Letters

Trusting the techno-fixes

In connection with Mick Hamer’s very welcome words on concentrating solar power (CSP) [‘The scrubbers, the sulphates and the sunshield solution’] I would like to correct one important point. It is quite wrong to suggest that there would be “huge transmission losses” in bringing solar electricity from North Africa to the UK. With a Europe-wide ‘supergrid’ (of highly efficient high-voltage direct current transmission lines) there would be less than 10% loss of power. This kind of grid would reduce energy wastage by allowing electricity to be moved from areas of surplus to areas of need. It would also smooth out the variability of wind power by drawing on wind across a very wide area. Finally, it would provide access to large-scale, remote sources of renewable electricity such as offshore wind, wave and tidal power.
Gerry Wolff, TREC-UK

One promising approach to carbon sequestration that was missing from Mick Hamer’s article is what is often called ‘biochar’. Very briefly, it takes vegetable matter (crop waste, forest debris) which has already captured CO2, reduces it to charcoal through pyrolysis, a process that captures the gases released (which include hydrogen and other non-carbon fuel gases), leaving the carbon behind as a solid - charcoal. The charcoal is then ploughed into the ground where it combines with mychorhizal fungi to act as a very efficient fertiliser for further vegetable growth, which in turn can be fed back into the cycle. The net result is that the carbon captured by the plants is returned to the soil in a stable form.

There are several positive aspects to this approach. It is relatively low-tech, imitates nature, is local in application and, if applied on a global scale, could capture a significant proportion of the carbon dioxide emissions we release each year. Moreover, it would provide large quantities of fuel. So it has multiple positive effects.

There are a number of projects exploring this technology in the US, Canada and Australia, and early results are very promising. A more detailed overview of the process can be found at www.eprida.com, one of the companies working on its development.
Peter Russell, by email

We haven’t managed to get food and water to the human population yet - so what hope is there for sorting out the overheating planet by technical means?
Malcolm Handoll, Five Senses

In praise of quality

I have just read ‘Lamb in full flower’ [GF64], and would like to pass on my appreciation of the fact that the hard work done by these often forgotten farmers is slowly beginning to be recognised.

Here on Dartmoor we are just starting on this road of collaboration between farmers to share the story of how we create the landscape and showcase the rewards from the wonderful quality beef and lamb it produces.
Andy Bradford, Brimpts Farm, Devon

The chicken or the egg?

I find it hard to believe that it was consumer power alone that phased CFCs out of aerosols, as Julia Hailes claims [‘What’s in your wallet?’, GF64]. Au contraire, it was legislation on one side of the Atlantic that preceded consumer power on the other. The US (yes, you read that correctly) passed laws to phase out CFCs in 1978, a good ten years before the UK eventually followed suit.

It’s good to see The New Green Consumer Guide is on its way, but why has it taken so long? The original guide promised a follow-up edition, as well it might - its lists of ozone-friendly aerosols became obsolete with the passing of the Montreal Protocol of that same year. Moreover there were other issues that the authors only tackled briefly, such as the environmental impact of clothing.
Louisa Radice, Exeter

Go local in the local

It’s all very well tinkering with the supply chain to make alcoholic drinks more sustainable - by manufacturing lighter bottles or using organic hops [‘Ten green bottles’, GF64]. However, it’s not much good for the environment if the ingredients are trucked hundreds or indeed thousands of miles before being made into beer, or the bottles are non-returnable.

For me the ‘greenest tipples around’ tend to come from small, real ale microbreweries, of which there are now nearly 400 within the UK. Many of them source most of their ingredients as locally as possible and sell the vast majority of their ale in returnable casks in local pubs - so there are far fewer lorries and  bottles involved. And let’s face it, real ale is much better for us than lager, with fewer chemicals added in the brewing process.

My own local micro-brewery, Red Squirrel in Hertford, may not be well known outside the area, but by its very nature and scale is able to make its entire supply chain much more sustainable - something that’s way out of reach for some of the national and international brands you feature.
Dee Monaghan, South Herts CAMRA

24 June 2007