangered and threatened species by acquiring land to protect, restore and enhance the habitat of these species.

California is taking steps through its Adaptation Strategy, Adaptation Planning Guide, exploration of local vulnerabilities and risk areas.

What Are We Measuring?

To estimate the human contributions on climate, we measure the greenhouse gas emissions from cities in the San Diego region by economic sector. We also track public opinion polling on the concern for climate change. Learn more about the data.