Carlisle & District

Environment Group Topics 2012

Three topics discussed by the Environment Group at the end of 2012 were hydropower, fracking and climate change. In October members of the group went to Settle to see for themselves a 50 kW Archimedean Screw. The Screw generates electricity from normal river flow on the River Ribble, diverted through the screw at a weir which has existed for many decades. Hydropower is one of the non fossil-fuel generating sources of energy for which installation grants can be obtained. Energy fed into the national grid from such sources also attracts feed-in tariffs which make the projects financially attractive to local communities. Members of the Group were able to see the scale of the operation at Settle, the minimal site disruption caused by installation of the screw and, precisely on cue when one of our members was looking, a salmon jumping the weir on its way upstream. A pleasant discussion of the pros and cons of these sorts of initiative started at the site and was continued over a very agreeable pint of real ale in a local pub before returning home on the Carlisle Settle railway on which, of course, we’d arrived earlier in the morning.

Anybody wanting to see the Settle Archimedean Screw actually working might like to visit www. on the Internet and view a You Tube video of the Screw working on October 10, shortly after our own visit on October 4.

Fracking was our November topic. Fracking (Fracture cracking) is the American term used to describe the extraction of natural gas from impermeable shales. It is a relatively new technology used widely in China and the United States to obtain natural gas from sources which, without this extraction technique, would remain undeveloped. It involves drilling a vertical borehole some 3km deep, turning the drill at right-angles underground and drilling horizonatally for another 3 km. Small, underground, explosions are set off to fracture the shale which are then expanded by the insertion into them of water at very high pressure. Water is then ‘sucked’ back up the borehole and the natural gas, held in minute pores within the shale, is released to flow naturally to the surface where it is collected, stored and processed. This, it goes without saying, is a highly simplified description of the process.

Fracking has recently been tried near Blackpool and Southport in Lancashire where it controversially is said to have set off small earthquakes, sufficient for the whole experiment to have been suspended for a year. The government appears very sympathetic to this technology since some estimates suggest it could supply Britain with new natural gas supplies for several decades. Many envionmentalists see all sorts of objections to ‘fracking’ and the whole subject will no doubt be thoroughly debated in our national press over the next few months.

In December the Group returned to a discussion of global warming. Following the ‘climategate’ controversy over the reliability of global warming predictions made a few years ago the debate about global warming has ‘cooled’ down a bit! However, recent studies undertaken by researchers at the University of Berkeley in California, originally sceptical about the reality of global warming, apparently confirm earlier predictions of global warming made by NASA and the British Met. Office. In fact, the Berkeley studies apparently suggest that the rate of warming may be greater than the first studies claimed. Many people believe that the greater uncertainty of the world’s weather in the last few years (including in the UK) may be the early signs that our climates really are changing. This, therefore, appears to be another environmental topic that we shall have to keep our eyes on in 2013.