This is the paper I submitted for the Virgin Earth Challenge in early 2007. I got a letter recently saying that Virgin did not wish to invest in my project. I didn’t realise that I was proposing a commercial project; I thought the idea was to find ideas to save the world.
This paper was written before I found out that many other scientists were suggesting similar ideas. (JG 2008)
On the Control of Global
Temperature.
(by means of jet fuel
additives.)
Contents
Page
1 Philosophy.
Page
5 Implementation
Page 18 App. 1 Why
We Can't Solve Global Warming by Reducing Emission Of CO2.
Page 21 App. 2 Stability –and Control
Engineering.
Page 24 App. 3
References.
Page 25 App. 4
Biography and contact details of author, John Gorman.
Part 1: Philosophy.
I
will suggest in this paper that the normal philosophy of trying to eliminate
effects on the environment and restore a natural balance will not solve this
problem on its own. Instead, our
philosophy should be to control global temperature directly by some means.
Sea Level.
Rise
in sea level is the most obvious undesirable consequence of global
warming. For the rich countries of the
world only a few metres would be catastrophic for many major cities. Similar
rises would inundate the living areas of millions of poorer people in
Bangladesh and various island communities.
The
recent Intergovernmental Panel on Climate Change estimates a rise of
approximately half a metre this century but there is much uncertainty in this
figure. The potential rise from the
loss of Greenland and Antarctica is about 80 metres or from Greenland alone
about eight metres. All the rest of the
world’s glaciers would contribute less than one metre.
All of these ice masses
are melting, now, at today's very slightly elevated global temperatures. Because of the delay between heat input and
temperature rise, this would continue even if we could hold global temperature
at today's level. In order to stop this
melting completely, it is only reasonable to assume that we will have to reduce
atmospheric CO2 concentration to preindustrial levels. This would, we hope,
return us to the previous stable situation.
Stability
Stability of sea level and
global temperature has been a characteristic of the few thousand years of recorded
human history. This is misleading. A longer look at history shows violent
swings in climate. In the last million years there have been ten ice ages, with
sea levels hundreds of metres lower than present and ten relatively short
interglacial phases, with sea levels in some cases significantly higher than
the present. (Five metres higher during the last interglacial period, 125,000
years ago. Ref 0)
Based purely on the
average length of previous interglacial phases the present one should be close
to its end and an ice age should be starting soon. For all its problems, global warming has certainly eliminated
that possibility.
We have now disturbed the
temporary stability of the world’s climate. If we were, by some means to reduce
atmospheric CO2 concentration to preindustrial levels, there is no guarantee
that we would return to the previous stability. We might find ourselves at
almost any part of the ice age / interglacial cycle.
If at some artificially
induced cool point in global temperature we were unlucky enough to have a
nuclear war or a volcanic eruption as large as Mount Tamboro in 1815 (Ref 1)
the first steps towards an ice age would be very likely and we would be
desperately spraying coal dust onto glaciers to absorb heat!
Some people believe that
the present situation is just a natural variation, which does not require
action. I suggest that the natural
variations that did occur just prior to recorded history would now be
catastrophic for our complex society. We must now use the present situation to
ensure the long-term stability of global temperature and sea level.
Proposal.
We
should accept some elevated level of CO2 concentration in the atmosphere above
preindustrial levels and the consequent global warming tendency.
To
counteract this we should concentrate our efforts on screening solar radiation
in some controllable way.
The
combination of these two effects would then allow us to control global
temperature and sea level, even in the event of most foreseeable natural
variations.
Note
1) This is not to suggest that we should ignore CO2 emissions or that we should
not capture CO2. This is merely to
suggest that we should accept some elevated level in the long-term as part of
the control system. This elevated level might be above the present level.
Note 2) This control system will work regardless of the cause of the present increase in global temperatures. If the major cause were extra solar radiation rather than extra CO2, then stability would still be achieved by this system.
Note 3) Compare the way that this system would react to a major volcanic eruption with the previous scenario’s possibly disastrous consequences. In this case we could turn off the solar screening as soon as the eruption occurred allowing the global warming effect of the elevated CO2 concentration to oppose the cooling effect of the eruption products. A nuclear war, and nuclear winter, may be unlikely but a volcanic eruption at least as severe as 1815 is inevitable at some stage.
