San Diego County Ecosystems: Ecological Impacts of Climate Change on a Biodiversity Hotspot

California Energy Commission (CEC) | August 27th, 2018

The diverse ecosystems, habitats, plants, and animals in the San Diego County region will be impacted by climatic shifts in multifold ways due to current and future vari

The diverse ecosystems, habitats, plants, and animals in the San Diego County region will be impacted by climatic shifts in multifold ways due to current and future variability, along with other factors including habitat loss and fragmentation, land use shifts, and changing fire regimes. While home to a major metropolitan area, San Diego County still hosts expanses of native and preserved habitats where management and conservation action could be greatly enhanced through science-based assessments and planning for climate change and increased climate variability. Projections of climate change in the region include warming by 4-9° F on average, and a 15-25% decrease in fall and spring precipitation with an increase in variability resulting in more frequent and intense droughts punctuated by increasingly rare yet extreme precipitation and flooding events. In addition, an increase in fire events and potential lessening of coastal marine influence may also affect San Diego’s ecosystems. Climate warming superimposed upon the pronounced spatially-varying temperature in the San Diego region will likely be associated with range shifts for many species resulting in novel community assemblages and biotic interactions and could create phenological mismatches. More frequent and intense heat waves may disproportionately affect younger age classes and reduce reproductive and survival rates of species sensitive to temperature extremes. With increasingly variable precipitation, drought may occur more frequently due to increased occurrence of dry days and could intensify because of warmer temperatures. Since drought disproportionately affects some species, these projected changes may cause structural changes to ecosystems. Santa Ana winds, occurring during increasingly dry fall months, would create ideal fire conditions. Coastal low clouds and fog along San Diego’s coast buffer this zone from the effects of warming and drying through shading and cooling. Although these marine stratus clouds will remain a presence, future changes in this phenomenon are uncertain. The spatial and temporal scales at which climate variations and change operate must be considered to build resilience into natural systems. Effective conservation actions will need to build on ongoing efforts focused on landscape-scale planning rather than more traditional single-species approaches. To carry this out will require cross-jurisdictional, multidisciplinary collaboration by scientists, policy-makers, planners, land managers, and the broader conservation community, which has a decades-long history of accomplishment in San Diego County.

San Francisco Bay Shore Inventory Mapping for Sea Level Rise Planning

San Francisco Estuary Institute (SFEI) | April 5th, 2016

With rising sea levels and the increased likelihood of extreme weather events, it is important for regional agencies and local municipalities in the San Francisco Bay Are

With rising sea levels and the increased likelihood of extreme weather events, it is important for regional agencies and local municipalities in the San Francisco Bay Area to have a clear understanding of the status, composition, condition, and elevation of our current Bay shore, including both natural features and built infrastructure. The purpose of this Bay shore inventory is to create a comprehensive and consistent picture of today’s Bay shore features to inform regional planning. This dataset includes both structures engineered expressly for flood risk management (such as accredited levees) and features that affect flooding at the shore but are not designed or maintained for this purpose (such as berms, road embankments, and marshes). This mapping covers as much of the ‘real world’ influence on flooding and flood routing as possible, including the large number of non-accredited structures. This information is needed to: 1. identify areas vulnerable to flooding; 2. identify adaptation constraints due to present Bay shore alignments; and 3. suggest opportunities where beaches, wetlands, and floodplains can be maintained or restored and integrated into flood risk management strategies.

San Francisco Estuary Blueprint 2022

San Francisco Estuary Partnership (SFEP) | September 8th, 2022

In the past few years, the San Francisco Estuary region has confronted epic wildfires, historic rainfall intensity and flooding, and chronic drought. The whiplash of thes

In the past few years, the San Francisco Estuary region has confronted epic wildfires, historic rainfall intensity and flooding, and chronic drought. The whiplash of these events has confirmed that climate change has already begun to impact human and wildlife communities from Sacramento to San Francisco, and beyond. Furthermore, a global COVID-19 pandemic has disrupted regional planning and project implementation everywhere, presenting new challenges to traditional processes and creating an unfamiliar working landscape for resource managers. Finally, the pervasive, horrific violence against Black, Brown, and Asian and Asian-American people has amplified long-term calls for racial justice, galvanizing new commitments to address historic and present inequity through every thread of our social fabric. These events have set the context for the multi-stakeholder process that updates the San Francisco Estuary Blueprint.

