A Plain Language Climate Primer for a Non-Scientist
This essay is intended to cover as broad a spectrum of the climate debate as possible. Since the climate is such a huge subject with massive amounts of data and multitudes of scientific studies it is necessary to be brief and to condense discussion to only the more important points in each category. It is intended to give as broad a perspective as possible without a book as the result. Hopefully, I have managed to write in a language that is easily understood by the layperson. I have tried to include links to articles and studies that are reasonably easily understood.
I do not think that there is such a thing as a comprehensive climate scientist, so none are quoted. Rather, climate science seems to be a conglomeration of scientists from many relevant fields and with different expertise. This does not seem to prevent scientists from totally unrelated fields stating so-called learned opinions. Often they only muddy the waters, increase the bias or polarize the discussion.
If you have been following my posts on this blog, you are no doubt aware that I am not convinced of significant future global warming or that CO2 can have a substantial influence on climate. I am not convinced that we have suffered any significant consequences of a warmer climate or that there are any imminent threats of weather catastrophe as a result of warming.
My conclusions to date are that we are seeing significant consequences from an increase in atmospheric CO2 but that these consequences are almost entirely beneficial or benign, both to mankind and the natural environment. The same is probably true of any perceived warming that we may have experienced to date.
I am certain that man has a measurable effect on climate and that it is quite consequential locally and to a small extent globally. I am also certain that atmospheric CO2 levels will continue to increase, partly as a result of human burning (not only fossil fuels.) I think it is also possible that the oceans are still warming from the last glaciation and perhaps adding some CO2 to the atmosphere.
My viewpoints have been evolving and changing with continued study.
So why is such a benign and helpful gas as CO2 cast as a villain of climate change. Some say that it traps heat in the lower atmosphere. Well, not quite true. It has the ability to absorb and reradiate longwave radiation in common with almost every other element that is not totally transparent to energy. As such, it could absorb some portion of the heat radiation from the earth and radiate some smaller proportion back. CO2 does not create any heat. At the best, it can only influence the insulation value of our atmospheric blanket. By itself, it can only have an insignificant impact and to contribute any significant warming, it requires a large positive feedback provided almost exclusively by water vapor.
Those that blame CO2, in the absence of any definitive proof, say there is no other obvious cause for an apparently warming climate. Well, our variable sun is pretty obvious. Are the variations sufficient to increase the warmth of the planet significantly? Perhaps not. It may require positive feedback as well. Any of those feedbacks that work for CO2 should work as well for the sun. There are, however multiple possibilities that would have an impact on solar heating but have no influence on the effectiveness of CO2. Examples would be orbital variation, axis tilt, or particles emitted from the sun and affecting cloud formation.
How else then, can man affect the climate besides emitting CO2? You have probably heard the rather philosophical proposal that a butterfly flapping its wings in Japan could result in a hurricane in the U.S.A. Highly unlikely, or there would be an awful lot of hurricanes. It serves to illustrate, however, that even the tiniest action could have major impacts. Something like tipping the first domino of a long string.
It is hard to quantify what impact any single human action might have on the climate as a whole, but there are seven billion of us. We obviously change the albedo of a large proportion of the land area through agricultural practices, roads, parking lots and buildings.
We change the reflective quality of the cryosphere through snow clearing, tracking and by spreading dark particles. You have likely heard of the urban heat island effect. Aerosols added to the atmosphere can add insulating properties, reflective properties or aid in the formation of raindrops. Trees planted or removed have a considerable effect. Water management projects affect the entire hydrological system and the weather (and climate for a time) in turn. Then there is the waste heat escaping from homes, machines, and factories. Prevention and suppression of wildfires affect weather. Wildfires have an effect from both heat and smoke. The release of gases, including CO2, to the atmosphere, without doubt, have some effect.
It is apparent that there is an anthropogenic factor in climate and weather. The problem is to quantify each effect and to determine what it actually is. Does one cause more or less warming, cooling, precipitation, drought, wind, cloud, etc.? The net effect may actually be close to zero. It seems rather absurd to place most of the blame on an otherwise innocuous trace gas. It is even more absurd to think that we can significantly control our impact through the control of this one trace gas, especially with so little evidence to implicate it.
There seem to be only two arguments to support the attribution of a warming climate to CO2 in the atmosphere. One is laboratory experiments that affirm that CO2 can absorb and reradiate some longwave radiation. This does not evidence that it actually has a significant effect on the atmosphere but only suggests that it could.
The other argument is that CO2 levels correlate with past temperature trends. This correlation seems to be very weak. Cause and effect are not clear. In fact, most data seems to show only incidental correlation and much shows rising CO2 levels following rising temperatures. Some indicate falling temperatures in spite of high CO2. If the correlation does not hold up or is not robust, it follows that the CO2 can only have an insignificant effect.
The graphic is by Bill Illis and sourced from WUWT comments.
It seems an incontrovertible fact that CO2 is steadily rising and it is highly likely that some or perhaps even most of the rise is due to the burning of fossil fuels. Since a considerable rise has already happened and it seems likely that the rise will continue, we really have to consider the consequences of this rise.
One consequence would seem to be a warming of the lower atmosphere. The degree of warming is the subject of much scientific debate. Many scientists have tried to quantify the warming relative to CO2. The usual metric has been degrees warming per doubling of the gas. There are many estimates out there. The ones I have seen range from 0.17 to 3 degrees K. This is such a wide range as to be virtually unusable. The 0.17 is almost indistinguishable from zero and 3 degrees is over 1/4 of the probable range of temperatures for the last 600 million years. The graphic below is taken from Global Warming - So What.
Warming is possibly one consequence of rising CO2, but what are the consequences of warming? We can discuss these later and separately.
Another substantial consequence is global greening as a result of CO2 enhancement of plant growth. Some estimates attribute most of a 15% increase in global plant cover to increased levels of CO2. This also translates to an equivalent increase in food production from crops which means less natural land is appropriated for agriculture. It is difficult to find anything bad about this. It even means an increased uptake of CO2 or in other words a negative feedback. Less clear is the effect on oxygen levels which appear to have been in gradual decline for the previous million years or more.
Atmospheric warming is a possible effect of CO2 increases, but what are the consequences of warming? There are two separate considerations here. What degree of warming are we considering and who or what do the consequences accrue to? Of course, the big question is, will warming continue or is cooling a possibility?
It is pretty obvious from the paleo record that plant and animal life has flourished through periods much warmer than today. Plant and animal diversity was possibly much greater than it is on our relatively cold planet of today. In fact, if moisture is sufficient, biodiversity today is much greater in the warmer regions of the planet. The only life stupid enough to try surviving at the south pole is human scientists. (Sorry, couldn’t resist.) So if paleo history teaches us anything, it would be that warming is not necessarily bad, at least within limits. It also seems apparent from paleo history that nature has imposed an upper limit on warming for at least the past many millions of years.
So, warming does not seem to be detrimental to life in general. Where then is the danger? It seems it could only be to human civilization, infrastructure, constructs and the resulting secondary threats to life and health. Let’s explore some of these.
Seal level rise, if a result of warming, is likely the biggest and most imminent threat to a substantial portion of civilization. So, how much of a threat is it? Sea levels have been rising more or less steadily for the last 8 thousand years. According to best estimates, it has averaged no more than 7 or 8 inches (roughly 18 to 21 cm) for each of the last several centuries. I won’t get into the extreme difficulty in establishing an accurate measure of sea level. Different methods of measurement, and data from different areas, often differ widely. Complications are rebounding land masses from the last glaciation and land subsistence in other areas. There is considerable media babble about an acceleration of sea level rise, but to me, the evidence is unconvincing with considerable conflicting evidence. The sea level rise we are seeing is probably primarily a result of a gradual warming of the oceans coinciding with the beginning of this interglacial (following the initial rapid melt). Of course, there are likely many other factors involved.
