A New Look at the Urban Heat Island Effect

By Andy May

Nicola Scafetta has just published a new paper in Climate Dynamics examining evidence of the urban heat island (UHI) effect (Scafetta, 2021). The paper is not paywalled and can be downloaded here. In summary, Scafetta shows that part of the recent warming shown in the HadCRUT 4 global temperature record may be due to the UHI effect. He uses an analysis of diurnal maximum (Tmax) and minimum (Tmin) temperatures, climate model output, and a comparison of sea surface temperatures (SST) to land temperatures to estimate the possible influence on the HadCRUT 4 record.

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The Rational Climate e-Book

By Andy May

Patrice Poyet has just published a new 431-page eBook entitled, The Rational Climate e-Book, it is free to download here. Dr. Poyet studied geochemistry, remote sensing, and computer science at Ecole des Mines de Paris / Nice University. He received his doctorate in 1986. As an expert computer modeler, he spends much of the book evaluating climate computer models and uncovers their often-unstated underlying assumptions.

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The CO2 Kink; Firn to Ice Transition

Guest Post by Renee Hannon

Introduction

This post examines CO2 data collected in Antarctic firn and its journey as firn transitions to ice where CO2 is eventually trapped in bubbles. Atmospheric gases within the firn and trapped in bubbles are smoothed due to gas mixing processes with depth and time. The bubble trapping zone, also known as the Lock-in-Zone (LIZ), is a mysterious thin interval where CO2 concentrations decrease significantly with depth creating a kink in CO2 concentrations.

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May/Middleton: Rebuttal to Geological Society of London Scientific Statement on Climate Change

Guest essay by David Middleton and Andy May

A pdf version of this post can be downloaded here.

The Geological Society of London recently published a statement on climate change:

Geological Society of London Scientific Statement: what the geological record tells us about our present and future climate

Geologists Andy May and David Middleton have spent the past few days reviewing the Geological Society of London Scientific Statement and have assembled a rebuttal to some of the more questionable items in the paper.

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Michael Mann’s 2008 Reconstruction

By Andy May

In my last post, it was suggested that Michael Mann’s 2008 reconstruction (Mann, et al., 2008) was similar to Moberg’s 2005 (Moberg, Sonechkin, Holmgren, Datsenko, & Karlen, 2005) and Christiansen’s 2011/2012 reconstructions. The claim was made by a commenter who calls himself “nyolci.” He presents a quote, in this comment, from Christiansen’s co-author: Fredrik Charpentier Ljungqvist:

“Our temperature reconstruction agrees well with the reconstructions by Moberg et al. (2005) and Mann et al. (2008) with regard to the amplitude of the variability as well as the timing of warm and cold periods, except for the period c. AD 300–800, despite significant differences in both data coverage and methodology.” (Ljungqvist, 2010).

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Changing Climate Debate History

By Andy May

While researching my next book, I found a bit of interesting deception on the Intelligence Squared web site. This is the organization that hosted the famous March 14, 2007 global warming debate on the motion “Global Warming is not a Crisis.” Debating in favor of the motion were the late Michael Crichton, Professor Richard Lindzen (MIT, now emeritus), and Professor Philip Stott (University of London, emeritus). Against the motion were Dr. Brenda Ekwurzel of the Union of Concerned Scientists, Dr. Gavin Schmidt of NASA, and Professor Richard Somerville of the Scripps Institution of Oceanography.

The debate was held at the Asia Society and Museum in New York City. Their auditorium holds 258 people and, I presume, every seat was filled. The audience was polled on the assertion before the debate and after. According to the verbatim transcript of the debate (one of the tabs on the Intelligence Squared link above), moderator Brian Lehrer, announced the results at 1 hour 37 minutes:

“And now the results of our debate. After our debaters did their best to sway you…you went from, 30% for the motion that global warming is not a crisis, from 30% to 46%. [APPLAUSE]

01:38:58

Against the motion, went from 57% to 42%… [SCATTERED APPLAUSE, MOANS] And “undecided” went from 13% to 12%. The hardcore ambivalent are still among us. [LAUGHTER] So, in terms of opinion change, those in favor of the motion, have carried the day, congratulations to the team for the motion.”

