On Don Easterbrook’s Updated Projection

Don Easterbrook has updated his projection graph. Unfortunately, he did not update the graph that I complained about a few weeks ago, shown on the left in Figure 1. In that graph his projections started around 2010. He appears to have updated the Easterbrook projections graph on the right, where the projections started in 2000.

Figure 1

I raised a few eyebrows a couple of weeks ago by complaining loudly about a graph of global surface temperature anomalies (among other things) that was apparently created to show global cooling over a period when no global cooling existed. My loud and persistent complaints were in response to Figure 4 from Don Easterbrook’s post Cause of ‘the pause’ in global warming at WattsUpWithThat. In response to my reaction to his graph (and other things), Don Easterbrook wrote the post Setting the record straight ‘on the cause of pause in global warming’, which did not address my concerns.

It was on the thread of the “Setting the record straight” post that I presented how Don Easterbrook created the cooling of global surface temperatures during a period when no such cooling existed. The cooling effect was created by splicing global lower troposphere temperature anomalies from 1998 to about 2008 onto a graph of NCDC global surface temperature anomalies. See my Figure 2.

Figure 2

The graph in question was not created by splicing land surface air temperature data from 1998 to 2010 onto the end of the land+ocean surface temperature data as Don had explained in his “Setting the record straight” post (my boldface).

This curve is now 14 years old, but because this is the first part of the curve that I originally used in 2000, I left it as is for figure 4. Using any one of several more recent curves from other sources wouldn’t really make any significant difference in the extrapolation used for projection into the future because the cooling from 1945 to 1977 is well documented. The rest of the curve to 2010 was grafted on from later ground measurement data—again, which one really doesn’t make any difference because they all show essentially the same thing.

There are two errors in the above quote. First, the graph in question could not be 14 years old, because it included TLT data from 1998 to about 2008. Second, land surface temperature data do not show “essentially the same thing” as land+ocean surface temperature data. Land surface temperature data have continued to rise since 1998.

The graph in question also included a curve in red identified as “IPCC projected warming” and a number of Don’s predictions, blue curves, starting around 2010. See the full-sized version of Easterbrook’s projections that started in 2010 here. It’s a cleaner version of Don’s Figure 4 from his two posts.

On the thread of the “Setting the record straight” post, Anthony Watts asked Don Easterbrook to update the graph in question. See Anthony’s January 21, 2014 at 9:26 am comment here. (At that time we were responding to Easterbrook’s statement that he had merged land surface temperature data with land+sea surface temperature data.)

THE NEW EASTERBROOK PROJECTION

About a week after his original post, Don presented an update to his projections. See my Figure 3. As noted in the opening, it was not an update of the graph in question. The graph in question included projections starting around 2010 and it included an “IPCC projected warming” curve. On the other hand, the projection in Don’s newly furnished update starts a decade earlier in 2000 and excludes the “IPCC projected warming”.

Figure 3

Don wrote about the updated graph:

Here is an updated version of my 2000 prediction. My qualitative prediction was that extrapolation of past temperature and PDO patterns indicate global cooling for several decades. Quantifying that prediction has a lot of uncertainty. One approach is to look at the most recent periods of cooling and project those as possibilities (1) the 1945-1975cooling, (2) the 1880-1915 cooling, (3) the Dalton cooling (1790-1820), (4) the Maunder cooling (1650-1700). I appended the temperature record for the 1945-1975 cooling to the temperature curve beginning in 2000 to see what this might look like (see below). If the cooling turns out to be deeper, reconstructions of past temperatures suggest 0.3°C cooler for the 1880-1915 cooling, about 0.7°C for the Dalton cooling (square), and about 1.2°C for the Maunder cooling (circle). We won’t know until we get there which is most likely.

This updated plot really doesn’t change anything significantly from the first one that I did in 2000.

Again, that wasn’t the graph in question.

It is also blatantly obvious that his graph does not include the data from 2000 to 2013. Don has curiously omitted one of the primary reasons for someone to update a projection graph.

