Global Temperatures and Incomplete Rationale of My Own Skepticism
Posted by Jeff Id on April 5, 2011
Ok I admit it! Apparenlty I can’t quit blogging completely, but doing software calculations is way beyond the scope of my time abilities. There is a detail which may interest some here that has too little discussion in the ‘climate wars’ . It’s a matter of reason, again which doesn’t disprove AGW but which seems to me should be cause for pause in the alarmist message.
Heat capacity of ocean water: 3993 J/kg/K
Heat capacity of air: 1005 J/kg/K
This is the number of Joules (energy) to raise temperature 1 degree Kelvin which is the same as 1 degree Celcius. Energy cannot be created or destroyed to my knowledge so these are physically knowable values. Since they are in kilograms, we only need to look at kilograms atmosphere vs kilograms of ocean to make the following graphs.
From Wikipedia - The atmosphere has a mass of about 5×1018 kg
So multiplying out, the energy content of the atmosphere is – 1005 *5×1018 kg =5 x1021 Joules/Degree Kelvin
Energy content of the ocean is – 3993 *1.4×1021 =5.6×1024 Joules/Degree Kelvin
So we know increasing CO2 captures more heat in the lower atmosphere and we know that this heat is claimed to be the cause of global warming. Where everything gets real fuzzy is when the energy content of the ocean is taken into consideration. Models do use the ocean heat content, but in order to demonstrate warming, only the energy of the surface ocean layers can be considered. Of course there are layers and layers (pun intended) of papers that discuss the issues, but in reality very little is actually ‘known’.
Why is it important that climate models only look at surface layers? Because subsurface ocean temps exhibit little variance and even with the worst IPCC scenario’s would exhibit little variance from AGW. It is assumed that all ‘significant’ heat comes and goes from the ocean surface. I wonder though if anyone would be able to demonstrate a tenth of a degree change in the deep ocean over the last 100 years? The answer again is we don’t know if it did, but we do know that a 0.1C release of oceanic subsurface energy would measurably change the surface temperature of the earth in that time period. All that would be required would be ocean current changes but we really don’t have a clue if deep ocean current’s have changed. CO2 atmospheric temp change depends on the assumption of stability 0f heat flow from the deeper oceans. I’m not going to spend a lot of time on this but in case you wonder why many of us are skeptics of catastrophic global warming:
So when they show you the scary graphs of UHI contaminated surface temperature as compiled by Zeke, including graphs from myself using what I believe are superior anomaly combination methods developed by Roman M:
Remember, they/we are showing you the increase in atmospheric energy of the near zero thickness PANCAKE on the left side of Figure 1, the huge energy column on the right is not included in air temperature graphs of Fig 2 or on the left side of Fig 1. When you see the reconstructions of global temperature including ocean surface temps, the energy pancake on the left isn’t much thicker.
If you were to transfer enough ocean energy directly to the atmosphere to create 4 degrees of atmospheric warming, how much would that change the average temperature of the Earth’s water?
Would you believe — 0.001 Degrees C of ocean temp change? The left side pancake wouldn’t look any different in Fig 1! Hell, it wouldn’t change if we were in another oceanic current inspired ice age — think about that.
It’s just math folks. The ocean contains so much energy that a thousandth of a degree change can throw 1C into our air temp instantaneously. Unfortunately the discussion is more complex than this because we need then to look at what happens to the release of that heat to space. The real balance is about energy flow vs content rather than instantaneous heat, but realistically tenths of a degree C of atmospheric warming over 30 years are absolutely NOT proof of CO2 global warming doom.
Of course climate models take all of this into account. They also take Hadley cells and cloud formation into account. They take convection, conduction, evaporation, precipitation etc. all into account. The whole exercise is layers of guesses and estimations. Some with less scientific honesty than others but before chucking them all to the wind, some of these people are good people and even good scientists.
I’ve spent enough time on this today, but continued overconfidence in the meaning of UHI contaminated surface temperatures IS one of the main reasons I’m a skeptic of catastrophic global warming. Every time you see a plot of surface temperatures, we should shoulder shrug and ask – what about total oceanic energy.