So, how serious is the threat? There is not much threat to life since you could obviously walk or crawl faster than any possible rising sea. Of course, the danger zone for storm surges will extend farther back from present-day coastlines. The threat, however, is considerable to cities and their infrastructure that is built too near to sea level. This threat is not immediate and much construction will be obsolete before inundation is likely but good land use planning and some protective measures are probably in order.
What has happened so far? A few cities in the world are now below sea level. They are usually protected by seawalls but may be vulnerable to storms. Most are the victims of subsistence but sea level rise is a compounding factor. Some low lying island nations may be at risk but so far it is not evident.
Retired NASA meteorologist Thomas Wysmuller explored the correlation between CO2 and sea level rise and found no measurable linkage between Sea Level and CO2. As Wysmuller stated: “For the past 2,000 years, Sea Level rise was unchangingly linear, increasing between 1 & 1.5 mm/yr. The maximum rise is about 6 inches per century. This has continued for the past 135 years, even though CO2 concentrations have increased by 38%.”
A recent study has actually found that coastlines are gaining land.
There are many claims that extreme heat waves will kill many more people than currently. Extreme heat does cause considerable death amongst the vulnerable but inexpensive energy and a caring community would go a long ways towards lessening the toll. What may be counterintuitive to some is that even moderate cold appears to be much more deadly.
The following graphic is from The Lancet.
Fraction of all-cause mortality attributable to moderate and extreme hot and cold temperature by country. Extreme and moderate high and low temperatures were defined with the minimum mortality temperature and the 2·5th and 97·5th percentiles of temperature. distribution as cutoffs.
It seems likely that a warmer climate would reduce cold-related deaths.
Extreme weather events are a major cause of death and destruction. It appears, however, that there is virtually no connection between extreme weather and a warming climate or increasing CO2 to date. Any future projections of increasing extreme weather appear to be based entirely on models. If historical warming has not caused an increase in extreme weather events, what are the odds of it having a future impact?
Global Accumulated Cyclone Energy (ACE) since 1970. The chart below shows that storm activity worldwide over the past 4 years is at a 45-year low and that the trend has been in steep decline since 1990. Source: www.wunderground.com.
Fraction of the global land in D0 (abnormally dry), D1 (moderate), D2 (severe), D3 (extreme), and D4 (exceptional) drought condition (Data: Standardized Precipitation Index data derived from MERRA-Land)
Wildfires are often cited as an increased threat from a warming climate. Once again, the historical data does not seem to agree. The next graphic is from C3 Headlines. The data is relevant to North America.
The second graphic is for Germany.The source.
I admit that this data is picked, but it is from countries with good records, modern firefighting and prevention methods and where fire is not used as an agricultural aid. There are so many metrics to wildfires that it is difficult to get an accurate picture. There does not, however, appear to be any obvious link to warming or CO2.
Floods are one of the most deadly natural catastrophes. Often they are the result of cyclone activity or direct human failures such as dam or levee breaks, making it difficult to attribute them to any particular trigger. It would seem to make sense that a warmer climate would lead to more precipitation but the signature is difficult to detect. Steadily increasing CO2 since 1950 and an irregular increase in temperature should show as a distinct increase in precipitation and probably an increase in the number of heavy precipitation events. I cannot find definitive indications that this is true.
I am not sure the above shows any trend or not.
Some scientists are saying that they can detect the fingerprint of global warming on recent extreme weather events. I think they are finding what they want to find or in weather parlance are handing us a snow job.
Scientists that promulgate catastrophic climate change scenarios, seem rarely to mention possible positive outcomes. If they cannot avoid doing so, they invariably claim negative results far outweigh the positive. Often without any confirming data.
