Climate Change

Increasing temperatures, larger wildfires, heavier rain storms, and rising sea levels and storm surges associated with climate change are posing a significant risk to our natural and human resources and to the State’s transportation infrastructure.

The Climate Change Branch in Caltrans’ Division of Transportation Planning is responsible for overseeing the development, coordination, and implementation of climate change policies in all aspects of the Department’s decision making. It serves as a resource for technical assistance, training, information exchange, and partnership-building opportunities. 

Caltrans’ climate change efforts are twofold 1) create and maintain sustainable practices to reduce greenhouse gas emissions from transportation operations and projects, and 2) Implement adaptation measures to increase the resilience of the State Highway System to climate impacts and address vulnerabilities.    

Benefits of climate change mitigation and adaptation include:

  • Lower Greenhouse Gas and Pollutant Emissions
  • Longer Service Life of Transportation Assets
  • Reduced Costs and Need for Weather-related Maintenance
  • Improved Safety for All Users
  • Improved Ecosystem Resiliency and Health

Climate Change Highlights

Greenhouse Gas Reduction

Caltrans is focused on reducing greenhouse gases emissions associated both with Caltrans’ business operations and the State transportation system at-large to mitigate the scale and speed of climate change. The Climate Change Branch coordinates with all Caltrans’ functions to develop policies, plans, and projects which support the increased development of pedestrian, bicycle, transit, and alternative-fuel vehicle infrastructure. The Branch also produces an annual greenhouse gas report to identify progress in reducing the emissions from Caltrans’ business operations.

Climate Adaptation

The Climate Change Branch identifies climate risks and develops adaptation strategies, in concert with asset managers, to protect the traveling public and transportation infrastructure. As climate change increasingly impacts the State Highway System, the Branch is engaged in creating adaptive design strategies including “natural infrastructure”, risk-based management plans, and opportunities to develop solutions in concert with local and regional organizations.

Possible impacts of climate change and extreme weather events on the transportation system in California

California's transportation system extends through deserts, mountains, coastal areas and floodplains and will therefore experience a range of impacts as the climate changes.  Climate change has many potential effects to our transportation networks:

  • Intense storms may cause flooding of roadways and washout of transportation infrastructure.
  • Sea level rise is already affecting some of California's roads and bridges by undermining (scouring) the supports.  Roads along the coast are also vulnerable to damage from flooding.
  • As wildfires increase, slopes near transportation networks can become more unstable and prone to landslides during rainstorms.
  • Higher temperatures and longer heat spells will likely increase the buckling and rutting of roads, warping of rails, and difficulty in maintaining and constructing roads during the day.
  • Sea ports and low lying airports (San Francisco, Oakland, and San Diego) are also susceptible to sea level rise associated with the warming climate.  Many ports and airports have begun taking action to protect against sea level rise by strengthening their barriers.

What is Caltrans doing in response to climate change and extreme weather events?

At Caltrans, we are focused on doing our part to mitigate greenhouse gas emissions from our operations, and to adapt to the changing climate to ensure that the State Highway System is safe for the traveling public.  In 2013, Caltrans released "Caltrans Activities to Address Climate Change - Reducing Greenhouse Gas Emissions and Adapting to Impacts" – a report that highlights Caltrans' statewide climate change efforts. 

Caltrans recently completed a vulnerability assessment in District 4 (San Francisco Bay Area) and will assess the remaining districts by 2018 (see above).  These assessments identify the sections of the highway system at highest risk to extreme weather events related to climate change.  

Using the results of the Climate Change Vulnerability Assessments, Caltrans will prioritize sections of the highway system for adaptation planning and strengthening.  In addition, Caltrans engineers have already begun incorporating more resilient designs for long-life projects in anticipation of increased future climate stressors.  These actions will help Caltrans to reduce maintenance costs and will keep the State Highway System functioning effectively and efficiently. 


