Global warming.

[Forum Monk]

Nuke 'em all and Simcha sort them out!

[Digit]

Isn't it nice to know we have the power to reverse GW if we have to?

[john]

OK. We will take the natural process argument on.

1.) The yearly burning of billions of tons of coal and oil and wood based fuel has no effect on the environment.

2.) The deforestation of the globe over the last two centuries has no effect on CO2 emissions.

3.) We ain't guilty! Its just planet Earth doing its thing

4.) The Emperor's clothes are just beautiful.

5.) And by the way, you need to sign this loyalty oath before you go on the next mission (Catch 22).



john

[Minimalist]

John,

The question is twofold.

1- Does the earth go through periodic cooling and warming phases?

2- Is human activity exacerbating the warming on this occasion.

My personal opinion is that the answer to both questions is "yes."

[Digit]

Morning John. I think you are doing a Marduk on me and answering questions I didn’t ask so I’ve re done my questions and your answers.

John, did you read this link when I posted it earlier?
Note the questions on cloud formation.
What is your opinion on the notes about atmospheric temperatures?
Looking at the graph I posted how do you explain the previous variations if you believe that man is the primary cause of GW?
What happens if you are wrong and the graph's curve repeats previous variations and drops dramatically?
Are you of the opinion that if we do not cut emissions the temps will continue to rise?
What do you think will happen if we do cut emissions?
________________________________________
OK. We will take the natural process argument on.

1.) The yearly burning of billions of tons of coal and oil and wood based fuel has no effect on the environment.

2.) The deforestation of the globe over the last two centuries has no effect on CO2 emissions.

3.) We ain't guilty! Its just planet Earth doing its thing

4.) The Emperor's clothes are just beautiful.

5.) And by the way, you need to sign this loyalty oath before you go on the next mission (Catch 22).

My personal opinion is, as I’ve said previously, that we are contributing. The graph I showed, plus others, show a co relationship between CO2 and temperature that would be silly to ignore.
The graphs show in the past a rapid rise in both followed by a collapse.
Now, what causes that collapse?
If CO2 is the driver where does the CO2 go to?
If the temperature is the driver why the collapse?
Are you saying that the present rise in both will not be followed by a collapse?
Please present your evidence.
As regards deforestation, as a keen wood worker, such is my sympathy on that I use entirely salvaged materials, but I would point out that central Africa has been drying out for many more years than man has been using fossil fuels, and if that were not so the loss of tree cover that has resulted would not be seen as one of the driving forces that started man on his upward course. In addition, it is estimated that the Amazonian rain forest is only 1500 years old.
And again, what has been the driving force behind earlier CO2/temp rises? Till we understand that I suggest your case should be listed as ‘not proven’.

[Forum Monk]

In my opinion, only a fool would say, man has no effect on the environment when there is plenty of evidence to the contrary. As it has been said all along, the real question is, if it were possible to factor out all the other causations, i.e. natural cyclical variation, milankovitch cycles, solar variation (Duke University, 2005) and say man-made greenhouse gases are the one and only, "smoking gun", what would the temperature trend be?

Now, for the sake of argument let us assume that man is solely responsible, what to do? (These are random thoughts on the matter - no science - just opinion):

There is massive deforestation occuring in some rain forests around the world. Why? People need to eat, and in order to eat they need farm land, and pastures for cattle, sheep, etc. Some think the solution is, the US and other so-called first world countries (though IMO Brazil is no longer third world) should subsidize these nations in order to save the forests. Now there's a plan. Let's pay these poor nations to stay in the dark ages and let's feed them as well. Think of all the cheap and available labor we could have if these people didn't have to fend for themselves. Sounds like a variant of communism to me.

There is the burning of fossil fuels on a massive scale. Why? The world economy requires cheap transportation. No problem, we can use alternate fuels. Oh wait, there are no alternate fuels, except maybe the grease used to make McDonalds french fries (are we allowed to call them french or are they still freedom fries?). To be fair, the U.S. in particular should be a little more conservative in its gas consumption but how do you police the emerging nations like China, India, and Brazil who fuel needs are increasing daily? We carry a big stick and give everyone one more reason to hate us.

Huge amounts of CO2 emissions come from burning coal which is used to generate electricity. Its hard to think where we'd be without this resource. What are the alternatives here? No one wants nuclear (except nations like Iran which have yet to face the problems of waste management), there's too little water for hydro and solar is inefficient, which means costly. As Joe Citizen, I'm tapped out. If you tell me a plan that's gonna cost me money it will be a very hard sell.

A large amount of emissions are created by human waste, dumps, etc. Again, there are no alternatives. I am not in favor of shooting it into space and as far as I know, that stupid garbage barge from New York is probably still sailing around looking for a place to dump its load.

More emissions come from rice production. Take away the rice, and about 3 billion people will starve. 'nuff said.

More emissions come from cattle. - see rice.

I wonder how long it will take to fix these problems. In the meantime, if the dooms-dayers are correct, the earth will be hot enough to boil water and I won't be around to worry about it anyway.

Have a nice day

[marduk]

In my opinion, only a fool would say, man has no effect on the environment when there is plenty of evidence to the contrary.

your president tell you that

the only safe power source is static electricity
what some boffin should do is invent a balloon several miles in circumference and rub it up and down a huge wool jumper
this would create enough electricity to enable us not to rely on fossil fuels anymore
and in the event of a meltdown the worst that would happen is there would be a loud pop and everyones hair would stand on end for a little while

[Digit]

Seems a very sensible approach to me Monk. It's all very well for gloom and doom merchants to say we must reverse GW but personally I'd rather be warm than frozen.
Previous 'Hockey Sticks' seem more common than Charley's hand axes, if we could understand what caused the earlier variations we would be in a much better position to explain currect trends I think.

[john]

Right. 'S long as we're getting technical here, some food for thought.

W h y d o e s a t m o s p h e r i c C O 2 r i s e ?



Contents (Version 3.1, October 1996)

1. Why does atmospheric CO2 rise ?
2. Carbon fluxes and reservoirs
2.1 Natural carbon fluxes
2.2 Anthropogenic carbon fluxes
2.3 Carbon reservoirs
3. Fluctuations of the CO2 rise
4. References
5. Acknowledgements. Administrivia



1. Why does atmospheric CO2 rise ?

Time and again, some people claim that human activities are only
a minor source of atmospheric carbon dioxide (CO2) which is swamped
by natural sources. