Guest DIY by David Middleton
It looks like at least some of this money was well-spent.
I stumbled across something very useful yesterday on Climate-Dot-Gov’s U.S. Climate Resilience Tool Kit page.
The widget generates CMIP5 or PMIP3 model outputs for specific countries and a temperature change map of the world. You can also spit out plots of each model. And these outputs display the actual temperature ranges rather than anomalies.
Since Greenland is such a great climatic playground, I started playing around with it.
Greenland Stays Frozen in an RCP8.5 Bad Science Fiction Nightmare
The first thing I did was to hit Greenland with RCP8.5.
Greenland RCP8.5 1980-2004 vs 2071-2095 –> 5.1 °C
While the histogram indicates a 5.1 °C rise in the average annual surface temperature. It’s thought that the Sangamonian (Eeemian) interglacial was at least 5 °C warmer than today. However, most of that 5.1 °C rise appears to be in winter and the average July temperature is projected to still be below freezing, only 2-3 °C warmer than the 1980-2004 mean.
Since we know that RCP8.5 is just bad science fiction and that global temperatures are behaving more like RCP2.6 to RCP4.5…
Let’s look at RCP4.5 and RCP2.6…
Greenland RCP4.5 1980-2004 vs 2071-2095 –> 2.9 °C
Greenland RCP2.6 1980-2004 vs 2071-2095 –> 1.8 °C
Again, note that most of the warming is in winter. Greenland’s average July temperature barely changes. The Greenland ice sheet will barely notice this.
“And Now For Something Completely Different”
Andy May’s brilliant analysis of NCA4 featured this image:
“A comparison of 32 climate models and observations. The observations are from weather balloon and satellite data. The two observational methods are independent of one another and support each other. The plot is after Dr. John Christy of the University of Alabama in Huntsville (Christy 2016).”
Andy noted the following:
INM-CN4 is labeled and it, alone, is tracking the observations with enough accuracy, yet it does not predict dangerous temperatures in the future or any significant human influence on climate.
This drew some standard ad hominem and/or unsupported dismissals of Dr. Christy’s work and derision of INM-CM4. So I downloaded UAH 6.0 and HadCRUT4 and plotted 5-yr running means at the same scale as Dr. Christy’s 2016 plot.
HadCRUT4 and UAH 6.0 plotted on Christy 2016.
UAH 6.0 generally plots within 0.1 °C of the average of 3 satellite datasets, closest to INM-CM4. HadCRUT4 plots well-below the model-mean closest to the only model that runs hotter than INM-CM4. Note that there’s not a lot of difference between HadCRUT4 and UAH 6.0. (0.1-0.2 °C is not a lot of difference).
Here are the RCP8.5 and RCP 4.5 outputs for INM-CM4 in Greenland:
Greenland INM-CM4 model, RCP8.5. Greenland still frozen in 2100 AD, barely warmer than the coldest part of the Holocene, the Little Ice Age.
Greenland INM-CM4 model, RCP4.5. Greenland still frozen in 2100 AD, barely warmer than the coldest part of the Holocene, the Little Ice Age.
Both models indicate that Greenland won’t be significantly warmer in 2100 than it was in 1850. Almost all of the warming comes from an increase in the minimum temperatures.
1850 was very cold by Holocene standards.
Alley’s reconstruction ends in about 1850… only very slightly warmer than the coldest Holocene temperatures.
References
Alder, J.R., Hostetler, S.W., Williams, D., 2013. An Interactive Web Application for Visualizing Climate Data. Eos Trans. AGU 94, 197–198. DOI: 10.1002/2013EO220001.
Alder, J.R. and Hostetler, S.W., 2013. CMIP5 Global Climate Change Viewer. US Geological Survey https://ift.tt/2KKGVyF doi:10.5066/F72J68W0
Alley, Richard, B. (2000). The Younger Dryas cold interval as viewed from central Greenland. Quaternary Science Reviews. 19. 213-226. 10.1016/S0277-3791(99)00062-1.
via Watts Up With That?
November 30, 2018 at 08:54AM
Iowa Climate Science Education 