Scenarios, sustainability, and critical infrastructure risk mitigation in water planning

This paper examines the state of water supply planning facing unprecedented challenges for ensuring reliable, resilient, safe, and affordable water supplies in Texas and throughout the US. Analysis of water planning methods and practices reveals a robustly sophisticated quantitative modeling capability. Its focus is on both near-term and long-term capital investment requirements and managing operating costs. Water planning focuses on drought mitigation and flood risk management as predominant concerns. But climate change is impacting whole watersheds as well as water systems subject to sea level rise incursions that disrupt wastewater systems. Significant cross-impacts between energy and water add new risks to both energy and water infrastructure, with uncertainties still difficult to robustly quantify. Energy-water nexus issues reflect deeper planning challenges concerning critical infrastructures. Critical infrastructure planning tends to be sectoral-specific even though interdependencies and cross impacts can create broadly impactful cascade effects. Future-state water planning should be done in the context of critical infrastructure planning. Both will benefit from integrating qualitative scenario planning into established quantitative planning models. Doing so expands the complexity that can be captured in planning while providing narratives and using decision-making and public communications tools

Water planning in an age of change

This review paper examines a variety of methodologies that underpin current water planning in the United States – spanning the city, state, and Federal scales – and identifies ways in which changing realities and greater interdependencies between various different critical infrastructures are driving the need for new water planning approaches and processes. Specifically, new sources of uncertainty and their implications are examined, and challenges relating to water supply, allocation, decision making, safety and security, and the information and processes of planning are delineated. In this context, the usefulness of adding scenario planning to current water planning processes is assessed, and ways in which it can be implemented effectively are described. Opportunities for One Water planning to be augmented by critical infrastructure planning and enhanced risk mitigation are also discussed. Recommendations are articulated that are relevant to states, cities, and utility agencies, in order to ensure that they are more resiliently prepared for a substantially more uncertain planning environment in the future, with particular attention to critical infrastructure for water and for other services and the interrelationships between them

Energy Systems (Chapter 6)

Warming cannot be limited to well below 2°C without rapid and deep reductions in energy system carbon dioxide (CO2) and greenhouse gas (GHG) emissions. In scenarios limiting warming to 1.5°C (>50%) with no or limited overshoot (2°C (>67%) with action starting in 2020), net energy system CO2 emissions (interquartile range) fall by 87–97% (60–79%) in 2050. In 2030, in scenarios limiting warming to 1.5°C (>50%) with no or limited overshoot, net CO2 and GHG emissions fall by 35–51% and 38–52% respectively. In scenarios limiting warming to 1.5°C (>50%) with no or limited overshoot (2°C (>67%)), net electricity sector CO2 emissions reach zero globally between 2045 and 2055 (2050 and 2080). (high confidence)

A review of commercialisation mechanisms for carbon dioxide removal

The deployment of carbon dioxide removal (CDR) needs to be scaled up to achieve net zero emission pledges. In this paper we survey the policy mechanisms currently in place globally to incentivise CDR, together with an estimate of what different mechanisms are paying per tonne of CDR, and how those costs are currently distributed. Incentive structures are grouped into three structures, market-based, public procurement, and fiscal mechanisms. We find the majority of mechanisms currently in operation are underresourced and pay too little to enable a portfolio of CDR that could support achievement of net zero. The majority of mechanisms are concentrated in market-based and fiscal structures, specifically carbon markets and subsidies. While not primarily motivated by CDR, mechanisms tend to support established afforestation and soil carbon sequestration methods. Mechanisms for geological CDR remain largely underdeveloped relative to the requirements of modelled net zero scenarios. Commercialisation pathways for CDR require suitable policies and markets throughout the projects development cycle. Discussion and investment in CDR has tended to focus on technology development. Our findings suggest that an equal or greater emphasis on policy innovation may be required if future requirements for CDR are to be met. This study can further support research and policy on the identification of incentive gaps and realistic potential for CDR globally