Before
Mount Pinatubo in 1991 an eruption was considered "very likely" for
about six months. The solar screening
could probably be turned off in anticipation without disrupting the control
system.
Conclusion
On Philosophy.
I believe a world with an
elevated atmospheric CO2 concentration is a safer world, in its ability to
maintain stable temperature and sea level in the face of natural and man-made
influences, than a world with no atmospheric pollution was or would-be.
All we need to do is find
a way of screening some solar radiation and to be able to control it reasonably
quickly. This is the subject of the
next section "Implementation".
With this control we will
stop the previous ice age/interglacial cycle.
We may be able to eliminate the effects of a reasonably large volcanic
eruption (e.g. Mount Tamboro 1815.
"1816 -- the year without a summer" Ref 1) and we will be able
to mitigate the effects of a very large volcanic eruption (and possibly also a
"nuclear winter") Additionally the control system will work
regardless of the real cause of the present global warming.
Part 2. Implementation Of a Solar Radiation
Screen.
The idea of screening
solar radiation is, of course, not new.
There have been several television programmes recently on the subject
following a meeting at NASA in California in November 2006. I will divide these to three different
categories:
1) In space.
2) In the troposphere.
(Lower atmosphere below about 9km,30,000 ft.)
3) In the
stratosphere. (i.e. atmosphere above
the troposphere.)
1)In
Space.
As well as being very
expensive, any form of screening in space could not be controlled or switched
off. This would make it useless as a
part of the global temperature control system proposed in this paper.
2)Troposphere.(lower atmosphere up to
30,000ft-9km approx)
Any screen in the troposphere must essentially be cloud. The whole of our weather and cloud is in this lower part of the atmosphere and any other chemical or particle put into this part of the atmosphere would quickly be brought to earth in rain. There are several detailed proposals on increasing cloud cover. These would obviously be very easy to control since any artificial input would quickly be swamped by the natural weather systems as soon as it was switched off or reduced.
Unfortunately there is considerable
scientific disagreement as to whether cloud cover has a net global warming or
global cooling effect. This seems to
apply to cloud at all levels including aircraft vapour or contrails. The paper ‘In Search of Balance’ by Charlson, Valero & Seinfeld in Science by was summed up in the online magazine Live Science
with the headline “Scientists
Clueless over Sun's Effect on Earth” (Ref 2) Technically
the problem seems to be that we can easily estimate the loss of incoming solar
radiation due to clouds, but it is nothing like so easy to evaluate the
blanketing of outgoing radiation from the earth.
While this scientific
uncertainty exists it is hard to see any cloud system being implemented.
3)Stratosphere.
In the stratosphere there
is one area of scientific unanimity. In
the last 250 years there have been 13 large volcanic eruptions. All have these have resulted in global
cooling in the subsequent one or two years.
The data available from these eruptions has been studied in detail by
many different researchers with not a single voice opposing that basic
statement. (Ref 3)
In
particular the eruption of Mount Pinatubo in 1991 allowed the confirmation of
many previously developed theories and models of climate. It was also confirmed
in that case that the level of global cooling would be enough to completely
counteract global warming over the same, or indeed a longer period. (Ref 4 “--1991
Pinatubo eruption produced a cooling forcing larger than the warming forcing of
all the anthropogenic greenhouse gasses in the atmosphere at that time.”)
It was also universally
accepted that the cooling is the result of volcanic products, which spread
throughout the stratosphere in both hemispheres and persist for one to two
years. Where there was not such universal
agreement, was on the particular components of the eruption, which are most
effective in global cooling. The
assumption in the past was that it was solid dust particles. More recent
research tends to suggest that micron sized droplets of sulphuric acid, an
aerosol, is more important. This
results from chemical reactions, in the atmosphere, of the sulphur or sulphur
dioxide produced in the eruption.
Resulting from this
understanding, several proposals have been made to simulate these volcanic
products in the stratosphere and at least two of these were discussed at the
NASA meeting in California in November 2006.
Firstly there was the
Nobel prizewinner, Paul Crutzen's, proposal to launch rockets, which would burn
hydrogen sulphide in their stratospheric phase, releasing sulphur dioxide. The animations of this have had wide
television coverage since the meeting.
