A Green New Deal can’t be concocted out of hot air.
Stefan Rahmstorf 2002
- February 9, 2019
- 3637 views
The thermohaline circulation has been described as the planet's great heat engine. It is a pipeline driven by density gradients created by surface heat and freshwater variations that play an essential role in moving heat around the globe and in determining its climate.
Shimokawa and Ozawa considered the question Thermodynamics of the Oceanic General Circulation – Is the Abyssal Circulation a Heat Engine or a Mechanical Pump? and concluded that abyssal circulation (the thermohaline) can be regarded as a heat engine because mechanical work is generated to maintain the circulation. This circulation, however, is slow, about 1000 years to make a complete loop, and the only useful mechanical work it influences is the winds.
An isometric view of this circulation was produced by Lynne d. Talley in relation to Antarctica, in the article Closure of the Global Overturning Circulation Through the Indian, Pacific, and Southern Oceans, which unfortunately changes the color scheme of the water compared to the Rahmstorf figure, which is the color scheme used throughout the balance of this article.
Trenberth and Caron in Estimates of Meridional Atmosphere and Ocean Heat estimate the total heat flux transported by the Earth's atmosphere and oceans away from the equator towards the poles is 5 petawatts (5*1015 watts) with about 2 petawatts attributed to the oceans where 93 percent of the heat of warming is accumulating.
The current energy imbalance of the planet attributed to global warming is 0.38 petawatts at this time or about 17 percent of the total heat transported through the oceans each year.
The Earth’s energy imbalance is measured in watts per square meter which muddles the issue because the bulk of the heat accumulating on the surface arrives 23.5 degrees either side of the equator between the Tropic of Cancer and the Tropic of Capricorn per the following section of the global map.
And this heat is further distributed unevenly per the following section of the global heat map where the heat is shown from yellow to red according to its intensity.
The following is a sectioning of the Rahmstorf thermohaline map in the same proportions as Figures 3 and 4.
The following is a representation of 5 petawatts of heat moving away from the equator towards the poles.
And the following is a top view of a 3D model of the section represented by Figure 5.
Whereas the thermohaline, in particular, the red line representing the surface flow in Figure 2, is a narrow channel, the thermocline is spread across this area more like the heat in Figure 4 as represented by the array of smaller red lines in Figure 7.
An Isometric view of the 3D model is shown in Figure 8 and shows how the thermocline thickens from east to west in the Atlantic and the Pacific and reverses in the Indian Ocean. In all cases because of the prevailing winds that mix the surface waters and thicken the thermocline as represented by the red circles.
This mixing moves heat to a maximum depth of about 250 meters in the Eastern Pacific per Figure 9.
Figure 10 on the other hand shows how surface heat can be moved below the thermocline by heat pipes (orange) 1000 meters long, into anthropogenic heat engines (yellow), and returns by diffusion as represented by the pink cylinders to the surface where the residual heat not converted in the heat pipes is recycled (purple bars).
These heat engines can convert about 7.6 percent of the 0.38 petawatts of warming to primary energy while reducing surface heat, ocean acidity, sea level rise and storm surge none of which is accomplished by any other form of energy.
Although these systems are scaled correctly spatially, there is a time component to these cycles as is adjusted below.
Heat is removed from the surface at a rate of 75 meters/sec by the heat pipe and unconverted heat diffuses away from the heat engine back to the surface at a rate of 4 meters/year because these cycles are a microcosm of and become embedded in the thermohaline circulation that takes around 1000 years to complete a cycle.
Figure 12 is a side view of the heat pipes that convert the heat of warming to mechanical energy and shows how much deeper these are than the thermocline and their relationship to the surface.
Figure 13 shows an isometric view of the bottom showing how the heat moved to deep water would have very little influence on the thermohaline circulation.
By far most of the heat of warming would be isolated in this box the same way as the 7 percent of the warming that is accumulated in the atmosphere, in ice, and in the land is trapped by greenhouse gases that would be reduced by the replacement of fossil fuels with this renewable energy.
Figure 14 shows how these systems remove heat from the rest of the surface to service the heat pipes and to replace the heat migrated out of the region by the thermocline water of the thermohaline circulation.
They are the inverse of Figure 6.
There is a quantum aspect to these systems in that starting with an initial 0.38 petawatts of warming we derive 3,250 years’ worth of energy at a rate of 29 terawatts a year even as the .38 petawatts is degraded and is constantly moved out of the region and is replaced by new solar energy that is circulated by the thermohaline.
In a recent CNBC article about the “New Green Deal” Daniel Finn-Foley, senior energy storage analyst at Wood Mackenzie Power and Renewables is quoted as saying, "There is no solution for 100 percent renewable that doesn't require massive amounts of storage."
This is simply untrue. Global warming is 100 percent renewable, already stored and recyclable energy.
If you want a New Green Deal, you best not try to concocted it out of hot air.