### Grant McDermott

Assistant Professor
Dept. of Economics
University of Oregon

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# Murphy vs Nordhaus vs Me summarized

It might be difficult to keep track of things in my previous post, because the lengthy discussion involves numerous claims and counterclaims. With the aim in simplifying things, here is a comment that I left on Daniel Kuehn's blog. I think that it provides a decent summary of my views:
Regarding "dancing around the issues"... Bob, my point here is that by choosing to interpret the WSJ skeptics (and Nordhaus' response) the way you do, you are either: a) Ignoring the obvious implications that they intended for their readers, or b) Rendering their specific claims as trivialities.

E.g. If you seriously believe that the skeptic claim about temperatures this decade $$-$$ i.e. "they have been flat" $$-$$ was not meant to convey any deeper message about future climate trends, do you then think that this observation is of any real use in of itself? Of course, if you think that it does say something important about long-term climate trends, which is the only thing that really matters in this debate, then you are back to the Nordhaus' response.

The Tol article is separate to the above and I do think that you highlight an important point regarding the net benefits associated with modest warming. Not many people understand this and you claim that Nordhaus badly misleads his readers by saying "Richard Tol finds a wide range of damages, particularly if warming is greater than 2 degrees"... despite the fact that Tol's own graph clearly shows net benefits up until that point. [See here - Ed.]

My response is that Tol specifically deals with this issue in his paper. He points out that these are "sunk" benefits, which we stand to accrue regardless of our policy choices today. The inertia in our climatic and economic systems will already ensure that we reach the edge of these positive gains from warming (due to increased agricultural yields, etc). Any action that we take against CO2 emissions today are solely aimed at tackling temperatures above two degrees, i.e. where things start heading into serious negative territory.

Bob, may I ask you whether you think your IER article helped readers understand this crucial point?