The Global Warming Challenge

Evidence-based forecasting for climate change

Archive for the ‘scientific approach’ Category

Mr Gore’s tipping point forecast either biased, or very unlucky

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Since we started monitoring the Gore-Armstrong bet back in 2008, global mean temperatures have only rarely been as warm or warmer than Mr Gore and the IPCC’s +0.03 °C per year warming forecast would have had us believe. How rarely? Well, roughly one-month-in-five, or 21% of the 77 months to date. As we’ve pointed out before, one would expect the figure to be 50% if the Gore/IPCC forecasts were unbiased. Mr Gore must be very unlucky, because the chances that so few months would turn out to be as warm or warmer than unbiased forecasts is less than one-in-eight-million.

But wait, Mr Gore and the IPCC warned us that there was more chance that temperatures would be higher than their forecasts, than that they would be lower. In other words, they claimed their forecasts were biased toward slower warming than the rapid warming they really believed would occur. We haven’t calculated the vanishingly small odds that global temperatures would turn out to be so uninclined to warm taking into account the declared downward bias in their forecasts, but we suspect that Mr Gore and the IPCC have been feeling that the Earth has let them down.

For keen followers, the latest month of The Bet, May 2014, is shown in the chart on the right.

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June 16th, 2014 at 2:41 am

If “consensus” is evidence for alarm, what evidence its absence?

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Much has been made of the claim that there is an overwhelming consensus of scientific opinion that we will suffer dangerous manmade global warming during the 21st Century. Putting aside the unscientific and rather desparate nature of resorting to a vote to decide how the Earth’s climate will behave during the current century and beyond, is it true? In their Wall Street Journal op-ed of May 26, 2014, Joseph Bast and Roy Spencer examine the evidence, and shred the claim of consensus on dangerous warming in it various forms. Their op-ed is also available here.

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May 29th, 2014 at 5:05 am

March 2014 temperatures: More evidence on Gore warming bias

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The average global temperature for the first quarter of 2014 was less than 0.01°C different from Professor Armstrong’s no-trend forecast. With 75 months of data now in, we wondered whether there was any evidence of bias in Professor Armstrong’s or Al Gore’s forecasts. We found that there was. Both Armstrong’s and Gore’s forecasts appear to have a bias toward forecasting temperatures that are warmer than the measured temperatures. In the case of Scott Armstrong’s no-trend forecasts, they have to date averaged 0.02C warmer than the recorded temperature. In the case of Al Gore’s IPCC alarming warming forecasts, they have averaged 0.12C warmer. We think policy makers should prefer less-biased forecasts. The updated Climate Bet graph is to the right.

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April 10th, 2014 at 6:25 am

Armstrong and Green on climate models in NIPCC’s Climate Change Reconsidered II

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A summary of the critique of the use of complex mathematical models for forecasting long term climate change by Kesten Green, Scott Armstrong, and Willie Soon is published in the Nongovernmental Panel on Climate Change’s Climate Change Reconsidered II: Physical Science (2013).

The reference is as follows, and links to the relevant section and to the entire NIPCC report are available from the Global Warming Audit pages of the site, here.

Armstrong, J. S., & Green, K. C. (2013). Global climate models and their limitations: Model simulation and forecasting – Methods and principles. pp. 14-17 in Idso, C. D., Carter, R. M., & Singer, S. F. (Eds.), Climate Change Reconsidered II: Physical Science. Chicago, IL: The Heartland Institute.

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December 21st, 2013 at 11:32 pm

New scientific report on climate change

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The Nongovernmental International Panel on Climate Change (NIPCC) has released a new report on the science of climate change: Climate Change Reconsidered II: Physical Science. The key takeaway messages are (1) the human impact on climate is very small and (2) any change in temperatures that might be occurring or will occur in the future is so small that it will not be noticed against the climate’s entirely natural variability.

As part of the NIPCC’s process for preparing this volume, scores of scientists from around the world evaluated the most up-to-date research on the physical science of climate change. This report is at least as comprehensive and authoritative as the reports of the United Nations-funded Intergovernmental Panel on Climate Change (IPCC) … and the NIPCC report is faithful to the scientific method. Whereas the mission of the IPCC is to find a human impact on climate change and thus justify government control of greenhouse gas emissions and our economy, the NIPCC has no agenda other than discovering the truth about climate change.