This would spread an aerosol of sulphuric acid. Obviously the sulphur dioxide and the
sulphuric acid would be chemically active and would have some effect in
depleting the ozone layer. As Paul
Crutzen's Nobel prize was for his work on the ozone layer, he is in a good
position to claim that the effect on the ozone layer would not be excessive.
Another proposal discussed
at the meeting was the spreading of crushed diatomite into the
stratosphere. This seems to have
received no publicity. Diatomite is a
mineral, mined in various places including Scotland, which consists of the
shells of micron sized sea creatures.
The shells are made of silica, which is sand chemically, and would
therefore be chemically inert in the stratosphere and on falling to earth. Because of their small size and purity these
particles would probably have good reflective properties and would, like other
volcanic products, stay in the stratosphere for one to two years. No particular method of delivery into the
stratosphere was suggested except that aircraft would obviously be
involved. (In the words of Robert
Chatfield, a host of the NASA meeting: ""if --it is possible to disperse
the diatoms individually (how to do that is not obvious.)" This proposal
stems from a wish to avoid the chemical effect of the sulphur products.
I suggest that both the
sulphur dioxide and the silica particles could be delivered into the stratosphere
by dissolving an additive in jet aviation fuel.
Proposal.
An Aviation Fuel Additive To Counteract
Global Warming
This
proposal is the reason for this paper and is indeed the only original part of
this paper. Some original experimental
work has been done and is described in detail elsewhere. (Ref 5)
Different
chemicals would obviously be required for the two products but the delivery
system would be the same and is therefore described first as follows.
How
to Deliver Products Into the Stratosphere.
Obviously we would not
want to release these products at other phases of the aircraft flight so it is
not suggested that an additive should be put generally into aviation fuel. We would want to burn fuel containing the
additive specifically when the aircraft was cruising in the stratosphere.
The following information
comes from a 747-400 captain flying regularly from the Far East to Europe and
the West Coast of United States. Being
near retirement, and having started his career with the RAF, he describes the
flight plan provided to him for a long flight now as amazingly comprehensive
and accurate. Such plans rely on
detailed knowledge of weather along the whole route including lower
stratospheric winds.
In addition he tells me
that it is perfectly possible for the pilot to select, for instance, the outer
starboard wing tank to feed the outer starboard engine at a particular time
during the flight.
It would seem therefore to be perfectly possible to put the additive into one tank only and to use that tank when the plane was defined in the flight plan to be in the stratosphere. Aircraft cruising altitudes vary between about 30 and 40,000 ft (9 to 12km). The lower boundary of the stratosphere varies from about 20,000 ft. (6 km) near the pole to close to 55,000 ft. (17km) at times on the equator. These heights also vary considerably with weather conditions so careful planning as part of the flight plan would obviously be necessary.
Fuel
Additive To Produce Sulphur Dioxide on Burning.
Sulphur dioxide is already
present in the combustion products of aviation fuel. This is because of the organic sulphur compounds naturally
present in oil and great trouble is taken to reduce the proportion because of
the acid effects of sulphur dioxide in the lower atmosphere. It should be very easy to use these same
sulphur compounds as the additive, which would then only be burned in the
stratosphere. Since these compounds are
already present in aviation fuel it is very unlikely that they will cause any
problem to the engine.
I have been experimenting
with dimethyl sulphide, which is the nearest that I could get to Paul Crutzen’s
hydrogen sulphide with an organic compound. It is a clear oily liquid which
dissolves in aviation kerosene in any proportion. The solution burns in a
paraffin blow lamp exactly like pure kerosene.
Fuel
Additive to Produce Microscopic Silica Particles.
I propose adding tetra
ethyl silicate to aviation fuel. This will, on burning, produce particles of
silica similar in size to the diatoms referred to previously.
At first sight it might
seem difficult to produce solid particles from the liquid fuel. It is however
perfectly normal chemistry to have a compound which is mainly hydrocarbon like
jet fuel but has one or two other atoms in the molecule which have a solid
oxide on burning.
I have been experimenting
with tetra ethyl silicate. There is
only one silicon atom of the thirty-three in the molecule. The rest of the molecule is hydrocarbon so
it is not surprising that it is a colourless liquid similar to aviation
kerosene, which dissolves in kerosene in any proportion.
