18/01/10
Water is the medium through which all the key impacts of climate change will be felt.
In the UK, we have already seen a significant increase in the kind of extreme events that we can expect to see more of in coming decades, and the impacts of too much or too little water have been felt by millions over the last few years.
Rainfall generally appears to be decreasing in summer and increasing in winter, with winter rain increasingly falling as heavy events, a key factor in river and surface water flooding.
So far though, we have got off lightly. The impacts on the UK are modest by comparison to the effects in many parts of the world. The fifteen warmest years on record have all occurred since 1990.
Islands and coasts have been devastated by storms and sea level rise, huge areas have been decimated and depopulated by extreme droughts, and aquifer pollution has contaminated and eroded drinking water supplies. There is the prospect of water wars as regions and nations compete for scarce and dwindling supplies.
As a society, we have an economic imperative and moral duty to address the many and varied links between climate change and water.
Climate change has been one of the top priorities for the water industry for many years, but the challenge is such that it cannot be addressed by working alone. Take two examples.
First, the impacts of climate change on water availability are, if uncertain, relatively well understood.
The Environment Agency has estimated that river flows in summer and autumn could drop by 50 to 80 per cent by 2050 in some parts of the country, and levels of groundwater, which provides one-quarter of public water supplies and much more in some areas, could fall by ten per cent by 2025.
This will also have knock-on and serious consequences for water quality, with less dilution of pollutants combining with eutrophication of water bodies.
One solution to all this is for water companies to construct or commission new sources (reservoirs, boreholes, etc) and build additional water treatment capacity to ensure drinking water quality is maintained. This will be part of the solution but will not be sufficient and would be unduly expensive without complementary measures.
Protecting and enhancing the environment and public supplies demands an integrated approach that controls pollution at source, promotes sustainable drainage and ensures incentives in one area (such as Common Agricultural Policy reform) do not conflict with legislation and objectives in another (like the Water Framework Directive).
Such an approach has another benefit, which brings us to the second example. Greenhouse gas emissions from the UK water industry are around five million tonnes CO e per year, less than one per cent of the UK's total.
Despite a major focus on energy efficiency (the industry uses 10% less energy to supply water or treat wastewater than five years ago) and renewable energy (generation increased by forty per cent last year and the industry now generates around nine per cent of its energy needs from renewable sources), this is still increasing.
This is largely the result of additional drinking water and wastewater treatment required to meet increasingly stringent environmental and quality standards.
Work by the industry shows that around half of all wastewater treatment sites could require significant additional investment if we seek to achieve the aims of the Water Framework Directive largely through end-of-pipe measures.
And this is a conservative estimate as in most cases we don't yet know what treatment would be needed. So, reducing pollution at source would not only be a sensible adaptation measure, it would also be a step towards meeting national greenhouse gas reduction targets.
As a society we can both adapt to the impacts of and help mitigate climate change by using water efficiently. Around five per cent of total UK emissions are associated with the heating of water in the home.
Again, water companies have a role, in education, raising awareness, installing meters and offering advice or water efficient products to customers. But, like other aspects of resource efficiency, this is a much broader issue that requires consistent and coordinated action from a range of organizations to deliver behaviour change.
The government, regulators, media, retailers, manufacturers and many others must come together around water efficiency in buildings, labelling schemes and communicating the urgency for action, the link to climate change and simple steps that we can all take. This is starting to happen, driven by Waterwise, the Energy Saving Trust and others.
There is no doubt that climate change is a massive challenge, for the water sector in particular. But there is also a real opportunity, that we cannot afford to let slip. Future generations may not forgive us if we fail to grasp the opportunity, but it requires new ways of working and a fresh approach to some old problems.
A version of this article, by Bruce Horton, appeared in Energy and Environmental Management Magazine, January/February 2010.
