Quote:
Originally Posted by strongmanmike
I am staying out of this but rest assured I and MANY others feel your frustration on this issue... I would like to say thanks for your succinct assessment on this matter 
Amen |
Thanks Mike! It's the price of a climate research training that you have to deal with vocally uninformed (or sadly misinformed) people claiming that you, and
every single relevant national science academy, and virtually every one of tens of thousands of relevant academics on the planet is wrong. All repeating tired old talking points that have been debunked a hundred times over, and who have collective blindspots to such things as the last 15 years being the time of the fastest accumulation of heat in the part of the world that collects >90% of global warming (Levitus et al 2012). No, the 2% of surface temperatures which have slowed (not stopped), despite every natural forcing going negative, is somehow much more important
. That even in surface temperatures, La Ninas in the late 2000s are warmer than every El Nino pre-1998, is apparently no problem. That if you extend the 1975-1998 trendline through the 2000s, there is no significant change - there is simply
a positive trend in La Ninas, El Ninos and neutral years. I wonder if the 'hiatus' will be so popular among the blog skeptics after the next significant El Nino (absent a big equatorial volcanic eruption)?
I can't really be bothered dealing with each point of your latest Gish Gallop Renato, in which there is another worn list of long-debunked talking points, but I will address just one:
Mike Mann published one of the most talked-about papers in climate science in 1999, showing that average temperatures across the Northern Hemisphere had gradually trended slightly cooler over the past 1000 years, before very sharply warming in the past century. On a hemispheric (and subsequently a global) scale, the European historical periods known as the Medieval Warm Period and the Little Ice Age were not at all apparent. To cut a long story short, the MWP and LIA were found to be neither global in extent or in timing (as questioned by Hughes and Diaz in a seminal paper in 1994), and so while it was warm in Europe, other regions were cooler, and vice versa. This fits very well with the understanding that climate forcings were not changing too much over these periods except for the continuation long, slow cooling from a Northern Hemisphere precessional insolation peak which culminated in peak warmth in the mid-Holocene. Modern forcing from increased greenhouse gases is enormous by comparison.
Mann's paper has been replicated something like a dozen or more times, many of which are shown
in the relevant figure from the IPCC AR5 WG1 report. More recently than that, it was replicated by the massive PAGES 2k project,
which you can read a summary of here,
and yes, you can even go and read the actual sources too.
This area is of particular interest to me, as my PhD and postdoc were on studying Holocene palaeoclimate and glacier changes in the North Atlantic region (and where even the undergrads can see the scale of recent glacier retreat
). Now a couple of statisticians
claimed to find errors in Mann's methods. Strangely, they didn't try and replicate the work (just throw mud at it), and when others examined the statisticians' work, it was found to have numerous serious errors of its own, including a chronic case of cherry picking, where the program they used pre-selected the results they wanted. But nowadays, that's all ancient history, as there are so many replications of the original study, with widely differing methods and proxy sources, that Mann's work has been verified beyond any reasonable doubt. That's the scientific process.
But still some would try and throw mud at Mike Mann. Including those who think an undergraduate essay mark is supposed to impress me
