Glenn Tamblyn left a reasonable sounding comment on the previous thread in reply to my comment that I find oceans to be very dangerous to human life in general. My point is that oceans are very cold and very large heat sinks and that makes them powerful moderators of temperature. Earth normally exists in an ice age, and we are lucky to be born in this particular time of warmth and comfort. Of all natural disasters that WILL befall Earth, the coming ice age is the one I worry about most. As I wrote, Glenn’s reply sounds like it is reasonable and I think it represents how much of the AGW concerned population thinks.
I’ve copied his comment below and will attempt to present my side of the argument after that. Hopefully, some will find it interesting.
“the real monster we should be worried about is that giant body of extremely cold water that dominates our planet”
Let me put some context to that comment.
Human energy consumption is at a rate of around 17 trillion watts.
Total geothermal energy flows from within the earth at around 44 trillion watts.
Total energy accumulation in the oceans, measured by the ARGO system, is currently at around 250 trillion watts.
Total energy arriving from the Sun, after allowing for albedo is around 121,826 trillion watts.
If the energy from the sun could not be radiated out to space and all instead remained and accumulated here then result would be enough to:
– Boil Sydney Harbour dry in 12 seconds.
– Boil the oceans away in around 900 years
– Melt the entire Earth’s crust in 5,000 to 10,000 years.
Obviously that energy can escape to space. But there is still a restriction on that flow in the form of the GH effect. So I would have though that anything that involves adjusting the control valve regulating that outflow is something we would want to be very conservative about.
That 250 trillion watts accumulating in the oceans, obviously isn’t coming from anywhere here on earth; there is no energy source big enough to supply it.
And the world hasn’t stopped warming. There is still at least 250 trillion watts worth of warming. And if all that energy that is currently going into the oceans had all gone into the air instead, air temperatures would be rising at 15 C/decade. If the Earth were a desert world, with only very, very shallow seas and not huge oceans there would be absolutely no question mark about the impact of CO2 – its effect would be blatant and immediate.
Are you really that confident that the oceans are the thing we should be so worried about?
Glenn, science is all about magnitudes as you know, so I need to restate the point that CO2 in the amounts we humans can release can only slow radiation to space by some finite amount, and heat still radiates from Earth at the same rate it comes in at no matter how much CO2 you add. My point is that the oceans are such a large sink of heat that even all those trillions of watts alleged to be received by global warming they are barely detectable with our best instrumentation. We can discuss what would happen to air if the ocean were not there, but the oceans are there, and they are not going anywhere.
Someone left a comment here a couple of weeks ago about the oceans collecting the heat and then releasing it in the future with a vengeance. While Glenn is not making that claim, I want to make the point that once the relatively small amount of heat is distributed into the ocean heat basin, it is functionally permanently lost with respect to atmospheric warming per thermodynamic laws. The only caveat being that the ocean surface has less heat content so so it can warm measurably and is returned to the atmosphere. In thermodynamics, we know that heat only flows from hot to cold and entropy doesn’t allow us to pick only the hot molecules from the ocean so there is no hot water in the oceans waiting to cook us by surprise in the future.
There is no giant ball of heat waiting for us below the surface, in fact, we have the opposite problem. –A giant ball of cold.
I wrote a post on this a long time ago. I did a quick calculation and plot of ocean heat content and atmospheric heat content. I found the ocean had approximately 1000 times the heat capacity of the atmosphere. If we mixed 1 degree of atmospheric warming into the whole of the ocean, it would result in 0.001 degrees of ocean temperature rise.
The only reason we have seen any temperature change on Earth is because the ocean surface warmed a little. In fact, the measured ocean surface makes up most of the measurement in global average temperature. I found this cool plot of ocean temperatures on line:
I’m not sure where the reference is for it but it gives a very nice visual of a typical slice through the ocean. Note the large area of blue-purple indicating the majority of the worlds oceans consist of waters below 5 degrees Celcius. That is really cold water folks and it is a LOT of it. If it were to come to the surface at a faster rate than we have seen, even by a little, the changes to global temperature would be extreme.
This body of water is a huge moderator of our climate and all of the global warming we can imagine isn’t going to warm it up much, because despite Glenn’s scary language, the magnitude of CO2 based warming simply isn’t sufficient. Glenn uses the number 250 trillion watts for total energy accumulation rate. I found the same number at climate progress, a widely known extremist left-wing propaganda outlet that should not be trusted by any thinking person, but we will use it uncritically here. Two hundred fifty trillion is 2.5 x10^14 J/second. If we have a heat capacity of 5.6×10^24 J/K we get 2.24×10^11 seconds until the ocean were warmed one degree. That corresponds to 710 years of heating to increase the ocean volumetric temperature by one degree which is still somewhere around zero C average temperature. In other words, climate progresses unrealistic worst possible case doom scenario’s are not sufficient to significantly affect oceanic heat content.
No I am not claiming the ocean is well mixed but that reservoir is definitely there and only a small change in circulation can bring that monstrous body of energy sinking power those few hundred meters to the surface and eliminate even a thousand years of worst case global warming imagination.
I am claiming though that the oceanic driven cold spell — will happen. We call them ice ages, they are coming again and currently we do not have the power to stop them. The cold is sitting right there off our shores, for anyone to see and measure. It’s not an imagined monster or a projected monster like global warming, it is a real monster, as real as the next big asteroid impact or supervolcano that we all know must come again.
Glenn also writes a hypothetical situation as to what would happen if the Sun’s energy could not be radiated into space. While this leads to some amusing alarmist style talking points, the bottom line is that we would die. That’s it. Nice and simple. Fortunately, our planet remains in a general energy balance that shifts very little over even millions of years of time. This is due to the laws of physics so there is no danger whatsoever that it will suddenly or gradually stop radiating to space – so I hope Glenn and other readers won’t worry about that anymore. :D
To finalize my comments, I would point out to Glenn that climate models have beyond scientific question statistically failed in their projections of temperatures. The sensitivity atmospheric temperature to CO2 from measured data, is therefore much lower than was predicted and that includes the argo data. Alternatively rather than a CO2 sensitivity misjudgement, all that heat that Dr. Trenberth is famously looking for, very well could be sitting in the deep ocean making too little impact over 100 years to actually measure and all it would take is a tiny bit more (or less) oceanic intermixing than models predict for that huge heatsink to be the true source of measured climate change. It could potentiall have overwhelmed the CO2 effect without our knowing. If it were intermixing less on a short term scale, the extra wattage the Argo floats picked up would mean even less of the energy from CO2 than the best observationally based sensitivity calculations indicate. One should not assume uncritically that the energy all came from CO2 based warming. The best evidence we have however shows about the atmosphere increases 1.3 C per doubling of CO2 concentration, and that is very low.
So yes Glenn, I am very sure that with respect to climate, oceans are what we should be concerned about. They are very cold and too large for us to heat up to livable levels by CO2 emissions. So in the future, I hope you won’t concern yourself anymore about harbors boiling, sheep shrinking, extra hurricanes etc.. None of that is real, it is just propaganda which exists in the minds of alarmists.
Ice ages however….are real.
Whether you are liberal or conservative, the economy IS real too and we can all agree that from many examples around the globe, economies have shown a great deal of sensitivity to human meddling. Costs of doing business include taxation, and a wide variety of barriers to operations. It is also really obvious that shutting down coal plants and preventing replacement with functional energy generation is more than a little stupid. We must be more careful in these times of high governmental economic load not commit economic suicide simply out of fear of CO2, which appears to be somewhere between a complete non-issue and an overall benefit to life on Earth. Yet that is exactly what the anti-industrial environmental movement is trying to do.