Great article on what we know and don't know about the LIA and it's effect on climate change today. Nice to see a scientist admit we don't know what we don't know. A refreshing change from AGW pushers that claim to have the wisdom of God. He brings up some interesting points such as how the IPCC has ignored the LIA because they can't explain it. "And what does the IPCC have to say about it?" "Both model simulations and results from detection and attribution studies suggest that a small drop in GHG concentrations may have contributed to the cool conditions during the 16th and 17th centuries. Note, however, that centennial variations of GHG during the late Holocene are very small relative to their increases since pre-industrial times. The role of solar forcing is less clear …." In the 1,535-page AR5 Working Group 1 report this is all the space the LIA got. Brief discussion: "AGW skeptics often claim that present-day sea level rise and glacier ice loss are a result of a natural recovery from the LIA. AGW believers counter that a “recovery from the LIA” is not an acceptable explanation; a causative mechanism must be identified. But they too are unable to come up with a mechanism which explains why sea levels have been rising and glaciers retreating for a well over a hundred years, long before man-made CO2 emissions became significant. Global warming certainly doesn’t explain it. Figure 12, which matches up Church and White’s global sea level reconstruction – the one used by the IPCC – against the HadCRUT4 global temperature record, shows sea levels rising since 1870, and at a constant rate between 1925 and 2000, regardless of what temperatures did. Sea levels don’t respond immediately to changes in temperature, but the fact that sea level rise was unaffected by global temperature fluctuations again suggests that a factor other than temperature was the dominant cause:" And what might this factor have been? A natural recovery from the LIA, of course. There’s still a lot we don’t understand about how the Earth’s climate works. http://euanmearns.com/the-end-of-the-little-ice-age/ Who is Roger Andrews you ask? "On specific energy and climate issues I’m guided by what the data tell me, not by claims made in the scientific literature. This is why you will find me disagreeing with most of the “consensus” views on climate change but not all of them. My main concern for the future of my three grandchildren isn’t climate change, but that the misguided efforts of the people who want to save the world from it will leave them freezing in the dark." http://euanmearns.com/about-roger-andrews/
That's a strange blog post. It's like the guy is arguing that CO2 either has to be 100% responsible for temperature changes or 0%. But, he just can't accept that it's the net effect of all physical processes. I think he's also saying that he rejects the hypothesis that the increased solar radiation and a decrease in volcanic activity were contributing factors even though he presents valid lines of evidence showing that solar radiation did, in fact, increase and that volcanic activity did, in fact, decrease. He also doesn't make any mention of the fact that solar radiation has been flat to declining since 1960 and yet the Earth has been warming at an accelerating pace. Though, he does correctly point out that there is a correlation with CO2 and glacial retreats. But then he goes on to say that these glacial retreats and ocean rises were occurring before man made CO2 release began as way of arguing that CO2 can't be an influencing factor today. Nevermind, that his charts actually show glacial retreats beginning in the mid 1800's and at about the same time as anthroprogenic CO2 release. Likewise, his own chart shows a clear and distinct period of accelerated ocean level rise after 1925. And finally, I'd like to point out that his insinuation that ocean level rise must be in lock-step with surface temperature rise for AGW to be true is absolutely false. This is a gross misunderstanding of the physics of heat storage, thermal expansion, and the heat flux processes between the ocean and atmosphere.
The most glaring of all your failed efforts is the one I put in bold. This attempt at correlation equals causation is laughable. To claim the minute amount of C02 we put into the atmosphere in the mid 1800s caused the glacial retreats to commence is to prophesize that all glaciers would be gone by now with the amount of C02 we now add in relation to the pathetic 1800s era. Instead glaciers are actually growing in major areas including the Himalayas which the IPPC did actually predict would soon be gone.
I don't think glacial retreating began because of anthroprogenic CO2. I think it began because of increased solar radiation and reduced volcanic activity. I'm just saying that his claim that glacial retreating had been underway for well over 100 years before anthrogenic CO2 emissions became significant doesn't jibe with his own charts.
Just because YOU and HE don't know doesn't mean scientists and the rest of us are equally as clueless. Meanwhile scientists are making progress and building models that provide useful skill in reproducing both past and present temperature trends. So when I see these blog posts that provide no insights or a model for explaining global temperature trends and only cast doubt on those who are trying I have no choice but to side with those whose model works and is backed up with an abundance of evidence. It's like he's stuck on this idea that global temperature trends can only ever be driven by a single thing. He doesn't even consider that it it's the net effect of all physical processes and agents that matter. That's probably why he ends his blog with the proverbial throwing of his hands in the air and basically saying he has no idea. He just "knows" that it was "natural" as if "natural" is an actual fundamental physical process.
Some wannabe scientist in a forum that for all iI know bags groceries for a living is smarter than this guy? "In my career I have worked on hundreds of projects all over the world, although of course I didn’t visit all of them. Some of the projects were a little off the beaten track too, One of the most challenging was being given six months to figure out how to quench an active plus-200C geothermal system on Lihir Island, Papua New Guinea, so that the gold deposit there could safely be mined. Somewhat to my surprise, the plan worked."
I think you have that backwards. Some wannabe blogger thinks because HE can't figure out the significant influencing factors for the LIA then nobody else should be able to either. My position on matters of climate generally align with the scientific consensus. It's not that I think I'm smarter than this guy. It's that I think the world's leading experts on the topic of climate change have a much better handle on climate change than some random guy who apparently just dabbles in climate change issues as a hobby. I have no problem with people dabbling in matters of science especially when they do so learn. I happen to do it with a lot scientific fields (climate being one of them). But, what I do have a problem with is this Dunning-Kruger like cognitive bias that makes people overestimate their own knowledge and think they are smarter than everyone including all of the leading experts in the field.
