Climate change: the cost of Marsden B

Today, we learned that the cost of our Kyoto obligation - in essence the cost of failing to act early to reduce emissions - has risen to $656 million. The primary reason for this rise is an increase in the expected price of carbon credits, from US$6 per tonne to US$9.65 per tonne.

Meanwhile, the Greens have pointed out that Mighty River's proposed coal-fired Marsden B power station is set to cost us $60 million a year to cover its emissions. That's $300 million over the first commitment period. It's unclear the extent to which this is included in the Projected Balance of Units (I think the answer is "yes, in the abstract"), but regardless of whether it is or isn't, it is clear that this thing is going to cost the public a large amount of money, which could be used for far better purposes. So why the hell are we letting the project go ahead?