In a study published online today in Nature Climate Change, Prof Declan Conway and Sabrina Rothausen argue that greater focus on the energy requirements of the water sector will be a crucial part of the policy response to the huge challenges it faces in the coming decades.
Transparency in the water industry's energy use is also likely to be important for it to meet carbon-reduction commitments while responding to other measures of sustainability, such as the need for stricter quality standards and increasing demand.
To date, much attention has been given to the need for sustainable water resource management, but far less to the growing energy use and associated emissions from the water sector, for example through processes involved in water treatment and distribution and domestic heating of water.
"Pressures on water management include stricter water-quality standards, increasing demand for water and the need to adapt to climate change, while reducing emissions of GHGs," said Prof Conway, professor of water resources and climate change.
"The processes of abstraction, transport and treatment of fresh water and wastewater all demand energy. Adapting water management to meet increasing demand, regulatory standards and the effects of climate change will in many cases require greater energy use."
He added: "Energy use in the water sector is growing, yet its importance is under-recognized, and gaps remain in our knowledge. In this study we define the need to integrate energy use further into water resource management and identify opportunities for the water sector to understand and describe more effectively its role in GHG emissions, through regulatory and behavioural responses, to meet future challenges."
Some recent studies have highlighted the importance of GHG emissions from energy use in the water sector. They show that water-related energy use in the US accounts for nearly 5% of total GHG emissions, and the proportion is even higher in the UK, although there it is mostly associated with end uses of water, such as heating. In countries with very high freshwater withdrawals, most of the water is used for irrigation and the energy used in its extraction and transport is often considerable. Estimates for India suggest that emissions from lifting water for irrigation could be as much as 6% of total national emissions.
Climate change represents a huge challenge to the sustainable management of water resources. In recent decades, developments in industrial, agricultural and domestic water use, and in water-quality regulation, have greatly intensified the treatment and transport of water. Moreover, rising demand for food and biofuels, and their international trade, threaten to drive expansion of irrigated cropland and cropping intensity and hence greater use of water for agriculture. These activities generally require high energy consumption and have contributed to increases in energy use in the water sector in many parts of the world.
The 'perfect storm' scenario of sustaining increases in food production given climate change impacts and the need to reduce GHG emissions, together with increasing competition for water, provides a strong rationale for better integration of water and energy use.
There is also a need to achieve better connections between mitigation and adaptation. Consideration of alternative water supply systems, treatment technologies or water allocation may have a tendency to overlook the carbon cost; some measures regarded as sustainable water management, such as desalination, are very energy intensive. This is particularly the case in the absence of regulatory pressure, as is currently the case in most countries.
In Greenhouse-gas emissions from energy use in the water sector, Prof Conway and Ms Rothausen, of the School of International Development, quantify energy use in the water sector and detail the extent of current knowledge on emissions from the water sector and agricultural water use. Their review shows that energy use and GHG emissions in the sector are under-recognized, in part because of differences in the scope of water-sector boundaries, data availability, methodological approaches and whether results are expressed as energy use or GHG emissions.
Ms Rothausen explained: "Although end use often has the highest energy use of all water-sector elements, it has not traditionally been seen as a direct part of the water sector and is often unaccounted for in water management and policy.
"What evidence there is shows that energy use in the water sector is considerable and growing. This growth is likely to continue, sometimes as an unintended policy outcome, with greater pressure to use and maintain quality of water resources. Despite some recent progress, we need to better understand and profile the role of the water sector as a GHG emitter. A co-ordinated view of the water sector will promote more comprehensive assessments of energy use, while standardized methodologies will enable comparisons between assessments of different technologies and processes, and between regions or countries."
Greenhouse-gas emissions from energy use in the water sector is published online on June 26 in Nature Climate Change (DOI: 10.1038/nclimate1147).
Press office | EurekAlert!
Minimized water consumption in CSP plants - EU project MinWaterCSP is making good progress
05.12.2017 | Steinbeis-Europa-Zentrum
Jena Experiment: Loss of species destroys ecosystems
28.11.2017 | Technische Universität München
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications
Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...
Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.
The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
11.12.2017 | Physics and Astronomy
11.12.2017 | Earth Sciences
11.12.2017 | Information Technology