To simulate a jet engine I
have used a paraffin blowlamp. The
solution burns just like paraffin. At a
concentration of 1% a mist or smoke is visible in a spotlight beam. It is probable that the mist is microscopic
crystals of silicon dioxide. This is chemically the same as the diatomite,
which was proposed at the NASA meeting in November 2006.
Tetra ethyl silicate is so similar to
aviation kerosene that it will probably make no difference to the engine when
used in low concentration. Obviously this needs to be tested properly and it is
also possible that the microscopic particles will coalesce near the end of the
turbine and cause erosion. (Ref 6)
It
is also obviously necessary to confirm that the combustion product is silica,
to determine the size of the particles, to compare this with the diatomite
particles and many other points.
As suggested above there
will have to be detailed testing of both additives in a jet engine. This would be done at a static engine test
facility where the exhaust could be analysed with regard to particle size and
type. Safety and the effects on the engine,
the pumps, the fuel tanks etc. would all have to be checked. Such testing is however the bread and butter
of the aviation industry and could be completed very quickly.
Assuming satisfactory
completion of such engine testing, atmospheric testing could be started almost
immediately. I would like to point out
here that this is the only way that a solar screening proposal discussed at the
NASA November 2006 meeting could be started quickly.
I would also like to point
out that it is the only proposal that I have heard of, where satisfactory
testing could be transferred into large scale implementation immediately at
negligible cost.
Atmospheric
Testing.
Though this method of
distribution is new, the idea of distributing micron size silica particles has
been proposed previously and was discussed at the NASA November meeting. As I understand it silica has been proposed
because it is chemically inert, unlike sulphur dioxide, and because it is
available in micron sized particles in the form of the mineral diatomite. The
particles are micron sized because each is the shell of a sea creature called a
diatom.
The possible effectiveness
of silica as a sunscreen has therefore been discussed together with possible
problems and advantages and various atmospheric testing scenarios. There is as yet no suggested way of distributing
the diatoms individually into the upper atmosphere. This would of course be solved by this fuel additive proposal
with other possible advantages like control of particle size by varying the
concentration in the fuel.
In brief, atmospheric
testing scenarios have already been defined by experts in the field and could
be implemented almost immediately following the jet engine test facility
phase. For example the suggestion of
Gregory Benford of the University of California (Ref 7)
Such testing could be of
each of the additives proposed, in different areas or at different times, at
different altitudes to compare effectiveness.
For the testing phase commercial aircraft would of course not be used,
instead it is probable that military aircraft could be made available. If so, spreading could be done at higher
altitudes than would be possible with most commercial aircraft. The B-52 for instance flies up to 50,000
ft.(15km) Such an aircraft would probably also have a military arrangement of
fuel tanks with some smaller emergency tanks and greater flexibility to connect
tank to engine. This could be very convenient in testing.
Initial
testing would be mainly aimed at checking that there were no unexpected
problems and that those negative effects predicted were only as expected.
Obviously
one would also check that solar radiation screening was of the expected level
corresponding to the concentration of the product in the stratosphere.
It
should not be expected that there would be any actual global or local cooling
effect from a necessarily local experiment.
It
is unlikely that there would be any negative effects at ground level. The stratospheric concentration necessary to
provide the global cooling effect should be far less than the stratospheric
concentration caused in 1992 by Mount Pinatubo. This is because the cooling resulting from Mount Pinatubo was of
the order of one degree centigrade.
This is approximately 50 times the present rate of global warming.
Since
no ground level harmful effects of Mount Pinatubo were reported worldwide it is
very unlikely that significantly lower concentrations will be detected at all
at ground level.
What quantity would be needed?
The following is a very rough estimate of feasibility. Bluth et al. 1992 estimated that Mount Pinatubo put ten million tons of SO2 into the stratosphere in 1991, so maybe five million tons were still there one year later. This reduced the global temperature by about 1C, which is about fifty times the current annual rate of global warming. (0.14 to 0.2 of a degree C per decade!) So we might need 100,000 tons in the stratosphere continuously to counteract current global warming. If it stays up there for one and a half years, we will need a continuous input of 200 tons per day.
There are about 77,000 commercial aircraft flights per day! The daily use of jet aviation fuel approaches a million tons worldwide! If we assume a 5% solution of the SO2 producing chemical or tetra ethyl silicate used for one twentieth of the flight time, that would deliver 2500 tons!
