Tests for renewable energy and the Severn Barrage

Comment 2007

 * Tidal power - The Wildlife Trusts’ approach. Tests for renewable energy proposed, September 29 place, place, topic

Prior to the launch of a Sustainable Development Commission report on tidal power, The Wildlife Trusts challenges the government to commit not only to mitigation - reducing carbon emissions – but also to adaptation - helping wildlife and people cope with inevitable climate change.

The Wildlife Trusts propose a series of key tests for any renewable energy proposal, including all tidal power proposals, looking at both mitigation and adaptation: “Our tests go further than routine environmental assessments at present. We believe this is crucial if we are to see truly sustainable development. Any proposal for cutting carbon emissions through tidal power is completely counter-productive if it costs us more than it saves by damaging the natural habitats and processes which can help us tackle climate change.” Brian Eversham, The Wildlife Trusts.

Mitigation

 * Is this the best possible use of renewables technology?
 * Does it minimise its carbon budget in construction and maintenance?
 * Does it reduce future natural capacity for carbon sequestration in peat or shallow-water marine deposits?
 * Does it impact on current natural carbon stores - organic sediments, peat, other soils?
 * Will it cause associated development - roads, houses, industry, airports? What is the carbon impact of these?
 * Will it cause ‘rebound’ - extra carbon emissions because of changing people’s behaviour for the worse?

Adaptation

 * Will the development protect existing wildlife sites of local, national or international importance? These are critical in allowing wildlife to adapt to climate change.
 * Will the development enhance existing natural habitats and create new ones?
 * Will the development improve landscape connectivity, so wildlife can move around to adapt to climate change? Wildlife highways can also provide more carbon-free travel for local people - footpaths and cycle ways through wildlife-rich green space.
 * Will it help moderate the local climate for the benefit of people and wildlife?
 * If any damage to wildlife is unavoidable, is there a tried and tested way of replacing the damaged wildlife habitat? Is that cost-effective - economically and in carbon terms.

Mitigation
The current barrage proposals are a reworking of plans which have been around for decades. Does the leading edge of the renewables industry consider the barrage to be progressive? Huge volumes of aggregates and concrete will be used - in-channel turbines or lagoons may use far less. Chalk-forming marine algae (collolithophores) account for 43% of carbon sequestration. This does not happen in the open ocean - it’s concentrated in shallow seas. The Bristol Channel and south-west approaches are a hotspot for these algae, and any disruption to water movement and nutrient flow in the estuary could have a serious impact on these natural carbon sinks. Sediments in the estuary are rich in organic material, and may release their carbon if flows are disrupted. The economic case for the barrage may depend on massive developments of roads, airport, housing and business parks, which are very unlikely to be carbon neutral. There may even be a major road on top of the barrage. A new road across the barrage would generate more traffic.
 * Is this the best possible use of renewables technology?
 * Does it minimise its carbon budget in construction and maintenance?
 * Does it reduce natural capacity for carbon sequestration (future storage) in peat or shallow-water marine deposits?
 * Does it impact on natural carbon stores - organic sediments, peat, other soils?
 * Will it cause associated development - roads, houses, industry, airports? What is the carbon impact of these?
 * Will it cause ‘rebound’ - extra carbon emissions because of changing people’s behaviour for the worse?

Adaptation
The UK’s seas and estuaries are the best in Europe. The Severn Estuary is a key part of a critical European network of internationally important wildlife sites - it’s essential we maintain and enhance these for wildlife to cope with climate change. It’s a Special Protection Area for its waders and waterfowl, a candidate Special Area of Conservation for its intertidal habitats, and a Ramsar wetland of international importance for wildlife. The whole area is also a Site of Special Scientific Interest. Current proposals talk in vague terms of compensating for losses, but no enhancement is possible. No No
 * Will the development protect existing wildlife sites of local, national or international importance which are critical in allowing wildlife to adapt to climate change?
 * Will the development enhance existing natural habitats and create new ones?
 * Will the development improve landscape connectivity, so wildlife can move around to adapt to climate change?
 * Will it help moderate the local climate for the benefit of people and wildlife?
 * If any damage to wildlife is unavoidable, is there a tried and tested way of replacing the damaged wildlife habitat? Is that cost-effective - economically and in carbon terms.

It’s extremely difficult to engineer coastal habitats, and virtually impossible to predict what the outcomes of attempting to create saltmarsh and intertidal mud might be. The potential losses in the Severn estuary are many times larger than any coastal habitat creation scheme. Compensation habitat for the estuary could cost £3-4 billion.

Quote
“We tend to forget the sea is absorbing 43% of the carbon in the atmosphere. Tiny organisms in the sea are fixing carbon and storing it for millions of years. The UK’s coastal waters are a hotspot for such chalk-forming plankton. If we start to play about with our estuarine and marine ecosystems, we risk losing one of our best allies in the fight against climate change.” Joan Edwards, The Wildlife Trusts