By Andy May

I love visiting WUWT and Climate, Etc., but most of the visitors to these sites, like me, are skeptical that the current global warming is dangerous. I’ve often visited the notable alarmist websites, such as skepticalscience.com and realclimate.org, to gain an understanding of why they think the current warming is dangerous and man-made. I’ve even written posts on their views, like here, and I’ve cited their posts where appropriate. But, what about the regular educated population of people who believe global warming is dangerous and carbon dioxide is a pollutant? To be a well-rounded climate science writer shouldn’t I engage with the climate-scientist-on-the-street?

I was recently invited to join the facebook group “March for Science.” At first, I ignored the invitation, after all marching in the streets is a political thing and has nothing to do with science. But, “climate science” is also a political thing these days and has little to do with science, at least the science I knew during my 42-year career as a scientist. So maybe this is a forum I could benefit from, I was fairly sure I’d be bloodied a bit by the experience, but I might learn something. What is the caliber of the forum members? Would it be all ad hominem attacks and appeals to the so-called 97% consensus, or would some of them engage in a real scientific debate on the dangers or lack thereof, of global warming or climate change? Would they debate the evidence that CO2 concentration dominates climate change? I was curious.

Figure 1 is the banner page of the forum, click on the image below to go to the page. I’m not 100% sure this will work for everyone because the page is invitation only.

Figure 1

The photo at the top of the page is not very encouraging. They are not a very scientific looking bunch. The signs are not very scientific either, “speaking TRUTH to power” sounds more like a religious or political slogan than a scientific one. More scientific and more appropriate slogans would be like these:

Science is a perspective. Science is the process that takes us from confusion to understanding in a manner that’s precise, predictive and reliable. Brian Greene, American physicist.

What seems to be missing in common discussions of climate change, whether man-made or not, whether caused by CO2 or not, is that science is a job and a learned skill, it’s a process. It most definitely is not something someone believes in or has faith in, it is not a set of facts anointed by self-appointed “climate scientists” and passed down to the great unwashed masses to be believed without question. Although, unfortunately, you find many who think that. You will see statements from my adventure in the March for Science that sound much like that.

To the best of my knowledge the great Columbia physicist Brian Greene has not spoken out about climate science, but he has stated that:

“… in order to have great breakthroughs in science, you’ve got to go against what the elders are saying.”

Or put another way, go against the consensus. As you might expect, the March for Science members talked a lot about the consensus. Brian Greene does discuss how science became a political prisoner here.

Figure 2 are the rules for posting. I found these encouraging, but quickly found out after my first post that they aren’t followed by many of the members.

Figure 2

But, many visitors to WUWT and judithcurry.com don’t follow the rules either, to be fair.

For my first post, I chose to write about Dr. Spencer’s excellent discussion of the American Meteorological Society’s (AMS) criticism of U.S. Energy Secretary Rick Perry. See figure 3 below, click on the figure to read Dr. Spencer’s post or click here. Mr. Perry stated that he did not believe that carbon dioxide was:

“… the primary control knob for the temperature of the Earth and for climate.”

Perry continued that we should not be debating whether man affects climate, humans do affect climate, the debate is over “how much.” This is a very reasonable position to take and Dr. Spencer explains this quite well. The data we have today doesn’t show the amount of current warming attributable to man-made greenhouse gases, the man-made CO2 effect is too small to measure. Dr. Spencer writes about this problem in his book The Great Global Warming Blunder:

“Our satellite instruments still do not have the absolute accuracy to measure the small imbalance from Earth orbit that is believed to exist from more carbon dioxide in the atmosphere, so we cannot even directly measure the mechanism that supposedly causes global warming! As of 2009, it is estimated that humanity’s CO2 emissions …[have] caused an estimated 1.6 watts per square meter of extra energy to be trapped, out of the estimated 235 to 240 watts per square meter that the Earth on average emits to outer space on a continuous basis. We really don’t know the exact magnitude of the average flows of energy in and out of the Earth to better than several watts per square meter. It could be 235, 240, or 245 watts per square meter. I find it amazing that the scientific community’s purported near-certainty that global warming is manmade rests on a forcing mechanism–a radiative imbalance–that is too small to measure.”

Dr. Spencer is well qualified to make this judgement call, he is a co-recipient (with Dr. John Christy) of NASA’s Exceptional Scientific Achievement Medal for their pioneering work on global temperature monitoring using satellite microwave data. He is the NASA U.S. Team Leader for the Advanced Microwave Scanning Radiometer, currently flying on NASA’s Aqua satellite. If you are curious about how Spencer and Christy, and the others on their team measure atmospheric temperatures from satellites, I recommend the excellent and easy to understand post by Dr. Spencer (see here).