This very rough calculation does confirm that delivery by commercial aircraft is feasible. In fact it suggest s that a fleet of dedicated high altitude aircraft such as B52’s could also do the job.
There are hundreds of academics in this field worldwide with a lifetime’s experience of the effects of volcanic eruptions. Some of these would obviously have to be involved in planning the testing phase and of course in implementation and would be able to make much more accurate estimates.
In addition, the reflective properties of SO2 based aerosols are known from volcanic studies but silica could be more or less reflective requiring therefore less or more material. Only experiment will give this information.
Possible Problems.
1)
The Jet Engine. It is very unlikely that the additives will
have any effect on the engine until the silicon dioxide coalesces into
particles in the exhaust. This might
however be at some point in the turbine and might cause some erosion. Testing will show whether this is no
problem, a minor problem or a major problem.
If
there is only slightly accelerated erosion of some of the turbine blades this
might be accepted by the airline industry as only a small price to pay for
avoidance of the restrictions which will undoubtedly hit commercial flying
unless a solution is found to global warming.
Hopefully
the particles will not solidify until the exhaust cools after the exit from the
turbine.
2)
Ideally
we would want the best screen to be laid near the equator where the greatest
solar radiation concentration is. This
is however where the bottom of the stratosphere is at its highest; in some
cases being as high as 17 kilometres (55,000 ft.) This could be no problem at
all or it might be a small problem.
It
is probable that careful flight planning will give perfectly adequate screening
near enough to the equator. For
instance a flight plan could ask an aircraft to rise to its maximum safe
altitude for a relatively short period at a point where the stratosphere was
known to be slightly lower.
The
only commercial aircraft, which flew high enough to be always in the
stratosphere over the equator, was Concorde.
Looking slightly further ahead the airline industry might be delighted
to have an excuse for reintroducing high-level supersonic aircraft with
subsidies because they are so environmentally friendly! The seriousness of the global warming
problem justifies such major steps.
3)
Silica, Sand and Asbestos.
Just
as silica is the same as sand chemically it is also the same as asbestos
chemically. Although this sounds
worrying it will probably not be a problem for various reasons.
--
micron sized particles stay in the stratosphere for one or two years so only
small quantities will be falling into the troposphere.
--
particles from the stratosphere will generally be brought to earth in rain soon
after they drop into the troposphere.
--
asbestos fibres are relatively long fibres rather than particles. These are particularly difficult for the
lungs to remove.
--
in a modern urban life we breathe a multitude of particles that cannot be
dissolved by the body such as carbon particulates from vehicles.
--
only those who have a high exposure to particulates over a long period due to
their job seem to get the serious lung diseases such as asbestosis, silicosis
and pneumoconiosis. Or they smoke!
-- for most people and animals a certain
level of dust, including nondegradable minerals, is just one of the things our
lungs are designed to deal with.
This
aspect of silica as a diatom has also been looked at by attendees at the NASA
November 2007 meeting. For instance Bob
Chatfield of NASA said "Diatomaceous earth hardly seems to have clear
dangers.--Concentrations in the removal region in the troposphere should be
minute ---Near-surface respirable concentrations reduced by at least a factor
of ~5000 --Tentative conclusion; The form of the particle does not appear
particularly health-affecting compared to other particles currently in the
atmosphere in ultra trace quantities.---The diatom consequences are just not
that uncertain, and could well be studied" (Ref 8)
4)
Since experts
in this field are already looking at the pros and cons of the use of silica
particles (diatoms) it seems unnecessary to expand on the other possible problems
here. Such climate experts would
obviously have to be involved in detailed planning of a test phase.
Incidental Advantages.
1
) Ultraviolet Screening.
A
short deviation onto heat, light and radiation might help some readers. Others will of course wish to skip this.
It
would be easy to get the impression that heat only exists in infrared radiation
not in light. In fact heat energy is
present in all light wavelengths and radiation. It is just that cold bodies like the earth and people can radiate
infrared energy while they cannot radiate light. That is why infrared night cameras work. During the day we see people and things only
due to reflected light, which has been radiated from the sun.
