International audienceImproving the efficiency of water use is usually presented as an opportunity for large water savings, particularly in the agricultural sector. Warnings that this may not translate into reduced consumption is sometimes associated with the rebound effect or Jevons paradox, an appealing concept that can be used to analyse and prevent undesired consequences in the rush for efficiency gains. This article, based on the energy sector, shows that the concept helps to identify possible unintended consequences of increasing efficiency and shows how efficiency gains are shared in society. However, it might be conceptually misleading when applied to water since it reinforces a myth on the consideration of water savings and efficiency, and may be also too restrictive. The recent modernisation of irrigation practices in Spain highlights that the rebound effect is only one of many possible consequences of efficiency improvements

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.

This paper proposes a framework for the identification, assessment and analysis of the water–energy–food nexus at a basin scale. This methodology is applied to the Duero river basin in Spain to detect the most important conflicts derived from water, food and energy interdependencies. Some of the most important issues are the limitations posed by rising energy prices for irrigated agriculture due to modernization, limitations to water treatment, and the possible emergence of new water demands for energy by hydraulic fracturing for oil and gas and enhanced bioenergy.