Back in July last year, we posted on the deep divisions among UK environmentalists over a tidal barrage across the Severn Estuary. On the one hand, many climate change campaigners were pointing out that this could provide between 5 and 10% of the UK's energy needs through a clean, renewable and predictable source (minus the embodied energy of building such a project of course). On the other hand, conservationists and those concerned with biodiversity were incensed at the potential loss of unique wetlands and wildlife habitat (the Severn Estuary has one of the highest tidal ranges in the world). Now the UK's Sustainable Development Commission, a government advisory body, come out in support of the scheme, but only with some very strict conditions, including creating new habitat and ensuring public financing. The full report can be read here. Meanwhile, the commission's chairman Jonathon Porritt, explains in a blog post over at the Guardian why his organization has chosen to wade in [sorry] on the side of constructing the barrage, albeit cautiously:
"Steering through these positions, the SDC took a "conditions-led" approach. What are the deal breakers that might kill off this deal? Is it feasible in engineering terms? We believe it is. Is it feasible in financial terms? We believe it is, though not without big strings attached. And can it be done in a way that is completely compatible with those EU directives? We believe it can, even though there will be significant environmental impacts.
Achieving consensus on this was not easy. If the price to be paid for a barrage includes the demolition of the habitats and birds directives, then on no account should such a proposal proceed. But we strongly disagree with those who argue that a Severn barrage cannot meet the tests for compliance with the directives. The most important of these, once "overriding public interest" has been demonstrated, is the compulsory requirement to provide "compensatory habitat" for what would be lost in building the barrage. Namely, a vast and unique area of inter-tidal habitat.
The scale and cost of that compensation package is unprecedented - and massive. But we feel it should also be seen as an unprecedented opportunity, enabling the government to bring forward ambitious habitat restoration proposals as part of the urgent need for the UK to start adapting to the inevitable impacts of climate change."
Other environmentalists were not impressed. In another article on the subject at The Guardian, Mark Avery, Conservation Director for the Royal Society for the Protection of Birds, argued that even the clean energy that would be generated would come too late to halt climate change, given the initial upfront energy expenditure involved:
"Construction [of the barrage] will cause the emission of 10m tonnes of carbon. Greenhouse gas savings will be substantial in the long run, but those savings could be too late to avert the damage of climate change. It would be far better to spend the £15bn to £20bn the barrage will cost on measures that will cut emissions more quickly. The Severn estuary is an irreplaceable refuge for wildlife."
Whatever the final decision is on the Severn Estuary Barrage, it seems clear that energy efficiency should be at least as high a priority as constructing such mega-generation schemes. ::Sustainable Development Commission::via The Guardian::