Rahmstorf (2009): Off the mark again (part 5), Variation of gamma

Another post on Vermeer’s and Rahmstorf’s 2009 PNAS paper, “Global sea level linked to global temperature.”   This time we consider the variation of gamma (γ) in equation 4 of part two.  The curious result will be that for γ>1 the temperature will continuously increase, while the sea level rise rate will continuously drop.

In Part 1, I laid out the basic problem.

In Part 2, I went into a little more detail on the math.

In Part 3, I gave a few examples that show some bizarre consequences that would result if equation were correct.

In Part 4, improbable parallel universes.

This is very simple. 

The plots below will show hypothetical temperatures that satisfy equation 4 of part 2, with all parameters equal, except γ.  But the fact that the temperature is derived from this equation is not really important.  The important thing is that the version with a faster increasing temperature has a decreasing sea level rise rate, and vice versa.

How can this be?

As before, these bizarre results are not my invention – they follow directly from Vermeer’s and Rahmstorf’s equation relating sea level rise rate to temperature.  The answer to the question is very simple:  Vermeer’s and Rahmstorf’s model does not make sense.  Their model causes realistic temperature scenarios to yield unrealistic sea level rise rates.

A future post will discuss Vermeer’s and Rahmstorf’s misguided concept of a “positive, but time-lagged, sea level response.”

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