The Royal Society for the Protection of Birds and the National Trust have just issued a joint report into the impact of shale gas development on the UK's environment. These being green organisations it's always fun to go and do some fact checking.

I picked on the "Wildlife disturbance" section, because in itself this seemed a bit unlikely. When I visited Dart Energy's sites near Stirling I noted their proximity to the M9 motorway. The iGas site near Manchester is right alongside the M62. And besides, the drilling process only lasts a few weeks, so it's hard to imagine any long-lasting impact.

The report makes this claim:

...in the Mesa Verde National Park in Colorado, 64 compressors (associated with shale gas extraction) outside the protected area, resulted in an average 34.8 decibel (dBA) rise above typical ambient sound within the park. Along the eastern border of the park, nearest to the highest density of compressors, sound levels increased by a mean of 56.8 dBA above ambient conditions. This compares to the US Environmental Protection Agency recommended “safe noise level” of 55 dBA.

A recent study modeled the impacts that compressors from oil and gas operations might have on Mesa Verde National Park in Colorado. The study found that the sound of 64 compressors outside Mesa Verde elevated the sound level within the park by 34.8 decibels on average, and by 56.8 decibels on the eastern side of the park (which sits closest to the compressors).

Yes folks, you read that right - it's not a measurement of actual sound levels, this is a simulation (the original study is here) that has been reported as fact by our green friends.

As an aside, you might also like to consider how realistic this simulation is. As I understand it compressors are used as part of the drilling and fracking process. So I wonder about the likelihood of 64 sites operating simultaneously within a relatively small area.