The
hot sun radiates heat throughout the whole visible spectrum (and beyond) and
much of this gets to the surface of the earth and is eventually absorbed
warming the earth. CO2 in the
atmosphere doesn't change this much because it doesn't absorb visible light. Although the earth can't radiate light it is
always radiating quite a lot of infrared, much of which would escape into
space. This is where CO2 does make a
big difference by significantly increasing the proportion of the infrared from
the earth's surface, which is absorbed in the atmosphere. This is global warming or the greenhouse
effect of the CO2.
To
be effective, screening of solar radiation must reflect part of the incoming
radiation back into space. It so
happens that the micron sized particles of silica will reflect ultraviolet
light rather than parts of the visible spectrum. This is due to the particle size.
Much
life on this planet is already dependent on the ultraviolet screening provided
by the ozone layer. Ultraviolet is
largely harmful to life and, as we know, to human skin being the main cause of
skin cancers. It is probable that a
reduction in ultraviolet radiation at the surface could be seen as a
significant advantage for a sun loving population.
Since
the wavelength, which is preferentially reflected, depends on the size of the particle
it may be possible to choose the particle size specifically to reduce the
proportion of the most harmful ultraviolet radiation.
2)
Global Temperature Distribution
One
of the effects observed following recent volcanic eruptions was warmer winters
in higher latitudes (further from the equator) in addition to the general
global cooling. This effect was
observed particularly in 1992 after Pinatubo in 1991 and is now well understood
in terms of climate models.
This
could mean that the significant global cooling necessary to halt Arctic and
Antarctic melting would not necessarily mean more unpleasant winter weather for
those living in northern latitudes. ( The Arctic melting would still be reduced
by the cooler summers.)
As
this system of solar radiation screening is brought into operation there will
be many such local effects, some predicted some not. Climatologists will use their climate models to predict effects
and weather patterns and will have to modify their computer models where
effects are found which are not predicted.
Climatology or climate engineering or
geo-engineering will change to become a completely new science, which is not
only dedicated to explaining and predicting global climate, but to controlling
it to ensure long term stability of sea level and global temperature. Then Charles Dudley Warner’s comment "everyone talks about the weather but no one does
anything about it" will no longer be as amusing as it was in 1900.
Go to
introductory page of website
|
|
Go
to Global Warming Home page
Appendix
1. Why We Can't Solve Global Warming by Reducing Emission Of CO2.
--
The most obvious problem so far is melting in Greenland and the Antarctic
Peninsula.
--
These ice masses are melting seriously now in a way that has not occurred
during this interglacial phase since the last ice age ended 10,000 years
ago. (Position statement by British
Antarctic survey--Ref9. Also Ref 10 for Greenland)
--
This melting is occurring at today's very slightly elevated global
temperatures.
-- Even if we could keep global temperature at today's level, the melting would obviously continue indefinitely. This will result in a sea level rise of maybe 15 metres (seven to eight metres for the whole of the Greenland ice sheet plus the same for the Antarctic Peninsula assuming a similar geographical size and assuming that the melting did not extend to the whole of Antarctica.)
But
the situation is worse than this because there is no possibility of keeping global
temperature rise to today's level.
Because
the temperature would continue to rise even if we could stop all emissions
today.
--
This is because of the net heating effect of the CO2 already in the
atmosphere. This is now forty per cent
above the preindustrial level and would only decline very slowly (decades or
centuries) to that preindustrial level.
--If
we could stop all emissions now, it is reasonable to assume that the rate of
increase of global temperature would remain at about 0.2°C per decade for most
of this century. This would give a
further rise of about 2° C by 2100
But
the situation is worse than this because there is no possibility of stopping CO2 emissions
now.
Which is fairly obvious. But maybe we can keep total emissions close
to present levels by international agreement. This might limit the rise to 4 -
6°C by 2100. (The IPCC figure.)
But
the situation is far worse than this.
Because
global industrial development is bound to result in increased emissions. Probably greatly increased in the short-term.
This
is simply because of the human numbers involved. The rich nations of the world
constitute about one billion people of the six and a half billion now. By 2050
the UN estimates that there will be nine billion. Presumably ten billion well
before 2100.
This
rich tenth of the worlds population has a carbon footprint ten to twenty (USA)
times that of the poor population.
Even
if the rest of the rich world followed the UK’s legal commitment to cut
emissions by 60% by 2050, it would only require one billion of the present
agricultural population to become urbanised to cancel any gains.
