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I downloaded the PDF from that URL years ago, for free, no membeships, etc. Their main graph is on their page 2 of the PDF. By eyeball, their graph looks a lo

by graycat 10y ago

I downloaded the PDF from that URL years ago, for free, no membeships, etc. Their main graph is on their page 2 of the PDF. By eyeball, their graph looks a lot like the graph in the Wikipedia page you gave. I was unsure just when the Medieval Warm Period was, but the Wiki graph seems to say it was near year 1000. My eyeball reading of the graph in the PDF says that the temperature in year 1000 is essentially the same as in year 2006 when the PDF was published, and the increase from year 900 to year 1000 was much like the increase from 1906 to 2006. I may be off by some 0.1 C or some such, but there are several curves so that about get to take your pick. Bottom line: Year 1000 wasn't a disaster and wasn't caused by humans releasing CO2, so I'm not much worried about now and not convinced that the current temperature or recent increases were caused by CO2. E.g., was the Little Ice Age caused by less CO2? I doubt it!

throwaway5752 10y ago
We will have to agree to disagree on the chart. For better or worse, the 2016 global land+ocean anomaly is on track to be double 2006 (1.2 C vs 0.6 C), or .06 C past the cutoff of the y-axis and well above the reconstructed MWP peak. "E.g., was the Little Ice Age caused by less CO2? I doubt it!" Who knows? Based on what I could find from ice core studies it appears atmospheric CO2 was 5-10% lower from 1600-1800. I don't anyone making a causative claim.
- graycat 10y ago
  You may be reading the graphs more carefully than I am. For anomalies since 2006, I am skeptical because it looks to me like the current administration has NASA, NOAA, EPA, or whatever cooking the books. From you is the first I've heard that CO2 levels decreased during the Little Ice Age (LIA). Makes some sense -- it was darned cold then which means less biological activity. But there is a cute point: During the LIA, no doubt a lot of people were burning everything they could find to stay warm and, thus, emitting more CO2. Still, CO2 concentrations went down. Gee! The biggie point about the LIA is the Maunder Minimum: That is during the LIA, the sun had nearly no sun spots. Then that agrees with the model in the YouTube video with the URL I gave that claims that the cause of climate change is changes in the rates of sun spots. Just why sun spots could change climate (not really that the sun might be hotter) is explained in the video. The model in that video is not really predictive if can't predict sun spots. At times in the past could do that since there was a definite cycle to sun spots, and the period was right at 11 years. Then, if from such a cycle can predict sun spots, then can use that model to predict climate. To me now, a question is, what the heck are the sources of the rise in CO2 concentrations of the past, say, 100 years? While I'm not convinced that the CO2 levels now are affecting the climate, I'd still like to know where the CO2 is coming from. So, there is a big system with some parts emitting CO2 sources, and others taking it in, sinks. One source is volcanoes, and maybe over half of those are in the ocean. Supposedly another source is sea water: So the warming, from wherever, is slowly heating the ocean, and warmer water absorbs less CO2. So, maybe left over from the LIA, the oceans have a lot of CO2 and as the climate warms from whatever causes are releasing that CO2. The estimates I've seen for the amount of CO2 from human activities has too much variation to take seriously. Then the estimates of CO2 from other sources also has huge variation. Ah, back to work.

by graycat 10y ago

throwaway5752 10y ago

We will have to agree to disagree on the chart. For better or worse, the 2016 global land+ocean anomaly is on track to be double 2006 (1.2 C vs 0.6 C), or .06 C past the cutoff of the y-axis and well above the reconstructed MWP peak. "E.g., was the Little Ice Age caused by less CO2? I doubt it!" Who knows? Based on what I could find from ice core studies it appears atmospheric CO2 was 5-10% lower from 1600-1800. I don't anyone making a causative claim.

graycat 10y ago
You may be reading the graphs more carefully than I am. For anomalies since 2006, I am skeptical because it looks to me like the current administration has NASA, NOAA, EPA, or whatever cooking the books. From you is the first I've heard that CO2 levels decreased during the Little Ice Age (LIA). Makes some sense -- it was darned cold then which means less biological activity. But there is a cute point: During the LIA, no doubt a lot of people were burning everything they could find to stay warm and, thus, emitting more CO2. Still, CO2 concentrations went down. Gee! The biggie point about the LIA is the Maunder Minimum: That is during the LIA, the sun had nearly no sun spots. Then that agrees with the model in the YouTube video with the URL I gave that claims that the cause of climate change is changes in the rates of sun spots. Just why sun spots could change climate (not really that the sun might be hotter) is explained in the video. The model in that video is not really predictive if can't predict sun spots. At times in the past could do that since there was a definite cycle to sun spots, and the period was right at 11 years. Then, if from such a cycle can predict sun spots, then can use that model to predict climate. To me now, a question is, what the heck are the sources of the rise in CO2 concentrations of the past, say, 100 years? While I'm not convinced that the CO2 levels now are affecting the climate, I'd still like to know where the CO2 is coming from. So, there is a big system with some parts emitting CO2 sources, and others taking it in, sinks. One source is volcanoes, and maybe over half of those are in the ocean. Supposedly another source is sea water: So the warming, from wherever, is slowly heating the ocean, and warmer water absorbs less CO2. So, maybe left over from the LIA, the oceans have a lot of CO2 and as the climate warms from whatever causes are releasing that CO2. The estimates I've seen for the amount of CO2 from human activities has too much variation to take seriously. Then the estimates of CO2 from other sources also has huge variation. Ah, back to work.