I did ask in some other thread if somebody wanted to discuss this. So boooooring. But I want one relatively new paper to get somewhere near your eyes. Mann or Marcott? Nah, they been and gone. Now we have PAGES 2k Consortium 2013. Continental-scale temperature variability during the past two millennia. Nature Geoscience 6: 339-346. DOI: 10.1038/NGEO1797 This had 78 authors, all of whom are in on the conspiracy to minimize older temperature variations (if indeed any such conspiracy exists). They used alkenones, borehole temperatures, diatoms, insects, stable isotopes, Mg/Ca ratios, planktonic foraminifera, pollen accumulation, sediments, tree rings, and several others (by abbreviations I don’t recognize). In short it would appear they used all proxies that fit their length and resolution criteria. Absent polar ice-cores (not well enough time resolved). The journal would ask you to pay for this, but in half a minute you can find a free copy elsewhere on the web. Supplemental information is free as always (but vast as you’d suppose). I think it answers the question of how much of the past was globally warmer as well as it can be answered now. I include here part of their figure 4. See detail in the original, but here we can see most of the time was higher than 1850 temperatures, which agrees with the GISP2 ice-core records we occasionally talk about. About half was higher than 1950. Two ‘blue boxes’ (each representing 30 years) were higher than their last HADCRUT backward-looking 30-year average (through 2010), and none would be higher than 30 years backward from April 2016 (HADCRUT4 latest). Between 600 and 800 AD they show 120 years during which T increased by almost 0.2 degrees C. This is the largest increase prior to the instrumental record. Last 100 years increased 0.68 degrees C. Gradual cooling since 900 AD has been sharply reversed. Any ideas as to why?
If how Earth’s surface temperatures have been are of interest, I’d again draw your attention to: PAGES 2k Consortium (78 authors) (2013), Continental-scale temperature variability during the past two millennia. Nature Geoscience 6, 339-346. I attach part of their Figure 4 with some additional decorations. We have to do this because the earlier Mann Hockey stick lacking earlier ups and downs was so contentious. Upper panel of attached shows 4 different, newer paleo-T reconstructions. One in particular (Moberg) was touted on affinity websites as ‘Mann-killer’ because it did show earlier T excursions. Taken as a group they do show Medieval Warm Period around year 1000 and Little Ice Age bottoming out around year 1600. None of their ending times support a claim that current T is lower than before. Paleo proxies can’t do that. What I would point out is that all of those earlier variations happened when CO2 was flat and relatively low. So CO2 did not cause them, and whether currently high and increasing CO2 does increase T cannot be clearly known from proxies over this time scale. High volcanic activity (the pink vertical bars) generally corresponds to lower proxy T, and mechanisms for that are well known. Detailed records of sunspots are shorter. Profound sunspot gap centered about 1650 was cold by these proxies; this is suggestive but lacks a clear mechanism. Smaller, briefer cooling around 1800 happened during (or before) weak solar cycles, but Tambora volcano (1816 year without summer) argues against a direct solar connection. Weak solar cycles around 1850 happened just as proxy Ts were increasing. Most recent decline in solar cycles happened during warming, and brings us into the present with +CO2 and instrumental T measurements. Here shown only by HADCRUT 4 record; no others differ. As we should know, CO2 absorbs infrared energy and T is now increasing. It is certainly possible that the next few solar cycles may be weak. If they happen to be accompanied by large volcanic activity, +T may slow down. A weak sun by itself seems not to have that power, at least in this higher-CO2 world. Finally consider the lower panel, the PAGES 2k Consortium paleo-T reconstruction. It has ‘smoothed out’ MWP and LIA, and presented a generally cooling world until 1850, changing then to warming. Mann as scapegoat was not among the 78 authors. So one would have to attempt to discredit PAGES people, their ill-gotten Ferraris or whatever. My point is that Mann and his 1998 (or whenever it was) hockey stick is out of the picture; not even cited here. Paleo climatologists have moved on. Might we all not do the same? Focus our attention on this current +T, +CO2 century in which we live? Maybe it will get just 1 or 2 degrees Centigrade warmer, but in it we must address +energy +food +water for +population. If we don’t, by scapegoating Mann or any other superseded work, that would be pretty dumb.
Give me a ten million dollar federal grant and Ill give you a hella bigger Hockey Stick than that. These Climate Scientists are going to be Uber drivers very soon . If they are intelligent enough to qualify.
Take away all my fun. <GRINS> But I have no problem with the goal. I've already turned up the squelch so we can chat. I took the Berkeley Earth data for land averages per month and ran them through a Gaussian filter. Then I trimmed it for my life span: There are other data sets to select: Berkeley Earth Now if we use a calculus trick, we would pull the 'Average High' and 'Average Low' and plot them to get an idea of the temperature spreads. We might also do "Land + Ocean" to get a global view. Bob Wilson
That sounds like a solicitation for a bid to switch sides. Are Koch-tupus grants not big enough for your new tastes? [My spouse began playing an audio book during our New Year's trip: Jane Mayer's Dark Money]
Just so you know Berkeley Earth failed peer review for over a year. Finally they had to create their own new fake journal with the sole intent of publishing their own fake science.Its amazing what hurdles you can leap with billions of $climate change funding. Biggest scam Ive ever witnessed. But Bob knowingly uses them as evidence of global warming.
It is amazing what just two robber baron brothers have achieved with 'weaponized philanthropy' that is now approaching $1 Billion per year.
Fake news is now a word-of-the-year, or something like that. So it's easy to understand a temptation to call something you disagree with fake. Those interested in the journal Geoinformatics and Geostatistics could visit website Archive | Quarterly Journal | Geological Articles | Planet and make your own conclusions about what that journal has published over 4 years.