But
the situation is far, far worse than this. China expects half a billion agricultural
workers to move to the towns by 2030 (not 2050!) Jeffrey Sachs in the Reith
lecture on 17th April estimated world economic activity by 2050 at
six times today’s level. And most of the development will be low tech. This
means coal, which can be dug out of the ground and has the worst CO2 footprint
of all energy sources.
In
conclusion;
emissions will continue to rise. Global temperature will continue to rise, and
probably accelerate. Melting of the ice masses throughout the world will
continue and probably accelerate. Sea level will rise and probably accelerate.
These
human numbers, and a multitude of other reasons, make it vital that we reduce
carbon emissions and other forms of pollution, but this will not solve the
problem of global warming this century.
Most
people who have read and watched the debate unfolding are fully aware of all of
this. They understand the global situation and realise that no reduction in
emissions will save the Greenland ice sheet and the coral reefs.
This
was my situation till I started reading the academic literature on climate less
than a year ago. It was with amazement that I found that the academics
concentrated on reduction of emissions with religious zeal and that any talk of
geoengineering solutions was not ‘politically correct’.
This
‘corporate thinking’ even opposed the proposal of the Nobel laureate, Paul
Crutzen leading to the comment by Ralph Cicerone, The President of the American
Academy of Sciences; "Various individuals have opposed the publication of
Crutzen's paper for sincere reasons that are not wholly scientific,"
I
am concerned that this attitude by the experts is stopping the development of
the only tool that we have at the moment to control global temperature and sea
level and restore stability.
It
is essentially a natural tool, the simulation of a volcanic eruption, but with
only 2% of the intensity of Mount Pinatubo in 1991-2. It doesn’t seem to have
major disadvantages. It may have complications that we don’t predict but it is
hard to envision any that are more catastrophic than not doing anything.
Note; This is not an argument against reducing carbon emissions by all possible means. The human numbers and a multitude of other reasons make this vital, but no reduction of emissions will lower global temperature and avoid sea level rise.
(This section was
originally in the main text as “stability” but was considered too detailed.)
It
is important to understand the delay between cause and effect in sea level
rise.
Man
made greenhouse gas emissions raise the concentration in the atmosphere but the
rate of emission today defines the rate of increase of concentration
today. The concentration today depends
on the emissions of the last 30 years or more.
Similarly,
the rate of increase of global temperature today depends upon the concentration
today but the actual temperature today depends on the atmospheric
concentrations over the past 20 or 30 -- or maybe 100 -- years. This is because it takes time to warm up a
large body like the earth(only its surface!), its seas or its atmosphere.
This
delay applies even more to sea temperature where heat does not easily travel
downwards.
There
is another large delay before an increased global or sea temperature causes
significant melting of a large ice mass like the Greenland or Antarctic ice
sheet. But the melting will continue for ever unless the temperature is lowered
to the preindustrial level.
One
obvious conclusion from this should be that the melting of these ice sheets,
and sea level rise, would continue for centauries even if we were able to stop
man-made emissions immediately.
If
we were to postulate controlling sea level by controlling greenhouse gas
emissions we would probably have to extract enough from the atmosphere to lower
the concentration below preindustrial levels for a time in order to stop the
melting of the ice sheets. As well as
being highly undesirable for plant life, which needs CO2, this would probably
make the world much more likely to enter a new ice age.
Control
Theory.
A
short deviation into control theory would probably help some readers but others
can of course skip this.
The
first mathematical approach was by James Clerk Maxwell in the early days of
steam engines. Real theoretical
understanding of control advanced enormously with the development of weapons in
the middle of the 20th century. One of
the simple points is that you must be able to change the control input much
more quickly than the natural rate of change of the thing you're trying to
control otherwise it will oscillate or swing wildly.
Take
as an example the pitch control of an aircraft. i.e. nose up or nose down.
The pilot can alter the angle of the elevators at the tail very
quickly. The aircraft itself only
responds relatively slowly to this input.
The result is good control. If
the pilot had to announce "would 10 passengers please move from seats at
the front to seats at the back" the plane would obviously be
unstable. This is because of the delay
in applying the control input. I would
suggest that attempting to control sea level or global temperature by
controlling CO2 emissions or extractions from the atmosphere would also be
unstable because of the delays mentioned above.
