First my comments and then the response.
On Sat, Aug 10, 2019, 2:41 PM John Coffey wrote:
Steve,I am going to claim that I have researched this issue far more than most people. I have been concerned about this issue for 30 years, and I have tried to find out as much as I could about it.I would refer you to figure 4 on this page: https://www.pnas.org/content/99/7/4167I made a distinction between the long term trend and the short term trend. Throughout geological time, atmospheric CO2 has been on a major decline. The first atmosphere on planet earth had a 42% CO2 level and now we talk about 400 parts per million. Human beings have temporarily reversed this trend. The CO2 level has dropped considerably over the last 40 million years, and the Earth has also cooled considerably over that time. We entered a series of intermittent ice ages about ten million years ago and technically have been in an ice age for the last 2.58 million years.Over the years I have tried to look at the actual data and I have not been impressed. What we have done over a 200-year period has been a small blip on the geological scale.Whereas we are predicted to double the CO2 level to 800 PPM by the year 2100, this is about the time that we predicted to run out of most fossil fuels. The direct effect of atmospheric CO2 is logarithmic, which means that you have to keep doubling it to have the same effect.I think that the whole point will be mute when nuclear fusion comes along in 10 to 20 years.The debate over CO2 boils down to what the Climate Sensitivity is to a doubling of atmospheric CO2. This has everything to do with what the positive feedback is. There is widespread disagreement on these numbers. A great many predictions were saying that the Climate Sensitivity was going to be over 5 degrees celsius which is enough to melt the polar ice caps. Some predictions were as high as 12 degrees. However, the IPPC gives a generally accepted range of 1.5 to 4.5 degrees based on dozens of models and they also give 3 degrees as an average. The reason the iPCC lowered the low end from 2 degrees to 1.5 is that they accepted a paper which got 1.5 degrees as the climate sensitivity from 20nth century data. I noticed over decades that predictions keep getting revised downward. Very recently, I have been seeing a movement to prevent us from rising 2 degrees by the year 2100, claiming that we can limit this to 1.5 degrees with the very catchy slogan "half a degree makes a difference." This is like they are admitting that the Climate Sensitivity is only 2 degrees. Maybe half a degree does make a difference, but I saw recently that someone was proposing that we spend 122 trillion dollars to prevent this half a degree difference, which is just absurd.There is an overlap between what the climate alarmists and the climate skeptics believe. Everybody agrees that the direct effect of doubling atmospheric CO2 level is a 1.1 increase atmospheric temperature. However, there is much disagreement over how much effect the feedbacks will have, which is why there are widespread predictions on what the Climate Sensitivity is. I saw one climate scientist claim that there is a 60% feedback. However, the climate skeptics make predictions of Climate Sensitivity from .55 to 2.3 degrees, with most skeptics thinking that it is around 2 degrees. It appears to me that the skeptics and the alarmists aren't as far as apart as they used to be.Many skeptics have pointed out that the temperature will vary by 30 degrees celsius in a single day, so they don't consider 2 degrees to be a major problem. There are very legitimate scientists who think that climate threat has been exaggerated.Almost everybody is using the year 1880 as their starting point because that is presumably when accurate records were kept. During that time the CO2 level has gone from 290.8 Parts per Million to 410 PPM. (https://www.co2.earth/daily-co2) Most sites are reporting a temperature increase of less than 1-degree celsius since 1880. Something that I noticed is that since 1880 the average temperature increase has been less than 1/100th of a degree per year and the CO2 change has been less than 1 part per million per year. In past years when I tried to look at actual data, I did some calculation and got 2.3 degrees as the Climate Sensitivity.I have always qualified my remarks by saying that I would like to see where the data takes us going forward.If you deleted the United States completely, the net effect on temperature by the year 2100 would only be about a tenth of a degree, because other countries like China are the major contributors. China builds more coal plants every three years than what exists in the United States.In past years I wrote the following. Although wordy, I think that it has important points, although I have already made most of them.Best wishes,John Coffey
The numbers are not very impressive. Since 1880, which is the measure most people use, on average the CO2 level has gone up less than 1 part per million per year and the temperature has gone up less than 1/100th of a degree celsius per year. You could argue that since about 1970 things have accelerated a little, but a little less than double. The temperature went up on average of 0.016 degrees celsius pear year. It is going take a very long time to reach the five degrees needed to melt the polar ice caps, which are according to every source going to take 5,000 years to melt. Meanwhile we will be out of most fossil fuels by the year 2100 and coal will be gone by the 2150. The only thing that will save us from running out of energy will be nuclear fusion, which fortunately is not that far off.
The amount of carbon on planet Earth by definition remains pretty much the same. Man has been burning fossil fuels, which puts carbon into the atmosphere. Where did the carbon in the fossil fuels come from? It mostly came from plants and bacteria that got buried underground due to geological processes. Over millions of years natural processes turned the plants and bacteria into fossil fuels. Where did the plants and bacteria get their carbon from? They got it from the atmosphere. The carbon that we are now putting into the atmosphere originally came from the atmosphere.
To better understand this, we have to understand the complete history of atmospheric carbon dioxide on planet Earth. The original earth atmosphere was an amazing 42% carbon dioxide compared with the roughly .04% that we have now. That original atmosphere had so much pressure that it could crush a man flat. About 2.5 billion years ago, cyanobacteria began using photosynthesis to convert carbon dioxide into free oxygen, which lead to the creation of our oxygen rich "third atmosphere" 2.3 billion years ago. At that time the carbon dioxide levels were about 7,000 parts per million, but it went into a somewhat steady but uneven decline because geological processes would sequester carbon underground. The decline was uneven because as part of the "carbon dioxide cycle", sometimes geological processes like volcanoes would cause massive amounts of carbon dioxide to be released back into the atmosphere.
