Thongchai Thailand


Posted on: January 23, 2021

The Conversion of a Climate-Change Skeptic: By RICHARD A. MULLER. CALL me a converted skeptic.


In conversation with Professor Richard Muller, Berkeley Earth - YouTube


Abbreviations: AGW = Anthropogenic Global Warming, ETCW = Early Twentieth Century Warming anomaly,

1) Three years ago I identified problems in previous climate studies that, in my mind, threw doubt on the very existence of global warming. {RESPONSE(1): What were these problems and how were they resolved? This is a critically important issue without which this statement is just emotional talk and not information}

(2) Last year, following an intensive research effort involving a dozen scientists, I concluded that global warming was real and that the prior estimates of the rate of warming were correct. {RESPONSE(2): All global temperature reconstructions and satellite data show a rising trend in global mean temperature and that therefore that “global warming is real”. Not sure why this determination required intensive research involving dozens of scientists}

(3) I’m now going a step further: Humans are almost entirely the cause. {RESPONSE(3): Whether global warming is real is not the issue. The issue is human cause by way of fossil fuel emissions. The step further is not a step further. It is the essence of the theory of AGW. The theory holds that humans are the cause of the current warming by way of rising atmospheric CO2 driven by the fossil fuel emissions of humans and that therefore it can and must be attenuated with the “climate action” of not burning fossil fuels}. This has been the theory since Callendar 1938 and in modern times raised to a level of fear by Hansen 1988. That “humans are almost entirely the cause” is its essence and this it is well known. The data show, and has shown for decades, that the correlation between CMIP5 forcings and temperature is almost the same whether or not we include natural forcings: LINK: .

(4) My total turnaround, in such a short time, is the result of careful and objective analysis by the Berkeley Earth Surface Temperature project, which I founded with my daughter Elizabeth. Our results show that the average temperature of the earth’s land has risen by two and a half degrees Fahrenheit over the past 250 years, including an increase of one and a half degrees over the most recent 50 years. {RESPONSE(4): The “past 250 years” from 2012 takes us to the 1760 “pre-industrial” start year for AGW found in the first IPCC report in 1990. Since then the IPCC has changed the “pre-industrial” beginning of AGW to 1850. The 1.18C warming since pre-industrial in 2012 is inconsistent with mainstream climate science where the amount of warming from pre-industrial to 2020 was 1.2C. As for the warming of “one and a half degrees” in 50 years from 1963 to 2012, the reason for citing this 50-year warming trend is unclear and it leaves readers with a “so what” puzzle.}

(5) Moreover, it appears likely that essentially all of this increase results from the human emission of greenhouse gases. {RESPONSE(5): Here we find that what is a bedrock foundational concept in AGW climate science only receives a rating of “appears likely”. This assessment implies that human cause, the heart and soul of the AGW climate action movement against fossil fuels that was so strongly supported in Item#3 above, is now weakened from “humans are almost entirely the cause” to “appears likely”.}

(6) These findings are stronger than those of the IPCC that defines the scientific and diplomatic consensus on global warming. In its 2007 report, the I.P.C.C. concluded only that most of the warming of the prior 50 years could be attributed to humans. It was possible, according to the IPCC consensus statement, that the warming before 1956 could be because of changes in solar activity, and that even a substantial part of the more recent warming could be natural. {RESPONSE(6): With regard to “the warming before 1956”, that era of global temperature data is understood in climate science as the ETCW anomaly (Early Twentieth Century Warming) that is not explained by the theory of fossil fueled human caused warming. This gross inconsistency with an important issue in mainstream climate science does not present the image of someone who has seen the light and is now a “converted skeptic”. ETCW LINK: } . It appears that the “stronger than the IPCC” findings reported here is a consequence of the absence of the ETCW issue in the interpretation of the temperature data.}