If you live in Canada or Russia it is pretty hard to imagine anything bad about a few degrees of warming. Most places would welcome a little more precipitation. Almost every aspect of CO2 fertilization is welcome in any area of the world. Greenlanders and polar bears seem to be thriving during warmer periods. You have to dig pretty deep to find bad things about reducing sea ice extent or the melting back of glaciers. It seems it has all happened before. The planet and its inhabitants just adjusted to new realities.
Below is some perspective on ice extents. Proxy data for the graphs is sourced from sediment cores taken in Bering sound. The graph is sourced from JQS Journal of Quaternary Science.
So is there any danger possible from climate change? Paleo history seems to indicate a reasonably impermeable upper limit to warming. An upper limit which does not seem to have had detrimental effects on most forms of life. There also seems to be a lower limit, perhaps not quite so impermeable. This lower limit is definitely detrimental to life and would be catastrophic for modern man and civilization. This lower limit is almost certain to be reached again. Fortunately, this is unlikely for a very long time, relative to human lifetimes, even if the glaciation has already started (which the above graph seems to hint at.) A few decades ago, however, some scientists were warning that an ice age could be imminent. Some were the same ones that have been warning us about imminent catastrophic warming.
Climate change, which is caused by warming, which is caused by increasing CO2, seems to be the linear progression of reasoning by many scientists. However, climate change does not require warming nor does warming require CO2. The primary argument seems to be that the degree of warming is too great to be explained without the impact of increased CO2 levels. The secondary argument is that warming will have significant climatic impacts such as extreme weather. There is complete agreement that the climate changes.There is no disagreement that CO2 levels have risen or that they are likely to continue to rise.There is little disagreement that global average temperatures are higher than they were shortly before the beginning of the last century. There is no doubt that there is consensus on these points but dig a little deeper and you will find raging controversy and many diverse opinions. There is real denial in the alarmist refusal to confront evidence contrary to the expectation of catastrophe.
There is significant disagreement on the degree of warming observed. Current estimates seem to be for warming between 0.6 to 0.8 degrees Celsius for the 20th century. Even if you agree, it is pretty easy to argue that this is an insignificant warming that is not great enough or linear enough to indicate a trend. There is also considerable concern that measurement errors may exceed the temperature change detected. My own opinion is that there is little point to arguing as the amount of warming is so close to zero as to be insignificant. It also seems that most warming observed has been from a low point near the end of the “little ice age” and has not yet exceeded temperatures during the “medieval warm period.” Many people like to start temperature graphs from 1880 (a low point) to emphasis warming.
The IPCC and others use models as a tool that supposedly predicts rapidly accelerating warming in the years ahead. Models, however, are not really a predictive tool but can only suggest probabilities in the near term and possibilities in the far term. The number of possibilities grows rapidly as you get farther from a starting point. So far nearly every model of future temperature trends is quite obviously wrong. The graph below was sourced from the Daily Caller. Their source was Patrick Michaels, Cato Institute
In 37 years of satellite data, the average of the models has been wrong by as much as the total estimated warming of the 20th century and will likely diverge further as time progresses.
The above is a simplified graph for clarity. Below is one sourced from Andy May's blog. It shows many different models runs, some far from reality and some a little closer.
There is one model simulation that seems to be remarkably accurate to date. It is the Russian model “INM-CM4”. The following is a quote directly from Andy May's blog “This model uses a CO2 forcing response that is 37% lower than the other models, a much higher deep ocean heat capacity (climate system inertia) and it exactly matches lower tropospheric water content and is biased low above that. The other models are biased high. The model predicts future temperature increases at a rate of about 1K/century, not at all alarming and much lower than the predictions of the other models.”
I think models can be valuable tools but climate models to date would seem to be immature methodology. Models are not likely to improve if scientists involved continue to stick to a climate scare theology. We should not try to match observations to the models but should recognize the oh-oh moments when the divergence is unacceptable and look for the faults in the models.