The estimates that man-made carbon dioxide is causing most of the current warming are based on computer models and not on measurements. More on this calculation from model output can be read on my blog (here) or in Chapter 10 of the AR5 report by the IPCC here. The AMS position is the usual:

“thousands of independent scientists and numerous scientific institutions around the world agree … that [human] emissions of carbon dioxide are the primary cause [of climate change]”

Thus, they simply say trust climate scientists and provide no evidence for their assertion. This is not surprising, since there is no evidence.

Figure 3

Figure 4 has the Like/Dislike breakdown after a few days.

Figure 4

I was a bit surprised that the likes outnumbered the dislikes. Reading the 420+ comments, one would think that the dislikes would be higher, but more likely they were just more vocal. With the basic background covered, I’d like to discuss key parts of the discussion. I participated in the discussion in my spare time over 3 days, but when it became very repetitive on June 25, I stopped. There were numerous threads in the discussion, I will deal with the major topics in turn.

Ad hominem arguments

Most of the comments were ad hominem attacks on either Dr. Spencer or myself, I’ll show a couple of these, then move on to the more interesting stuff. After several attacks on my manhood, mental health and qualifications and seeing nothing about Mr. Perry’s statement or Dr. Spencer’s post, I posted the following which I stole from David Middleton:

Figure 5

This led to 23 replies, a selected few are presented in figure 6.

Figure 6

Most of the 23 replies are along the lines of Tom Stark’s comment. I think Lorcan McGuinness is in a class of his own. Scott McDonald’s comments are quite good. By the way, “OP” stands for original poster (me). So, there are gems to be found in all of this.

Does CO2 dominate climate change?

Besides the ad hominem thread, we had several others of interest. Many presumed to know my motives (sinister, of course) or my interests, like in the following:

Figure 7

So, Ms. Oomen’s professor asserted that we would be insane to deny the existence of radiative forcing. She does not say what radiative forcing she is talking about, but presumably she means CO2. She supplies no evidence or references supporting her assertion, only her MSc in Physics. There were a lot of comments like this, I ignored them.

The effect of solar variability and is the Little Ice Age global?

Then there was this comment by Gilman Ouellette that I thought was quite good, it was the first comment with any substance. I include my reply.

Figure 8

Mr. Ouellette’s first link is to a composite graph of TSI from several satellites from 1975 to June 2010. See figure 9.

Figure 9

The point he is making is that the variability of total solar irradiance (TSI) is too small to matter. This is the same claim that is made by the IPCC in AR5. However, there is vigorous debate on the issue. Soon, Connolly and Connolly have challenged the TSI reconstruction used by the IPCC here and claim the Hoyt and Schatten reconstruction is better and fits the climate record better.

Khider, et al. (2014) compared a very quiet TSI record by Steinhilber et al. (2009) to a western Pacific Ocean temperature reconstruction and determined that the sensitivity to solar variability is 9.3°C to 16.7°C/Wm-2, if Steinhilber is the correct record of TSI. This is very high, much higher than the IPCC estimate of 0.7 to 1°C or the Tung et al.(2008) estimate of 1 to 1.5°C. They offer two possibilities for this:

“There remains the possibility that (1) the Steinhilber et al. [2009] reconstruction underestimate actual TSI variability and (2) the response to small changes in solar irradiance was locally enhanced in western tropical Pacific.”

As discussed in more detail here, Steinhilber et al. (2009) is the TSI reconstruction used by the IPCC to compute human influence on the climate. They believe, as Mr. Ouellette does, that solar output varies very little and, as a result, does not influence climate change. Yet, there are many other, equally likely and peer-reviewed TSI reconstructions that show much more variability. These are shown on the left side of figure 10:

Figure 10 (source: Soon, Connolly and Connolly, 2015)

The top TSI reconstruction by Hoyt and Schatten as updated by Scafetta and Wilson (2014) actually explains most of the warming in the past 150 years, reducing the calculated human influence (Soon, Connolly and Connolly 2015).

