One hundred fourteen nations
committed to limiting the global average temperature increase to no more than 2
degrees Celsius above pre-industrial levels.
Copenhagen Accord also includes a reference to considering limiting the
increase to below 1.5 degrees, as demanded by vulnerable developing countries.
It is anticipated by the end
of this year the average global temperature will have risen half way towards the
2 degree limit and two thirds of the way to 1.5 degrees.
Prior to 1998 global temperatures were increasing at a rate of about 0.21
degrees each decade. From 1998 to 2012 however the observed decadal rate of
warming was just
0.04 degrees. This slowdown or “hiatus” has been attributed to the movement
of heat to deeper water in the eastern Pacific Ocean as a consequence of
stronger than normal trade winds.
Were we capable of perpetuating the
hiatus rate of temperature increase, as in fact we can, or even better it, 1.5
degrees, or better, is achievable.
The trade winds stacked warm water
in the eastern Pacific driving the thermocline down to a depth of about 300
meters. Once these winds subsided however, in 2013, this stacked water sloshed
back to the west and to the surface with the result 2014 and 2015 have
successively been the warmest years ever recorded.
| Hiatus Thermocline
During the hiatus the vast
majority of this heat was never mixed nor was it diluted by the by the enormous
heat sink of the ocean abyss that exists below the thermocline.
The oceans are the repository of 93
percent of the heat of global warming. Since warm water rises, most of this heat
sits near the surface of the ocean while the temperature at depth approaches
water’s freezing point. This differential makes the oceans, particularly
tropical waters, the largest battery on the planet. When heat flows from a warm
source to a cold sink through a heat engine, just as when electrons flow from
the negative to positive terminal of a battery, energy is produced.
It is estimated the oceans have the
potential to produce
14 terawatts of primary energy through ocean thermal energy conversion or
OTEC, or about the same amount of energy as is currently derived from fossil
NOAA estimates the ocean battery is being charged at a rate of about 330
terawatts each year and since there is no draw down of this inexorably
increasing charge we are experiencing the escalating consequences of global
Due to the low thermodynamic
efficiency of a heat engine operating within the temperature range of the oceans
OTEC requires the movement of about 20 times more heat to the deep than the14
terawatts of power the oceans are capable of producing.
In other words, virtually all of the
heat the ocean battery is accumulating is either converted to work or benignly
moved to deep water.
In support of this premise, in the
late 1970s a team from the Applied Physics Laboratory of
Johns Hopkins University estimated that the surface water temperature of the
oceans, and therefore the lower atmosphere as well, would be reduced by 1C each
decade through the production of 5 terrawatts of OTEC power.
The relocation of this heat to the
deep would be benign due to the large thermal capacity of water. It is
estimated that in spite of all the heat they are absorbing, at depths from
500 to 2000 meters, the oceans are warming by about .002 degrees Celsius every
year, and in the top 500 meters, they’re gaining .005 degrees C.
The benefit of this heat
absorption is noted by
Levitus, who points out that if all of the heat the oceans absorbed to a
depth of 2000 meters from 1955–2008, which raised their temperature by an
average .09 degrees Celsius, was instantly added to the lower 10 kilometers of
the atmosphere that layer would be warmed 36 degrees Celsius.
It is obvious therefore that the
objective of Copenhagen is well within reach provided we produce the energy the
world demands with the right technology.
heat pipe design overcomes
the cost and environmental concerns of conventional OTEC designs and moves heat
through the phase changes of a low boiling point working fluid, to a depth of
1000 meters. From there it would take 250 years, at a return rate of 4 meters
annually, to reemerge and by that time carbon dioxide concentrations in the
atmosphere will have declined due to the replacement of fossil fuels with zero
emissions energy and these concentrations can further be reduced significantly
electrolysis process that produces hydrogen as an energy carrier for
mid-ocean derived power.
Full capacity OTEC -14 terawatts -
could sequester about 79 billion metric tons of carbon dioxide each year.
That amount of power would also
produce 1.8 trillion kilograms of hydrogen through the electrolysis of 16
trillion kilograms of water and when reconstituted on land through the
production of energy in a fuel cell or by burning in an engine the byproduct
would be 600 gallons of water for every person on the planet.
model estimates the social cost of anthropogenic greenhouse gas emissions at
$326 trillion by 2200.
A new University of Cambridge
that melting permafrost will release sufficient carbon dioxide and methane to
increase that cost by an additional $43 trillion.
The technology that slows or
reverses global warming can not only prevent these losses, it can generate
trillions of dollars in revenue for the providers of the technology.
We can't afford not to keep warming