(7) Our Berkeley Earth approach used sophisticated statistical methods developed largely by our lead scientist, Robert Rohde, which allowed us to determine earth land temperature much further back in time. {RESPONSE(7A): The result of “sophisticated statistical methods” curiously shows a temperature reconstruction that looks pretty much like the existing reconstructions (chart below) suggesting that existing reconstructions may have played a role in their estimation. However, this strong agreement supports the claim that the author, once a denier, having verified the temperarure reconstruction to his satisfaction, has changed from a climate change denier to a climate change believer. Yet, that it is warming is not the real issue in AGW climate change as it has warmed before multiple times during the Holocene prior to the Industrial Revolution: LINK: . The real issue is the “A” in AGW – that it is human caused by way of fossil fuel emissions and that therefore it can and must be attenuated by humans with climate action in the form of moving the world’s energy infrastructure from fossil fuels to renewables. It is not possible for an AGW skeptic to embrace this theory simply on the basis of a verification of the rate of warming}.

Annual Temperature Anomoly

{RESPONSE(7B): As for going further back in time beyond 1950 or even beyond1970, the analysis is in violation of the well established ETCW issue in climate science previously mentioned. Tet another issue is that, unlike the Hadcrut reconstruction, where the work of Colin Morice provides the uncertainty in the data estimation LINK: , this essential information is not provided in the new reconstruction offered with “sophisticated statistical methods”. It is noted here that there is significant disagreement in climate science with respect to the “pre-industrial” reference year and reference temperature that marks the beginning of AGW. The estmation of the pre-industrial year has evolved from 1760 to 1850 and then to 1950 by NASA and 1970s by climate scientist Peter Cox: LINK: The estimation of uncertainty is an important and essential aspect of statistical analysis.}

(8) We carefully studied issues raised by skeptics: biases from urban heating (we duplicated our results using rural data alone), from data selection (prior groups selected fewer than 20 percent of the available temperature stations, we used virtually 100 percent), from poor station quality (we separately analyzed good stations and poor ones) and from human intervention and data adjustment (our work is completely automated and hands-off). In our papers we demonstrate that none of these potentially troublesome effects unduly biased our conclusions. {RESPONSE(8) The comparison of the new temperature reconstruction thus improved with the new methodology of evaluating station quality and using a hands off approach does not appear to have made a significant difference to the warming rates when compared with the existing reconstructions as seen in the chart above. The station quality and other improvements made may have reduced the uncertainty in the estimate, however, but no uncertainty information is provided}.

(9) The historic temperature pattern we observed has abrupt dips that match the emissions of known explosive volcanic eruptions; the particulates from such events reflect sunlight, make for beautiful sunsets and cool the earth’s surface for a few years. There are small, rapid variations attributable to El Niño and other ocean currents such as the Gulf Stream; because of such oscillations, the “flattening” of the recent temperature rise that some people claim is not, in our view, statistically significant. {RESPONSE (9): Here the author tries to explain away the so called “hiatus” in warming that had been proposed by skeptics as evidence against AGW. The claimed hiatus is a 14-year period from 1998 to 2012 when no warming is seen in the data. This skeptical argument has no merit on the basis of the generally accepted definiton of climate by the WMO as long term (more than 30 years). The long term warming trend may be the creation of many short term warming, cooling, and flat periods that in themselves do not have an AGW interpretation. The GIF image below is taken from a related post on global warming data: LINK: shows strong evidence for long term global warming from 1979 to 2020 but with wild fluctuations in decadal warming that include warming, cooling, and neither warming nor cooling. Such short term fluctuations are understood as Internal Climate Variability” LINK: . They have no interpretation in terms of AGW and they don’t require rationalization in terms of volcanic eruption arguments that are in fact invalidated anyway because of circular reasoning (A hypothesis derived from the data cannot be tested with the same data). The “hiatus” debate in AGW is a non sequitur. It does not appear that the sophisticated statistical methods used in the transition from skeptic to believer are as sophisticated as previously thought. As a footnote, with respect to the statement about “El Nino and other ocean currents”, kindly note that El Nino is not an ocean current.}.