Well, let’s sum up to now. There seems to be very little evidence of any negative consequences to date that can be directly attributed to warming and even less for a connection to CO2. There has been no clearly documented increase in the incidence of extreme weather. There is no indication from observations of a significant increase in warming for the 21st century and certainly no indication of an acceleration. The models have been wrong and there is every indication that most will continue to diverge from reality unless their input is changed. It seems that CO2 only very loosely correlates to warming, that climate sensitivity to CO2 is low, and that other factors override and swamp man’s contribution to climate change. If there is a direct connection between the recent sea level rise and current rising atmospheric temperatures, it is certainly not obvious.
Beyond that, it seems likely that atmospheric temperatures will continue to slowly rise, for at least a little while, without much other than beneficial consequences. Let’s hope that is true, a cooling of any magnitude would have mostly negative consequences. Sea levels will likely continue to rise at a rate consistent with the past few centuries. Slow enough to allow for easy adaptation.
The catastrophe theorists are attempting to introduce another elephant into the room, ocean acidification from increasing atmospheric CO2. First of all, the ocean is not acidic, will never be acidic, and is not even significantly approaching acidity. What they are calling acidification is an assumption of a small decrease in the ocean’s average alkalinity. I am calling it an assumption as I don’t think there is any way to accurately measure the ocean’s pH level. It would be rather difficult to dip a piece of litmus paper in each of the 1.3 billion cubic kilometers of water in the oceans. Actually, the pH may vary at a higher resolution than that. I assume the decrease is inferred from expected interactions between CO2 and seawater. Well, I think that calculation would be rather difficult given the extremely small concentration of CO2 in the atmosphere compared to the vast volume of ocean water. There have been some direct measurements in recent years but they are very limited in number. It is possible they could suffer from error or bias. The NOAA has published an essay about the quality of ocean pH data in the NCEI (formerly NODC Data Archives.) It could help you understand the difficulties in determining changes in ocean pH. I have run into problems linking to the site, However. You could google this to try yourself. Quality of pH Measurements in the NODC Data Archives. Probably a better discussion of the difficulties here.
One of the greatest difficulty in arriving at a true average pH is that daily fluctuations often exceed 1 whole unit of ph. The total expected decrease in pH over the 21st century is 0.3. Note that the pH scale is logarithmic. A ph of 5 is 10 times as acidic as a pH of 6. A pH of 7 is neutral, neither acidic or basic.
Once again we have to consider consequences. Some scientists are predicting severe consequences for shellfish. This does not seem to be strongly supported by experimentation. Experiments may be contradictory and some show conflicting results for different species. I am not suggesting that there are no consequences to ocean life from increasing CO3 concentrations in the atmosphere and it’s interaction with the sea. I would suggest that our understanding of the subject is very rudimentary. More study is definitely in order and much of the study and experimentation to date needs confirmation.
As an aside, freshwater clams and snails seem to have little difficulty maintaining shells in water that is much more acidic than seawater. Although stream and lake water is buffered to varying degrees by contact with soil and rock, rainwater in the U.S varies between a pH of about 4 to 5.5. There can be greater variation. The chart below is from the USGS.
Others say they are seeing severe repercussions to coral but what they seem to be suggesting is a more indirect connection to CO2 through warming water. Other well-qualified scientists dispute them. I am not very well versed in marine biology and suggest you do your own research. My own opinion of the research that I have seen so far, is that it is not very definitive.
The image below is from 2 conch shells. The one on the left is from today’s normal conditions. The one on the right was raised under very high CO2 concentrations (2850 ppm), more than 7 times today. Sourced from Oceanus magazine that describes an experiment with shellfish and CO2.
The subject matter of this essay is so huge that I had difficulty coming to an ending. Eventually, I had to just stop. Each part of it could be expanded greatly and I advise any interested readers to expand their information base through further research.
Shortly before I finished this I read a book, Mirrors and Mazes by Dr.Howard Thomas Brady.
The link describes his qualifications. It has just been released and is one of the most up to date on the climate debate. It is not overly long or difficult to understand. I would recommend it. It does seem to align fairly well with my own thinking. It is available at Amazon.com or Amazon.ca