The Science of Climate Change: Are you a Denier?
WASHINGTON: The clarion call for concern over climate change and global warming is not being trumpeted by a bunch of deranged tree huggers and wacky environmentalists. This call for concern has been addressed and documented by the United Nations. An article outlining issues of concern by the United Nations warned that we have a little over a decade to take proactive measures to slow down and reverse what are believed to be harmful man-made effects. (Only 11 Years Left to Prevent Irreversible Damage from Climate Change, Speakers Warn during General Assembly High-Level Meeting)
Because of passionate opinions, it is necessary to provide the empirical rationale to address what contributes to changes in our cyclical planetary climate and weather patterns.
The gases in our atmosphere
A quick primer will reveal gases in our atmosphere, among which are constituted by (but not limited to) Nitrogen, Oxygen, Argon, Carbon Dioxide, and Ozone. Nitrogen is important to life because it is an important building block for enzymes, DNA and other components of living cells. Oxygen is important because it provides the fuel that produces energy. Argon is an inert gas, and is very useful in arc welding and cutting. It is also used in incandescent and fluorescent bulbs to minimize the effect of oxygen corroding the filament.
Ozone is very important because it helps to block a significant amount of harmful ultraviolet rays from reaching the earth.
But what about Carbon Dioxide?
To appreciate why many attribute the reported and perceived increase in average annual global temperatures, consider the following. If two rooms, each with a size of 1000 cubic feet (10’ X 10’ X 10’) were empty, and one room had all regular air removed and replaced with 100% carbon dioxide. The other room is filled with regular air. What would happen when each is heated to 200 degrees Fahrenheit, before shutting the heat off?
The room with pure Carbon Dioxide would cool at a much slower rate than the room with regular air. The reason is that the molecular structure of the CO2 would retain the heat for a much longer period. Thus, Carbon Dioxide is considered by many to be a potentially dangerous greenhouse gas if its levels go unchecked into the foreseeable future.
Carbon Dioxide is also found in the oceans.
In fact, concentrations there are much higher than in the free atmosphere. Seawater absorbs CO2; colder water absorbs more. Mechanical motions in the ocean also affect the air/sea interaction and release/absorption of CO2 in/from the atmosphere. Biological and plant life in the ocean also affect CO2 levels. Algae and seaweed (plants) absorb CO2 and release oxygen. Non-plant living organisms take in oxygen and release CO2.
Combustion from fossil fuels, coal, factory emissions, and other man-made activity all release increased levels of carbon dioxide into the atmosphere. So it would stand to reason that regardless of our political affiliation, socioeconomic status or nationality, we should all seriously consider and embrace the Green New Deal that many U.S. politicians espouse and promote. Right?
Well… not so fast.
We should first look at the actual atmospheric composition of the aforementioned gases.
Our atmosphere is defined as “…a gaseous envelope surrounding the earth that has motion relative to the earth.” The greatest amount (by far) is Nitrogen, which comprises 78% of the air. Next is Oxygen at 21%. Argon is at 0.94% (just under 1%). The remaining gases combined are less than 0.1% and are referred to as trace elements.
That means nitrogen, oxygen, and argon comprise over 99.9% of the air we breathe. Carbon dioxide, even though it might be demonstrated to retain more heat than regular air (as in the hypothetical example described earlier), comprises a scant 0.04% of our atmosphere (400 parts per million). That amount has not changed appreciably in the past 50+ years.
Yet proponents of global warming and climate change make the argument that CO2 levels have increased incrementally in recent years. Therefore we’re on a collision course with environmental disaster. They claim that we are seeing more record high temperatures, as well as stronger and more frequent tropical storms and tornadoes.
While new record high temperatures and changes in the frequency of tropical storms and tornadoes are objective statistics, causation (i.e.: what you attribute the changes to; cause & effect) is not as simplistic as some try to make it. A good starting point is to go back to the basics and establish the most important factors in the amount of heat measured on earth. The top two are Angle of Incidence and Albedo.
Angle of Incidence
The angle of incidence is an indicator of how direct (or indirect) the sun’s rays strike the earth’s surface. The angle of incidence is formed between a line representing the sun’s rays, and a line perpendicular to the earth’s surface.
Illustration courtesy of ScienceABC.com – Angle ‘i’ is the angle of incidence.
In the above diagram, the green line is perpendicular to the (brown) surface. The yellow line would be a line representing the sun’s incoming ray. If that sun’s ray were more direct (coming more straight up and down, as when the sun is overhead at around noon), the angle of incidence (i) would decrease. If the incoming sun’s ray becomes less direct (coming in more in line with the surface, as when the sun is setting in the evening or rising in the early morning), the angle of incidence (i) would increase.
As the angle of incidence increases, incoming solar radiation decreases, and there would be less heating at the surface. The inverse is also true: As the angle of incidence decreases, incoming solar radiation increases, and there would be more heating at the surface.
The second most important factor in the amount of heat received at the surface is albedo, which is the amount of reflectivity of an object. Simply put, light objects reflect more sunlight; dark colors absorb more sunlight.
On a hot summer day, the interior of a dark vehicle will get hotter much sooner than a vehicle with a light color. Likewise, if you wear a dark suit, you will be warmer than someone dressed in a light colored suit.
To recap, the two most important factors in determining the amount of heat at the earth’s surface are the angle of incidence and albedo.
Heat transfer in our atmosphere occurs as one of the following:
- Convection, and
Radiation is considered in one of two forms:
Short wave (solar) radiation from the sun, and longwave (terrestrial) radiation that is RE-radiated/emitted by the earth. Conduction is heat transfer by direct contact. For example, if you sit in a chair for several minutes, and then stand up to feel the seat, why is the seat warm? It is because an amount of heat was transferred from your body directly to the seat.
