Persistent spatial structuring of coastal ocean acidification in the California Current System

Nature Portfolio (Springer Nature) | May 31st, 2017

The near-term progression of ocean acidification (OA) is projected to bring about sharp changes in the chemistry of coastal upwelling ecosystems. The distribution of OA

The near-term progression of ocean acidification (OA) is projected to bring about sharp changes in the chemistry of coastal upwelling ecosystems. The distribution of OA exposure across these early impact systems, however, is highly uncertain and limits our understanding of whether and how spatial management actions can be deployed to ameliorate future impacts. Through a novel coastal OA observing network, we have uncovered a remarkably persistent spatial mosaic in the penetration of acidified waters into ecologically-important nearshore habitats across 1,000 km of the California Current Large Marine Ecosystem. In the most severe exposure hotspots, suboptimal conditions for calcifying organisms encompassed up to 56% of the summer season, and were accompanied by some of the lowest and most variable pH environments known for the surface ocean. Persistent refuge areas were also found, highlighting new opportunities for local adaptation to address the global challenge of OA in productive coastal systems.

Persistent spatial structuring of coastal ocean acidification in the California Current System

Nature Portfolio (Springer Nature) | May 31st, 2017

The near-term progression of ocean acidification (OA) is projected to bring about sharp changes in the chemistry of coastal upwelling ecosystems. The distribution of OA e

The near-term progression of ocean acidification (OA) is projected to bring about sharp changes in the chemistry of coastal upwelling ecosystems. The distribution of OA exposure across these early-impact systems, however, is highly uncertain and limits our understanding of whether and how spatial management actions can be deployed to ameliorate future impacts. Through a novel coastal OA observing network, we have uncovered a remarkably persistent spatial mosaic in the penetration of acidified waters into ecologically-important nearshore habitats across 1,000 km of the California Current Large Marine Ecosystem. In the most severe exposure hotspots, suboptimal conditions for calcifying organisms encompassed up to 56% of the summer season, and were accompanied by some of the lowest and most variable pH environments known for the surface ocean. Persistent refuge areas were also found, highlighting new opportunities for local adaptation to address the global challenge of OA in productive coastal systems.

Perspectives and Guidance for Climate Change Analysis

California Department of Water Resources (DWR) | August 14th, 2015

California's water managers face a climate that changes and is changing as a result of both natural and anthropogenic influences. In some settings and for some variables,

California's water managers face a climate that changes and is changing as a result of both natural and anthropogenic influences. In some settings and for some variables, California’s natural climate variability still dominates anthropogenic influences and will continue to do so for the foreseeable future. In other cases, anthropogenic influences are already evident in important aspects of California's climate. Much research is still required to unravel this tangled web of atmospheric interactions. In any case, California water planning under a changing climate needs to recognize that the causes of variations and changes include both anthropogenic and natural drivers. This technical information record summarizes the scientific and technical guidance and perspectives of the California Department of Water Resources’ (DWR’s) Climate Change Technical Advisory Group (CCTAG) on the use of climate models and associated technical tools for water resource planning. DWR values the work of the members of the CCTAG and will consider this advice as it moves forward in developing specific actions. DWR empaneled this CCTAG in February 2012 to advise DWR on the scientific aspects of climate change, its impacts on water resources, the use of planning approaches and analytical tools, and the development of adaptation responses. DWR requested specific assistance with developing: • A set of future climate scenarios and analysis procedures appropriate for DWR planning. • An approach to extreme climate change scenarios to provide “stress tests.” • Interim guidance on modeling extreme weather events that cause flooding (time permitting within the tenure of the CCTAG).

Phenomenological vs. biophysical models of thermal stress in aquatic eggs

Ecology Letters (Wiley) | January 1st, 2017

Predicting species responses to climate change is a central challenge in ecology. These predictions are often based on lab-derived phenomenological relationships between

Predicting species responses to climate change is a central challenge in ecology. These predictions are often based on lab-derived phenomenological relationships between temperature and fitness metrics. We tested one of these relationships using the embryonic stage of a Chinook salmon population. We parameterised the model with laboratory data, applied it to predict survival in the field, and found that it significantly underestimated field-derived estimates of thermal mortality. We used a biophysical model based on mass transfer theory to show that the discrepancy was due to the differences in water flow velocities between the lab and the field. This mechanistic approach provides testable predictions for how the thermal tolerance of embryos depends on egg size and flow velocity of the surrounding water. We found support for these predictions across more than 180 fish species, suggesting that flow and temperature mediated oxygen limitation is a general mechanism underlying the thermal tolerance of embryos.

