The True Climate Mechanisms
Changing global temperatures induce air circulation changes as the air seeks to restore the sea surface/surface air temperature equilibrium and at the same time resolve ocean induced variations in the sun to sea / air to space equilibrium.
The circulation changes alter all the processes involved in the rate of energy transfer from surface to space. In so far as the air circulation fails for a time to maintain temperature stability then radiation from surface to space will also change but in due course stabilty is always restored between the four said parameters (sea surface / surface air / sun to sea / air to space).
Only huge catastrophic changes capable of altering the temperature of the whole body of the oceans can set a new global equilibrium in the short term (less than millennia). The sun can also do it gradually but it takes centuries e.g. from Roman Warm Period to Mediaeval Warm Period to Little Ice Age to now. The solar effect is heavily modulated over time by ocean cycles. A change in the composition of the air alone cannot do it.
The role of water vapour combined with the latent heats of evaporation and condensation gives the circulation changes the major part of their ability to accelerate energy transfer from surface to space.
So, the most common and by far the largest forcing at any given time is multi decadal variations in energy emissions from the oceans. In the background are slow century scale changes in solar output.
Temperature changes induced by sun and oceans drive air circulation changes which drive changes in every aspect of climate including convection, conduction, evaporation, condensation, precipitation, windiness, cloudiness, albedo and humidity as regards both quantities and distribution.
Water vapour in itself is not a driver nor does it have cycles or periodicities of it’s own. It’s a very useful contibutor to the whole process though and without it the Earth would be entirely different
Any ocean surface warming is caused by solar energy previously absorbed working it’s way back to the surface.
It is true that warmer and/or more humid air above that water slows down the energy flow from water to air but that has no effect on the temperature of the main body of the oceans.
When the energy flow from water to air slows down there is no overall warming of the oceans. All that happens is that the energy flowing from ocean to air ‘pools’ for a while at the surface. It effectively waits in a ‘queue’ at the surface until the air circulation and weather systems increase their speed of ejection of energy to space and neutralise the warming.
That is what happens when oceans naturally increase their emission of energy and the response of the air is exactly the same whether the warmer ocean surface is a result of enhanced energy emission from the ocean or enhanced energy in the air from another cause such as more humidity or more CO2.
The air has to balance both the energy from ocean to air with energy from air to space AND energy from sun to ocean and energy from air to space over time. Everything we observe is a feature of that interplay.
To deal adequately with any warming of the air from extra CO2 or any other increased GHG the air circulation and weather systems just shift their size and/or positions to adjust the rate of energy emission to space to restore equilibrium.
The equilibrium they work back towards is set by the rate of energy flow from the sun modulated by the rate of energy flow through the oceans.
The air circulation changes ensure that over time the energy radiated to space matches the energy received from the sun despite disruptions in the flow caused by the effects of the ocean cycles or changes in the composition of the air.
The occasional surges of warmth in the stratosphere in winter fit into my scenario. When a large surge of polar air moves equatorward it draws a pulse of energy from the oceans in the lower latitudes and pumps it into the stratosphere where most of that energy is pushed out to space but a portion is not pushed out and descends again thus strengthening the high pressure systems on the poleward side of the mid latitude jets.
Features such as that occur more frequently and are larger when the oceans globally are in net absorption mode (surface cooling) such as now. At such times the poleward air masses are ’stronger’ than the equatorward weather systems. The opposite applies when the oceans are in net emission mode as I describe more fully in my articles.
Everything we see in the air and the oceans is part of that natural energy balancing interaction and human emissions have no part to play other than a very small insignificant human induced shift in positions or intensities of the main high pressure systems. Wholly imperceptible in the face of natural variability.
Published by Stephen Wilde April 12, 2009