Global warming; in from the cold.
- Nov 12, 2018 1:15 am GMT
- 4698 views
A black body is an academic construct that says an object at a uniform temperature absorbing all radiation falling on it at all wavelengths has a characteristic frequency that depends on its temperature.
Such a body is incapable of doing work.
Fortunately, the Earth isn’t a black box. It is blue, green, brown, gray, transparent and white with the thermal implication of each wavelength. Rather than having a uniform temperature, it is a thermal onion ranging in temperature from 6000 °C at its core to -55 °C at the top of the troposphere and from these layers we can extract all the energy we will ever need. Particularly when guided by the mathematical maxim that a straight line is the shortest distance between two points.
The effective temperature of an idealized Earth is -18 °C without its atmosphere. With it the average surface temperature is currently about 15 °C; 5 °C cooler than the accepted indoor summertime standard for North American homes and businesses and 7 °C cooler than the winter standard of 22 °C.
Most of us use the terms global warming and climate change interchangeably but NASA defines “global warming” as: the upward temperature trend across the entire planet since the early 20th century, and most notably since the late 1970s, due to the increase in fossil fuel emissions since the industrial revolution.
Worldwide since 1880, the average surface temperature has gone up by about 0.8 °C relative to the mid-20th-century baseline (of 1951-1980).
In the alternative “climate change” is the broad range of global phenomena created predominantly by burning fossil fuels, which add heat-trapping gases to Earth’s atmosphere including the increased temperatures ascribed to global warming, but also the changes like sea level rise; ice mass loss; the shifting of plant, animal and fish habitats; and extreme weather events.
The study, Quantification of ocean heat uptake from changes in atmospheric O2 and CO2 composition released recently says the oceans have absorbed 60 percent more heat per year than had been previously thought, 13 zettajoules, which equates to 412 terawatts or the amount of energy that would be used by every person on the planet leaving 543 (100-Watt) light bulbs on continuously.
This is equivalent to a radiative forcing of 0.79 Watts per square meter.
The oceans are a better gauge of global warming trends than the atmosphere, which warms and cools more erratically, and accordingly, the oceans can be a more reliable and constant source of renewable energy.
Commenting on the study, Dr. Kevin Trenberth of the University Corporation for Atmospheric Research, said, some ocean heat stays in the upper layer of the oceans, making it the heat that comes back to haunt us. We experience the ocean heat when it powers stronger hurricanes, melts ice shelves, raises sea levels and helps fuel El Nino.
Warm is a subjective adjective. It is typically associated with comfort.
Worldwide warming of about 1.2 °C is making much of the planet anything but comfortable.
The use of tools and the harnessing of energy is what sets us apart as a species. Both were accelerated by the Industrial Revolution that saw a massive growth in the consumption of fossil fuels that in turn has engendered environmental consequences that we have yet to be motivated enough to come to grips with.
To make ourselves comfortable, light our homes and convey us from place to place we have learned to rely on heat engines like the one shown in following schematic of the second law of thermodynamics.
They convert heat or thermal energy, and chemical energy to mechanical energy that can be used to do work by bringing a working substance, typically in nature water, from a higher state temperature to a lower temperature.
The yellow circle in the schematic is the heat engine. The upper rectangle is an evaporator. The trapezoid is a turbine. The lower rectangle is a condenser and the small circle is a pump. The workflow shown by the small arrows shows a vapor heated in the evaporator, flowing through the turbine to produce work, the large arrow, the spent vapor then flows through the condenser and then a to a pump that moves the condensed fluid back into the evaporator.
The circular offshoot of the work arrow is the work required to drive the pump and to move the fluid and vapor through the heat exchangers.
Heat sources, cold sinks, and heat engines come in various configurations and by studying these and their natural analogies we can devise tools that can maximize the natural energy potential of the planet and shift its effective temperature and greenhouse gas concentration back to preindustrial levels.
The following two schematics represent the horizontal movement of heat through the atmosphere from the equator to the pole and the vertical movement of heat from the surface to the tropopause. The headers show the distance between the hot source and the heat sink; the assumed speed of the wind using a Beaufort number of 6 for a strong breeze for the horizontal velocity and 12 for a hurricane for the vertical velocity; the time in hours for the heat to move from the hot source to the heat sink at the assumed velocity; and whether or not the movement of heat results in the melting of polar ice, which is assumed to be a detrimental to the environment.
As with all straight lines, the shorter the distance between the hot source and the cold sink the more effective is the conversion of the heat to work.
As the following representation from NOAA indicates the natural movement of heat through the atmosphere from the equator to the pole is a convoluted, circular, and downhill path. The (blue arrows) represent wind cells that are heat engines in their own right that produce winds and evaporate water while dissipating and moving heat from the equator to the pole.
The height of the tropopause is proportional to the mean tropospheric temperature, which drops about 6.5° C with each 1-kilometer increase in altitude. Large hurricanes can rise to a height of 15 kilometers and require surface temperatures between 26.5 to 30 °C to form, while the average temperature of tropical waters is about 20 °C. The ideal summer room temperature.
The top of the tropopause is only about 3 kilometers above the surface of the North Pole, which has an average summertime temperature of only 0 °C.
The maximum amount of work done by any natural event is the hurricane that can release as much as 600 terawatts of heat in a single storm. About two thirds as much energy as is being released into the oceans annually by global warming.
Virtually all the heat of a hurricane is used to evaporate water, which then falls backs as rain, with only about 1.5 terawatts of the total energy being dissipated as wind.
