Eli was particularly struck by a couple of answers to the first few questions,
Q: "Is there a simple short but compelling answer that can be given when you run into someone who just insists "oh, the climate has always changed. This is natural and scientists just want to scare us into giving them more funding"?"hilary, washington DC
A: The Earth has experienced many large climate changes in the past (also see questions 6 and 7 of our report). However, current changes in climate are unusual for two reasons: first, many lines of evidence demonstrate that these changes are primarily the result of human activities (see question 2 and 3 of the report); and second, these changes are occurring (and are projected to continue to occur) at a much faster rate than many past changes in the Earth’s climate (see question 6 in the report). Human societies, developed in the context of a rather stable climate, are likely to be vulnerable to the rate and magnitude of the changes anticipated through this century if greenhouse gases emissions are not curbed.In the way of science, the answer goes on for a to:dr spell, but one paragraph is enough.
Q: "Why have so many regional and global temperature records for the early 20th century been revised downward, increasing the apparent warming of the 20th century? How do we know better than those who took the measurements at the time?"Monckton of Brenchley, Edinburgh
A: In the early days of weather observations, there was rather poor coverage of the world, and most thermometers were in Europe and North America, and they were not necessarily well-sited using standardised enclosures. Interpreting the early data is therefore not straightforward, as there are various possible biases in the observations that should properly be allowed for, and there are also problems in dealing with the non-uniform spatial coverage.
Several groups routinely produce and maintain long-term estimates of global and regional temperature, and they all try to manage these difficulties in different ways. When new information becomes available (e.g. from historical research or data “archaeology”) they can use it to readjust early observations to make them more comparable to later ones, so past data may be revised (either upwards or downwards). Reassuringly they all get very similar results after about 1880.
That sceptical has an element of snarktical in it.Occasionally problems may be introduced, as well as corrected, and the question may relate to a specific adjustment made in the NASA global temperature record in December 2009, which was a downward adjustment to US temperatures owing to confusion over whether or not the records received from NOAA had already been adjusted or not. This affected the records after 2000, but the effect globally was very small, and it was quickly corrected, see http://www.columbia.edu/~jeh1/mailings/2009/20091216_TemperatureOfScience.pdf .
Recently another (and sceptical) group used a new and quite different statistical method to reanalyze the historic data, and they have obtained extremely similar results too, so it seems that these adjustments do not have a big effect on the main findings.
(see http://berkeleyearth.org/about)
Anyhow, discuss.
They are less patient with Monckton's claim of "no global warming at all for 17 years and 5 months" based on RSS.
ReplyDeleteThe RSS monthly temperatures are not at the surface, but are one version of the satellite temperature record, and we presume the questioner refers to the so-called TLT (Lower Troposphere) record. This does reveal an upward trend that fits reasonably well with that suggested by models although on the low side (see the detailed analysis of this by Santer et al. 2014 Nature Geoscience, (23 February) doi:10.1038/ngeo2098.) What is outside most model simulations is the 1997/98 El Niño warming, and the questioner appears to have taken the highest point on that curve to produce a very misleading estimate of the recent trend. Question 10 of our document addressed this question, and it is also addressed in several other recent publications: see in particular several articles in Nature Climate Change in March 2014.
No debating with members of The Flat Temperature Society is possible.
ReplyDeleteNo debating is possible with members of the no debating society as well.
ReplyDeleteBring them on .
And while you're up , tell the Academic Senate of the University of the University of Rochester what you think of Monckton's latest fuelleton, aimed at lawrence Torcello, Rochester's greatest living philosopher, now that Jack Benny's man has left the scene.