Climate change: IPCC report is 'code red for humanity'

What if climate change was perpetuated by giant sloths who want to drive humans to extinction? We can play the “what if” game and I think it’s important to keep an open mind in science, but to quote Walter Kotschnig, not so open that our brains fall out.

We can use a bit of Bayesian inference here. Given the current data, the probability of natural cycles (or ground sloths) being the root cause seems low. Given the potential risk, hanging our hat on that small chance seems like an irrational choice. Or a potential one that just reduces our cognitive dissonance so we feel better about ourselves.

I know there’s many people who bristle at the thought of any authority outside of themselves but that can become an epistemological bias in its own right.

Likewise, the comment adds very little to the discussion because the compliment can be said with equal validity.

”-The free market- puts more power in the hands of the people causing the problems.”

Can easily extend to individual consumers just as your statement points the finger at government

Okay, let's look at the observational data:

There was a movie, An Inconvenient Truth. With data from Antarctic ice cores, the movie showed, for the atmosphere, a graph of temperature and CO2 concentrations going back about 800,000 years.

As I watched the movie, it appeared that the claim was that the graph showed temperature and CO2 concentrations going up and down together. Then the movie concluded that the higher concentrations of CO2 caused the higher temperatures. Then there was a claim that currently more CO2 from human activities would rapidly cause significantly higher temperatures.

But, we could look at that graph more closely, and doing that we will see three situations:

(1) When temperature started to increase, CO2 (concentration, here and below) was low, not high. So, something caused the warming, but it was not high CO2.

(2) About 800 years later, CO2 had increased. Presumably the cause was more biological activity from the higher temperatures.

(3) Some thousands of years later, while CO2 was high, the temperatures fell again. There was a cause, but it was not low CO2. Indeed, the high CO2 did not keep temperatures from falling.

Net, from that 800,000 years of data, there is no evidence that high CO2 caused high temperatures. It would be more accurate (though of course still wrong) to say that the data supported that CO2 caused LOWER temperatures.

For some more recent data, there was some significant warming during the time of the Roman Empire and during the Medieval Warm Period, and there is no evidence that the cause was high CO2. There was some significant cooling during the Little Ice Age from roughly 1300 to 1900, but there is no evidence that the cause was low CO2. There was some cooling from 1940 to 1970 and concerns in the media about another ice age, and those years were when there was more CO2 from human activity from WWII and the post-war economic boom. So, in those years, with more CO2, we got some cooling instead of warming.

Again it would be more accurate (though of course still wrong) to say that the data supported that CO2 caused COOLING.

For some details, can start with "Global Cooling" at

https://en.wikipedia.org/wiki/Global_cooling#1974_Time_magaz...

which discusses the two famous magazine stories, the 1974 Time story and the 1975 Newsweek story, worrying about "global cooling" and asking if we were entering a new ice age. For more on these magazine stories, at

https://longreads.com/2017/04/13/in-1975-newsweek-predicted-...

can see the April 28, 1975, Newsweek article “The Cooling World”.

So, net, there is no data on temperature and CO2 from the past that says that CO2 will cause warming.

Yes, CO2 is a greenhouse gas. This means that it absorbs some light in the infrared but not the visible. In the case of CO2, it absorbs light out in the infrared in three narrow bands. The absorption spectrum is given at

https://webbook.nist.gov/cgi/cbook.cgi?Spec=C124389&Index=0&...

Part of the mechanism is Planck black body radiation.

We have had some warming since the Little Ice Age. It may be that we are still pulling out of the Little Ice Age, e.g., it can take a long time for the oceans to warm up. But even with this warming, it's cooler than in the Medieval Warm period and the Roman times when the polar bears didn't go extinct, the ice in Greenland and the Antarctic didn't melt, the oceans didn't rise and flood the coasts, and humans didn't suffer. Apparently the main effects were greater agricultural productivity, e.g., in England, grapes were grown for wine.

Could the warming since the Little Ice Age be due to CO2? No: The warming is at the surface, and CO2 absorbs high in the troposphere with definition at Google:

the lowest region of the atmosphere, extending from the earth's surface to a height of about 3.7–6.2 miles (6–10 km), which is the lower boundary of the stratosphere.

which, from MIT climate scientist Richard Lindzen, Alfred P Sloan Professor of Atmospheric Sciences, Emeritus, at Massachusetts Institute of Technology, has gotten cooler, not warmer.

Several attempts were made to model the atmosphere and calculate and predict the effects of human sources of CO2 on temperature. Nearly all the efforts predicted temperature increases that were rapid and significant.

It has now been some years since the times of the predictions, and the predictions and reality are compared in the graph at

http://www.energyadvocate.com/gc1.jpg

Summary: Nearly all the predictions were way too high.

Result: The prediction have no meaningful credibility.

Current Summary: There is no credible evidence from either the 800,000 years of the earth or the climate models that human sources of CO2 have had, are having, or will have significant effects on temperature or climate.

As a result of this lack of evidence, there is no scientific reason to attempt to lower human sources of CO2.

In particular, wind and solar power are intermittent and, thus, challenging for use in our electric grid.