Taking
the aircraft analogy one step further it should also be obvious that the pilot
could not talk through a voice tube to someone at the tail who would manually
adjust the elevators. The adjustment
would obviously be delayed too much on the pilot's intentions and the plane
would oscillate wildly up-and-down.
However this is exactly the system that was used throughout most of the
history of steam powered ships. In this
case it worked perfectly well in steering ships because the response of the
ship is so much slower than that of a plane.
In control theory, the control input must be compatible with the
response of the whole system.
All
of this is the bread and butter of many different branches of engineering but
might be new to the climatologists who would have to implement a control system
for world temperature. In the aeroplane
analogy the trainee pilot will initially tend to make large corrections in
pitch but will quickly learn the skill to fly smoothly. Early automatic pilot equipment used various
analogue systems to simulate the skill.
Almost all automatic pilot systems would now use digital calculations
called algorithms based on control theory that is well understood. Similar theory would have to be developed
for global temperature control.
Using
another everyday analogy; A skilled driver taking a right turn a bit too fast
will feel the tail sliding to the left. He will adjust the steering to the left
slightly and the car will smoothly come out of the turn. The less skilled
driver will not recognise what is happening till the car is pointing much too
far to the right whereupon he will steer sharply to the left. This will
straighten the car up much too sharply; the tail will swing to the inside of
the turn, spinning the car into the ditch on the outside of the turn.
The
moral is “we must react to global warming now. It will be much more difficult
if we let the deviation get bigger before reacting.”
Appendix 3. -References.
Ref
1 1816-the Year without a Summer
Ref
2 Livescience website article
“Scientists Clueless –“
Ref3 Page 2 in
Robock, Alan,
2000: Volcanic eruptions and climate. Rev. Geophys., 38,
Ref 4 Page 1086 vol8 journal of Climate 2nd paragraph of “The volcanic Signal in surface temperature observations” Robock &Mao http://climate.envsci.rutgers.edu/pdf/RobockMaoJClim1995.pdf
See also “Individual
large eruptions certainly produce global or hemispheric cooling for 2 or 3
years and this signal is now clearer”.
Page 12 in Robock, Alan, 2000: Volcanic eruptions and climate. Rev. Geophys.,
38, 191-219
Ref 6 www.naturaljointmobility.info/TESinjetengine.htm
Ref
7 Saving
the Arctic - geoengineering | Google Groups start of thread by Greg Benford
Ref
8 ditto Contribution by Bob Chatfield
Ref
9 British Antarctic Survey. Climate Change Position Statement
Ref 10 Greenland. Also Dallas Times and many other articles.
Appendix
4. Biography and Contact Details of Author.
(Relevant bio details only as written for google
geoengineering group.)
Unlike most of the members of this group, none of my careers have been even vaguely connected with geoengineering or climate. Born in 1943 (63 now) I studied engineering at university and control engineering in a post degree year. My first job was on the control of the electric motors in steel mills using analogue computers for control and simulation.
Next I worked for Digital
Equipment (DEC, the PDP 8 and 11 for those old enough to remember them!) in
Maynard Mass., Munich and Reading UK on the interfacing of computers to control
things. My last big project was an
engine test control system with lots of different digital control algorithms.
My second short career was
as a ski instructor and my third career since 1983 or so is on seating, office
chairs, car seats, the human spine and chiropractic.
As a control engineer I
have always found it obvious that we must control global temperature. This morning I received a multi-page glossy
from the Institution of Mechanical Engineers for a conference on "Climate
Control". Great, I thought -- I'll
go to that -- till I looked at the price of £1000 for three days and realised
that it was about climate control in cars!
We expect temperature
control in our cars, houses and offices.
Why is it not obvious that we need control for global temperature?
I only mention the ski
instructor bit because I love snow, ice, glaciers and wild snowy places. I am absolutely convinced, from what I have
read and seen for myself, that really serious melting is underway in all these
places.
John Gorman. Oaklands,
New Mill Lane, Eversley, Hants. UK
Home tel. 0118 973 2365 email gormans@waitrose.com
Website; www.naturaljointmobility.info/globalwarming.htm
Go to
introductory page of website
Go
to Global Warming Home page
|
|