Section 1.1.1 of the report addresses forecasting principles and methods, and was co-authored by J Scott Armstrong and Kesten C Green. It is on p.14 of the Chapter 1 of the report, which is available here.

Talks on climate forecasting from Doctors For Disaster Preparedness Conference

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The Doctors for Disaster Preparedness Conference in Houston (July 12 to 15 2013) featured several talks related to the dangerous manmade global warming alarm, including one from’s Professor Scott Armstrong. A video of his talk, “Evidence-Based Forecasting for Global Warming”, is available here. Willie Soon’s talk, “Five or more failed experiments in measuring global sea level change”, is available here, and Antony Watts’s talk, “Ten tests to determine whether you should be concerned about global warming” is available here.

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August 17th, 2013 at 1:29 am

Perhaps it would have been fairer to Mr. Gore…

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The May 2013 data has been released and shows the monthly temperature anomaly was below the 2007 average that is the starting point of the Armstrong-Gore graph for the fourth month running. So far, the total error of Mr Gore’s warming forecast is 21% larger than the error of Professor Armstrong’s no-change forecast. See the updated Climate Bet graph at right for the details.

It occurred to us that the bet would have been fairer to Mr Gore and the IPCC if we had used the data that were available to Mr Gore when he released his movie “An Inconvenient Truth”, during 2006, as the base-year for The Bet. (The base year that we use for The Bet, 2007, was the most recent data available when Professor Armstrong issued his challenge to Mr Gore.) And so we re-ran The Bet using the 2005 average (the latest full year available to Mr Gore when he released his movie) as the base year. Mr Gore’s forecast in the re-run is for a 0.03ºC p.a. increase from the 2005 average and Professor Armstrong’s is simply the 2005 average.

In the event, re-running The Bet from 2008 to date using 2005 as a base results in a total error for the Gore/IPCC alarming warming forecast that is 31% larger than the error of the no-change forecast. We think Mr Gore would likely prefer to stick with the current Bet arrangement, even though it is not as fair.

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June 6th, 2013 at 1:41 am

Changes in the Sun mean changes in the climate

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Bob Carter, Willie Soon, and William Briggs describe the evidence that changes in radiation from the Sun are the major source of changes in the Earth’s climate in a new article in Quadrant. The claim may seem uncontroversial, but global warming alarmists argue that human emissions of carbon dioxide have such a big effect that they dominate solar changes and are inexorably and dangerously boosting global mean temperatures. The Climate Bet is a test of these hypotheses, with Scott Armstrong “betting” on unpredictable changes in solar radiation and Al Gore on CO2-induced warming… and you know how that has been going.

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March 14th, 2013 at 12:19 am

The New York Times warns civilization likely to end due to manmade warming – Professor Armstrong tries to avert panic.

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On November 24, 2012, The New York Times published an article titled “Is this the End?,” which warned that manmade global warming is likely to destroy our civilization. The article was published nine days after the NYT published Cass Sunstein’s article advocating that policies on dangerous manmade global warming should be based on cost-benefit analyses, that the government had calculated a net benefit for costly policies, and that Ronald Reagan once agreed with a cost-benefit analysis. I was unable to contact Professor Sunstein to find the sources of the “cost-benefit analyses.” In an effort to calm panic-stricken readers, I wrote a Letter to the Editor at The New York Times revealing that while cost-benefit analysis is indeed the proper method, none has shown likely net harm arising from global warming. Evidence-based forecasts of dangerous warming and of the effects of alternative policies are missing. Strangely, my evidence-based forecasts that our civilization is not threatened by dangerous warming did not meet the NYT criteria of “All the news that’s fit to print.” If you know any NYT readers, please inform them that they are safe.

Wall Street Journal readers were spared panic. They had read No Need to Panic About Global Warming in January 2012.

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November 27th, 2012 at 5:43 am

Fun Climate Forecasting Quiz

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Test your climate forecasting skills: It’s anonymous, and fun!

Go straight to the Quiz on the page here, make your forecasts for the two 25-year periods offline, then check the outcome and grade your response here.

To learn about the latest developments in climate forecasting, read the draft paper by Kesten Green, Scott Armstrong, and Willie Soon from the recent International Symposium on Forecasting in Boston (June 2012). The link to the paper is here, and supporting materials are towards the bottom of the page.