It takes a lot to shift an established anticyclone. The falling, compressing and warming continental air that has brought us what may turn out to be the driest May/June/mid-July in eastern parts for about two centuries will not give ground readily to Atlantic air. Hopes that the remnants of Hurricane Storm Chris, hitching a ride on the jet stream as it moves out of eastern Canada, might provide sufficient power next week to dislodge our long-standing high pressure and bring, at least, a temporary break in the drought seem less confident now as this early-season hurricane heads north towards Iceland.
It would be fair to say that our experience this summer has been a chastening one. The average citizen has become sensitised to the value of that precious commodity: water. As the scarce supplies have been carried on to fields to feed cattle, or domestic basinfuls and bucketfuls recycled to try and keep plants indoors and outdoors alive, as plugs have been left in sinks, kettles have been boiled half empty, showers have been shortened, we have become conscious as never before of our water footprint.
Water footprint
Just like our carbon footprint we can also measure our water footprint. Taking all the various production processes into account, water volumes to produce particular items have been quantified, and the figures are surprisingly large. it takes about 30 litres of water to produce a cup of tea, about 960 litres for a loaf of bread and an astonishing 15,500 litres to produce 1kg of beef. At a personal level we use about 133 litres per day, roughly the same as is drunk by a dairy cow. Our vulnerability to not having enough water is now much more appreciated, as we face hard choices in what may well become a scarcer resource in the years ahead.
Future research will enable us to put a figure on what contribution climate change made to the present drought event, just as it will for the Beast from the East or our recent winter flood events.
Our water footprint and our carbon footprint are linked together
Though our climate models are not yet capable of providing certainty on future rainfall trends, they converge on a suggestion that we will experience wetter winters and drier summers, something that my colleague Dr Conor Murphy’s reconstruction of three centuries of Irish rainfall records tentatively suggests is already happening. With temperature, the models are much more certain.
We can say with a high degree of confidence that the present exceptional temperatures are likely to become the norm during the lifetime of our children unless serious steps to reduce global greenhouse gas emissions are taken.
Adapting to future conditions will require an investment in water infrastructure on a major scale if we are to become a climate-resilient island. It will require a major augmentation of supply, especially for the Greater Dublin region, to ensure that short-term choices between water for houses and water for jobs are not made to the detriment of the next generation. Increased supply must not be done, however, at the expense of water quality in our rivers, lakes and estuaries.
The ability of rivers to absorb waste-water flows in times of low flow must be more carefully managed and the Water Framework Directive must be taken more seriously. The continuing deterioration of our formerly pristine water bodies, in particular, is a shameful legacy to pass on to the next generation.
‘What if’ questions
Managing water will ultimately come down to choices made in individual catchments for much of Ireland. Here the “what if” questions will have to be thoroughly researched to inform policy choices. What if we plug the leaks? What if our population grows by a certain percentage? What guidance can downscaled climate models give us for future rainfall receipt? What if we improve conservation? How much time will this buy us before water stress emerges and major infrastructural surgery is needed? For each catchment, the answers will be different.
Some will have groundwater resources to call on; some will have porous soils or unhelpful stream networks; some will have no lakes or peatlands or upland sources. In Maynooth University we developed and tested such a tool for the area around Kells in Co Meath some years ago. The answers were complicated, but emphasised the need to plan now for coping with inevitable climate changes over the next few decades.
Water is a visible and easily measured commodity. Our water footprint is determined to a large degree by everyday personal choices. Our carbon footprint is less obvious. But they are intertwined. The need to pull our weight in tackling climate change is demonstrated by the growing range of climate shocks we are experiencing. What is clear is that sympathy for our plight is unlikely to be generous if we continue to be Europe’s laggards in this area. Perhaps the events of this summer will provide the catalyst for a change in attitudes.
John Sweeney is emeritus professor of geography at the National University of Ireland, Maynooth