Energy systems support technical solutions fulfilling the United Nations' Sustainable Development Goal for clean water and sanitation (SDG6), with implications for future energy demands and greenhouse gas emissions. The energy sector is also a large consumer of water, making water efficiency targets ingrained in SDG6 important constraints for long-term energy planning. Here, we apply a global integrated assessment model to quantify the cost and characteristics of infrastructure pathways balancing SDG6 targets for water access, scarcity, treatment and efficiency with long-term energy transformations limiting climate warming to 1.5°C. Under a mid-range human development scenario, we find that approximately 1 trillion USD2010 per year is required to close water infrastructure gaps and operate water systems consistent with achieving SDG6 goals by 2030. Adding a 1.5°C climate policy constraint increases these costs by up to 8%. In the reverse direction, when the SDG6 targets are added on top of the 1.5°C policy constraint, the cost to transform and operate energy systems increases 2%-9% relative to a baseline 1.5°C scenario that does not achieve the SDG6 targets by 2030. Cost increases in the SDG6 pathways are due to expanded use of energy-intensive water treatment and costs associated with water conservation measures in power generation, municipal, manufacturing and agricultural sectors. Combined global spending (capital and operational expenditures) to 2030 on water, energy and land systems increases 92%-125% in the integrated SDG6-1.5°C scenarios relative to a baseline 'no policy' scenario. Evaluation of the multi-sectoral policies underscores the importance of water conservation and integrated water-energy planning for avoiding costs from interacting water, energy and climate goals.

No abstract

Nature-based solutions (NBS) offer multiple solutions to urban challenges simultaneously, but realising funding for NBS remains a challenge. When the concept of NBS for societal challenges was first defined by the EC in 2017, financing was recognised as one of the major challenges to its mainstreaming. The complexity of NBS finance has its origin in the multiple benefits/stakeholders involved, which obscures the argument for both public and private sector investment. Since 2017, subsequent waves of EU research- and innovation-funded projects have substantially contributed to the knowledge base of funding and business models for NBS, particularly in the urban context. Collaborating and sharing knowledge through an EU Task Force, this first set of EU projects laid important knowledge foundations, reviewing existing literature, and compiling empirical evidence of different financing approaches and the business models that underpinned them. The second set of EU innovation actions advanced this knowledge base, developing and testing new implementation models, business model tools, and approaches. This paper presents the findings of these projects from a business model perspective to improve our understanding of the value propositions of NBS to support their mainstreaming.

The Indus River Basin covers an area of around 1 million square kilometers and connects four countries: Afghanistan, China, India, and Pakistan. More than 300 million people depend to some extent on the basin's water, yet a growing population, increasing food and energy demands, climate change, and shifting monsoon patterns are exerting increasing pressure. Under these pressures, a ''business as usual'' (BAU) approach is no longer sustainable, and decision makers and wider stakeholders are calling for more integrated and inclusive development pathways that are in line with achieving the UN Sustainable Development Goals. Here, we propose an integrated nexus modeling framework co-designed with regional stakeholders from the four riparian countries of the Indus River Basin and discuss challenges and opportunities for developing transformation pathways for the basin's future.

No abstract

Hydropower has been increasingly seen as a two-fold solution to the provision of renewable energy and water storage. However, the massive deployment of both large and small scale hydropower projects has been reported to cause important environmental impacts at the basin scale. This study assesses the differential contributions to regional energy and water security of large (LHP) and small (SHP) scale hydropower deployment in the Spanish Duero basin, as well as associated cumulative environmental impacts. This is performed through a selection of indicators measured in absolute and relative terms. The results suggest that LHP deployment contributes more to energy and water security, performing better in 10 of the 12 indicators. It also shows higher absolute environmental impacts on flow regime and habitat loss. Meanwhile, when analyzed in relative terms, SHP shows greater impacts in all categories as a result of cumulative effects cascading along the rivers system. These findings suggest that optimizing the use of existing hydropower infrastructure would be beneficial for energy, water and environmental security. This could be implemented by substantially reducing the number of low capacity plants with almost no impact on final energy generation, while enhancing the pumping and storage potential of higher capacity plants.After a golden age during the 1940s, 1950s and 1960s, when hydropower was considered the revelation of clean energies, a series of large scale hydropower projects (LHP) were deployed worldwide. However, ever since, the range of associated environmental and social impacts have become increasingly evident, marking the start of a wide debate over its value [6]. More recently, a countertrend towards small scale hydropower (SHP) projects has emerged, each providing similar benefits to the larger infrastructures, but with reduced impacts due to their smaller size, land and infrastructure requirements. This new panacea has prompted both emerging economies with high untapped hydropower potential and countries with limited capacity for large hydropower technology to deploy a mosaic of SHP projects along river and sub basins. Several examples can be found in China, which has developed a strong hydropower basis in recent decades [7,8], particularly in the Yunnan [9,10] and Tibet regions [11]. Other examples in Asia are found in Turkey [12,13], India [14], Thailand [15] and the transboundary Mekong River region [16]. This trend has also played out in Latin America, where SHP deployments are spreading in countries such as Brazil [17,18] and Colombia [19]. Europe has not lagged behind, with around 21,800 operating small hydropower plants [20] primarily concentrated in 10 the UK (120) [21]. However, several studies have raised concerns over the cumulative environmental impacts posed by a large deployment of small hydropower projects [22,23], which can match or outweigh those of large hydropower projects providing an equivalent energy output [6,8,9,12,[24][25][26]. As such, debate centers around whether or not hy...

This article uses logistic growth curves to analyze and compare the historical dynamics in technology deployment and unit upscaling experimented by the three main desalination technologies: multi-effect distillation (MED), multi-flash distillation (MSF) and reverse osmosis (RO). It also explores whether these dynamics follow a number of patterns identified in another well studied technology family with increasing strategic importance for desalination, i.e. energy technologies. The analysis suggests that thermal technologies (MED and MSF) are in an advanced growth phase and approaching saturation, with deployment levels likely to peak before 2050. The logistic fit for RO lacks enough significance to derive meaningful future capacity projections. RO also shows a remarkably high average-to-maximum unit capacity ratio mirroring a modular and more granular nature. Meanwhile, the three technologies are found to meet a series of common patterns in the temporal and spatial sequence of deployment identified in energy technologies. Based on such patterns and technology natures, PV-RO hybrid systems may hold the highest potential to overcome the cost and energy footprint challenges of desalination in the future. This analysis can guide the integration of desalination into modelling frameworks intended to assess future technological scenarios to address water scarcity and sustainable development goals related challenges.

We have witnessed the great changes that hydrogeological systems are facing in the last decades: rivers that have dried up; wetlands that have disappeared, leaving their buckets converted into farmland; and aquifers that have been intensively exploited for years, among others. Humans have caused the most part of these results that can be worsened by climate change, with delayed effects on groundwater quantity and quality. The consequences are negatively impacting ecosystems and dependent societies. The concept of resilience has not been extensively used in the hydrogeological research, and it can be a very useful concept that can improve the understanding and management of these systems. The aim of this work is to briefly discuss the role of resilience in the context of freshwater systems affected by either climate or anthropic actions as a way to increase our understanding of how anticipating negative changes (transitions) may contribute to improving the management of the system and preserving the services that it provides. First, the article presents the basic concepts applied to hydrogeological systems from the ecosystem’s resilience approach. Second, the factors controlling for hydrogeological systems’ responses to different impacts are commented upon. Third, a case study is analyzed and discussed. Finally, the useful implications of the concept are discussed.