California Energy Commission

Bold action is needed to address unmanageable time scales, limited access to information, and a need to build capacity.

The COVID-19 global pandemic and associated government lockdowns dramatically altered human activity, providing a window into how changes in individual behavior, enacted en masse, impact atmospheric composition. The resulting reductions in anthropogenic activity represent an unprecedented event that yields a glimpse into a future where emissions to the atmosphere are reduced. Furthermore, the abrupt reduction in emissions during the lockdown periods led to clearly observable changes in atmospheric composition, which provide direct insight into feedbacks between the Earth system and human activity. While air pollutants and greenhouse gases share many common anthropogenic sources, there is a sharp difference in the response of their atmospheric concentrations to COVID-19 emissions changes, due in large part to their different lifetimes. Here, we discuss several key takeaways from modeling and observational studies. First, despite dramatic declines in mobility and associated vehicular emissions, the atmospheric growth rates of greenhouse gases were not slowed, in part due to decreased ocean uptake of CO2 and a likely increase in CH4 lifetime from reduced NO x emissions. Second, the response of O3 to decreased NO x emissions showed significant spatial and temporal variability, due to differing chemical regimes around the world. Finally, the overall response of atmospheric composition to emissions changes is heavily modulated by factors including carbon-cycle feedbacks to CH4 and CO2, background pollutant levels, the timing and location of emissions changes, and climate feedbacks on air quality, such as wildfires and the ozone climate penalty.

Development of a gas turbine engine starts with optimization of the working process parameters. Turbine inlet temperature is among the most influential parameters that largely determine performance of an engine. As typical turbine inlet temperatures substantially exceed the point where metal turbine blades maintain reasonable thermal strength, proper modeling of the turbine cooling system becomes crucial for optimization of the engine’s parameters. Currently available numerical models are based on empirical data and thus must be updated regularly. This paper reviews the published information on turbine cooling requirements, and provides an approximation curve that generalizes data on all types of blade/vane cooling and is suitable for computer-based optimization.

Abstract State and local governments, businesses, community organizations, and the general public are taking an increasingly significant role in climate impact assessment. Driven by impacts to constituents and customers and threats to human health, essential services, and property values, local organizations are on the front lines of responding to climate change. National and international efforts such as the U.S. National Climate Assessment and Intergovernmental Panel on Climate Change provide fundamental scientific understanding as well as methods and modeling tools. Subnational climate assessments can build on this foundation and tailor models and analyses to specific local or decision contexts. However, subnational climate assessment and adaptation presents new scientific and research challenges, such as those related to downscaling climate models, simulating extreme events, and understanding local values and institutional practices. As state, local, and sectoral assessments become more common across the nation, there is a critical opportunity to share learnings and identify challenges and pitfalls. Building off a National Academies of Sciences, Engineering, and Medicine activity focusing exclusively on subnational climate assessment, we consider the methods and results from a variety of examples to synthesize findings about current practices and the future of subnational climate assessment.

Reducing greenhouse gas emission in the electricity sector at the lowest possible cost. Supporting California's loading order to meet energy needs first with energy efficiency and demand response, next with renewable energy (distributed generation and utility scale), and finally with clean, conventional

Insights from behavioral and experimental economics research can inform the design of evidence-based, cost-effective agri-environmental programs that mitigate environmental damages and promote the supply of environmental benefits from agricultural landscapes. To enhance future research on agri-environmental program design and to increase the speed at which credible scientific knowledge is accumulated, we highlight methodological challenges, identify important gaps in the existing literature, and make key recommendations for both researchers and those evaluating research. We first report on four key methodological challenges—underpowered designs, multiple hypothesis testing, interpretation issues, and choosing appropriate econometric methods—and suggest strategies to overcome these challenges. Specifically, we emphasize the need for more detailed planning during the experimental design stage, including power analyses and publishing a pre-analysis plan. Greater use of replication studies and meta-analyses will also help address these challenges and strengthen the quality of the evidence base. In the second part of this paper, we discuss how insights from behavioral and experimental economics can be applied to improve the design of agri-environmental programs. We summarize key insights using the MINDSPACE framework, which categorizes nine behavioral effects that influence decision-making (messenger, incentives, norms, defaults, salience, priming, affect, commitment, and ego), and we highlight recent research that tests these effects in agri-environmental contexts. We also propose a framework for prioritizing policy-relevant research in this domain.

The concentration of greenhouse gases, including CO2 and methane (CH4), in the atmosphere has been steadily rising since the beginning of the Industrial Revolution (Etheridge et al., 1996, 2002; NRC, 2010). Anthropogenic CO2 emissions from the combustion of fossil fuels have been the main contributor to rising CO2-concentration levels in the atmosphere, followed by CO2 emissions from land use, land use change, and forestry (LULUCF).

California's hydrogen funding program is part of the Alternative and Renewable Fuel and Vehicle Technology Program (ARFVTP) administered by the California Energy Commission (CEC). It's the single largest public initiative of its kind in the United States today. Together with various stakeholders, the program is designed to co-fund modern hydrogen stations for fueling hydrogen-powered vehicles. CEC's strategic hydrogen infrastructure planning focuses on early-adopter cluster communities. The program is strongly supported by a proactive group of seven auto-makers who committed specific numbers of vehicles (also transit buses) to be rolled out in order to sustain particular future fueling station locations. The program uses performance-based incentives to encourage lower cost, faster installed, higher capacity stations, and those that exceed California's 33.3% renewably-sourced hydrogen transportation fuel mandate. This allows for a more substantiated business case and helps leverage public funds for a successful outcome for the hydrogen fueling network in California.

The State of California is developing and implementing a new generation of environmental policies to transition to a low-carbon economy and energy system in order to reduce the risks of future damages from global climate change. At the same time, it is increasingly clear that climate change impacts are already occurring and that further effects cannot be completely avoided. Thus, anticipating and planning for emerging and potential future climate change impacts in California must complement the state’s greenhouse gas mitigation efforts. These impacts will depend substantially on the future evolution of the state’s social structure and economy. To support impact studies, this report describes socioeconomic storylines and key scenario elements for California that are broadly consistent with the global “A2” and “B1” storylines in the 2000 Special Report on Emissions Scenarios of the Intergovernmental Panel on Climate Change, including qualitative socioeconomic context as well as quantitative projections of key variables such as population, urbanization patterns, economic growth, and electricity prices.