You can hear the debate and the results on an NPR recording as well.

Gavin Schmidt was intensely embarrassed at their clear defeat in the debate. As Anthony Watts wrote in 2018, eleven years after the debate, Schmidt was so demoralized and defeated he still would not appear on stage with skeptical scientists, like Dr. Roy Spencer. Schmidt reportedly said debates are not worthwhile, regardless of the outcome. This is quite shocking to hear, debate is at the heart of scientific research. If you will not debate your points, you are not doing scientific work.

As you can probably imagine, I was nearly knocked to the floor when I clicked on the Intelligence Squared tab for the debate results on 28 December 2020. This was after I had listened to the debate and read the transcript. Under the tab on December 28 and still there January 6th, I read the winner, post-debate, was Against the motion, by 89%! Someone with access to the Intelligence Squared web site had radically changed the results from a win for the climate skeptics to a win for the alarmists. You may still be able to see this when you go to the web site. I wrote to them about this error December 28, and have received no answer.

There is certainly no excuse for lying about the results of this famous debate, but someone did.

Why do the HadSST Sea-Surface Temperatures Trend Down?

By Andy May

The simple answer is that the portion of the ocean, roughly 54%, that has HadSST values is getting cooler. But Nick Stokes doesn’t believe that. His idea is that the coverage of the polar regions is increasing fast enough that, year-by-year, the additional cooler cells are causing the “true” upward trend in ocean temperature to decrease. I decided to examine the data further to see if that makes any sense.

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Ocean Temperatures, what do we really know?

By Andy May

This is the last in my current series of posts on ocean temperatures. In our previous posts we compared land-based measurements to sea-surface temperatures (SSTs) and discussed problems and contradictions in the land-based measurements (see here). This first post was overly long and complicated, but I needed to lay a foundation before getting to the interesting stuff. Next, we covered the basic thermal structure of the ocean and how it circulates its enormous heat content around the world (see here). This was followed by a description of the ocean surface or “skin” layer here. The ocean skin is where evaporation takes place and it is where many solar radiation wavelengths, especially the longer infrared wavelengths emitted by CO2, are absorbed, then evaporated away, or reflected.

The next post covered the mixed layer, which is a layer of uniform temperature just under the skin layer. The mixed layer sits above the thermocline where water temperature begins to drop rapidly. The next post discussed the differences between various estimates of SST, the data used and the problems with the measurements and the corrections. The emphasis was on the two main datasets, HadSST and NOAA’s ERSST. The most recent post discusses SST anomalies, the logic was, if all the measurements are from just below the ocean surface, why are anomalies needed? Why can’t we simply use the measurements, corrected to a useful depth, like 20 cm?

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Sea-Surface Temperature Anomalies

By Andy May

My previous post on sea-surface temperature (SST) differences between HadSST and ERSST generated a lively discussion. Some, this author included, asserted that the Hadley Centre HadSST record and NOAA’s ERSST (the Extended Reconstructed Sea Surface Temperature) record could be used as is, and did not need to be turned into anomalies from the mean. Anomalies are constructed by taking a mean value over a specified reference period, for a specific location, and then subtracting this mean from each measurement at that location. For the HadSST dataset, the reference period is 1961-1990. For the ERSST dataset, the reference period is 1971-2000.

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Sea-Surface Temperatures: Hadley Centre v. NOAA

By Andy May

My last post compared actual sea-surface temperature (SST) estimates to one another to see how well they agreed. It was not a pretty sight; the various estimates covered a range of global average SSTs from ~14°C to almost 20°C. In addition, some SSTs were declining with time and others were increasing. While I did check the latitude range of each of the grids I averaged, John Kennedy (HadSST climate scientist in the UK MET Hadley Centre) pointed out that I did not check the cell-by-cell areal coverage of the HadSST grid, relative to the NOAA ERSST grid. He suspected that the results I presented were mostly due to null grid cells in HadSST that were populated by interpolation and extrapolation in the ERSST dataset. The original results were presented in Figure 6 of my previous post which is Figure 1 here.

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