Jeffery S Patterson throws away the signal at WUWT

Anthony Watts does attract some strange characters to his denier blog WUWT.  Beggars can't be choosers and Anthony couldn't write a decent article all by himself if you paid him.  He relies on guest articles to keep his blog alive.

There's a new chap he's picked up from somewhere called Jeffery S. Patterson, who enjoys playing with numbers.  I'm not terribly interested in his numbers.  What interests me is the way his numbers take him away from reality.

Jeffery gets a lot wrong

In the midst of today's article (archived here) he writes a few very odd things:

The linear trend in slope evident in Figure 1a implies a parabolic temperature trend. The IPCC makes oblique reference to this in the recently releases AR-5 Summary for Policymakers:

“Each of the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850 (see Figure SPM.1). In the Northern Hemisphere, 1983–2012 was likely the warmest 30-year period of the last 1400 years (medium confidence).”

True enough, but that has been true since at least the mid-1800s. The implication of the IPCC’s ominous statement is that anthropogenic effects on the climate have been present since that early time. Let’s examine that hypothesis.

First up, I see nothing in his quote from the IPCC that is an oblique or otherwise reference to a parabolic temperature trend.  All I read is that it's been getting hotter lately.

Secondly, the earth hasn't had each decade since the mid-1800s successively warmer than the last.  Nor has each decade since the mid-1800s been the warmest in the last 1400 years.  In fact, the early part of the twentieth century was a bit chilly - at least in comparison to now.

Here's a chart showing decadal temperatures and how the last three full decades (1971-80 to 2000-09), plus the current one so far, have been warmer than all those before them in the record. The decades from 1920 to 1949 were also successively warmer followed by two cooler decades.:

Data Source: NASA

Talking of the last 1400 years, here's a chart, Box TS.5, Figure 1  from the AR5 WG1 Technical Summary (page TS-103) for the Northern Hemisphere, going back around 1200 years.  The top chart is radiative forcing and the bottom chart is reconstructed and simulated NH temperature anomaly from a baseline of the average from 1500 to 1850.  Click to see it larger.

Data Source:  IPCC AR5 WG1 - Box TS.5, Figure 1 (page TS-103)

Jeffery later writes:

Around the year 1878, a dramatic shift in the climate occurred coincident with and perhaps triggered by an impulsive spike in temperature. As a result, the climate moved from a cooling phase of about -.7 °C/century to a warming phase of about +.5°C/century, which has remained constant to the present. We see that this period of time was coincident with a large spike in solar activity as shown in figure 7.

As far as his "cooling phase of about -0.7°C/century" goes, he doesn't use data prior to 1850 so how on earth he can say that with a straight face I don't know.  Even had he gone back in time he'd have been way off beam.  The earth did cool for about 5,000 years after the Holocene optimum, but it was at nothing like -0.7°C/century.   That amount of cooling would have taken us into a very deep ice age had it gone on for 50 centuries!

Jeffery mentioned the high temperature in 1878.  In fact that's what he's called his article: The Great Climate Shift of 1878.  Except there wasn't!

There was a big spike in the HadCRUT temperature record in 1878 as the chart below shows, but the "shift in the climate" (as indicated by surface temperature) didn't start in earnest until the early twentieth century:

Data Source: HadCRU

Below is the radiative forcing chart blown up. The top is volcanic forcing, the middle is total solar irradiance (TSI) and down the bottom are well-mixed greenhouse gases (WMGHGs). There is no sign of a spike of any type in 1878.  TSI went up in the twentieth century and there were a couple of large-ish volcanoes early in the 19th century but that's about it.

Data Source:  IPCC AR5 WG1 - Box TS.5, Figure 1 (page TS-103)

Jeffery seems to have adopted a narrative of the type that surface temperature can rise all by itself, given an initial prod, even though that prod is not sustained.  He is a science denier who looks to mathturbation to disprove human induced global warming.  But what he writes isn't supported by the data.  Here is how he finishes his article:

The climate record of the past 163 years is well explained as the integral second-order response to a triggering event that occurred in the mid-to-late 1870s, plus an oscillatory mode regulated by solar irradiance. There is no evidence in the temperature records analyzed here supporting the hypothesis that mankind has had a measurable effect on the global climate.

Jeffery is a bit weird with his "integral second-order response to a triggering event" - that doesn't seem to have had any lasting effect and that couldn't have been caused by the sun.  All he did was remove the rising trend and then looked at the data with the trend removed and said that there's no anthropogenic signal.  He's not the first to try that trick on one pretext or other.  John McLean, Bob Carter and Chris de Freitas tried that one on a few years ago and were picked up quick smart!