[thedoc (OP)]

Elizabeth asked the Naked Scientists:
   
What is the most  efficient, clean and cheap source of energy?

What do you think?

[alancalverd]

The sun is effectively inexhaustible. If we use it to grow crops for food and biofuel, the entire cycle can be carbon neutral but it won't sustain the present human population at an aspirational level of comfort. The answer is simply to reduce the human population (by not making babies - what can be easier than doing nothing?) to about one fifth or one tenth of the present level. Then our grandchildren and subsequent generations can all enjoy a Western standard of living for ever - or at least until the sun explodes.