Caltrans Greenhouse Gas Emissions and Mitigation Report

The purpose of the Caltrans Greenhouse Gas Emissions and Mitigation Report is to document and evaluate current Caltrans procedures and activities that track and reduce greenhouse gas (GHG) emissions and to identify additional opportunities for further reducing GHG emissions from Department-controlled emission sources, in support of Departmental and State goals. The resulting product is the Greenhouse Gas Emissions and Mitigation Report, which provides a comprehensive overview of Caltrans’ emissions. The final report will serve as an update to the 2013 Caltrans Activities to Address Climate Change report. 

To view the Greenhouse Gas Emissions and Mitigation Report, please click here Greenhouse Gas Emissions and Mitigation Report (PDF)

Vulnerability Assessments

Caltrans is conducting Climate Change Vulnerability Assessments to identify segments of the State Highway System vulnerable to climate change impacts including precipitation, temperature, wildfire, storm surge, and sea level rise. 

The climate change data were developed in coordination with climate change scientists and experts at Federal, State, and regional organizations at the forefront of climate science. 

The results of the Climate Change Vulnerability Assessments will be used to guide analysis of at-risk assets and develop adaptation plans to reduce the likelihood of damage to the State Highway System, thereby allowing Caltrans to both reduce the costs of storm damage, and to provide transportation that meets the needs of all Californians.

You can view the inventory of Vulnerability Assessments here. 

Vulnerability Assessment Statewide Summary Report

The Caltrans Vulnerability Assessment Statewide Summary Report provides an overview and synthesis of the results of the 12 District Vulnerability Assessment Summary Reports and highlights Caltrans’ planned next steps. Advancing these next steps will enable Caltrans to incorporate climate change assessments into project development and integrate such considerations into multiple aspects of agency decisions. These efforts will culminate in a resilient highway network for the State of California.

Vulnerability Assessment Statewide Summary Report

Adaptation Priorities Reports

Building upon the Vulnerability Assessments, Caltrans is currently developing the Climate Change Adaptation Priorities Reports, which will be completed statewide by spring 2021. These reports will evaluate at-risk assets and prioritize exposed assets while exploring facility-level adaptation solutions within each district. The prioritization in these reports considers, amongst other things, the timing of the climate impacts, their severity and extent, the condition of each asset (a measure of the sensitivity of the asset to damage), the number of system users affected, and the level of network redundancy in the area. The analysis performed in the Adaptation Priorities Reports will enhance resiliency and ensure safety on the State Highway System.

You can view the current inventory of Adaptation Priorities Reports here.

Caltrans Climate Change Communication Guide

The Climate Change Communication Guide is just one component of Caltrans’ broader work on advancing climate change adaptation and greenhouse gas mitigation efforts. The guide articulates best practices that the Department uses to educate, inform, and strengthen collaboration internally, among external partners, and with the public on the topic of climate change.   Because different audiences have different communication needs, the guide assists in the facilitation of conversations on climate change at all levels.  It also guides and enhances climate change consideration and integration throughout Caltrans. 

To view the Communication Guide, please click here Climate Change Communication Guide (PDF)

SB1 Adaptation Planning Grants

Caltrans is pleased to announce the release of the Fiscal Year (FY) 2019-20 Caltrans Transportation Planning Grant awards. A statewide total of 198 grant applications were received and requested approximately $62 million for: Sustainable Communities Competitive, Strategic Partnerships (including transit), and the third and final year of Adaptation Planning. Of these applications, 84 transportation planning projects were selected for grant awards, totaling approximately $27.8 million. Award and Non-Award lists for each grant are provided below. In addition, Metropolitan Planning Organizations will receive $12.5 million in Sustainable Communities Formula grants to further their Regional Transportation Plan/Sustainable Communities Strategy. Grant applicants are encouraged to contact Caltrans district staff to request feedback for unsuccessful applications and receive technical assistance with application development. It is envisioned that these planning grants will provide much needed funding to support regional sustainable communities strategies and ultimately achieve the State's greenhouse gas reductions targets of 40 and 80 percent below 1990 levels by 2030 and 2050, respectively.