Sunday, 29 January 2017

Why Temperature is not important.

Anthony Cox

Alarmists base their hysteria on temperature trends. Everything is getting hotter and the current temperature is hotter than it has ever been. It doesn’t matter that the temperature records which alarmists rely on are adjusted, homogenised and altered to show warming where often there is none or exaggerate warming which does occur or that whatever warming is occurring is unexceptional and natural.

However, apart from fabricated temperature records, there is another reason why alarmism is wrong in its reliance on phony temperature records.

The true measure of climate on Earth is the energy balance. Energy, primarily from the Sun, enters the atmosphere while energy leaves. Alarmism uses the diagram from Trenberth et al 2009 to show energy fluxes.

This KT diagram has manifest problems as this diagram shows:

The official energy movement based on KT incorporates many estimates and assumptions which are plainly wrong. But in addition to that alarmism ignores the Earth’s Energy balance as depicted by Outgoing Longwave Radiation (OLR). OLR is the only way energy can leave the Earth and the record of OLR is a much better indicator of climate than any corrupted measure of temperature.

The data and further graphs of OLR can be seen at the NOAA site.

As temperature increases, more energy leaves the Earth. There is NO trapping of heat as alarmism claims and is based on. This is consistent with a basic law of physics, the Stefan-Boltzmann Law (SB). SB is:

E = sigma x T^4,where sigma = 5.67×10^-8, and T is temperature in K

Every surface which is above absolute zero emits radiation. The hotter the surface and the higher its temperature the more radiation is emitted by a power of 4. If the surface of the Earth or the atmosphere gets warmer it emits more radiation and cools. This a moderating effect which has kept the temperature of the Earth within a narrow range of temperature for millions of years:

Throughout the history of the Earth, the temperature range has been no more than 15ºC. Yet alarmists would have you believe that because humans are emitting a tiny amount of CO2 that the temperature on Earth will soon exceed the temperature of Venus! Mad.

Another aspect to the irrelevance of a global average temperature (GAT) is also related to SB. There has been considerable hysteria from the alarmists about temperature increase in the Arctic. Again this temperature increase has been perfectly normal and within natural variation. But even if the Arctic is heating up at a faster rate than the rest of the Earth that does not mean the Earth itself is heating up overall.

Again this is because of the difference between temperature and energy. As noted every surface above zero emits radiation but the amount of radiation emitted depends on the temperature. A colder temperature even if it has increased by more than a warmer temperature will still emit LESS radiation than the warmer temperature. This is again due to SB which shows the relationship between temperature and energy emitted is based on ^4: an increase in temperature increases the energy emitted to the power 4. For example, a temperature increase from 200K-250K radiated energy increases from 91-222 W/m^2 – an increase of 131 W/m^2. From 300-350K radiated energy increases from 459-851 W/m^2 – an increase of 392 W/m^2. How can a 50K (50 C) rise in temperature cause such a difference in radiated power for different starting points? That’s the reality we live in and is easily expressed in mathematical form as T^4.

The alarmists fudge this fundamental point by concentrating on temperature. If the Arctic is increasing in temperature but the rest of the world is not by averaging the Arctic with the rest of the world the alarmists can still show an increasing temperature when there is no energy increase. In an important paper Pielke et al describe this effect:

[6] At its most tightly coupled, T is the radiative temperature of the Earth, in the sense that a portion of the radiation emitted at the top of the atmosphere originates at the Earth’s surface. However, the outgoing longwave radiation is proportional to T4. A 1C increase in the polar latitudes in the winter, for example, would have much less of an effect on the change of longwave emission than a 1C increase in the tropics. The spatial distribution matters, whereas equation (1) ignores the consequences of this assumption. A more appropriate measure of radiatively significant surface
changes would be to evaluate the change of the global average of T4.

The alarmists get away with this trick of showing a higher GAT by adding all the temperatures then applying SB and the power ^4: (A + B)^4. The proper way of doing this is working out the radiation at each site then adding them together: A^4 + B^4.

For those interested in further analysis see: Luboš Motl.

The alarmists can show an increasing GAT while at the same time OLR is increasing and there is less energy on the Earth. It is a sleight of hand and deceit which underpins alarmism. Alarmism is literally built on hot air.