a reply to:
swanne
Do you have a personal theory as to what may have caused such a cycle?
Cyclical, usually sinusoidal, variations are quite common in control systems. It is actually quite unusual to not find some sort of minor fluctuation.
The climate itself is a massively complex MIMO (Multiple Input Multiple Output) control system, so massively complex that we do not yet understand all
of the feedback systems involved.
For example, if one wishes to address the atmospheric carbon dioxide levels, one feedback is through photosynthesis. Any warming in the planetary
atmosphere will adjust the growth season globally, allowing for flora growth to move closer to the poles. This uses more carbon dioxide from the air.
In addition, growth rates will increase; we know this because the exact same principle is used commercially in greenhouses - excess carbon dioxide as
high as 1500 ppmv is purposely added to the enclosed environment to accelerate plant growth. Both feedbacks, increased area of growth and increased
growth rates, will use more carbon dioxide form the atmosphere. in addition, we know that the atmospheric carbon dioxide level to heat retention
relationship is not linear... far from it. Considering that plant growth is cyclical in itself and slow to increase overall, it is quite possible that
this would create a sinusoidal variation of some undetermined period.
That is one example. There are many, many other possibilities, including a great number which are independent of atmospheric carbon dioxide levels.
The issue with using heat retention as a sole indicator is that heat retention is not necessarily the primary force driving planetary temperature.
Planetary temperature, at least on a local scale, is more easily monitored directly. Since climate is a summation of weather over time, it follows
that the preferred method of determining if excessive variations are occurring is to measure various local settings over time and analyze those
results. That is the first thing that begs investigation, after all: is a phenomenon occurring? That seems to be the disconnect when it comes to
Global Warming. If there is no Global Warming, any attempt to show why global Warming is occurring is moot.
That would be akin to calling a mechanic to see why one's car doesn't start before checking to see if it starts.
My work has thusly been based on determining if there is an issue and if so, to what extent is the issue occurring? My local climate shifts during the
course of the year between 20°F and 100°F, with regular variations of 10°F to 110°F. The annual average is around 60°F. Thus far I have not seen
any temperature readings outside those parameters (discounting fringe, sporadic and rare readings). The average annual temperature has increased and
decreased by less than 2°F in a sinusoidal manner, and at present the average annual temperature is within a few hundredths of a degree from circa
1950. That is so minor it can be chalked up to sensor variations and thus is not indicative of an issue.
If there is no indicated change over time with average annualized surface temperatures, there is no need to find out why average annualized surface
temperatures are changing.
This is the lie about Global Warming: if one is constantly being told why temperatures are changing, one will come to accept that such change is real.
After all, why else would anyone be trying to study it? Human experience is of a time scale already much faster than seasonal temperature variations,
so we have this tendency to think the summer is too hot or the winter is too cold. During winter, our memories of summer temperatures are still fresh
in our mind; during summer, our memories of winter temperatures are still fresh in our mind. I have watched, personally, since I started maintaining
this data about ten years ago, people in January remarking how cold it is while the average temperatures are above normal. I have seen the same thing
in July and August with the opposite complaint and reality. Yes, it is cold in the winter and hot in the summer... that's normal.
Studying heat transfer ratios based on atmospheric carbon dioxide levels is not a bad thing... but doing so because one believes there are global
changes occurring that are not actually occurring is merely an exercise in cognitive dissonance. At best, such a study is academic at this time.
Humans can handle carbon dioxide levels up to 1000 ppmv or more without suffering any serious effects; it is quite common for enclosed areas to reach
that point already (a carbon dioxide content of ~1000 ppmv is what we would colloquially call "stuffy" air). Plant life, the base of all the various
food chains, only begins to thrive at ~280 ppmv and thrives up to and likely beyond 1500 ppmv. A carbon dioxide concentration between 300 and 900 ppmv
seems to be optimal for life to flourish, and we are still well towards the lower end of that range. The change to 400 ppmv that has occurred during
the last few decades is actually a benefit to humanity and life in general, not a detriment. It has increased potential food supply and has had no
appreciable effect on temperatures nor deleterious effect on life.
TheRedneck