The engineering of solutions is easier if we know the reasons why. So I would like to add to the comments of Messrs Rivers, Porter and Wright (Letters, 26 March) and many previous correspondents.
Global energy demand vastly exceeds our present technologically-available, non-fossil fuel power sources. Even present nuclear fission is limited by available uranium reserves. So efficiency and demand reduction are paramount as there is urgent need to reduce carbon emissions.
Our emissions globally 'must peak in 20 years' says the Stern Review, and according to the science need to 'significantly reduce in 10 years'. Yet global carbon emissions are projected to double by 2050.
The situation starts to become 'interesting' by 2015 when atmospheric CO2 passes 400ppm. With no solutions in place, by 2030 it becomes 'dangerous' (450ppm) and by 2060 (exceeding 550ppm) Armageddon will like as not be on the way.
Martin Rodger
Poole, Dorset
Beginning of the end?
Nanogenerator consumes CO2 to generate electricity
Whoopee, they've solved how to keep a light on but not a lot else.