If the earth had no water, the earth's surface would be about 151F. With water; oceans, the earth currently averages about 59F. Water moderates the temperature and climate of the earth. How does manmade climate change take into account this most important variable in terms of global temperature and climate.? We have water hurricanes and not CO2 hurricanes within the earth's climate. Man made climate change should be called man made-up climate change, since water is the top dog, yet CO2 is trumping water in that mythology.
A simple way to compare water and CO2, is to look at heat capacity, which is defined as the amount heat needed to raise a material 1 degree. The higher the heat capacity, the more heat the material can store, before its temperature rises. Water has an unusually high heat capacity, which is why the earth is not 151 degrees but more like 59F. Water can store lots of heat without the temperature having to increase very much. If the solar heat was analogous to a hose, water is like a large swimming pool, where the water rises very slow. CO2 is more like a narrow tank that the hose can fill, vertically, much faster.
Water is unique on earth in that water exists in three phases on earth at the same time; ice, water and vapor. Typically the order of heat capacity, for materials, is the solid state is highest, then the liquid state, and then the vapor state. CO2 only exists in the vapor form, and has about 1/10 the heat capacity of the liquid water in the oceans; skinny tank versus the swimming pool. The even high heat capacity of the polar ice, compared to the oceans, could partially explain why it is not melting on schedule; even bigger pool.
If you plot the heat capacity of water as a function of temperature, it is not a flat sloped curve like CO2 and most other materials, where heat capacity increases with temperature. The hydrogen bonding of water, which gives water its's usually high heat capacity, also creates an anomalous heat capacity curve, where the heat capacity of water decreases with temperature and reaches a minimum at 104 F, then it increases again. This odd shape minimum curve has global climate implications.
In terms of CO2 and its typical heat capacity curve, since the upper atmosphere is colder, CO2 has less heat capacity the farther its gets away from the surface. The thermal insulation value of CO2 decreases, as its heat capacity decreases with distance from the surface. Lab experiments will measure higher heat capacity at STP, than in real life applications in the upper atmosphere. I hope they made the adjustment.
The reason this is important can be explained with a real life heat capacity analogy we encounter each summer. If you have even gone to the beach, in the summer, the dry sand will be very hot, while the wet sand will be cool, even though both have the same sun. This has to do with the differences in heat capacity of the water; higher, versus the sand; lower.
Heat capacity is also a measure of how well a material can redistribute heat, with higher heat capacity able to spread the heat faster, so temperature rises much slower at the main heat transfer surface. The dry sand, due to its lower heat capacity, cannot redistribute the heat very fast, so the sun heats surface material very fast, and the surface temperature rises faster; gets hot. The CO2 as it lower temperature as it rise heat up faster and radiates more heat into space.
The unusual heat capacity curve of water, allows the earth's mantle to impact global climate. Heat from the mantle, through crustal boundaries and tectonic plate movement; volcanoes, add heat to the ocean floor; thermal vents. The crust is not as thick under the deep ocean, as on land, so mantle heat can escape easier. Water is continuous from oceans into the mantle.
Since the heat capacity of water increases with temperate, after the minimum at 104F, a 1 degree temperature drop of 200F mantle water, can heat say, 104F water, more than 1 degree, since at 104F heat capacity is minimized; sand effect. The impact is a radiant heat boost maximum that allows the bottom to heat the water faster, in terms of temperature, with the same heat.
The top of the oceans, will see the heat capacity of water lowering, from cold ocean surface temperature, all the way to heating tropical heating to say 104F, with the same amount of heat, making the temperature rise faster, as we get closer to 104F; beach sand effect. The oceans slowly warm in the early summer and then get warmer faster.
The human body, at 98.6F, is designed by nature to be close to the minimum heat capacity of water; sweet spot. Tolerances are tight, with a 104F fever, at the heat capacity minimum of water, getting very close to upsetting the entire physiological equilibrium of the human body. Water regulates the human body and the earth's body.