San Francisquito Creek Baylands Landscape Change Metrics Analysis

San Francisco Estuary Institute (SFEI) | June 21st, 2016

The goal of this study is to develop a high level overview of the physical and ecological changes to lower San Francisquito Creek and the surrounding tidal marshes and mu

The goal of this study is to develop a high level overview of the physical and ecological changes to lower San Francisquito Creek and the surrounding tidal marshes and mudflats (referred to here as “baylands”) since the beginning of intensive European-American settlement. Building upon a previous reconnaissance-level historical ecology study (Hermstad et al. 2009), this study analyzes the changes in key landscape features (or landscape metrics) within lower San Francisquito Creek and baylands through comparisons of reconstructed historical (mid-1800s) and contemporary (2011/2012) conditions. The results from this study are intended to provide baseline information that can be used to help with developing restoration and flood control redesign alternatives and appropriate habitat restoration targets. This study is one component of the Flood Control 2.0 project, a regional effort funded by the U.S. EPA to help design flood control channels at the Bay interface that support tidal habitats while maintaining the required level of flood protection. Emerging strategies for flood protection focus on reconnecting channels to floodplains and tidal marshes and using available dredged sediment as a resource to increase marsh elevations and help keep pace with sea level rise. Lower San Francisquito Creek is one of three implementation projects that have partnered with Flood Control 2.0 to assess the benefits of an integrated approach for flood control and habitat management at the Bay interface.

Scaling protection and restoration of natural infrastructure to reduce flood impacts and enhance resilience

Shore & Beach (American Shore and Beach Preservation Association) | October 1st, 2019

Restoring natural infrastructure offers much promise as a means to reduce both flood hazard and exposure to complement and supplement other flood damage reduction

Restoring natural infrastructure offers much promise as a means to reduce both flood hazard and exposure to complement and supplement other flood damage reduction strategies. Interest increased in flood risk reduction methods using natural and nature- based features, in part, because of increased recognition that such could provide both flood risk reduction and other benefits, such as water quality uplift, community recreational space, and fish and wildlife habitat. Recent flood disasters and the rising costs of disaster response and recovery have triggered policy shifts toward economi- cally efficient investments that enhance greater community resilience. While natural infrastructure is becoming more widely recognized as a tactic for building community and ecological resilience to erosion and flooding, it remains underutilized. Actions to aid consideration of natural infrastructure and scale up its use are presented.

Scaling protection and restoration of natural infrastructure to reduce flood impacts and enhance resilience

Shore & Beach (American Shore and Beach Preservation Association) | January 10th, 2020

Restoring natural infrastructure offers much promise as a means to reduce both flood hazard and exposure to complement and supplement other flood damage reduction strat

Restoring natural infrastructure offers much promise as a means to reduce both flood hazard and exposure to complement and supplement other flood damage reduction strategies. Interest increased in flood risk reduction methods using natural and nature-based features, in part, because of increased recognition that such could provide both flood risk reduction and other benefits, such as water quality uplift, community recreational space, and fish and wildlife habitat. Recent flood disasters and the rising costs of disaster response and recovery have triggered policy shifts toward economically efficient investments that enhance greater community resilience. While natural infrastructure is becoming more widely recognized as a tactic for building community and ecological resilience to erosion and flooding, it remains underutilized. Actions to aid consideration of natural infrastructure and scale up its use are presented.

Sea level rise and the drivers of daily water levels in the Sacramento-San Joaquin Delta

Nature Portfolio (Springer Nature) | December 17th, 2023

Sea Level Rise Impacts on Wastewater Treatment Systems Along the U.S. Coasts

American Geophysical Union (AGU) | April 13th, 2018

Wastewater treatment plants are susceptible to flooding resulting from sea level rise. Previous estimates of wastewater exposure have only considered the impacts of mar

Wastewater treatment plants are susceptible to flooding resulting from sea level rise. Previous estimates of wastewater exposure have only considered the impacts of marine flooding at the local or regional scale. In this analysis, we quantify the exposure to marine flooding across the coastal United States and then consider the relative impacts of marine and groundwater flooding at the regional scale in the San Francisco Bay Area. We also estimate the number of people who may lose access to wastewater services if no actions are taken to prevent flooding at wastewater treatment plants. We find that the number of people impacted by sea level rise due to loss of wastewater services could be five times as high as previous predictions of the number of people who experience direct flooding of their homes or property. We also find that groundwater flooding poses a significant threat to wastewater plants in the San Francisco Bay region.

Sea Level Rise in California

Public Policy Institute of California (PPIC) | February 29th, 2024

Sea Level Rise Vulnerability Study for the City of Los Angeles

University of Southern California Sea Grant Program | December 31st, 2013

Climate change is expected to usher in an era of higher temperatures, increased precipitation and/or severe drought, and increased rates of sea level rise around

Climate change is expected to usher in an era of higher temperatures, increased precipitation and/or severe drought, and increased rates of sea level rise around the world. According to the National Research Council (NRC), global sea level has risen at an increasing rate since the late 19th / early 20th Century, when global temperatures first started to rise. Climate researchers believe sea level rise will drive storm surge and wave run-up higher than current conditions, thereby causing more extensive and frequent coastal, storm-driven flooding. Sea level rise in Los Angeles is expected to match global projections over the next century with anincrease of 0.1 - 0.6 meters (m), or 0.3 - 2.0 feet (ft), from 2000 - 2050 and 0.4 - 1.7 m (or 1.3 - 5.6 ft) from 2000 - 2100 (NRC 2012). Tides, wave-driven run-up, and storm surge play critical roles in coastal flooding in Southern California, especially when big wave storms occur at or near peak high tides. Sea level rise will potentially exacerbate the damage from these events.