Responding to the CO2 Coalition's "Facts #22 and #24" on Ideal Temperature

CO2 Coalition's "Fact #22" and "Fact #24" are designed to make you think that warm is better than cold for global temperatures and climate scientists like Michael Mann we should return the Earth's temperature to an "ideal" temperature during the Little Ice Age (LIA). In their "fact #22," they claim that "The most dramatic advances in civilization took place during the last four warm periods—including our own. The advancement of science, technology and the arts have been directly linked to warmer weather." To support this, they show a graph of Greenland Summit temperatures from the GISP2 ice core. 

I've pointed out elsewhere many of the problems they have when they use this graph to confuse local with global temperatures and misplot "current temperatures" from Box 2009. But here they add another layer of confusion to the claims they've made before because none of these "advancements in science, technology and the arts" occurred on the Greenland Summit that experienced these temperature changes. In order to test the hypothesis that warmer is better than colder for human advancement, wouldn't you want to look at what the temperatures were when and where these advancements happened? And then wouldn't you need some sort of attribution of the advancement to the temperature? We won't get any analysis like that from the CO2 Coalition. We will be given a slogan, though, in "fact #24." We're told, "Cold periods = crop failure, pestilence, famine and mass depopulation Greek Dark Ages, Dark Ages, Little Ice Age: Bad, very very bad." Penetrating analysis indeed!

In Fact 24, following their attempt at a very scary picture, we're told that "Dr. Michael Mann of Penn State stated that [the ideal temperature of Earth] would be the temperature before we started adding CO2 to the atmosphere. That temperature would put us squarely in the midst of the temperatures of the Little Ice Age (1250 – 1800)." And then we're told how bad the LIA was in northern latitudes in Europe (with no consideration for other parts of the globe), and a conclusion that "Those advocating for a return to the temperatures of the Little Ice Age are ignorant of the actual effects of such cold periods on humanity."

But did Mann or anyone else say that we should return to the temperatures of the LIA? CO2 Coalition forgot to supply the quote of Mann (or anyone) saying this. However, Mann has gone on record saying our goal should be limiting warming to below 1.5 C above preindustrial levels - we haven't yet left a safe range of temperatures, but we're in danger of doing so. "But if we continue on a fossil fuel-dependent pathway, we will leave that safe range we see in the evidence from past Earth history. That’s what makes this such a fragile moment – we’re at the precipice." And he also says,

There’s fairly compelling evidence from the past, combined with the information from climate models, that if we can keep warming below 1.5C then we can preserve this fragile moment. But if we go beyond 3C, it’s likely we can’t. In between is where we’re rolling the dice.

I'll leave it to CO2 Coalition to find and document where Mann claimed we should go back to the temperatures of the LIA. Until they supply the quote, I'll go with what I can actually find him saying, which is very consistent with what most climate scientists seem to advocate - we need to keep GMST from increasing above 1.5 C above preindustrial levels, and risk to civilization increases above that amount of warming.