The oft-stated belief among the alarmist climate science community (the IPCC and others) is that natural sources and sinks of carbon dioxide, CO2, are constant (or close enough to constant as to not matter), but the formation of CO2 by mankind's burning of fossil fuels over the past century is a serious, calamity-inducing problem.
Support for the above proposition can be found at numerous locations, below are just a few.
"According to leading climate scientists from around the world, anthropogenic climate change (that caused by humans) is a significant and growing problem that must be addressed in order to avoid the worst effects. Climate change is the result of various GHGs that are emitted into the atmosphere, such as carbon dioxide (CO2) and methane (CH4), which have a heat forcing effect on the atmosphere. Sharp rises of GHGs over the last century and a half have led to higher overall worldwide temperatures, reduced snowpack in the higher elevations, greater fluctuations of temperature and precipitation, global sea level rise and more frequent and severe extreme weather events, including hurricanes, heatwaves and droughts." -- California Air Resources Board website summarizing the state's Global Warming Solutions Act (AB 32).
"Over the past century, human activities have released large amounts of carbon dioxide and other greenhouse gases into the atmosphere. The majority of greenhouse gases come from burning fossil fuels to produce energy, although deforestation, industrial processes, and some agricultural practices also emit gases into the atmosphere.
"Greenhouse gases act like a blanket around Earth, trapping energy in the atmosphere and causing it to warm. This phenomenon is called the greenhouse effect and is natural and necessary to support life on Earth. However, the buildup of greenhouse gases can change Earth's climate and result in dangerous effects to human health and welfare and to ecosystems." -- US EPA website on Climate Change
What then, does a seasoned, experienced chemical engineer make of the above? The first thing one sees is that the standard practices of good basic science, and by extension good engineering practice, do not support the above conclusions that a) the atmosphere is warming, b) CO2 is causing the warming, and c) future events will be catastrophic if no action is taken to reduce or eliminate CO2 emissions from man's activities.
This post addresses a part of the issue, the question of how much, if any, the atmosphere has warmed in the past 100 years, more or less. A part of this discussion was already
|Fig 1: Land atmospheric temperature Anomalies, |
(figure 3-1-1, IPCC AR4, global extent)
From that article, "the key point: cities will have energy consumption and heat rejection issues no matter what type of system produces that energy. Considering for the moment electricity use, even if a city were all-electric for heating, cooling, cooking, and transportation, and even if that electricity were produced by zero-carbon-dioxide power plants (see below), the UHI would exist. In essence, a building has no idea what produced the electricity that heats (or cools) the building, runs the lights and elevators, and heats the hot water. An electric car, or bus, or delivery truck, or train, also has no idea what produced the electricity that each of those consumes. Therefore, even if all the electricity is from a zero-carbon-dioxide source, the cities would still have UHI and would corrupt the climate scientists' data. Such zero-carbon-dioxide sources include, but are not limited to, hydroelectric, wind, solar, nuclear, geothermal, wave, tidal, ocean current, ocean temperature-difference, water pressure recapture, river mouth osmosis, and river current. There are also carbon-neutral sources: landfill methane, cattle operation methane, Municipal solid waste (MSW), human waste sludge, plant-based ethanol, and other bio-fuels."
The issue is, then, what steps are properly taken in a scientific study, and were those steps followed in reaching the alarming conclusions of catastrophic global warming from above?
The four essential steps are:
1. Obtain valid experimental data, or collect existing data records if past history is part of the data
2. Determine causal factor(s) for the data via proper analysis
3. Develop a model based on the causal factor(s), test and validate the model, and
4. Predict future outcomes with the model, and check accuracy of predictions.
As support for the above, the chemical engineers' society in the US, AIChE, has this regarding models:
"Modeling is the art of simplification of complex physics underlying the chemical (and physical) processes to account for observed phenomena and make falsifiable predictions." -- note, "and physical" added by the author.
Now to more detailed analysis of cities, towns, pristine areas, and the temperatures measured there over the decades from approximately 1900 until 2015.
It is abundantly clear that no human influences on temperatures measured near ground level approximately 5 feet above grade, have existed or do exist in pristine locations. Human influences occur where people change their environment, as for example cooking, heating or cooling a house, lighting living space, using electricity to run various motors, using gasoline or diesel fuel to power engines in cars, trucks, and machinery. Where one solitary house is built on a large farm, there would be such activities and the house would radiate away the heat. We know that, over a long period, all of the heat input in the house is lost to the environment; to believe otherwise would require the house to continually increase in temperature. Clearly, that does not occur.
It is also clear that, prior to the widespread use of electricity, farming communities consumed fuel as wood, oil, kerosene, coal, and diesel as the opportunity occurred along with the need. The Rural Electrification Administration brought electricity to farmers during the 1930s and 1940s.
What is also known, as the UHI article above referenced states, is that two effects exist in cities that create urban warming without any influence from man-made CO2. The first of the two effects is more buildings in a small area, with the buildings each having a constant energy consumption over time. The second effect is the buildings each consuming more energy over time. It is clear that cities have grown since 1900, as almost all cities are larger in population and land area now compared to then. It is also clear that the energy consumption per capita has also grown. Using electricity data for the US, only 80 billion kWh of electricity were produced nation-wide in 1930. Eighty-five years later in 2015, the amount has increased by 50 times, to 4,000 billion kWh. The corresponding population growth was from 122 million (1930 Census) to 309 million (2010 Census), a factor of only 2.5. In addition, petroleum use greatly increased in the same period.
