Gary Griggs’s research while affiliated with University of California, Santa Cruz and other places

In a display of the increasingly destructive impact of climate change and sea level rise, in January 2023 unusually severe storms hit California’s west coast and devastated the infrastructure at Monterey Bay’s Seacliff State Beach. Additional severe storms in December 2023 compounded the damage. This article frames the potential application of a new approach for recovery planning along the California coast by examining historical failures, accelerating threats, and the economic and societal factors that create obstacles to long-term success at places such as Seacliff. While each situation differs, the Seacliff State Beach challenge is representative of an ever-widening dilemma faced by many seaside communities. The possibilities for coastal adaptation at Seacliff, based in part on California’s innovative state policies, provide an opportunity to consider sustainable and equitable planning approaches for local communities, government, business, and ultimately future generations.

California and most other coastlines around the world are being impacted by both long-term sea-level rise and short-term extreme events. Due to California’s long and intensively developed coastline, it is an important area for evaluating responses to these challenges. The predominant historic approach to coastal erosion in California and globally has been the construction of hard coastal armoring such as seawalls and rock revetments. The concept of living shorelines—defined as using natural elements like plants, sand, or rocks to stabilize the coastline—has been widely proposed as a soft or green response to coastal erosion and flooding. However, these approaches have very limited application in high-energy environments such as California’s 1100-mile-long outer coast and are not realistic solutions for protection from wave attack at high tides or long-term sea-level rise. Each of the state’s coastal communities need to identify their most vulnerable areas, develop adaptation plans, and plan eventual relocation strategies in response to an accelerating sea-level rise.

California and most other coastlines around the world are being impacted by both long-term sea-level rise and short-term extreme events. Because of California’s long and intensively developed coastline, it is an important area for evaluating responses to these challenges. The predominant historic approach to coastal erosion in California and globally has been the construction of hard coastal armoring such as seawalls and rock revetments. The concept of living shorelines – defined as using natural elements like plants, sand or rocks to stabilize the coastline – has been widely proposed as a soft or green response to coastal erosion and flooding. These approaches have very limited application in high-energy environments, however, such as California’s 1,100-mile-long outer coast and are not realistic solutions for protection from wave attack at high tides or long-term sea-level rise. Each of the state’s coastal communities need to identify their most vulnerable areas, develop adaptation plans, and plan eventual relocation strategies in response to an accelerating sea-level rise.

Mercaldi, B.; Brideau, L.E.; Tait, J.F., and Griggs, G., 2022. Seasonal morphological variability on estuarine beaches and implications for low-energy beach management. Journal of Coastal Research, 38(6), 11351147. Coconut Creek (Florida), ISSN 0749-0208. Estuarine beaches and other low-energy shorelines are critical for habitats and coastal infrastructure protection. Many different species inhabit estuaries because of the water bodies' unique characteristics, such as their mixed seawater and freshwater and variable tidal ranges. Estuarine beaches also have the important role of buffering storm wave energy. Yet, their natural physical processes are understudied. This research focuses on seasonal morphological variability of estuarine, low-energy beaches and evaluates the implications for beach management practices. Five sandy beaches were studied along the northern shoreline of Long Island Sound in the northeastern region of the United States. The studied beaches vary in location, width, length, and orientation within Long Island Sound to represent different exposures to wave energy. Three seasonal profiles were measured at each beach approximately every four months from late 2015 to early 2019 to document topographic changes. The results revealed minimal sediment movement throughout the study period and there was no evidence of significant cyclic cross-shore sediment transport to indicate patterns of seasonal profile changes. These findings reveal important implications for beach management practices on low-energy shorelines. Specifically, estuarine and other low-energy beaches should be studied on decadal time scales to document any long-term variability and post-storm recovery rather than the monthly or yearly time scales on which open-ocean beaches are typically evaluated. Additionally, estuarine beaches and other low-energy shorelines require specialized management practices that cater to their stagnancy to ensure adequate protection of coastal structures and infrastructure in the face of intensifying hurricanes and sea level rise.

Lester, C.; Griggs, G.; Patsch, K., and Anderson, R., 0000. Shoreline retreat in California: Taking a step back. Journal of Coastal Research, 00(0), 000-000. Coconut Creek (Florida), ISSN 0749-0208. Adapting to long-term sea-level rise has emerged as perhaps the most significant coastal management challenge of the 21st century. But this challenge has become fraught with controversy in California, especially around the idea of managed retreat. This article reframes the current adversarial and highly politicized dichotomous controversy about managed retreat with an overview of California's actual experience managing coastal shoreline hazards over the last half-century. The review shows that managed retreat in California is more than an either-or fight about private beachfront residential property. The article reviews a range of cases in which development or development potential has been moved back from the shoreline. The cases stand in contrast to the overly simplified debate about managed retreat and show that retreat has been happening on California's coast for decades. The discussion identifies the complexity and multiple dimensions of shoreline adaptation over long periods and concludes with some observations in hopes of shedding light on and opening more reasonable discussion of pathways to shoreline retreat and resilient communities. ADDITIONAL INDEX WORDS: Sea-level rise, coastal adaptation, managed retreat, California coastal management.

Climate change is already affecting many weather and climate extremes in every inhabited region across the globe [...]

The Earth’s climate is changing; ice sheets and glaciers are melting and coastal hazards and sea level are rising in response. With a total population of over 300 million people situated on coasts, including 20 of the planet’s 33 megacities (over 10 million people), low-lying coastal areas represent one of the most vulnerable areas to the impacts of climate change. Many of the largest cities along the Atlantic coast of the U.S. are already experiencing frequent high tide flooding, and these events will increase in frequency, depth, duration and extent as sea levels continue to rise at an accelerating rate throughout the 21st century and beyond. Cities in southeast Asia and islands in the Indo-Pacific and Caribbean are also suffering the effects of extreme weather events combined with other factors that increase coastal risk. While short-term extreme events such as hurricanes, El Niños and severe storms come and go and will be more damaging in the short term, sea-level rise is a long-term permanent change of state. However, the effects of sea-level rise are compounded with other hazards, such as increased wave action or a loss of ecosystems. As sea-level rise could lead to the displacement of hundreds of millions of people, this may be one of the greatest challenges that human civilization has ever faced, with associated inundation of major cities, loss of coastal infrastructure, increased saltwater intrusion and damage to coastal aquifers among many other global impacts, as well as geopolitical and legal implications. While there are several short-term responses or adaptation options, we need to begin to think longer term for both public infrastructure and private development. This article provides an overview of the status on adaptation to climate change in coastal zones.