Mr. Ouellette’s second reference refers to a paper that proposes that the Medieval Warm Period and the Little Ice Age did not happen around the world at precisely the same time. This is true, but between 1500 AD and 1900 AD every part of the world experienced their respective coolest period in the Holocene, see the world-wide Holocene temperature reconstructions here. Below you can see a blow up of the period 2000 BC to 2000 AD in figure 11:

Figure 11 (source here)

The Northern Hemisphere has a very long and deep Little Ice Age that covers the full period from 1500 to the late 1800’s. Each of the other regions also has its coolest period in this interval, but slightly offset from one another and the cool period is shorter than in the Northern Hemisphere. Thus, the world is at its coolest point globally during the period 1500 AD to 1850 AD, but the severity of the cold is not uniform and the depths of the cold are not synchronous around the world. The tropics and the Southern Hemisphere have their cold period earlier and the Arctic later than the Northern Hemisphere.

The Earth’s emission spectrum

Mr. Ouellette had another very pertinent post that I want to address. See figure 12.

Figure 12 (click on the figure to see a larger version of the graph)

Mr. Ouellette is correct that amplitude changes in the Earth’s infra-red emission spectrum depend, in part, on the temperature of the air emitting the radiation. It also depends upon the greenhouse gas concentration and CO2 is an infra-red (IR) active gas, so changes in CO2 will matter, but water vapor is far more important. Also, water vapor is the primary transporter, through latent heat of evaporation, of heat energy from the Earth’s surface to altitudes high enough that CO2 and other greenhouse gases can emit radiation to space. While it is true, that the NASA AIRS satellite has shown that IR radiation emissions have decreased as CO2 concentration has gone up, this does not prove that CO2 absorption was the only cause of the decrease, although it is likely one of the causes. There are too many unknowns to claim CO2 is the major cause, there is some evidence that global precipitable water in the atmosphere has decreased (see here), solar activity has certainly decreased (see here), ocean heat content has increased (see here) providing more energy storage. So, as I say above, Mr. Ouellette has overstepped his data a bit.

He switches to another topic next and points out that we can tell how much of the CO2 in the atmosphere is from fossil fuels and how much is natural by monitoring how the ratio of carbon-14 and carbon-13 change with time. Quite true, but again he hits the causation wall, is CO2 changing the climate? We still have no evidence for that, there are too many other plausible possibilities. As noted by Mr. Perry in the post, the question is, how much of the warming is due to CO2 and how much is due to other factors?

The so-called 97% Consensus

This is the myth that will not die, and any discussion of climate change will eventually degrade to a discussion of the so-called 97% consensus. It has been very thoroughly de-bunked by Professor Richard Tol here and here. Joseph Bast and Roy Spencer also do a good job of blowing up the myth here. So, I will provide no more commentary, but will show a representative comment to prove that some people still believe that nonsense.

Figure 13

Detection and attribution of man-made climate change

The attribution of climate change to human activities was a widely discussed topic. The posts on this topic are too long to include here, but if you can get to the thread (try here) some are worth reading. I will summarize the discussion. Generally, the idea that CO2 is the control knob for climate was explained using “what else could it be” logic. The proponents, like Chris Colose, acknowledge that solar variability and ocean transport and storage of heat energy could be factors, but claim they cannot account for all the temperature change, so CO2 emissions must account for most of the change. They do not question the low estimates of ocean or solar forcing that the IPCC uses, but others do. There is a discussion of the attribution of climate change to human activity here.

In short, their argument boils down to this: the world is warming, we know precisely how much nature contributed to this warming, so we subtract that from the total and remainder must be due to man’s CO2 emissions because there is nothing else that could have done it. A very weak case indeed.

What should be done about global warming

There was considerable discussion about what to do, if anything, about global warming. Most of the discussion was like the following:

Figure 14

So, one argument is, global warming may lead to a disaster and it may be due to fossil fuel emissions and solving it by reducing or eliminating the use of fossil fuels might be possible, so we should reduce our use of fossil fuels anyway, even if we are not sure. There are a lot of ifs and maybes in there. The opposing argument is, if we stop or reduce the use of fossil fuels, it might ruin our economies and what if warming continues anyway? Wouldn’t we need energy from fossil fuels to help us adapt to warmer temperatures? What if we are wrong about all of this? That was pretty much how it went.

Conclusions

Most of the 420+ comments were vacuous ad hominem attacks or assertions made without any support or references. But, a few were interesting and thoughtful by people who had obviously studied the subject and knew what they were talking about. I tried to touch on them above to give the reader a flavor of the more knowledgeable alarmist positions. It was a bit difficult at times to wade through the ad hominem attacks on Dr. Spencer and myself, but I still found the experience worthwhile. It gave me more of a perspective on the other side of the debate. There were also more people supporting my position than I would have expected. You can see some of their comments in the figures above. These are just a few of the favorable comments I received. So, even at web sites like this one, skeptical thinking can intrude. Maybe the climate science community isn’t quite as polarized as we often assume. Something to think about.