This is an important concept: Most of the incoming (solar) short wave radiation penetrates clouds. This is why you can get sunburned on a cloudy day. Also, very little short wave radiation is absorbed by the atmosphere. However, after incoming solar radiation reaches the earth surface, it heats the surface.
The earth then re-radiates this heat in the form of longwave radiation.
A large amount of this longwave radiation is absorbed by the atmosphere. Constituent gases: oxygen, nitrogen, argon, and trace elements (including carbon dioxide) absorb this longwave radiation. This absorption by atmospheric gases acts like windows of a greenhouse. The greenhouse retains the heat for a period of time, but it eventually cools as the heat source, the sun disappears. The heat then escapes into the upper atmosphere.
If extensive cloud cover exists over the area, the longwave radiation reflects downward back toward earth. This is because very little amounts of longwave radiation penetrate clouds. This creates a greenhouse effect, which is due to more heat being retained in the lower atmosphere.
On a clear, cloudless night, the temperatures will cool much more than they will on a night with low cloud cover.
The amount of moisture in the air will also have an impact on how cool the nighttime temperatures will get. In fact, a well-known forecasting indicator for nighttime temperatures (under mostly clear skies) is the *dew point of the air at the time of maximum heating at the previous afternoon. *Dewpoint: Temperature to which air must be cooled to reach a point where it is holding all the moisture possible (saturation).
Drier air (with a lower dew point) will cool faster than air with a higher dew point. The forecasted minimum temperature is modified several degrees warmer if there is extensive low-level cloudiness because of less lower level atmospheric heat is allowed to escape than on a clear night.
This trapping of low level atmospheric heat by extensive cloud cover over an area is primarily responsible for what is known as the greenhouse effect.
- Convection is air heated by conduction that rises in an upward vertical motion.
- Large scale HORIZONTAL motion of air is advection. Advection occurs slowly over a large area.
The air in the lower atmosphere tends to take on the characteristics of the underlying surface. When the air stays over an area long enough, it is classified as an air mass, based on basic properties: source region, moisture, temperature, and stability.
We will not get into factors relating to air masses across the planet, but their characteristics play into global climate: a) Source Region (where the air mass originates/forms); 2) Moisture (humid or relatively dry); 3) Temperature (comparison of whether it is warmer or colder than the surface it passes over); 4) Stability (whether or not the air mass has a tendency to rise, or remain settled.
Water vapor undergoes various changes of state.
It can go from a gas to a liquid (condensation), liquid to ice (freezing), ice to liquid (melting), liquid to gas (evaporation), and ice to gas or gas to ice without becoming a liquid (sublimation). Changes of state are either heating processes or cooling processes, depending on the surrounding air. If the moisture (undergoing a change of state) releases heat, it is a heating process.
As weird as it may sound, freezing is actually a heating process. That is because the liquid has to release heat (to the surrounding air) in order to become ice.
Tropical systems are fueled by the large scale release of heat into the surrounding air. But there must be a combination of key conditions in order to have conditions favorable for intensification of tropical systems into tropical storms or hurricanes.
Basically, you need warm sea surface temperature (80F or warmer), weak vertical wind shear, location of the developing system needs to be greater than 5 degrees latitude away from the equator (to have sufficient Coriolis force for circulation), and strong convective cloud activity clustered in a region. An absence of one or more of the above makes it improbable that a tropical system will develop into a tropical depression or stronger.
And even when all of the above conditions exist, it does not guarantee that the tropical system will develop further.
Climatological projections that use numerical computer for long-range predictions cannot accurately project tropospheric moisture into the future. Such models are DRY weather models. Furthermore, no weather forecast relies on interpolation of CO2 levels in the atmosphere. Again, an atmospheric gas that constitutes a mere 0.04% of the total has a negligible effect on meteorological conditions now or into the future.
Rising and sinking motion of air can heat (by sinking and compression) or cool (by rising and expansion) by the adiabatic process. This is changing the temperature without changing the amount of heat in the parcel of air. Think of it like a box the size of a microwave with a lighted candle inside. The lighted candle represents a specific amount of heat that remains unchanged. If you take the sides of the box and reduce (i.e.: shrink the sides) to half its former size, the temperature will increase (adiabatic heating).
Likewise, if you take the sides of the box and expand (stretch) them to twice its former size, the same amount of heat will have to be spread across a larger area.
Thus, the corresponding temperature will decrease (adiabatic cooling).
The resounding consensus today is that Global Warming and Climate Change have incontrovertible evidence to support what many have hypothesized. The Green New Deal embraces this position with brazen confidence that its premise and objectives are to be embraced without question. Any who dare question it are ridiculed, and their motives vehemently scorned and impugned. However, to sound the alarm without empirical evidence is not only irresponsible, but it is also disingenuous and dishonest.
We should do whatever we can to reduce excessive carbon emissions and do what we can to ensure that our air is clean as possible. Likewise, taking prudent measures to ensure clean water, reducing oceanic pollution, recycling, and developing alternative energy sources that result in a positive return on investment are all things we should strive for.
The above information was compiled and verified by the writer and has not been individually verified by CDN.
Lede Image: Clouds over Chicago Skyline – Photo by Alex Powell from Pexels – https://www.pexels.com/photo/reflection-of-buildings-on-water-2225386/
Bill Randall is a contributing writer for Communities Digital News and a retired military earth science professional. His professional experience has involved making precise oceanic, surface and upper atmospheric measurements and forecasts (northern and southern hemisphere), as well as interpreting them for operational and tactical military use.