As discussed in the previous posting, examination of ice cores can provide high quality data about the Earth’s climate from thousands of years in the past. Antarctica’s ice cores cannot be surpassed for the longest age records. Let us look once again at the Vostok ice core drilling. (Click on all the charts to enlarge.)
This illustration reverses the direction of time flow from that of the previous posting’s chart. It does expand the data from about 120,000 years ago to the present.
The chart blue line is the ice core temperature data referenced to the global temperature. The flat red line is the average of global annual temperature means for the period 1998 to 2008. This provides a reference with which to compare the past temperatures. And lastly, the green is the annual mean temperature for 2008. Several things are obvious. First, recent temperatures are not as warm as previous temperatures at their peak. Second, the globe began to exit the last glacial period about 15,000 years ago, and the temperature increased fairly rapidly (of course rapidly on this chart may be several thousand of years). It is not possible to attribute this rise nor really any other rise shown on this chart to something that man has done. The current period has been relatively stable.
Below shows the temperature data for EPICA Dome C charted with the Vostok data of the previous chart:
Time on this chart runs from the oldest on the left to the current time on the right. The Blue line is EPICA Dome C and the Red line is Vostok. Analysis of this chart is the same as the previous chart.
The infamous “hockey stick” temperature chart produced by Dr Michael Mann erased the Medieval warm period, when Greenland was green. While the hockey stick is largely discredited, the following chart shows ice core data from Greenland which puts the Medieval warm period back where it belongs.
The yellow box above may not contain large enough print to read so, here is what it says:
“From Greenland ice cores, researchers have reconstructed past temperatures back for 50,000 years. Above is a temperature history slice representing approximately 5000 years before the present (BP). The green curve is 3rd degree polynomial trend, which reveals an overall cooling trend since the height of the Minoan Warming.
Warning. The right end point (red circle) is approximately 100 years before the present. Needless to say, current temperatures and our perceived climate change is nothing out of the ordinary when compared to the past 5000 years.”
The warmers say that year 2015 temperature was the hottest in history. This posting shows that it was not the hottest in history and such claims are absurd. They make these claims for political reasons. Was it hotter than the year 1940 for example? Probably, although we can never be completely sure because the official temperature recorders continually revise the temperature history to support their contention that we are on a path to doomsday unless we do exactly what they tell us.
In the next posting we will look to see if CO2 drove the temperatures recorded in the ice cores.
cbdakota
H/T to C3Headlines.com for all the charts
Climate Change Sanity 
Is it global warming or natural climate change that happens every millíon years. Your thoughts.
Ifish64
Tough question to answer as there are so many possibilities. First off, I think the majority of the climate change is natural, at least historically that has to be the answer. See my last two posting and it is clear that man does not cause climate change. At the current time, I believe man has some effect on climate change, but I believe that most of it comes from natural sources.
First there is the Sun. It is the source of our energy. Radiant energy from the Sun transforms into heat. Some of the radiation produces chemical reactions such as those that go on as part of photosynthesis. I think that changes in the activity of the Sun cause changes in our global climate. When the Sun is less active, like it is right now, and has been on many occasions, I believe the planet tends to cool. When the Sun exhibits high activity, I believe the planet tends to warm up. The precise solar mechanism that cause these changes has not been formally identified although the Maunder Minimum, the Dalton Minimum and other Minimums seem the happen when the Sun’s activity has been low.
Secondly, reflectivity (albedo) can make a change in global climate. It is a fact that the polar regions reflect much of the Sun’s radiation back into space. Conversely, if soot (this could be man made) or volcanic ash coat the snow at the poles, that could cause more of the Sun’s radiation being absorbed—thus producing warming.
Several huge volcanic explosions, such as Krakatoa put so much SO2 into the atmosphere it created high level clouds thus increasing albedo. The temps around the world dropped by several degrees.
Low level cloud formation are increased by high energy gama rays according to some theories and this increase in clouds increase albedo reducing global temperature.
The seeming favorite of many scientists are the Milankovitch Cycles as the answer to why we go into and out of glaciation. There are three cycles,. One is the eccentricity of the Earth’s orbit. The axial tilt of the Earth and the last one is the precession (like in a gyroscope). These shorten the summer in such a way that ice forms and does not get fully melted at the end of the season. As seasons go by the albedo increases and the planet goes in to a glaciation period. What brings it out presumably is that the summers lengthen and the glaciation is reversed. But I am guessing.
Another theory is said to be the effect of angular momentum resulting from the alignment of the large gas planets on the solar systems barycenter, This somehow effects the acitivity of the Sun, if I remember the theory correctly.
I would have to look all of these causes up to assure that I am not wrong, but I would like you to look these up so you can form your own opinions.
The man-made part of global climate change –and if you are a warmer that always means global warming and never global cooling.
CO2 undoubtedly has some effect. It is a greenhouse gas. But the primary greenhouse gas is WATER. Usually as water vapor. The warmer’s standard theory is that for every doubling of atmospheric CO2, about a degree of warming occurs. But they use a multiplier(They call it “climate sensitivity”, if I remember correctly) to come up with their scary forecasts. The degree of change because of CO2 results increased evaporation of water. This water vapor acts as a greenhouse gas and causes 2 more degrees of warming. You can get their scary forecasts if you use that theory. Current, non-biased scientists have experimented and have reduced this implausibility theory dramatically. If you look back through my postings, you will find a discussion about “climate sensitivity”. Three to one is not really likely to be the real world. Their theory 1 degree by CO2 and 2 degrees by H2O,
Look at my next posting to see how the Ice core treat CO2 as the source of warming.
All of this pretty much from the top of my head. A better answer probably could be achieved if I were to take more time. But if you wander through my back postings, and then go look up stuff you will be better informed.
cbdakota
Thanks for your knowledge and expertise. You help climate change make more sense.
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