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Abstract. The extracellular concentration of H2O2 in surface aquatic environments is controlled by a balance between photochemical production and the microbial synthesis of catalase and peroxidase enzymes to remove H2O2 from solution. In any kind of incubation experiment, the formation rates and equilibrium concentrations of reactive oxygen species (ROSs) such as H2O2 may be sensitive to both the experiment design, particularly to the regulation of incident light, and the abundance of different microbial groups, as both cellular H2O2 production and catalase–peroxidase enzyme production rates differ between species. Whilst there are extensive measurements of photochemical H2O2 formation rates and the distribution of H2O2 in the marine environment, it is poorly constrained how different microbial groups affect extracellular H2O2 concentrations, how comparable extracellular H2O2 concentrations within large-scale incubation experiments are to those observed in the surface-mixed layer, and to what extent a mismatch with environmentally relevant concentrations of ROS in incubations could influence biological processes differently to what would be observed in nature. Here we show that both experiment design and bacterial abundance consistently exert control on extracellular H2O2 concentrations across a range of incubation experiments in diverse marine environments. During four large-scale (>1000 L) mesocosm experiments (in Gran Canaria, the Mediterranean, Patagonia and Svalbard) most experimental factors appeared to exert only minor, or no, direct effect on H2O2 concentrations. For example, in three of four experiments where pH was manipulated to 0.4–0.5 below ambient pH, no significant change was evident in extracellular H2O2 concentrations relative to controls. An influence was sometimes inferred from zooplankton density, but not consistently between different incubation experiments, and no change in H2O2 was evident in controlled experiments using different densities of the copepod Calanus finmarchicus grazing on the diatom Skeletonema costatum (<1 % change in [H2O2] comparing copepod densities from 1 to 10 L−1). Instead, the changes in H2O2 concentration contrasting high- and low-zooplankton incubations appeared to arise from the resulting changes in bacterial activity. The correlation between bacterial abundance and extracellular H2O2 was stronger in some incubations than others (R2 range 0.09 to 0.55), yet high bacterial densities were consistently associated with low H2O2. Nonetheless, the main control on H2O2 concentrations during incubation experiments relative to those in ambient, unenclosed waters was the regulation of incident light. In an open (lidless) mesocosm experiment in Gran Canaria, H2O2 was persistently elevated (2–6-fold) above ambient concentrations; whereas using closed high-density polyethylene mesocosms in Crete, Svalbard and Patagonia H2O2 within incubations was always reduced (median 10 %–90 %) relative to ambient waters.

Motor vehicle ownership and utilization are growing rapidly in Asia, because of rapid urbanization and growing urban incomes. This sudden growth is resulting in increasing traffic congestion, fuel use, and CO2 emissions and in deteriorating air quality. This paper presents a common framework to explore scenarios of vehicle and energy use and emissions in three South Asian cities: Bangalore, India; Colombo, Sri Lanka; and Dhaka, Bangladesh. Scenarios are built by separately analyzing transportation activity (in tonne kilometers or passenger kilometers), modal structure (i.e., share of tonne kilometers or passenger kilometers occurring on each mode), modal energy intensity (in energy burned per tonne kilometer or passenger kilometer), and emission factors. Although the types of data available across cities vary widely and there are deficiencies and inconsistencies in the available data, the analysis suggests that motor vehicle use would roughly double in each city by 2020 in the business-as-usual scenario, largely because of expected income increases; fuel use and CO2 emissions would triple; and pollution loading would rise exponentially. An alternative scenario of slower vehicle and energy growth is explored, premised on substitution of personal vehicles with buses and reduction in traffic congestion. Consequently, fuel use and CO2 emissions would only double in Bangalore and Dhaka, whereas in Colombo the increase would not be significantly lower than in the business-as-usual scenario. The cumulative carbon mitigation potential over a 15-year period would be 13% in Bangalore, 9% in Dhaka, and 2% in Colombo. The drop in pollution loading would be different in each city.

This study provides an overview of both traditional nearshore seaweed farming infrastructure and more recent developments intended for large scale farming in more exposed coastal waters where nutrient supply may be a limiting factor. The success of multi-species integrated multi-trophic aquaculture (IMTA) methods predominantly in East Asia is a clear low cost path to scaling up seaweed cultivation in the broader world that provides for both synergistic sharing of nutrients and reduction in water eutrophication. A number of innovations intended to adapt farming methods to deeper or more exposed coastal waters and semi-automate cultivation steps promise to maintain the viability of farming in higher labour cost countries. Co-location of IMTA/finfish and seaweed farming with grid-connected offshore renewable energy (primarily offshore wind) shows the greatest synergistic benefits for marine space usage, decarbonisation, and nutrient management. Seaweed growth can be accelerated by cycling farm infrastructure between the near surface and nutrient richer depths or upwelling cooler nutrient rich water to sub-surface seaweed crops. Such systems would inevitably require significant increases in infrastructure complexity and costs, jeopardizing their economic viability. Combinations of seaweed and higher value aquaculture products may improve the viability of such novel systems.

