Water - Earth's Only Thermostat

We're all fixated on Carbon Dioxide on our Earth. We have given it magical powers of heat capture, retention and throwback radiation into the hard surfaces that expel it during our dark hours. We ignore the fact that it is a trace gas (.04%), that it's absorption range in not in the bandwidths produced by a "warm" Earth, that it violates thermodynamic principles and laws when it supposedly back radiates, and that planets that have atmospheres with similar atmospheric densities as Earth along with almost pure C02  compositions (Mars at 95% / 950000 ppm - surface temp 210 K, outer atmosphere / blackbody temp also 210 K) show absolutely NO signs of global warming at all. 

Because of this, our counter arguments to C02 hysteria tend towards denying that any kind of global warming happens at all. This is wrong. Global warming DOES occur on our Earth. Our atmosphere IS warmed up by incoming and outgoing radiation along with other types of "cooling" actions that transfer heat from the Earth's surfaces to the gases of the atmosphere. Earth surface temperatures are calculated at 288 K and outer atmosphere temperatures are calculated at 255 K (ie. Blackbody temperatures). The reason for this difference is the existence of a warm atmosphere that holds back the upward movement of surface heat energy and thereby prevents it from instantaneously dissipating to outer space. 

We blame C02 for this "greenhouse effect", but this is simply wrong. The reason we heat up is WATER.


Want more information on why I am making these statements? - I give you the work done up to now that has led me to the position I now take in the "grand debate." Each one of these blogs expands on the thoughts that are presented above. Enjoy.

"Warmists" absolutely HATE to discuss water vapour because if they had to include it in their calculations they would be forced to admit that C02 is a minor player at best in the greenhouse like warming of Earth's atmosphere. Water is simply too prevalent and too overpowering in its absorption wavelength span and intensity that it overwhelms any effect of our minor levels of C02. It also has properties not possessed by C02 - in particular its ability to warm, evaporate, warm again and condense to clouds or freeze to snow while throwing off absorbed IR heat to outer space. NASA puts its concentration (as vapour) at an average of 25000 ppm, compared to C02 at 400 ppm. 

It's like the Elephant in the room that we should be focusing on while we put all our attention towards the mouse in the corner. 

Here are some facts about Earth's water that were gleaned from a Google search. 

At any one instant, the Earth's atmosphere contains 37.5 million-billion gallons of water vapor - enough to cover the entire surface of the planet with 1 inch of rain if condensed.Feb 5, 2018

The water cycle is all about storing water and moving water on, in, and above the Earth. ... Evaporation and transpiration change liquid water into vapor, which ascends into the atmosphere due to rising air currents.

Heat from the Sun causes water to evaporate from the surface of lakes and oceans. This turns the liquid water into water vapor in the atmosphere. Plants, too, help water get into the atmosphere through a process called transpiration! ... Water can also get into the atmosphere from snow and ice.

Nearly all of the water is located in the lowest layer of the atmosphere, the troposphere. ... In the atmosphere, water exists as a gas (water vapor from evaporation), as a liquid (droplets of rain and liquid water that coats solid particles), and as a solid (snow and ice).

The amount of water in the atmosphere seems huge but compared to the total level on the Earth is it relatively small. 

The amount of water that can be held in the air as vapour is determined by temperature and its relative humidity, as shown by the chart below which quantisizes the water held by air at 50% RH or 100% RH at different dry bulb temperatures.. 

A more extensive view of the relationship between atmosphere (air) and water can be drawn from a properly prepared Psychrometric Chart such as the one below. Good information once you learn how to navigate it. 

WHAT IS "AIR" ANYWAY?

The following table shows how the composition of Earth's atmosphere breaks down INCLUDING WATER VAPOUR at 2.5% , unlike so called "normal" analyses that ignore water and emphasize carbon dioxide by only looking at the composition of dry air.


OBJECTIVE ANALYSIS IF WATER'S THERMODYNAMIC PROPERTIES.

And, from the Engineering Toolbox, here is an extensive list of the thermodynamic properties of water:

ABSORPTION OF ELECTROMAGNETIC ENERGY BY WATER VAPOR.