Neither the rain nor the wind of hurricanes be readily converted to useful work.
The 2015 analysis of by Perez and Perez below, shows that solar and wind energy is the greatest renewable sources available, without commenting on the well-documented intermittence, cost, efficiency, storage expense, production pollution, wildlife impact and use of space problems associated with these sources. Plus, the fact that land masses represent only 30% of the Earth’s surface and terrestrial heat engines can’t draw down the 93% of the global warming heat accumulating in the oceans, which leads to sea level rise, the greatest climate risk of them all.
The following two schematics represent the horizontal movement of heat through the ocean. West to east under the influence of the Coriolis effect and from the surface to a depth of 1000 meters with OTEC heat pipes. The headers show the distance between the hot source and the heat sink; assuming the ocean current is the North and South Equatorial current that travels at a speed of 0.03 to 0.06 m/s and the speed of the vapor in the heat pipe is about half the 75 meters per second used by Prueitt in his 2007 patent application; the time in hours for the heat to move from the hot source to the heat sink at the assumed velocity; and if the movement of heat results in the melting of polar ice.
The vertical orientation of the heat source and cold sink is the only one that doesn’t use water as a working fluid. Ideally, this would be anhydrous ammonia or carbon dioxide. It is also the only cycle where heat flows counter to the thermohaline circulation and acts as an air conditioner for the surface thus reduces sea level rise because the coefficient expansion of seawater is half at the surface it is at a depth of 1000 meters.
Although the west/east model suggests heat should move from the west to the east, as the following triptych demonstrates, under normal conditions, heat accumulates in the west due to the Walker Circulation over the Pacific and to a lesser extent the Atlantic, while over the Indian Ocean the circulation is in the opposite direction.
The circulation (blue arrows) within the thermocline is a perpendicular, mirror, image of the atmospheric circulation of the Hadley cell shown above.
Essentially, the power of the wind trumps the ocean current.
As above, under normal and La Niña conditions, when strong Trade Winds blow clouds off the ocean and over the land, the Pacific loads up on heat as the thermocline thickness to the west and shrinks in the east, but during El Niños the reverse occurs as some of the heat built up under normal conditions dissipates into the atmosphere.
Essentially, the ocean above the thermocline acts as a shallow pan of water that sloshes heat from one side of the ocean back to the other.
As the following NOAA graphic, representing the temperature gradient across 10,000 kilometers of the Pacific Ocean at the equator for the month of January1994, a moderate El Niño year, demonstrates, a significant portion of the Pacific is much warmer than the average tropical surface temperature, and the difference above 20 °C is the heat that is available to heat and light our homes and offices, power our industries and to convey us and our cargo anywhere on the planet and eventually beyond.
As the following cyclone map, which correlates to sea surface temperature, shows, the warmest regions shift with the seasons back and forth between the hemispheres and across oceans.
Metrics like the effective temperature of the Earth and radiative forcing measured in watts per square meter tell us nothing about how to produce energy or how to mitigate the climate.
To do these things we have to learn how to utilize heat differentials and how to move the accumulated heat of global warming to the nearest available heat sink as rapidly as possible and to keep it down there for as long as possible.
The triangular energy island 735 meters on a side shown below, can gather 1.6 billion watts of heat a year from the ocean’s surface and in turn and convert that heat to 250 Megawatts of OTEC, wind, solar and wave power a year.
This configuration facilitates the movement of these islands from one ocean heat spot to the next, where they can graze on the heat of global warming.
Mated to systems that electrochemically convert electricity to hydrogen and sand, made of cement, these islands can be self-replicating and self-regenerating.
The 2001 study, Estimates of Meridional Atmosphere and Ocean Heat Transports by Trenberth and Caron shows that the atmosphere handles 78% of the total heat transport of the planet, totalling 5 petawatts in the Northern Hemisphere and 92% in the Southern Hemisphere leaving the oceans with only 15% of this transfer, which occurs only in the tropics between 0 and 17 degrees north.
The following NOAA map shows the latest estimate of how the heat of warming is spreading through the deep oceans.
The deep tropical Atlantic is cooling and the deep Pacific Ocean is experiencing little warming impact and therefore this is where the heat of warming needs to be relocated.
Such relocation would be simply a leveling of the heat load between the atmosphere and the oceans, which is occurring anyway. And is the most beneficial use of planetary heating.
The following graphic shows how this would be accomplished, by moving the heat of global warming below the thermocline, where it takes 250 years to return and can be recycled the same way atmospheric heat is cycled in the Hadley cell shown above.
Never foul your own nest, is an admonition we have collectively been loath to heed.
As a prime example, Alberta’s fossil fuel industry regulator recently estimated the cost of cleaning up aging and inactive oil and gas exploration wells, facilities, pipelines and tailings ponds in the province could cost $260 billion — or $200 billion greater than the previous public estimate.
Politicians and industry claim this is an exaggeration because supposedly these costs can and will will be paid out of future earnings.
Fat chance. Thousands of existing abandoned wells already pockmark the province and an accumulated debt of $96 billion by the 2023-24 fiscal year tells the real story.
"If you find yourself in a hole, stop digging”, Will Rogers.
If you are getting killed in the energy sector, the smart move is to start using the resource Nature provides.
Instead of letting global warming haunt us, we need to use new tools that harness the heat of global warming the same way our ancestors have used tools and harnessed energy for 200,000 years.
By thinking about the energy and the climate in new ways we just might be able to survive for another 200,000 years.
Now that is something worth thinking about.