Imagine a city that is more competitive, with higher-quality neighborhoods, lower infrastructure costs, and lower C02 emissions per unit of activity. This city has lower combined transportation and housing costs for its residents than other cities at similar levels of economic activity. Its residents can access most jobs and services easily through a combination of low-cost public transport, walking and cycling. Its core economic and population centers are resilient to natural hazards. It is able to finance improvements to public space, connectivity, and social housing by capturing value created through integrated land use and transport planning. Such a vision has never been more relevant for rapidly growing cities than it is today. Transit-oriented development (TOD) can play a major role in achieving such a vision. Based on an observation of methodologies applied in different countries, the World Bank's Community of Practice on Transit Oriented Development has developed a methodology called the 3 Value (3V) Framework, which outlines a typology to facilitate TOD implementation at the metropolitan and urban scale in various contexts. The 3V Framework equips policy and decision makers with quantified indicators to better understand the interplay between the economic vision for the city, its land use and mass transit network, and urban qualities and market vibrancy around its mass transit stations. This book provides examples of approaches taken by cities like London and New York to align their economic, land use, and transport planning to generate jobs and high value. We hope this book will help readers develop a coherent vision, policies, and strategy to leverage the value created through enhanced connectivity and accessibility and make cities even more appealing places to live, work, play and do business.

Abstract The ability to calculate the battery available capacity (BAC) for electric vehicles (EVs) is very important. Knowing the BAC and, thus, the driving range cannot only prevent EVs from being stranding on the road but also optimize the utilization of the battery energy storage in EVs. In order to determine the BAC, this paper presents a new neural network (NN) model of the lead–acid battery, based on the battery discharge current and temperature. Comparisons between the calculated BAC from the NN model and the measured BAC from experiments show good agreement. Furthermore, this new approach can readily be extended to the calculation of the BAC for other types of batteries.

For all of human history except the past two centuries or so, bioenergy provided nearly all the world’s primary energy. Then, fossil fuels largely replaced bioenergy, but concern about climate change and fossil fuel depletion will force a move back to renewable energy, including bioenergy. The main method used here to study the future of global bioenergy was a literature surview of relevant published papers, with emphasis both on those published after 2020, and those having a global focus. The key finding is that bioenergy is unlikely to greatly increase its share of global energy consumption, for several reasons. Liquid biofuel production for transport is likely to almost disappear as countries progressively phase out internal combustion engine vehicles. Traditional firewood use is also projected to fall. There are also doubts about the technical potential of bioenergy, not only because it must compete with the other uses for biomass—food, fodder, fibre and timber—but also because in many cases its climate change mitigation impact is less than for other approaches, including alternative renewable energy sources. The overall conclusion is that bioenergy will have a minor but still useful role in the future global energy system, but global energy reductions are likely to be more important for climate stability than bioenergy.

As of June 2017, 150 countries have ratified the Paris Climate Agreement. This agreement calls for, among other things, strong reductions in CO2 emissions by 2030 and beyond. This paper reviews the Nationally Determined Contribution (NDCs) plans of six Association of Southeast Asian Nations (ASEAN) countries and compares their current and projected future CO2 levels across sectors, and their stated targets in the context of their economic and demographic situations. This comparison reveals wide variations in the types of targets, with the “ambition” level changing as the perspective changes from total CO2 to CO2/capita and per unit gross domestic product (GDP). We also review national plans as stated in NDCs and find that while there are many types of policies listed, few are quantified and no attempts are made to score individual or groups of policies for their likelihood in achieving stated targets. We conclude that more analysis is needed to better understand the possible impacts of current policies and plans on CO2 emissions, and whether current plans are adequate to hit targets. Considerations on better aligning targets are also provided.

Distributed power system is the basic architecture of current power systems and demands close cooperation among the generation, transmission and distribution systems. Excessive greenhouse gas emissions over the last decade have driven a move to a more sustainable energy system. This has involved integrating renewable energy sources like wind and solar power into the distributed generation system. Renewable sources offer more opportunities for end users to participate in the power delivery system and to make this distribution system even more efficient, the novel "Smart Grid" concept has emerged. A Smart Grid: offers a two-way communication between the source and the load; integrates renewable sources into the generation system; and provides reliability and sustainability in the entire power system from generation through to ultimate power consumption. Unreliability in continuous production poses challenges for deploying renewable sources in a real-time power delivery system. Different storage options could address this unreliability issue, but they consume electrical energy and create signifcant costs and carbon emissions. An alternative is using electric vehicles and plug-in electric vehicles, with two-way power transfer capability (Grid-to-Vehicle and Vehicle-to-Grid), as temporary distributed energy storage devices. A perfect fit can be charging the vehicle batteries from the renewable sources and discharging the batteries when the grid needs them the most. This will substantially reduce carbon emissions from both the energy and the transportation sector while enhancing the reliability of using renewables. However, participation of these vehicles into the grid discharge program is understandably limited by the concerns of vehicle owners over the battery lifetime and revenue outcomes. A major challenge is to find ways to make vehicle integration more effective and economic for both the vehicle owners and the utility grid. This research addresses problems such as how to increase the average lifetime of vehicles ...