okay, 1st up...

why is sustainability good? heard someone quizzing yvette cooper on the radio this morning & he said something like "assuming you believe in sustainability..."

So what are the arguments for & against sustainability? Is it just as good to create something cheap and easily reproducible as something long term & lasting. For instance would we not have as much problem replacing infrastructure if everything we built had a shelf-life of a couple of decades, say, and we planned & budgeted to replace?