Update 2: Viscount Monckton was kind enough to respond to my further questions. They appear below my questions in italics. I will probably break this discussion up into separate posts if it continues–it’s getting a bit unwieldy here.
Update: At Viscount Monckton’s request I have added some charts that he sent with his response. He is confident the addition of these charts clarifies his points. (For all these charts, click to ’embiggen’.)
Viscount Monckton’s reply to my questions about recognizing the potential for human caused climate change was a 10-page Word document. I previously showed snips of his answers here. In this post I will put his full response to the first RAMA statement and add some of my own comments and questions in bold.
To what extent do you agree with the following propositions?
- Global surface temperatures have warmed by about 0.8 K over the past century or so.
(VM): Since 1900, global mean surface temperature as measured by the three longest data series – GISS, HadCRUT4, NCDC – has risen by approximately 0.9 K, a rate equivalent to 0.8 K century–1.
However, these results should be interpreted with caution, for each of the three datasets has been tampered with to depress artificially the temperature measurements recorded in the early 20th century and to increase them in the late 20th century, with the effect of increasing the apparent warming rate by 0.3 K, or about half, compared with the measured and recorded values.”
(TF) I assume from what follows that you don’t think the results have been interpreted with caution by some others. May I ask what your interpretation is? Do you think there has been global warming since 1945 and if so, how much?
(VM) I do not speak for others. However, of 0.9 K global warming since 1900, 0.3 K arose from adjustments to the terrestrial datasets; 0.2 K arose from uncorrected urban heat-island effects on poorly-sited thermometers; and an unknown amount – perhaps another 0.2 K, perhaps more – arose from natural influences before our influence on the climate became even in theory detectable in 1950. That does not necessarily leave much room for CO2-driven warming. No surprise, then, that of 11,944 climate papers published in the reviewed journals over the 21 years 1991-2011 only 64, or 0.5%, were marked by global-warming enthusiasts as stating that recent global warming was mostly manmade. There is no scientific “consensus” on that point and, even if there were, the head-count and argument-from-authority fallacies are no less fallacies today than they were when Aristotle first codified them 2350 years ago.
GISS, which depends on the NCDC dataset for its own record, also shows very substantial adjustments to what was actually measured – again with the effect of greatly increasing the apparent rate of warming compared with the true, measured rate:
(VM) “The U.S. Historical Climate Network, on which all three terrestrial datasets rely, has also been tampered with, to create a warming where the original measurements showed a cooling.”
“Here are examples from Australia and New Zealand. Many other nations have done similar tampering:”
(TF): ‘Tamper’ is an emotionally charged word. Do you think the adjustments that have been made were deliberately made to either lower past temperatures or increase more recent temperatures to show a higher rate of warming than has actually been the case?
(VM) The scale of the “adjustments” goes well beyond the routine technical corrections that are normally made in the year or two following the original measurements. The relentless reduction in early 20th-century temperature data, combined with the relentless boosting of late 20th-century temperature data, means that – whether or not the tamperings at both ends of the record were justifiable – a considerable fraction of the warming of the 20th century has arisen from the tampering. Caution is appropriate.
(VM): “Nor can it be safely said that the underlying warming rate in recent decades reflects the record increases in CO2 concentration that have occurred despite all the rhetoric about making reductions. The two satellite lower-troposphere datasets show no global warming for 18 years 6 months. As Dr Isaac Held, an IPCC lead author, has rightly stated, if that record goes to 20 years then the entire basis for the models’ predictions will require urgent re-examination.”
(TF): During the twentieth century there were two pauses in warming that lasted even longer than the 18 years 6 months that you note. Following each pause, warming resumed. Is there a reason you don’t expect such a resumption at the end of the current pause?
(VM) Again, caution is advisable, particularly in light of the fact that the current pause of 18 years 6 months, unlike the previous pauses over the 20th century, is occurring at a time when CO2 emissions and concentration are rising at record levels. To anyone with a clear eye, that is surprising.
(VM): “Furthermore, the published datasets, satellite as well as terrestrial, do not take sufficient account of the urban heat-island effect. Michaels & McKitrick (2006) analysed the temperature records and found a highly significant correlation between regional rates of economic growth and regional rates of warming – a correlation that should not exist at all if proper allowance for increased urban development near temperature sensors had been made. They determined that in recent the warming rate over land had been overestimated by double.
Therefore, it is likely that the 1930s were warmer than the present in the United States, and that the warming since 1900 may have been little more than half the rate shown by the terrestrial datasets.”
(TF): There have been numerous attempts to quantify the effect of UHI and they downplay any impact on global totals, given that urban areas do not comprise a significant percentage of the total land area and that land area is only 30% of the earth’s surface. Rural stations unaffected by UHI show similar rates of warming. How important is this issue to your overall view of global warming?
(VM) The advantage of the McKitrick & Michaels approach is that it provides an independent examination of the extent to which urban heat-island effects have been allowed for. There should not have been any significant correlation between regional rates of warming and regional rates of industrial or population growth if the urban heat-island effect had been properly corrected for. There was a significant correlation. No one has yet provided a convincing answer to the M&M analysis.
(VM): “Given the conflicting and much-altered testimony, one should look for an authoritative method of measuring change in global mean surface temperatures, such as sufficiently well-resolved measurements of ocean temperature, for the ocean heat capacity is two or three orders of magnitude greater than that of the atmosphere. However, the ARGO bathythermographs, the first global uniform dataset, have been operating for only 11 full years, and each of the 3600 buoys takes only three temperature and salinity profiles from 0-1900 m depth every month over 200,000 square kilometers. For the record, though, the warming rate over the 11-year run of data is equivalent to little more than 0.2 K century–1.”
(TF): Apart from agreeing with your assessment of the utility of better measurements of ocean temperatures, I have no questions here.