Yet, alarmist climate scientists include cities in their data for showing the Earth has increased in average temperature. That fact is not in dispute, as it is certain that temperatures measured in cities show a warming trend. The dispute is, and should always be, whether increases in atmospheric CO2 caused any of the measured warming. In cities, clearly there are at least two, and probably three or more causes of increased temperature in addition to any warming from CO2. The first two causes having just been discussed, more buildings in a small area, and more energy consumption per building or per capita, the third cause is now discussed.
The third cause of long-term temperature increase is an increase in local humidity, as measured by either absolute humidity or relative humidity. In some regions, this effect will not occur since the regions have been very humid for centuries. Such regions occur in the US in the deep South, in Florida, along the mid-Atlantic, and a few others. However, the dry western states and southwestern states certainly show the effect of local humidity increase.
The humidity effect has long been known, even to pre-teens and teen-aged children who spend time outdoors overnight, perhaps camping with various organizations. When camping overnight in humid areas (as I did on a monthly basis for several years near Houston, Texas with a well-known organization), one did not worry about getting too cold at night in the Spring, Summer, and early Fall. High relative humidity kept the air fairly warm. But, when camping in dry regions of west Texas, New Mexico, and Arizona, it was much colder at night in the same seasons. The lack of humidity allowed heat to easily radiate to space through the atmosphere, and the early morning temperature would be quite cool and even cold.
The effect on long-term temperatures in cities is obvious, as homeowners built houses with lawns that required watering, and cooling systems using water evaporative coolers were installed. Even commercial chilling systems for buildings and industries used cooling towers that sent out clouds of water vapor into the skies. Electric power plants with cooling towers, and industries such as refineries and chemical plants with cooling towers also contribute water vapor to the skies in and near cities.
Yet a fourth cause of a heating trend is now discussed. This, too, occurs in the dry desert regions. It is well-known that rain in the desert, and semi-arid regions, causes the atmosphere to cool. Therefore, the effect of prolonged drought on long-term temperature measurements must be considered. One effective way to measure long-term drought in the western US is to consider the annual water flow through the Colorado River, that flows through Lake Powell and Lake Mead. The long-term, at least over the past century, has been a decrease in annual flow of approximately 10 percent since 1905 (per USGS). It is also noted that droughts also occurred recently in non-Western states, in particular Texas.
There are, therefore, at least four causes of measured warming in addition to the warming (if any) caused by CO2 in the atmosphere. As discussed above, these four include more buildings (or population) in cities, more energy per capita in cities, increased humidity in arid and semi-arid regions, and natural droughts in various regions.
As stated above in the four points of valid science and good engineering practice, we require good experimental data and proper causal factor identification. Where multiple causes are known to exist, it is error to include data points in the database. Clearly, cities have many if not all of the four causes of increased warming discussed above, and must be excluded from any valid climate change database.
It is entirely inappropriate to adjust the temperatures in cities to account for known UHI influences of city growth, energy per capita growth, relative humidity increase, and increased drought. The proper treatment is exclusion from the data set.
UPDATE - 5 June 2016: Other non-CO2 factors also exist, in addition to the four discussed above. Three additional effects are discussed below: aerosols, measurement siting, and wind shadows. The effect of atmospheric soot, fine ash, and aerosols above a city impact the temperature measurements. Also, the location of the temperature measuring equipment impacts the temperature trend over time. Finally, buildings that deflect wind above or away from the temperature measurement site creates issues.
Cities in the 20th century had serious air quality problems due to uncontrolled burning of wood, coal, and heating oil. The smoke and soot from such fires are legendary and factual. There is no dispute over these occurring, as reports in newspapers were frequent on the impacts of the smell, difficulty in breathing, soot settling onto clothing and buildings, and entering homes and other buildings via open windows. London, England had especially bad days with the smoke in the 1950s. see link and this link The smoke, soot, and other airborne particulates blocked out the sun. Yet, when clean-burning natural gas was used in later decades, the air cleared, the sunshine reached the ground, most assuredly causing measured temperatures to increase.
The same thing occurred in the US with the Clean Air Act of 1973, and its implementation over the next decades. Particulate emissions as well as chemicals such as NO2, NO3, and SO3 were reduced, greatly improving air quality.
It should be expected that temperatures measured in cities would show an increase as the air became cleaner and cleaner after 1973.
The sixth non-CO2 impact on temperature measurements over time is the change in character of the measurement site. Much work has been done on this, with the US measurement sites documented and compared to official standards. The central issue is a measuring station may have been located in an acceptable area initially, many decades ago. However, urban growth and "progress" brought buildings, paved roads, parking lots, and other artificial heating impacts to the location.
The seventh non-CO2 impact on temperature measurements over time is measuring temperatures in a wind-shadow. Buildings in cities are usually multiple stories, and some of course are skyscrapers with dozens of stories. Clusters of such tall buildings can impact the wind, deflecting the wind upwards, or to the side. Where temperature measuring stations are located downwind of such buildings, the normal wind flow is obstructed. Over time, the measured temperature is higher and higher.
Finally, a temperature graph from IPCC's AR4 is now included above as Figure 1. That graph shows a steadily increasing trend from 1975 through 2005, rising approximately 0.9 degrees C in only 30 years. This is the basis for the false-alarmism of a 2 to 3 degree C increase in the next century. The temperatures in cities may, in fact, be somewhat warmer in the coming decades, but the increase has nothing to do with CO2. As noted above, there are at least seven causal factors that create the appearance of warming in cities, and none of them are CO2. Even if all electricity in all the cities was replaced overnight by hydroelectric power that produces zero CO2, cities would still be warmer today than 100 years ago. --- End Update
Roger E. Sowell, Esq.
Marina del Rey, California
copyright © 2016 by Roger Sowell all rights reserved