Another curiosity, there’s some data missing from his projections. It is supposed to represent “appended 1945-1975 temps”, meaning he spliced 1945-1975 global surface temperature anomalies onto the end of the 1999 data. However, the spike in response to 1972/73 El Niño is missing, and so is the spike in response to the 1957/58 El Niño. There’s also a spike missing in August 1945. The missing spikes stand out in Animation 1.

Animation 1

Or is that what the “appended” means…that he’s modified the 1945-75 data? I’m not sure why he’d delete those spikes, but I noticed it right away.

The little uptick at the end of the Easterbrook update is also a curiosity. It was the response to the Pacific Climate Shift of 1976, so the projection includes data beyond 1975.

And Don Easterbrook presented monthly HADCRUT3 data, as opposed to the annual NCDC data that he had used in his graph in question. I also have no idea why he would use HADCRUT3 data instead of HADCRUT4 data, especially when he wanted to use 1945 to 1975 data to show cooling during his projection. Why? HADCRUT3 data does not show cooling during that period, while HADCRUT4 data does. See Figure 4. That change in trend was a result of the revisions to the HADSST data…the corrections they made to eliminate the 1945 “discontinuity”.

Figure 4

I suspect that Don Easterbrook left out the “IPCC projected warming” curve because of the way he spliced the models onto his abridged and modified data in his graph in question (the one with the projections starting in 2010; i.e. his Figure 4 in both of his posts). See the animation here, from my January 19, 2014 at 6:34 am comment on the first of the Easterbrook threads.

MY REPLICA OF THE NEW EASTERBROOK PROJECTION

Don did not include the recipe for splicing the data starting in 1945 onto the data ending in 1999. Figure 5 is my attempt to replicate his newly updated graph. The January 1945 through December 1977 data was shifted back in time to start in January 2000. Then the relocated data was shifted upwards by 0.354 deg C so that the January 2000 (relocated January 1945) value equaled the December 1999 value. Figure 5 is a reasonable replica of Easterbrook’s revised update.

Figure 5

In Figure 6, I’ve included the surface temperature anomalies from January 2001 through December 2013. The Easterbrook projection looks a little low.

Figure 6

The projection really looks low when the data are presented in annual form, (see Figure 7), which is how Easterbrook presented his projections originally. The warming during the projection stands out like a sore thumb with the annual data.

Figure 7

NEW EASTERBROOK PROJECTION USING HADCRUT4 DATA

Figures 8, 9, and 10 run through the same process as Figures 5, 6, and 7, except that I’ve used HADCRUT4 data in the following three graphs.

Figure 8

# # #

Figure 9

# # #

Figure 10

The cooling in the projection using the HADCRUT4 data would have stood out even more if I had ended the data used in the projection in 1975, as Easterbrook had claimed. But I used the data through 1977 as he included in his graph.

NOTE: To maintain continuity between the monthly graphs and the annual graphs shown in Figures 7 and 10, I converted the monthly data to annual data. That is, I did not start with annual data for Figures 7 & 10 and splice annual data together.

MY UPDATE OF EASTERBROOK GRAPH WITH PROJECTIONS STARTING IN 2010

If Don Easterbrook had used annual HADCRUT4 data for his updated projection graph (black curve), and if he had spliced the 1945-1975 HADCRUT4 data on at 2010 (blue curve), and if he had used the multi-model ensemble mean of the CMIP5-archived models (using the RCP6.0 scenario) for his “IPCC projected warming” (red curve) using the same base years as the HADCRUT4 data, then his update to his graph in question would have looked like Figure 11. (I didn’t bother with his Dalton minimum or his Maunder cooling projections.)

Figure 11

The models look bad enough without having to add non-existent cooling to the data by splicing lower troposphere temperature data onto surface temperature data.

CLOSING

Global warming skeptics will be hurt, not helped, by those who manufacture datasets to create effects that do not exist.

Global warming skeptics do not have to help climate models look like crap. They’re doing a good job of that all on the own. See Figure 12.

Figure 12

SOURCES

The monthly HADCRUT3 data are available here. The monthly HADCRUT4 data are linked here. The annual HADCRUT4 data are available here. And the CMIP5 climate model outputs are available through the KNMI Climate Explorer.