You've all heard the environmental/waste argument "the Bitcoin network uses too much computing power."
Right now I don't think this is a good argument. We're not spending that many resources mining if you make the comparison with the cost of securing banks and credit cards. However, if bitcoins jump in price like a lot of us hope they will, this will be a legitimate problem.
Actually, it will never be a problem because modern computing technology is still extremely inefficient and there are no signs that it will improve anytime soon.
Most of the power (I don't remember exact numbers, but it is at least 75% or more) that CPUs/ASICs use is still wasted as heat.
So we can use the heat produced by CPUs, GPUs and ASICs to heat our buildings.
Problem solved. NEXT, PLEASE !