Climate change

Water resources, climate change and the nexus

The complex interdependencies between climate change, water and other social and environmental factors present a challenge for researchers and policy makers.

Reservoir|Peter Roome, License: CC-BY-NC-ND 2.0 Source: Flickr
Edited by Tracy Zussman

Scientific consensus supports the conclusion that human activity is the primary driver of recent global warming and that there has been “a detectable human influence on the global water cycle”. These climate change impacts on water are complex and affect different regions in different ways.

At the same time water resources have been subject to increasing stress from other factors - manufacturing, agricultural activity and domestic use being the most obvious – and these demands are projected to increase with populations rising and urban expansion accelerating in water-scarce areas.

Governments have identified water as a key to climate change adaptation (it’s mentioned in 93% of national climate action plans) and most efforts to reduce greenhouse gas emissions depend on reliable access to water resources.

It is perhaps surprising then that, until Paris in 2015, water management as a topic had been conspicuously absent from the climate change negotiations and the Paris Agreement still failed to mention water in any substantive way.

In Marrakech in 2016, water finally took centre stage in the conference proceedings with a dedicated “Action Day for Water” and the launch, by the Moroccan Government, of the Water and Climate Blue Book.

Continue reading: Science and complexity

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Science and complexity

A starting point in trying to address water issues in the context of climate change is to try to identify and understand the interdependencies between climate change, the water cycle and other demographic, economic, environmental, social and technological forces.

The science documenting the impact of climate change on water resources is strong. The 2014 IPCC Fifth Assessment Report says there is robust evidence that climate change will reduce renewable surface water and groundwater resources in most dry subtropical regions and that this will most likely intensify competition for water between sectors. The report particularly highlights increased risks in urban areas, including from extreme rainfall, inland and coastal flooding, drought and water scarcity. These risks are amplified for those lacking essential infrastructure and services or living in exposed areas. Rural areas are also expected to experience major impacts on water availability and supply with this in turn causing shifts in the production areas of food around the world.

But, when it comes down to understanding what impact efforts to mitigate and adapt to climate change will have the IPCC found that the complexity of these relationships between water, environmental and human factors means that the “tools to understand and manage these interactions remain limited.”

Continue reading: The Water Energy Food Nexus


Water and Climate Blue Book
World Water Council, 2016
Llaunched by the Morroccan government at COP22 in Marrakech, the blue book aims to raise international awareness on the vulnerability of water in the context of climate change and the urgency of action. It also speaks in favor of merging both agendas of water and climate, in order to ensure a total integration of water in the negotiations on climate change.The book also presents concrete actions in the water field to cope with the impact of climate variability, actions which have already been launched or are being implemented, including the Water for Africa initiative.
Climate Change 2014: Impacts, Adaptation, and Vulnerability
Intergovernmental Panel on Climate Change, 2014
Summary for policymakers on climate change impacts, vulnerability, and adaptation, based on the IPCC Fifth Assessment Report. As part of the Working Group II (WGII) contribution to the fifth assessment report of the Intergovernmental Panel on Climate Change, this summary for policymakers focuses on recent work assessing climate change impacts, vulnerability, and adaptation. Compared to previous WGII reports, this assessment considers a substantially larger knowledge base of relevant scientific, technical, and socioeconomic literature.
Climate change and water: IPCC technical paper VI
Intergovernmental Panel on Climate Change, 2008
This IPCC technical paper extensively and thoroughly examines the potential consequences of climate change on the world’s freshwater resources and the communities that depend on them. Its objective is to improve understanding of how water-related issues are linked to climate change and adaptation and mitigation responses. The methodology splits sections into observed and projected effects with error margins and a stress on uncertainty presented as necessary context.
Climate change and water: An overview from the World Water Development Report 3: Water in a changing world
United Nations World Water Assessment Programme, 2009
This World Water Assessment Programme Special Report brings together messages on water and climate change from the World Water Development Report 3: Water in a Changing World. Water in a Changing World shows that changes in our water resources are shaped to a great extent by a number of key externalities, among them climate change, and that decisions taken far from the conventionally defined water sector have a tremendous influence on water resources and how they are used or misused.
The United Nations World Water Development Report 3: water in a changing world
United Nations Educational, Scientific and Cultural Organization, 2009
This report provides a comprehensive analysis of the state of the world’s freshwater resources. The authors note that water is linked to the crises of climate change, energy and food supplies and prices, and troubled financial markets. Unless their links with water are addressed and water crises around the world are resolved, these other crises may intensify and local water issues may worsen, converging into a global water crisis and leading to political insecurity and conflict at various levels.
Summary for policymakers. Climate change 2007: the physical science basis
Intergovernmental Panel on Climate Change, 2007
The Working Group I contribution to the IPCC Fourth Assessment Report describes progress in  understanding of the human and natural drivers of climate change, observed climate change, climate processes and attribution, and estimates of projected future climate change.

The Water Energy Food Nexus

In attempting to deal with this complexity and develop policy recommendations to tackle climate impacts on water resources, many key institutions have applied a conceptual framing of these inter-relationships known as the Water Energy Food (WEF) Nexus. The Nexus approach tries to build an understanding of the synergies and trade-offs between competing demands for water, land and energy-related resources by moving away from a sectoral framing of resource management towards a more integrated perspective.