Piloting a Water Rights Information System for California

Center for Law, Energy, and the Environment (CLEE) | July 15th, 2021

California’s complex water management challenges are growing and intensifying. Systemic stressors like the more frequent and severe droughts and floods driven by climat

California’s complex water management challenges are growing and intensifying. Systemic stressors like the more frequent and severe droughts and floods driven by climate change are only making it harder to respond. Accordingly, California needs to dramatically improve the ability of local, regional, and State entities to make agile and effective water management decisions. We believe doing so will require enhanced understanding of our water resources and how they align with the needs of a range of agencies and stakeholders. Water rights data provide a crucial opportunity for advancing this understanding. We find that modernizing water rights data is feasible, affordable, and can increase transparency and clarity for better decision-making.

Planning and investing for a resilient California: A guidebook for state agencies

Governor's Office of Planning and Research (OPR) | November 17th, 2017

Executive Order (EO) B-30-15 (April 2015; Appendix A) identified three actions to advance adaptation and resilience: 1. Preparation of Implementation Action Plans to id

Executive Order (EO) B-30-15 (April 2015; Appendix A) identified three actions to advance adaptation and resilience: 1. Preparation of Implementation Action Plans to identify the steps that will be taken to realize the goals in Safeguarding California; 2. Direction to all State agencies to consider climate change in all planning and investment, including infrastructure investment; and 3. Direction to the Governor’s Office of Planning and Research (OPR) to establish a Technical Advisory Group (TAG) to provide state agencies with guidance on how to integrate climate change into planning and investment. This document is the product of the Technical Advisory Group (TAG) formed under EO B-30-15. The TAG was comprised of representatives from a majority of agencies, departments, offices and commissions of the Governor’s executive branch, and members of the public, including local and regional governments, non-governmental organizations, and the private sector (see Appendix B). This guidance document is designed to inform planning and investment processes to address the two primary elements of resilience – planning for future conditions and doing planning itself differently. This document introduces a four step process and a set of resilient decision making principles for state agencies.

Plant-water sensitivity regulates wildfire vulnerability

Nature Portfolio (Springer Nature) | February 7th, 2022

Extreme wildfires extensively impact human health and the environment. Increasing vapour pressure deficit (VPD) has led to a chronic increase in wildfire area in the west

Extreme wildfires extensively impact human health and the environment. Increasing vapour pressure deficit (VPD) has led to a chronic increase in wildfire area in the western United States, yet some regions have been more affected than others. Here we show that for the same increase in VPD, burned area increases more in regions where vegetation moisture shows greater sensitivity to water limitation (plant-water sensitivity; R2 = 0.71). This has led to rapid increases in human exposure to wildfire risk, both because the population living in areas with high plant-water sensitivity grew 50% faster during 1990–2010 than in other wildland–urban interfaces and because VPD has risen most rapidly in these vulnerable areas. As plant-water sensitivity is strongly linked to wildfire vulnerability, accounting for ecophysiological controls should improve wildfire forecasts. If recent trends in VPD and demographic shifts continue, human wildfire risk will probably continue to increase.

Plant-water sensitivity regulates wildfire vulnerability

Nature Portfolio (Springer Nature) | February 7th, 2022

Extreme wildfires extensively impact human health and the environment. Increasing vapour pressure deficit (VPD) has led to a chronic increase in wildfire area in the west

Extreme wildfires extensively impact human health and the environment. Increasing vapour pressure deficit (VPD) has led to a chronic increase in wildfire area in the western United States, yet some regions have been more affected than others. Here we show that for the same increase in VPD, burned area increases more in regions where vegetation moisture shows greater sensitivity to water limitation (plant-water sensitivity; R2 = 0.71). This has led to rapid increases in human exposure to wildfire risk, both because the population living in areas with high plant-water sensitivity grew 50% faster during 1990–2010 than in other wildland–urban interfaces and because VPD has risen most rapidly in these vulnerable areas. As plant-water sensitivity is strongly linked to wildfire vulnerability, accounting for ecophysiological controls should improve wildfire forecasts. If recent trends in VPD and demographic shifts continue, human wildfire risk will probably continue to increase.

Pluvial flood impacts and policyholder responses throughout the United States

Nature Portfolio (Springer Nature) | January 24th, 2025

Poleward shift of the major ocean gyres detected in a warming climate

American Geophysical Union (AGU) | February 24th, 2020

Recent evidence shows that wind‐driven ocean currents, like the western boundary currents, are strongly affected by global warming. However, due to insufficient observa

Recent evidence shows that wind‐driven ocean currents, like the western boundary currents, are strongly affected by global warming. However, due to insufficient observations both on temporal and spatial scales, the impact of climate change on large‐scale ocean gyres is still not clear. Here, based on satellite observations of sea surface height and sea surface temperature, we find a consistent poleward shift of the major ocean gyres. Due to strong natural variability, most of the observed ocean gyre shifts are not statistically significant, implying that natural variations may contribute to the observed trends. However, climate model simulations forced with increasing greenhouse gases suggest that the observed shift is most likely to be a response of global warming. The displacement of ocean gyres, which is coupled with the poleward shift of extratropical atmospheric circulation, has broad impacts on ocean heat transport, regional sea level rise and coastal ocean circulation.