This image has an empty alt attribute; its file name is gd-gif.gif

(10) What has caused the gradual but systematic rise of two and a half degrees? We tried fitting the shape to simple math functions (exponentials, polynomials), to solar activity and even to rising functions like world population. By far the best match was to the record of atmospheric carbon dioxide, measured from atmospheric samples and air trapped in polar ice. Just as important, our record is long enough that we could search for the fingerprint of solar variability, based on the historical record of sunspots. That fingerprint is absent. Although the I.P.C.C. allowed for the possibility that variations in sunlight could have ended the “Little Ice Age,” a period of cooling from the 14th century to about 1850, our data argues strongly that the temperature rise of the past 250 years cannot be attributed to solar changes. This conclusion is, in retrospect, not too surprising; we’ve learned from satellite measurements that solar activity changes the brightness of the sun very little. How definite is the attribution to humans? The carbon dioxide curve gives a better match than anything else we’ve tried. Its magnitude is consistent with the calculated greenhouse effect — extra warming from trapped heat radiation. These facts don’t prove causality and they shouldn’t end skepticism, but they raise the bar: to be considered seriously, an alternative explanation must match the data at least as well as carbon dioxide does. Adding methane, a second greenhouse gas, to our analysis doesn’t change the results. Moreover, our analysis does not depend on large, complex global climate models, the huge computer programs that are notorious for their hidden assumptions and adjustable parameters. Our result is based simply on the close agreement between the shape of the observed temperature rise and the known greenhouse gas increase. It’s a scientist’s duty to be properly skeptical. I still find that much, if not most, of what is attributed to climate change is speculative, exaggerated or just plain wrong. I’ve analyzed some of the most alarmist claims, and my skepticism about them hasn’t changed. Hurricane Katrina cannot be attributed to global warming. The number of hurricanes hitting the United States has been going down, not up; likewise for intense tornadoes. Polar bears aren’t dying from receding ice, and the Himalayan glaciers aren’t going to melt by 2035. And it’s possible that we are currently no warmer than we were a thousand years ago, during the “Medieval Warm Period” or “Medieval Optimum,” an interval of warm conditions known from historical records and indirect evidence like tree rings. And the recent warm spell in the United States happens to be more than offset by cooling elsewhere in the world, so its link to “global” warming is weaker than tenuous. The careful analysis by our team is laid out in five scientific papers now online at That site also shows our chart of temperature from 1753 to the present, with its clear fingerprint of volcanoes and carbon dioxide, but containing no component that matches solar activity. As carbon dioxide emissions increase, the temperature should continue to rise. I expect the rate of warming to proceed at a steady pace, about one and a half degrees over land in the next 50 years, less if the oceans are included. But if China continues its rapid economic growth and its vast use of coal (it typically adds one new gigawatt per month), then that same warming could take place in less than 20 years. Science is that narrow realm of knowledge that, in principle, is universally accepted. I embarked on this analysis to answer questions that, to my mind, had not been answered. I hope that the Berkeley Earth analysis will help settle the scientific debate regarding global warming and its human causes. Then comes the difficult part: agreeing across the political and diplomatic spectrum about what can and should be done.

Annual Temperature Anomoly

{RESPONSE (10): Here, in the critical issue of human cause, we find that all that sophisticated statistics used to test the data against a climate denial null hypothesis has suddenly vanished. That warming correlates with rising atmospheric CO2 is claimed to establish human cause with the critical confirmation bias assumption that the rise in atmospheric CO2 is human caused.

In related posts on this site we show that this assumed correlation between fossil fuel emissions and observed changes in atmospheric composition at an annual time scale is not found in the data: LINK: .

That the the climate change denier has seen the light and embraced the theory of Anthropogenic Global Warming (AGW) where the key word is Anthropogenic and the key implication is the need to get rid of fossil fuels, can now be further interpreted to mean that the denier that had used sophisticated statistical analysis to embrace the warming hypothesis, now needs to abandon sophisticated statistical analysis to embrace the essence of the climate movement in the form of anti fossil fuel activism. In summary, the Berkeley Earth project appears to be a staged drama concocted by the climate movement as a response to what is called climate change denialism to show that when the good denier takes the trouble to look at the data he gives up his denialism ways and so you can too.

Don't let confirmation bias narrow your perspective — News Literacy Project


Annual Temperature Anomoly

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