by Ross McLeod
(Caloundra, Qld, Australia)

How does carbon dioxide heat the earth?

The argument goes that carbon dioxide can absorb infra-red radiation emitted from the earth and hence it becomes hotter and this in turn results in a “back radiation” from the atmosphere of more infra-red radiation which in turn heats the earth thus raising the temperature. As the earth must adjust to this increased temperature it radiates more infra-red energy and so on.

The IPCC AR4 FAQ Figure 1 is from a paper “Earth’s Annual Mean Energy Budget” by Kiehl & Trenberth – February 1997.

Part 3. Radiative energy budget – a. Top-of-atmosphere fluxes concludes with this quote :

?Here we assume a ?solar constant? of 1367 W m-2 (Hartmann 1994), and because the incoming solar radiation is one-quarter of this, that is, 342 W m-2, a planetary albedo of 31% is implied.?

Now this is very important because it is the foundation stone on which the whole of the “settled science” is built.

Why is the incoming solar radiation one quarter of the solar constant?

It is NOT because of the “reflectiveness” of the earth and our atmosphere – called the albedo – they apply that later and reduce the incoming radiation to 235 Watts/aq metre.

At 235 watts/aq metre you can calculate the effective blackbody temperature of the earth as minus 18 Centigrade yet we all know the average is about plus 15 Centigrade so how come it is warmer than it otherwise would be?

The answer we’ve all been told is greenhouse gases!

But back to that troubling reduction in incoming solar radiation which is only glibly mentioned – almost hidden away in a long and convoluted section of prose.

Why is it 342 W/sq metre when clearly one piece of settled science is that 1367 W/sq metre is the “solar constant”?

It is because they want to talk in averages! Without this little “trick” there is no temperature “anomaly” between the maximum blackbody temperature of the earth – remember they claim it is minus 18C, you’ve seen this many times.

If the maximum blackbody of the earth is much more than plus 15 C then “greenhouse gases” have no heating effect.

A simple demonstration – do you really believe that on a summer day Alice Springs in central Australia reaches 45 C not because of the puny amount of energy in their diagram but because CO2 heats it up by more than 63 C over the so-called blackbody temperature?

The first reduction applied is that because at any one time half the globe is in darkness – hence no incoming solar radiation – they reduce the incoming solar radiation by 50% to arriva at a global average.

The second is the earth is a sphere and they want a plain circular disk to consider so they reduce the incoming solar radiation by 50 % again – because a disk with the same diameter has half the area as a heimsphere.

At first thought these simplifications sound plausible but they deliver non-sensical results like the Alice Springs one.

If this is acceptable to you as the basis for a theory which some claim is so urgent that we must all drastically change our lives or perish well all I can say is consider this :

Greenhouse gas theory is contradiction. From NASA, the home of James Hansen – the “head honcho” of global warming – sorry – climate change.

http://www.giss.nasa.gov/research/briefs/ma_01/

“Without naturally occurring greenhouse gases, Earth’s average temperature would be near 0°F (or -18°C) instead of the much warmer 59°F (15°C).”

http://lunarscience.nasa.gov/kids/moon_temperature

“During the day the temperature on the Moon can reach 253 Fahrenheit (123 Celsius), while at night it can drop to -387 Fahrenheit (-233 Celsius). The Earth, which has an atmosphere, has a much more comfortable range of temperatures. ”

Huh ??????? –

The moon with no Greenhouse gases is 123 degrees C during the day

BUT

“Without naturally occurring greenhouse gases, Earth’s average temperature would be near 0°F (or -18°C) instead of the much warmer 59°F (15°C).”

Doesn’t anyone see there is something wrong here ?

They’ve cooked the books by confusing average with maximum – without our atmosphere the earth would be almost exactly like the moon.

Our atmosphere protects us from the sun – it will not cause a thermal runaway greenhouse effect but rather keeps us cool during the day and warm at night because of water vapour.

Carbon dioxide cannot heat the earth – only the sun can.

In case you think I do not simply understand consider this :

CO2 does not have the physical properties necessary to have a dominant effect on climate.

At ~0.06 % of the atmosphere by weight it would have to emit 1667 joules/gram (the reciprocal of 0.0006 = 0.06%) to come to equilibrium with the rest of the atmosphere and cause a 1 degree C rise. This is simplistic because it is suggested CO2 back radiation actually heats the earth and the mass of the earth per square metre is obviously much more than the atmosphere thus the 1667 figure is WAYYYYY underestimated – that is it is even more improbable.

I think we might have noticed CO2 emitting 1667 joules/gram in the atmosphere – or perhaps we do if you believe that without CO2 Alice Springs would be minus 18 C in summer.

Water, on the other hand does have the physical properties to easily explain some features of climate.

Singapore rarely exceeds 32 C – why? It is surrounded by water which absorbs heaps of energy during evaporation.

Alice Springs hits 40 + C during Summer – why? Alice Springs is not on the equator. Singapore should get way hotter because the sun is almost always almost overhead.

Alice Springs is in a desert with little water to moderate temperature.

But why doesn’t Alice Springs get even hotter ?

This is the most convincing failing in the greenhouse global warming theory – they ignore convection as a means of heat energy transfer.

Convection in an atmosphere where hot air rises moderates surface temperture as well – radiation from the surface is an inefficient means of heat transfer – it’s why the “fan” is in the oven.

Convection is a more efficient energy transfer mechanism so the earth’s surface never gets anywhere near its true blackbody temperature when the sun is shining, and when considered with the huge energy transfer by water evaporating to water vapour where is the greenhouse heating effect?

I don’t believe it exists or if it does it is insignificant.