Archive for the ‘Uncategorized’ Category
The LA Times letters editor has apparently decided that they know The Truth in scientific matters and will not let anything else bescmirch their pages. We will let someone else check the Times record in this endeavour. In the meantime, Scott Armstrong has written an op-ed asking who benefits from such a policy. His article, titled “Los Angeles Times endorses censorship with ban on letters from climate skeptics” is here.
The latest, March 2013, global mean temperature data from UAH is now plotted on the Climate Bet Graph at right. The temperature anomaly was the same as it was in February and was again cooler than Scott Armstrong’s no-change forecast. Overall, Al Gore’s IPCC “bet” of warming of 0.03°C per annum has been 18% less accurate than the no-change forecast. Over the 63-month life of the bet to date, on the basis of cumulative absolute error, Al Gore’s alarmist forecast has been the better bet for the 8 month period ending January 2011 only.
Of the first 60 months of the 120 month (10 year) Climate Bet, Scott Armstrong’s naive model forecast* of no change in global average temperatures has been closer to the actual temperature than Al Gore’s IPCC-orignated 3°C per century warming forecast for 40 months. The updated Climate Bet Graph is to the right.
Mr Gore and much of the media are concerned about global warming. They should be relieved to learn that over the last five years (2008 to 2012) temperatures were flat or down from the previous month for 62% of months. The year 2012 ended with the global mean temperature for December the same as for the base year for the bet, 2007.
We calculate from the Hadley Center’s global average annual temperature estimates from 1850 to 2012 that the next five years would have to witness a rate of annual average temperature increase greater than 78% of previous five-year sequences in order for Mr Gore to win the bet. Perhaps, like the UK Met Office, he would like to reconsider his forecast.
*To learn more about the naive model, and the performance of no-change forecasts compared to the IPCC’s “forecasts”, see these papers:
Green, K. C., Armstrong, J. S., & Soon, W. (2009). Validity of climate change forecasting for public policy decision making. International Journal of Forecasting, 25, 826–832.
Green, K. C., Soon, W., & Armstrong, J. S. (2013). Evidence-based forecasting for climate change. [Working paper - not for citation].
The story of sea ice in the “other” Arctic, the Antarctic, seems to be largely untold. It turns out the extent of the Antarctic sea ice sheet has reached a record high. At least it is a record since satellite measurements began in 1979. Yes, I know, that is a short period and so not much of a record, but it is the same period that is used as the basis for Arctic sea ice record claims. Similarly, consistency requires that if one claims that Arctic ice has trended down then one must admit that Antarctic sea ice has trended up. For a chart of the time series and discussion on implications for temperatures, see the Real Science page here.
Test your climate forecasting skills: It’s anonymous, and fun!
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.
With a spell of some warmer than average weather over the last three months, the notional Al Gore’s bet on the IPCC’s .03C per annum warming forecast has been on the money for 23 out of 54 weeks. On the other hand, Scott Armstrong’s bet that temperatures would not change from the 2007 average in any predictable way has been on the money for the other 31 weeks, thus bettering the Gore hit rate by 35%.
In an article titled “Healthy polar bear count confounds doomsayers,” Paul Waldie in The Globe and Mail reported on 4 April…
“The number of bears along the western shore of Hudson Bay, believed to be among the most threatened bear subpopulations, stands at 1,013 and could be even higher, according to the results of an aerial survey released Wednesday by the Government of Nunavut. That’s 66 per cent higher than estimates by other researchers who forecasted the numbers would fall to as low as 610 because of warming temperatures that melt ice faster and ruin bears’ ability to hunt. The Hudson Bay region, which straddles Nunavut and Manitoba, is critical because it’s considered a bellwether for how polar bears are doing elsewhere in the Arctic.”
This report will come as no surprise to followers of theclimatebet.com, where we prefer scientific forecasting to politically motivated alarmism. For a recap on scientific forecasting’s contribution to the polar bear population question, Scott Armstrong’s letter 2008 to Senator Barbara Boxer, who chaired a hearing on the issue, is here.
The 2008 paper on polar bear population forecasting, by Scott Armstrong, Kesten Green, and Willie Soon, is available here.
To see the rest of Paul Waldie’s report on the happy state of the polar bear population in 2012, see here.
We have now, belatedly, updated the Armstrong-Gore Bet Graph (to the right). The four month spell of increasing global temperature anomalies earlier in the year petered out and we have now had two months of global average temperature decline. Since the beginning of 2007, temperatures have declined relative to the previous month 52% of the time. The longest run has been 6 months of declining temperatures, while the longest run of increasing temperatures has been 4 months.
The last three months have seen a revival of Mr Gore’s hopes of winning the notional Climate Bet, with global mean temperatures more than 0.3 degrees Centigrade warmer than the 30-year average. We’ve seen higher, and lower, temperatures before in the course of the bet however and, with more than six years to run and with the actual temperature close to Armstrong’s forecast for 25 out of the 43 months to date, the bet is still very much alive.
Global temperatures are back up to the level they were at the beginning of 2007… before they dropped below the 1981-2010 average for most of 2008. We don’t know where average temperatures (anomalies) will go next, but we do know that the Gore-Armstrong Bet is still very much alive.