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I added a greenland temperature chart overlayed with historical events. Yes, the previous warm periods mentioned where global, they where a lot warmer than toda

I added a greenland temperature chart overlayed with historical events. Yes, the previous warm periods mentioned where global, they where a lot warmer than today and things mostly got better. The last IPCC report fails to account for global greening, which is a giant effect. https://www.nasa.gov/feature/greening-of-the-earth-mitigates-surface-warming https://www.nasa.gov/feature/greening-of-the-earth-mitigates...

ben_w 5y ago
I’ve worked with MODIS satellite data. Quoting your own link: """The vegetation cooling effect is large from the energy dissipation perspective, but only about 10%-20% compared to the pace of global warming. The cooling effect from greening is less significant in tropical forests with high leaf areas.""" Regarding the previous warm periods, I was right, and I just now found the following reference to demonstrate this: """More recent research, including a 2019 analysis based on a much larger dataset of climate proxies, has found that the putative period [the Roman Warm Period], along with other warmer or colder pre-industrial periods such as the "Little Ice Age" and "Medieval Warm Period," were regional phenomena, not globally-coherent episodes.[7] That analysis uses the temperature record of the last 2,000 years dataset compiled by the PAGES 2k Consortium 2017.[7]""" [7] https://boris.unibe.ch/132301/7/333323_4_merged_1557735881.pdf https://boris.unibe.ch/132301/7/333323_4_merged_1557735881.p...
- irthomasthomas 5y ago
  Lüning et al. June 2019. "Abstract The Medieval Climate Anomaly (MCA) is a well-recognized climate perturbation in many parts of the world, with a core period of 1000–1200 CE. Here we are mapping the MCA across the Antarctic region based on the analysis of published palaeotemperature proxy data from 60 sites. In addition to the conventionally used ice core data, we are integrating temperature proxy records from marine and terrestrial sediment cores as well as radiocarbon ages of glacier moraines and elephant seal colonies. A generally warm MCA compared to the subsequent Little Ice Age (LIA) was found for the Subantarctic Islands south of the Antarctic Convergence, the Antarctic Peninsula, Victoria Land and central West Antarctica. A somewhat less clear MCA warm signal was detected for the majority of East Antarctica. MCA cooling occurred in the Ross Ice Shelf region, and probably in the Weddell Sea and on Filchner-Ronne Ice Shelf. Spatial distribution of MCA cooling and warming follows modern dipole patterns, as reflected by areas of opposing temperature trends. Main drivers of the multi-centennial scale climate variability appear to be the Southern Annular Mode (SAM) and El Niño-Southern Oscillation (ENSO) which are linked to solar activity changes by nonlinear dynamics." https://www.sciencedirect.com/science/article/abs/pii/S0031018219303190 https://www.sciencedirect.com/science/article/abs/pii/S00310... Edit: Bonus climate reconstruction from 1268 studies of the MWP https://www.google.com/maps/d/viewer?mid=1akI_yGSUlO_qEvrmrIYv9kHknq4&ll=-3.81666561775622e-14%2C-116.64931299999989&z=1 https://www.google.com/maps/d/viewer?mid=1akI_yGSUlO_qEvrmrI...

ben_w 5y ago

I’ve worked with MODIS satellite data. Quoting your own link: """The vegetation cooling effect is large from the energy dissipation perspective, but only about 10%-20% compared to the pace of global warming. The cooling effect from greening is less significant in tropical forests with high leaf areas.""" Regarding the previous warm periods, I was right, and I just now found the following reference to demonstrate this: """More recent research, including a 2019 analysis based on a much larger dataset of climate proxies, has found that the putative period [the Roman Warm Period], along with other warmer or colder pre-industrial periods such as the "Little Ice Age" and "Medieval Warm Period," were regional phenomena, not globally-coherent episodes.[7] That analysis uses the temperature record of the last 2,000 years dataset compiled by the PAGES 2k Consortium 2017.[7]""" [7] https://boris.unibe.ch/132301/7/333323_4_merged_1557735881.pdf https://boris.unibe.ch/132301/7/333323_4_merged_1557735881.p...

irthomasthomas 5y ago
Lüning et al. June 2019. "Abstract The Medieval Climate Anomaly (MCA) is a well-recognized climate perturbation in many parts of the world, with a core period of 1000–1200 CE. Here we are mapping the MCA across the Antarctic region based on the analysis of published palaeotemperature proxy data from 60 sites. In addition to the conventionally used ice core data, we are integrating temperature proxy records from marine and terrestrial sediment cores as well as radiocarbon ages of glacier moraines and elephant seal colonies. A generally warm MCA compared to the subsequent Little Ice Age (LIA) was found for the Subantarctic Islands south of the Antarctic Convergence, the Antarctic Peninsula, Victoria Land and central West Antarctica. A somewhat less clear MCA warm signal was detected for the majority of East Antarctica. MCA cooling occurred in the Ross Ice Shelf region, and probably in the Weddell Sea and on Filchner-Ronne Ice Shelf. Spatial distribution of MCA cooling and warming follows modern dipole patterns, as reflected by areas of opposing temperature trends. Main drivers of the multi-centennial scale climate variability appear to be the Southern Annular Mode (SAM) and El Niño-Southern Oscillation (ENSO) which are linked to solar activity changes by nonlinear dynamics." https://www.sciencedirect.com/science/article/abs/pii/S0031018219303190 https://www.sciencedirect.com/science/article/abs/pii/S00310... Edit: Bonus climate reconstruction from 1268 studies of the MWP https://www.google.com/maps/d/viewer?mid=1akI_yGSUlO_qEvrmrIYv9kHknq4&ll=-3.81666561775622e-14%2C-116.64931299999989&z=1 https://www.google.com/maps/d/viewer?mid=1akI_yGSUlO_qEvrmrI...