Oxfordreference advises that; “The black body temperature of the Earth is -23°C, but the actual surface temperature is about 15°C. The difference (38°C) being the amount by which the planet is warmed by the absorption of radiation within its atmosphere by the natural greenhouse effect.
Since few of us would survive sustained temperatures of -23oC, an appropriate level of greenhouse gases are vital for a sustainable environment.
NOAA however, shows that temperature records from the late 1800s early 1900s indicate temperatures were up to 3°C cooler than the twentieth-century average and James Hansen predicts that global heating will pass a sustained 1.5oC threshold this year.
Ninety-three percent of the heat of global warming is going into the oceans.
The 2019 Resplandy et al. paper Quantification of ocean heat uptake from changes in atmospheric O2 and CO2 composition estimated the oceans gained the equivalent of 409 terawatts of heat, about 20 times our annual primary energy consumption, each year between 1991 and 2016. And a joint NASA, NOAA study found the Earth’s energy imbalance doubled over the course of the 14 year period between 2005 to 2019, which James Hansen in his paper Global warming in the pipeline concluded was in large part due to a decline in aerosols, largely in China due to reduced air pollution and from legislated restrictions on ship emissions since 2010.
Heat accumulates in the tropics and dissipates at the poles. But near the equator, the oceans are becoming increasingly thermally stratifying, with lighter water near the surface and denser water at greater depth, which is a barrier to the efficient mixing of heat, carbon, nutrients, and the oxygen vital to life.
Global ocean oxygen reserves have declined by 2% over 50-years.
In the paper Negative-CO2-emissions ocean thermal energy conversion Greg Rau and I demonstrated that a thermally stratified ocean lends itself to the conversion of a portion of the heat of global warming to work in accordance with the laws of thermodynamics and to the movement, through heat pipes, of surface heat to deep water where it is no longer any kind of environmental threat.
Whereas Resplandy quantified ocean heat at about 409 terawatts, and the more current paper, Another Record: Ocean Warming Continues through 2021 despite La Niña Conditions put this at about 420 terawatts, our paper demonstrated that 7.6% of this heat can be converted to work. Which would amount to 32 terawatts or about 220% more than we are currently deriving from fossil fuels. And the 388 terawatts not converted by this process is sent to a depth of 1000 at a speed approaching that of sound, from where it returns by of diffusion at a rate of 1 centimeter a day through the deepest water and 1 meter a day through the mixed layer, the upper most 100 meters in about 226 years. At which time that heat can be recycled to produce more energy, in total 13 times, until the total heat of warming has been converted and the waste heat of those conversions has been dissipated to space.
The cost of the production of this energy ranges between $2 and 3 trillion a year depending upon whether the energy is used to produce an energy carrier like hydrogen to bring the power to shore or electricity that can produce value-added products and services produced at sea. Which must be measured against the $5 to 6 trillion we are currently paying for fossil fuels annually, for less than half as much energy, plus the $7 trillion the IMF says is the environmental cost of doing burning fossil fuels.
Since we are currently paying close to 4 times more for energy than as is necessary, it is little wonder we have an inflation problem and consequent political unrest. Which would be exacerbated by extensive carbon dioxide removal approaches that will make energy that much more expensive and dearer.
In the Rau/Baird paper, we demonstrated one gigawatt of negative-emissions OTEC (NEOTEC), would provide roughly 13 gigawatts of surface ocean cooling heat, while producing 1.3 × 105 tonnes of hydrogen a year (avoiding 1.1 × 106 tonnes of CO2 emissions/yr), and consuming and storing (as dissolved mineral bicarbonate) approximately 5 × 106 tonnes CO2/yr. Which would result in an indirect planetary cooling effect of about 2.6 gigawatts.
Whereas cooling the surface alone would sequester about 4.3 gigatonnes, at no added cost, 32 terawatts of NEOTEC, could potentially sequester 155 gigatonnes of CO2/yr at a cost of $53 trillion a year over the course of 7 years (at total of $370 trillion) for the carbon dioxide removal alone.
As the following graphic shows, atmospheric CO2 levels have been increasing at a rate of about 2 parts per million a year but 55% of those emissions are absorbed by the oceans and land, so to return to the preindustrial level of 280 ppm we could have to remove 2422 gigatonnes of CO2 from the atmosphere.
Since the CDR removal cost for a system like NEOTEC is ≈ $154 a ton, the total cost of this capture would be $370 trillion.
Since NEOTEC plants have a shelf life of about 30 years, at full capacity they would sequester more like all the CO2 in the atmosphere with a surface temperature of -23°C soon to follow.
The point being it is in our power to cool the surface with technology that produces copious amounts of energy at less cost than we are currently paying without paying more for carbon dioxide removal while mitigating every consequence of global warming. Which put to a referendum, I dare say, most citizens would be eager to vote for.
Economists claim the solution to climate change is putting a price on carbon, but the science tells us otherwise. And it also tells us that nuclear power and fusion as is the climate and energy flavor of the month for some politicians and special interests, could boil the oceans in as little as 400 years.