Archive for the ‘forecasting’ Category
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.
With 74 months of the Armstrong-Gore bet behind us and 46 months left to go, global mean temperatures have gone nowhere. That, of course, is the no-trend forecast that is the basis of Professor Armstrong’s bet. Mr Gore on the other hand claimed temperatures would go up, dangerously. In fact, most months of the bet (57%) have seen temperatures flat or down from the previous month. Professor Armstrong’s conservative forecast has been more accurate than Mr Gore’s alarmist forecast for nearly 69% of months so far.
Unlike Al Gore, Nobel laureate Brian Schmidt is willing to bet on what global mean temperatures will be in 20 years time, presumably with his own money. Schmidt’s offer to bet was in response to Australian Prime Minister Tony Abbott’s business advisor Maurice Newman’s skepticism over the IPCC’s alarming projections.
But reading on, Prof Schmidt, and the other warming alarmists who suddenly popped up saying “me too” are not so brave. As Jo Nova explains, they are only willing to bet that temperatures will be warmer, not that they will be dangerously warmer… they want the rest of us to pay for that bet.
Mostly down. In the course of the 72 months of the bet to date, the global mean temperature fell or remained flat compared to the previous month for 41 months, or 57% of the time. (In case you’re wondering, the UAH series records only 2 occasions over this period on which the temperature did not change from the previous month.)
We’re not sure how the ups-and-downs of the global temperature over these last six years accord with what Mr Gore had in mind when he issued his warning of an immanent and catastophic “tipping point”, but we know that his chances of winning the Climate Bet against the no-trend forecast proposed by Professor Armstrong have receded as the life of The Bet has progressed.
See the chart to the right with the latest (December 2013) data.
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 forecastingprinciples.com 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.
With eleven months of temperature data now in for 2013, it is highly unlikely that Mr Gore could win this, the sixth, year of The Climate Bet. For Mr Gore to win, the December global mean temperature anomoly would need to be substantially higher than any month so far in The Bet. Failing that unlikely outcome, the no-change forecast that Professor Armstrong is betting on will have been more accurate that Mr Gore’s IPCC-originated dangerous manmade global warming forecast for five of the first six years of The Bet.
With October 2013′s global mean temperature data in, we now have 70 months of evidence on the accuracy of Mr Gore and the IPCC’s alarming warming forecast of temperatures increasing at a rate of 0.03ºC per annum. If Mr Gore’s forecast were valid and unbiased, we would expect actual temperatures to be higher than his forecast roughly half of the time and lower roughly half of the time. We checked the record of The Bet. It turns out that, to date, the actual global mean temperature has been higher than Mr Gore’s forecast less than one-quarter (23%) of the time. By contrast, the measured temperature has been warmer than the no-change benchmark, Professor Armstrong’s bet, 46% percent of the time; very close to the ideal of 50%. The updated chart is to the right.
“There are no scientific forecasts of dangerous global warming” shouts a new article in the Financial Post. Readers of this blog know that already, but will likely want to read what the op-ed titled “Climate forecast: All’s well, despite what the IPCC says” by Kesten Green, Scott Armstrong, and Willie Soon has to say about the implications for government policy. It has already attracted lively discussion. The article is here.
The authors claim to provide the only scientific forecast of long-term climate, namely the naive no-change or no-trend forecast that is the basis of Professor Armstrong’s notional bet with Mr Gore. The forecast was originally published in 2009, and the International Journal of Forecasting article can be found here. The authors’ current working paper investigating possible improvements to climate forecasting for policy makers is here.
The September global temperature anomaly was the highest it’s been since January, and is close to Mr Gore’s “forecast” for the month. The balance of the bet remains firmly in Professor Armstrong’s favour, however: The error of the red-hot alarmist projection is to date nearly 20% higher than the error from the scientific cool-green no-trend forecast. See the updated chart (color coded) and table to the right.
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.