Thirty million years ago during the Oligocene Epoch, the average temperature of the earth was about 7 degrees Celsius warmer than it is now. There was no ice on the poles, but the amount of carbon dioxide in the atmosphere was in rapid decline during this epoch. About 23 million years ago, at the beginning of the Neogene period, ice began to form on the poles. About ten million years ago, a series of intermittent ice ages began that continue to this day. I found one source that said that we are still technically in an ice age because we still have ice at the poles.
These ice ages helped create human evolution. The ice ages caused Africa to dry up which lead to some deforestation. This forced some arboreal (tree-dwelling) apes to venture onto land. About 7 million years ago, the first apes that could comfortably walk upright appeared. They had evolved a new type of pelvis that allowed upright locomotion, which is about three times more efficient when trying to cross land.
The first tool making ape that resembled modern humans, Homo habilis, arose 2.5 million years ago. It would be soon followed by Homo erectus, and then about 200,000 years ago, modern humans, Homo sapiens would arise. However, Homo sapiens almost died out. About 50,000 years ago an ice age in Europe had caused Africa to almost completely dry up. The total human population had dropped to 7,000 individuals living on the southern coast of Africa. During this period humans learned how to fish, make new tools, and create permanent dwellings. When the ice age abated, these humans with their new tools spread out to rest of the world at a pace of about a mile per year. This was the beginning of the Upper Paleolithic (Late Stone Age) period.
More ice ages would follow, and during each ice age human population would decline. It is no coincidence that all of human civilization (i.e. agriculture, use of metals) would arise during a "brief" warm period between two ice ages starting about 10,000 years ago. I have heard that no matter what we do, we will enter a new ice age in about 10,000 years from now, but I have also heard speculation that the next ice age will be delayed by global warming. This actually should be our goal, since humans have always declined during the ice ages and always prospered during the intermittent warm periods.
During the geological time period of the earth, the amount of carbon dioxide in the atmosphere has been on an uneven decline and mostly disappeared. Atmospheric carbon dioxide is necessary for plant growth, and I have read that we were running dangerously low on atmospheric carbon dioxide, about 00.02%, before mankind at least temporarily reversed the trend. I just read a wikipedia article that said that atmospheric carbon dioxide will eventually get so low that all plants and animals will die off. What mankind has done is put carbon dioxide back into the atmosphere that was previously there, thus possibly delaying the next ice age. Currently the amount of carbon dioxide in the atmosphere is about 00.04%.
Carbon dioxide by itself cannot cause significant global warming. There are diminished returns. Carbon dioxide has to double again to produce the same effect as the last doubling. The effect is not linear but logarithmic. What the alarmists are worried about, and they could be correct, is positive feedback. The warming of the earth causes more water vapor to enter the atmosphere, and water vapor is a much stronger greenhouse gas than carbon dioxide, thus causing more warming. If this were true, however, the last warming period around the year 2000 should caused a continuous positive feedback, a runaway greenhouse, which didn't happen. Instead temperatures went into a major decline and hit a really big low point in the year 2007.
The skeptics believe that increased cloud cover reflects sunlight back into space thus causing a negative feedback. The skeptics are not "global warming deniers", which is a pejorative phrase used by global warming theorists to make the skeptics sound like holocaust deniers. These skeptics actually believe in global warming. At least, the legitimate skeptical scientists do. They just think that global warming is happening at a rate slower than predicted by the theorists. I can point you to an article that shows that the positive feedback models have been contradicted by the actual temperature data, which in reality has been closer to the negative feedback models.
The worst case scenario is that the polar ice caps will melt. If that happens we will lose some coastlines and all of Florida due to sea level rise. However, according to what I just read, it will take 5,000 years for the polar ice caps to melt. In other words, these are processes that take a very long time to happen. In this century we are only looking at modest temperature increases. In the meantime, humans are very adaptable. We are only five to ten years away from creating the first workable prototypes of nuclear fusion. It might take 25 years for this to be practical, but at that point if we wanted to get rid of fossil fuels altogether, we could. I think that we will also see advances in solar power, which is already happening, and battery technology to store the energy created by solar. In other words, we have it within our means to avoid any possible disasters that might be coming.
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Date: Sat, Aug 10, 2019 at 3:00 PM
Subject: Re: Planet Earth
To: John CoffeyUnfortunately the preponderance of scientific evidence is on my side. And I will take the data and analysis of the UN and NASA over your own. We simply aren't going to agree here again.Quite obviously the first atmosphere, while being formed by volcanic activity, would have contained higher levels of carbon dioxide. And of course there have been times when there had been higher global temperatures than current. Just not in human experience.The fact that most life occurs near water is also important, as ice continues fall from Antarctica. The amount of devastation to global life will be considerable, and is practically unavoidable, we will see begin seeing climate refugees within a decade. There is also the clear fact that climate change is among us already. Wildfires, droughts, superstorm, these are all at record levels.If humanity does survive we will never be the same.Ultimately John, I am done having the argument with people whether or not climate change exists and the dangers of it, or whether or not we have played a role. I can entertain discussion about what can be done about it, but the answer seems to be very little.This is another thing we just aren't going to see eye to eye on, I suggest we move on. The only reason I felt the need to respond is that you've gone on similar lines before and I think you have to be well aware of my position.