2018-2019 Executive Summary
The science community has invested heavily in understanding how climate change will manifest in the coming decades. Researchers have developed sophisticated monitoring programs to document carbon dioxide emissions in the atmosphere, track changes in air and water temperature, and measure acidity of the ocean. Similarly, researchers are using state-of-the-art computer models to predict how weather and rainfall patterns will be altered, how sea levels will rise over the next century, and the uncertainty and nuances that necessarily accompany multi-decade predictions. These detailed analyses are beginning to answer pressing societal questions about what the ways that global climate change will play out in local communities, and starting to drive long-term planning and priority setting by state, federal and local governments. Most climate change research focuses on physical changes in the ocean and terrestrial ecosystems, such as sea level rise and temperature. To effectively protect aquatic environments in the face of global climate change, water-quality managers also must know how animals, plants and entire ecosystems will respond to this changing physical environment. Just as importantly, managers need to know which strategies, tools and approaches are viable, cost-effective and optimized to help mitigate ecosystem impacts and how responses to climate change (e.g., seawalls, channel armoring, water diversion) may translate to secondary impacts to aquatic resources.
Toward that end, SCCWRP’s climate change research is focused on connecting rapidly growing knowledge about the physical aspects of climate change with assessments and prediction of how aquatic ecosystems will respond. SCCWRP is working to understand biotic response to four climate change stressors: (1) how changing rainfall and runoff patterns will influence California’s efforts to protect the environmental flows that sustain aquatic ecosystems, and how the state’s water resources management community can improve and better coordinate its approaches to protecting these flows, (2) how biological communities that live in low-lying coastal wetland environments will be impacted by rising sea levels in the coming decades, and how coastal resources managers can use this information to chart courses of action that maximize opportunities for these ecological resources to adapt, (3) how warming waters affect distribution of biota, including nuisance species such as cyanobacterial blooms, and (4) how rising ocean acidity affects the health of marine food webs. SCCWRP invests in creating and strengthening monitoring programs that evaluate the biological impacts of these changing environmental conditions, as well as building sophisticated computer simulations of how climate change will affect the health, distribution and resiliency of sentinel aquatic species.
This year, SCCWRP will continue to focus on understanding biotic responses to the stressors of climate change. SCCWRP’s focus for 2018-19 will be on:
- Assessment of acidification and its impacts: Among SCCWRP’s top priorities are developing a scientific understanding of ocean acidification, a phenomenon caused by oceanic assimilation of atmospheric carbon dioxide. This ocean acidification research compasses several topical areas, including: (1) developing and applying a coupled physical- biogeochemical model to estimate the current and future extent of acidification and hypoxia under climate change (see Eutrophication research theme) and to investigate the contribution of local pollution inputs to acidification and hypoxia, (2) defining biological endpoints affected by acidification and the chemical thresholds at which those effects manifest; this includes laboratory and field experiments, as well as workshops with leading experts to synthesize the effects of acidification on selected marine taxa, and (3) mining historical data to assess the extent to which acidification may have already manifested; SCCWRP is working with its member agencies to digitize and analyze historical data sets dating back 50 years or more, with the intent to examine possible local trends in acidification.
- Evaluation of coastal adaptation strategies to sea level rise: While prior SCCWRP research has focused on evaluating the susceptibility of coastal wetlands to the effects of sea level rise, SCCWRP will continue its work to evaluate adaptation strategies aimed at helping wetlands persist in the face of expected dramatic increases in mean sea level and storm surge. Computer modeling suggests that coastal California may experience several meters of sea level rise by the turn of the century. To understand how coastal wetlands might accommodate these changes, SCCWRP and its partners are developing linked physical and biological models that can be used to evaluate adaptation planning. These models are being used to evaluate how strategies such as augmenting accretion, management of mouth dynamics, and facilitating transgression can help reduce anticipated wetland losses associated with sea level rise.
- Evaluation of climate change and water resources management effects on southern California streams: Because climate change complicates decisions regarding how to balance competing ecological and human demands for in-stream flows, and because changing precipitation patterns and warmer temperatures are likely to reduce summer baseflows and increase the variability of winter storm flows, SCCWRP is working to help managers manage environmental flows to maintain desired biological endpoints in the context of changing runoff patterns and water management practices. SCCWRP is incorporating local downscaled predictions of changing temperature and rainfall patterns into flow ecology models to evaluate how climate change may affect decisions regarding in-stream flow management. This, in turn, will be used to inform deliberations regarding setting flow targets aimed at ensuring healthy biological communities, within the context of other demands on water supply.