Global warming is an increase in the amount of the sun’s energy that earth retains. This then may cause an increase in the temperature of the planet, referred to as global warming. Why “may cause”? Because the temperature of the earth is affected by many things that act to increase and reduce the amount of energy retained. It’s not just a single factor.
Temperature is the average thermal energy of a material’s molecules. Most of the time, temperature is expressed in degrees C (celsius) or F (Fahrenheit). There is also Kelvin (K), which does not use the designation of degrees because it is an absolute scale (zero K is where all molecular movement stops–a fascinating idea, I always thought*). People generally regard the measurement of temperature as what feels “hot” and “cold” rather than the thermal energy of a material.
Temperature is measured in various ways:
There were the liquid-filled tubes, originally containing mercury. Later, it was a colored liquid. I have always regarded these as most accurate since they are simple and straightforward. I really don’t have any evidence this type of thermometer is usually quite accurate except it’s simplicity and fewer moving parts seems to indicate less chance of error.
There were bi-metal thermometers, copper with steel attached to each other. The metal expand at a known rate as temperature rises and falls. Adding a couple of additional metal pieces allowed for min/max measurement without one actually having to be reading the thermometer at that exact point. Now, many thermometers are digital, based on electrical resistance. Based on my experience with various digital measuring devices, these seem the least accurate and require frequent calibration.
For AGW, there are also satellite measurements, requiring mathematic calculation to convert to temperatures. These give us a more global picture.
How many points are measured? With a satellite, you basically have full coverage of the globe. With land, you do not. The arctic and antarctic, remote areas and so forth have very, very few stations. The USA, Europe and much of North America have coverage while the southern hemisphere is much more sparse. One hears the complaint that North America, as in the US, is not global, but the stations are heavily weighted to the US. So in a sense, North America is a proxy for global, as much as those pine trees and their rings were.
Ocean temperatures have been added to global temperature calculations, but unfortunately, as is the case in so much of climate research, there exist two measuring systems which are completely and utterly different and do not correlate nor back up each other. There’s the ancient “bucket from a ship method” where temperatures were originally measured by literally dropping a bucket from a ship and taking the water temperature. Modern techniques based on this idea are better but still subject to large margins of error. Then there are the buoys a fortune was spent on but the buoys didn’t give the desired result of showing warming, so they seem to have been dropped out, another wasted fortune on climate research. (Eventually, they may prove valuable. One never knows.) All of this means there is no true measurement of “global temperatures”, just measurement where convenient or practical.
What about missing points? If one is using a grid to homogenize and average the temperatures before further averaging, you have to fill in missing points. How? I learned they were called “fudge factors” and were basically “scientific” guessing when I was in college. Now, we call it kriging and other high tech terms. With the aid of computers, we have lead ourselves to believe we can quite magically know what we do not know. Temperatures vary widely, even over short distances. To vainly believe one can estimate accurately is just hubris. Now, it might be “close enough” (like horseshoes and hand grenades “close enough”) but if the error bars are included, it looks pretty shaky. Plus, when we get to averages and anomalies, we’re talking a tenth of a degree as significant. We simply do not have the accuracy to make such claims, even though such claims are constantly made to that effect.
Temperatures used are generally min/max, homogenized and averaged. Homogenized is great for milk, but I am very unsure that it works for the betterment of temperature distributions. Ignoring extremes ignores the reality of temperature on this planet which again, varies widely even in small areas. There seem to be different methods calculating the averages and what gets homogenized. There’s also conflicting arguments about raw data showing more warming than homogenized or homogenizing creating warming. This is the problem with records, adjustments and statistics. It’s far too easy to adjust data to fit the theory. At this point, since there is only one theory that is accepted by many, manipulation in the direction of supporting warming is bound to happen, deliberate or not.
Reducing temperatures to min/max has problems. There is no way to know if the day was 70 degrees for several hours, or 50 degrees then 70 for an hour. There are many days where the min/max is only a point on the scale and not at all representative of the actual temperatures for the day. I realize we lack the capacity to calculate using the massive number of data points using all the temperatures for a day would involve, but get an accurate picture, that is necessary. After all, this is used to determine whether or not the earth is retaining more heat, the original stated goal. What we are doing now is short-cutting to help bolster a theory.
It’s very doubtful that using min/max combined is useful. Separating them would let us see where the warming is occurring more accurately. When the min and max are separated, nighttime temperatures are what seem to be going up. The Urban Heat Island effect can explain much of this, as well as the helping to explain the increase in daytime temperatures. Wind turbines can do the same thing on a windy night. AGW and wind advocates argue this does not matter and is local, but if one’s “local” increases are going into the overall average, there is a very real chance there is an effect. Satellites measure further up in the atmosphere, but still, using min and max rather than a daily average of say hourly temperatures may give a very incorrect average overall. I have read that measuring further up in the atmosphere is not useful since we don’t live there, but it’s perfectly fine for determining the energy budget. The objection is really irrelevant to the theory and only relevant to what happens with humans and ground temperatures.
There are other questions and concerns with the temperature measurments, calculations, etc that will be addressed later. This will be something of a series on global warming, an informal one albeit.
(It was said there are no negative Kelvins, but in 2013 it was determined there are negative Kelvins. Negative Kelvins are actually hot, not cold. There is no temperature below 0 Kelvin but there are negative Kelvins. It’s all very bizarre!)