Since it emerged the Nexus approach has been widely adopted and adapted to analyse the potential impacts of different policy measures and approaches that could be used to improve water management across different sectors in response to climate change.

A good example is the World Bank’s development of the “Water-Climate Nexus” which uses economic modelling to “document the drivers of the changing patterns in supply and demand for water in a climate change impacted world, and to offer solutions which ensure that water does not become a constraint on prosperity”. Their “High and Dry” report, despite warning that “water scarcity, exacerbated by climate change, could hinder economic growth, spur migration, and spark conflict”, ends up reaching the reasonably upbeat conclusion that, for most countries, taking action to allocate and use water resources better can negate the negative impacts of climate change. Among the instruments they put forwards as being most effective include better planning for water resource allocation, adoption of incentives to increase water efficiency, and investments in infrastructure to secure water supplies.

Not everyone is happy with the Nexus approach as it stands however. Methodological criticisms argue that the nexus approach adds little to other resource management tools, like Integrated Water Resource Management for example, and has failed to integrate emerging concepts of sustainable development.

Perhaps more seriously, it’s economic focus on balancing trade-offs between actors, the fact that it promotes a narrative of scarcity and looming crisis, some argue, leads towards a over-emphasis on solutions that involve investments in large-scale infrastructure.

At the same time the number of large influential global policy actors promoting it has all raised concerns in some quarters that the resulting power inequalities often restrict the emergence of alternative framings and “close down the consideration of alternative development pathways”.

Certainly, for now at least, the Nexus is fairly ubiquitous but most critics seem focused on evolving and improving the analytical framework and tools that the Nexus approach provides, rather than trying to replace it with something else entirely.

Continue reading: Back to introduction


The Water-Energy-Food Nexus: A new approach in support of food security and sustainable agriculture
Food and Agriculture Organization of the United Nations, 2014
This FAO note gives a brief introduction to the Water-Energy-Food (WEF) Nexus conceptual framework as a useful way to describe and address the complex and interrelated nature of our global resource systems.
Sustainable development and the water–energy–food nexus: A perspective on livelihoods
Science Direct, 2015
The water–energy–food nexus is being promoted as a conceptual tool for achieving sustainable development. Frameworks for implementing nexus thinking, however, have failed to explicitly or adequately incorporate sustainable livelihoods perspectives. This is counterintuitive given that livelihoods are key to achieving sustainable development.
High and Dry: Climate change, water and the economy
World Bank Publications, 2016
This World Bank reports finds that water scarcity, exacerbated by climate change, could hinder economic growth, spur migration, and spark conflict.
Making governance work for water-energy-food nexus approaches
Climate and Development Knowledge Network, 2017
This new working paper by Andrew Scott of ODI explores the effectiveness of governing for the “water-energy-food nexus” of issues. The author looks at approaches that understand the links between sectors, recognise these in decision-making and promote integrated policy-making.The concept of the water–energy–food (WEF) nexus has become widely used to help understand interdependencies among the three systems, and how they can be managed sustainably to meet growing demand. The water–energy–food nexus has especially been advocated to address conflicts among the sectors.
Nexus Nirvana or Nexus Nullity? A dynamic approach to security and sustainability in the water-energy-food nexus
STEPS Centre, Institute of Development Studies, 2014
STEPS Centre working paper proposing a dynamic approach to security and sustainability in the water-energy-food nexus. In the wake of various global crisis in energy, food, and finance since 2008, together with growing concerns and uncertainties surrounding climate change, many in the development field are urging a more integrated approach between key sectors. The concept of a water-energy-food nexus has emerged from a range of proponents, each supplying their own perspectives and agendas.
A review of the current state of research on the water, energy, and food nexus
, 2015
The purpose of this paper is to review and analyze the water, energy, and food nexus and regions of study, nexus keywords and stakeholders in order to understand the current state of nexus research.It starts with the hypothesis that to date the research in this area has been somewhat fragmented and there is no clear definition of the term. In addition, the relationships of all three resources such as water–energy, water–food and/or water–energy–food are interrelated and interdependent, which implies that the complexity of the nexus system has not yet been fully clarified. 
Water and climate change adaptation: policies to navigate uncharted waters
Organisation for Economic Co-operation and Development, 2013
Organisation for Economic Co-operation and Development (OECD) survey and report setting out the climate adaptation challenge for freshwater management, and providing policy guidance. Climate change is reshaping the future for freshwater, aggravating pressures and complicating planning, management, and investment in water infrastructure. This report is drawn from the results of an OECD-wide survey designed to gauge progress on climate change adaptation in the water sector.
Water, food and energy nexus challenges
World Business Council for Sustainable Development, 2014
Comprehensive yet concise report outlining the key challenges and projected demands in the global agricultural sector, from an energy-water-food nexus perspective. Based on several existing data-sets, this paper by the World Business Council for Sustainable Development seeks to provide a comprehensive yet concise overview of the main challenges associated with increasing demand for agricultural products.