The NYT told readers that the investments needed to curtail global warming would cost the world $10 trillion over the years from 2010 to 2030. It would have been helpful to also note that global GDP will be around $1500 trillion over this period, so that the estimated cost of these measures would be equal to approximately 0.7 percent of GDP. This means that they would impose approximately one sixth as much of a burden on the world economy as the defense department budget does on the u.S. economy.
--Dean Baker