Monday, March 26, 2012

Compare and Contrast

There is a small business in posting how the various global temperature series change and match up to the predictions of experts and, well, some not so. Wood for Trees has a great franchise, and Nick Stokes keeps the widgets coming. Eli's position has always been that looking only at global temperature throws away too much information to be satisfying and leaves great room for statistical hanky panky.

The Oxford Climate Prediction.Net folk have a new paper at Nature Geosciences (paywall). They graciously allowed others to run their simple GCM and from the large number of returns, and here is the point, they selected the ones that best matched the regional patterns of temperature anomalies from 1960 to 2010. The observed 20o1-2010 global pattern is shown in a below, the patterns from the selected model runs with a high and low ensemble members are shown in b and c.

Figure d and e show the predictions for warming as compared to the average for 1960 - 1990, which comes out between 1.8 and 3.0 C, significantly above the AR4. Hindcast skill needs improved evaluation parameterization for sure.

5 comments:

Anonymous said...

For those of us bunnies who read the text before delving into the figure or linked pages, could you note that the 1.4 to 3K range is for 2050? (or more precisely, the 2040-2060 period) (also, I think the lower bound is 1.4, not 1.8)

Thanks!

-MMM

Anonymous said...

Dr. Jay Cadbury, phd.

"Eli's position has always been that looking only at global temperature throws away too much information to be satisfying and leaves great room for statistical hanky panky."

How? What number could possibly be more important than the GAT? Nothing else is more inclusive. I think the constant drum beat of melting ice in the arctic has led to quite a bit of statistical humpty dumpty.

Jeffrey Davis said...

"Nothing else is more inclusive"

Global atmospheric temps ignores the vast bulk of the source of variability in the climate system: the oceans. The oceans also contain the vast majority of the heat reserved due to greenhouse gases.

Richard Mercer said...

Dr Cadbury

Here's what Jeffry Davis is talking about.


"Breaking News...The Earth is Warming... Still. A LOT"

at Skeptical Science - 3/16/11}

Global Ocean Heat Content increase in the last 50 years

"This is a rate of heating of 133 Terawatts. Or 0.261 Watts/m2

133 Terrawatts is 2 Hiroshima bombs a second. Continually since 1961.

It would boil Sydney Harbour dry EVERY 12 HOURS!

But why don't we notice this? Because instead of all this heating happening just in Sydney Harbour, this is spread out through out the worlds oceans. And they are huge: approximately 2,300,000,000 times the size of Sydney Harbour.

So HEAT THAT BOILS THE HARBOR (every 12 hours) WOULD ONLY WARM THE ENTIRE OCEAN BY A FRACTION OF A DEGREE .
(my emphasis)

t would have raised Air temperatures by around 42 °C over the last 1/2 Century!

a_ray_in_dilbert_space said...

Richard Mercer: "It would have raised Air temperatures by around 42 °C over the last 1/2 Century!"

Well, except it wouldn't have. If the heating had gone into the air, we would be much nearer equilibrium than we are. Instead, that is heat that the climate system will have to dissipate over a very long time--making it very unlikely that we'll ever return to present conditions before the Sun evaporates us.