Edward Byers

Water and climate risks to power generation with carbon capture and storage

Carbon capture and storage (CCS) provides the opportunity to minimize atmospheric carbon emissions from fossil fuel power plants. However, CCS increases cooling water use and few studies have simulated the potential impacts of low flows on CCS power plant reliability. We present a framework to simulate the impacts of natural hydrological variability and climatic changes on water availability for portfolios of CCS capacity and cooling technologies. The methods are applied to the River Trent, the UKs largest inland cooling water source for electricity generation capacity. Under a medium emissions climate change scenario, the projected median reductions in river flow by the 2040s was 43% for Q 99.9 very low flows and 31% in licensable abstractions between Q 99.9 and Q 91. With CCS developments, cooling water abstractions are projected to increase, likely exceeding available water for all users by the 2030s–2040s. Deficits are reduced when wet/dry hybrid tower cooling is used, which may increase reliability at low flows. We also explore alternative water licensing regimes, currently considered by the UK Government. Climate change and growing cooling demands, individually and jointly present risks that will be prominent by the 2030s, if unaddressed. These risks may be managed if water-efficient abstraction is prioritized when supplies are limited.

Multi-model and multi-scenario assessments of Asian water futures: the Water Futures and Solutions (WFaS) initiative

This paper presents one of the first quantitative scenario assessments for future water supply and demand in Asia to 2050. The assessment, developed by the Water Futures and Solutions (WFaS) initiative, uses the latest set of global climate change and socioeconomic scenarios and state-of-the-art global hydrological models. In Asia, water demand for irrigation, industry and households is projected to increase substantially in the coming decades (30-40% by 2050 compared to 2010). These changes are expected to exacerbate water stress, especially in the current hotspots such as north India and Pakistan, and north China. By 2050, 20% of the land area in the Asia-Pacific region, with a population of 1.6-2 billion, is projected to experience severe water stress. We find that socioeconomic changes are the main drivers of worsening water scarcity in Asia, with climate change impacts further increasing the challenge into the 21st century. Moreover, a detailed basin-level analysis of the hydro-economic conditions of 40 Asian basins shows that although the coping capacity of all basins is expected to improve due to GDP growth, some basins continuously face severe water challenges. These basins will potentially be home to up to 1.6 billion people by mid-21st century.

A continental-scale hydro-economic model for integrating water-energy-land nexus solutions

This study presents the development of a new bottom‐up large‐scale hydro‐economic model, Extended Continental‐scale Hydro‐economic Optimization (ECHO), that works at a sub‐basin scale over a continent. The strength of ECHO stems from the integration of a detailed representation of local hydrological and technological constraints with regional and global policies, while accounting for the feedbacks between water, energy and agricultural sectors. In this study, ECHO has been applied over Africa as a case study with the aim of demonstrating the benefits of this integrated hydro‐economic modeling framework. Results of this framework are overall consistent with previous findings evaluating the cost of water supply and adaptation to global changes in Africa. Moreover, results provide critical assessments of future investment needs in both supply and demand side water management options, economic implications of contrasting future socio‐economic and climate change scenarios, and the potential tradeoffs among economic and environmental objectives. Overall, this study demonstrates the capacity of ECHO to address challenging research questions examining the sustainability of water supply, and the impacts of water management on energy and food sectors and vice versa. As such, we propose ECHO as useful tool for water‐related scenario analysis and management options evaluation.

Tools for Tackling the Water-Energy-Food Nexus

Abstract Researchers and practitioners have developed many tools to study the water-energy-food nexus at a variety of scales and perspectives in order to aid decision-making. However, there is a recognised lack of tools that consider these interdependent and complex interactions in an integrated fashion. Whether to connect and federate wellestablished modelling systems and approaches, which may be challenging, or to design truly integrated tools for holistic consideration of the nexus issues, is also debated. This paper discusses four distinctly different approaches which appear to have wide-scale applicability, although demonstration of these approaches in multiple cases (besides the Polestar model which is already regional/ global) is yet to be applied. Sustainable implementation of any tools will require greater accessibility such that they may be more widely deployed by practitioners. Harmonisation of results and insights between different scales, so that decision-makers may consider global-local impacts, also remains a challenge.

Air Quality-Carbon-Water Synergies and Trade-offs in China’s Natural Gas Industry

Both energy production and consumption can simultaneously affect regional air quality, local water stress and the global climate. Identifying the air quality–carbon–water interactions due to both energy sources and end-uses is important for capturing potential co-benefits while avoiding unintended consequences when designing sustainable energy transition pathways. Here, we examine the air quality–carbon–water interdependencies of China’s six major natural gas sources and three end-use gas-for-coal substitution strategies in 2020. We find that replacing coal with gas sources other than coal-based synthetic natural gas (SNG) generally offers national air quality–carbon–water co-benefits. However, SNG achieves air quality benefits while increasing carbon emissions and water demand, particularly in regions that already suffer from high per capita carbon emissions and severe water scarcity. Depending on end-uses, non-SNG gas-for-coal substitution results in enormous variations in air quality, carbon and water improvements, with notable air quality–carbon synergies but air quality–water trade-offs. This indicates that more attention is needed to determine in which end-uses natural gas should be deployed to achieve the desired environmental improvements. Assessing air quality–carbon–water impacts across local, regional and global administrative levels is crucial for designing and balancing the co-benefits of sustainable energy development and deployment policies at all scales.Focusing on China’s six natural gas sources and three end-use gas-forcoalsubstitution strategies in 2020, this study shows that, except for coal-based synthetic gas, replacement of coalwith gas usually has air–carbon–water co-benefits, although with air–water trade-offs in the magnitude ofimprovement.