Governments and businesses have been urged to accelerate efforts to reduce the energy intensity of water processes, such as waste water treatment and transportation, in order to address the water industry’s sizeable carbon footprint.
Researchers at the University of East Anglia yesterday published a study online in Nature Climate Change, arguing that energy use and greenhouse gas emissions arising from water management processes are poorly understood, but are likely to become increasingly important over the coming decades.
Water related energy use, through processes such as treating fresh and waste water, accounts for five per cent of total greenhouse gas emissions in the US, and the proportion is even higher in the UK, according to the report’s authors Professor Declan Conway and Sabrina Rothausen.
Estimates for India suggest that emissions from lifting water for irrigation could account for as much as six per cent of total national emissions.
The study argues that the water industry has invested heavily in developing more sustainable resource management policies and techniques, but less attention has been paid to tackling growing energy use and associated emissions.
For example, biofuels are intended to reduce carbon emissions in the energy sector, but production might undermine food and water security leading to greater use of energy in these sectors.
The study also highlights the lack of investment in modernising water technology. In the UK business investment in water research and development dropped 60 per cent from 1999 to 2008, while government R&D schemes for the water sector are limited compared to the energy sector.
This relatively low level of investment means the industry has struggled to roll out new low carbon tehnologies, such as anaerobic digestion systems at waste water plants which, according to the report, could curb energy use across the sector by up to 4,940 million kWh a year.
The review calls for a greater understanding of the environmental impact of the water sector, and standardised methodologies for measuring its greenhouse gas emissions.
Rothausen also maintained that the end use of water should be seen as a direct part of the water sector and accounted for in management and policy.
“What evidence there is shows that energy use in the water sector is considerable and growing,” she said.
“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.”