Infra red Absorption? - here is the spectrum of electromagnetic radiation received and emitted by the Earth, along with the absorption spectrums for various gases, especially water. Notice the broad range of wavelengths that water is capable of absorbing, especially compared to rather narrow wavelengths that C02 is limited to. Water shows SIGNIFICANT absorption capability across the entire spectrum compared to all the other gases. The closest gases are oxygen and ozone (which operate on incoming UV light preventing it from getting to ground surface) and carbon dioxide which has small absorption bands which are even overlapped by water. All in all, WATER RULES!

HOW TO READ THE ABOVE CHART - The red spectrum curve shows incoming radiation from the Sun. It can be seen that ozone and scattering filter out a goodly portion of the dangerous short wave UV radiation, leaving visible wavelengths and infrared waves to penetrate down to Earth's surface. The downward "spikes" in the red spectrum show where water vapour and to a lesser extent carbon dioxide are absorbing wave energy and keeping them from getting to Earth's surface. This works until about 2 um. where absorption of incoming rays basically ends.

The blue curve shows the situation when Earth sends heat back out to the atmosphere via IR long wave radiation. Water vapor predominates the absorption of these wavelengths right from the 2 um start point to the 25um end point for IR. Carbon dioxide absorption around 15 um is overlapped by water vapor and accentuates the absorption at this point. The "window" in water absorption corresponds nicely with the blue outgoing unabsorbed radiation from the Earth. Conclusion - C02 has some minor effect around 15 um but really it is water that is the dominant gas absorbing both incoming IR and outgoing long wave IR. Water rules!


SO, HOW DOES WATER COOL THE EARTH AND WARM THE ATMOSPHERE - MECHANISMS:

Consider the following actions of water:

1. Evaporation - It takes a lot of heat to get water out of its liquid state and into its vapour state. Starting as ice we require 144 BTU to melt it, 180 BTU to get it 100 deg. C, 970 BTU to convert the liquid to vapour, and .5 BTU / lb. for each degree Celsius the vapour warms up. Evaporation plays a large part in overall heat removal.

2. The vapour is presented in air as relative humidity  (see graph above). It holds heat and doesn't readily give it up resulting in a warming overall of the lower atmosphere near the surface. High relative humidities hold a lot of heat and are felt in tropical areas at night as a somewhat oppressive humid blanket that can be uncomfortable to sleep in. This heat will eventually be lost to the rest of the atmosphere or even returned to Earth as morning dew, but the net effect is delay and holding of heat and then slow movement up and away.

3. The vapour rises because of its kinetic energy and also absorbs more heat coming up from the Earth as infrared electromagnetic waves. It transfers this heat to surrounding air molecules and, en masse, the all rise through thermodynamic convection (ie. thermals) to the outer levels of the troposphere.

4. As this gas mass rises, the drop in pressure induces adiabatic cooling resulting in a temperature drop shown in the chart at the beginning of this blob. This cooling effect has little effect on the phase of the "true gases" such as nitrogen, oxygen and carbon dioxide but it has a dramatic effect on water vapour.

5. Cooling causes the water vapour to lose the heat holding it in air as a true gas and instead to convert itself back to liquid form as water droplets or clouds. This massive condensation is accompanied by a massive loss of heat to the outer atmosphere as infrared radiation. The condensed water continues this heat loss as the water itself cools down towards 0 degrees Celsius where it may actually freeze and give up yet more heat. 

6. Aerosols such as clouds then have a secondary effect on Earth cooling. The water absorbs and also reflects heat coming in as short wave electromagnetic radiation from the Sun. This "albedo" effect sends much of the Sun's radiation straight back out to outer space, reducing the amount that penetrates and reaches Earth's surfaces. 

7. Thermostatic actions - the hotter the Earth gets, the more water it evaporates and the rate of cooling is increased. The higher water content forms more clouds that reflect more incoming heat energy resulting in less radiation reaching the Earth's surface. The whole effect is to counteract warming (and cooling) forces to maintain a constant temperature of Earth's atmospheric blanket and therefore of it's surface.