No it hasn't.
Sir Nick was low balling the cost of his proposals last year.
On May 31, 2007 we wrote:
...we're starting to get to the real number and we should be able to keep it all under a third-of-a-trillion dollars per year for the U.S. contribution (before adding in direct costs like putting vodka in your tank but that's okay, the Stern number of 1% of World Gross Product should be 2% minimum so we've got incorrect estimates piling on incorrect estimates anyway).
I don't know why he was having fun with numbers but he was. If a humble blogger can work the abacus I'm pretty sure Stern knew.
If he didn't, here's a headline from the Times of India, September 25, 2007:
Cost of dealing with climate change: 2% of GDP
...This was disclosed on Thursday by Jayant M Mau-skar, joint secretary in the environment ministry, at a conference on climate change organised at the Vatavaran Film Festival here. Mauskar said, "In 2000-01, India was spending 0.63% of its GDP on climate change adaptation and mitigation which has now risen to 2.17%. So we can say that Nicholas Stern's argument (that climate change action does not hurt economy much) is perhaps not true."
The actual dollar amount for the U.S. now looks to be $400-500 Billion per year.
From The Guardian:
The author of an influential British government report arguing the world needed to spend just 1% of its wealth tackling climate change has warned that the cost of averting disaster has now doubled.
Lord Stern of Brentford made headlines in 2006 with a report that said countries needed to spend 1% of their GDP to stop greenhouse gases rising to dangerous levels. Failure to do this would lead to damage costing much more, the report warned - at least 5% and perhaps more than 20% of global GDP.
But speaking yesterday in London, Stern said evidence that climate change was happening faster than had been previously thought meant that emissions needed to be reduced even more sharply....MORE