Independent, 20 December 2012:
No one doubts that unconventional fossil fuels such as shale gas and tar sands could provide energy for many years (letters, 15 December). The problem is that we need to limit temperature rises to 2 degrees centigrade and that means keeping atmospheric levels of CO2 below 450 parts per million (ppm).
Levels have already risen from 280 to 391 ppm and are currently increasing at 2 ppm per year. So we don’t have long before climate change becomes irreversible.
According to the Carbon Tracker initiative there are currently 2,795 gigatons of proven coal gas and oil reserves worldwide, five times more than can safely be discharged.
So why are we exploring unconventional sources such as shale gas and and why on earth are oil companies looking to drill in the Arctic? Energy conservation and renewables are the only rational way forward
Dr Robin Russell-Jones
Stoke Poges, Buckinghamshire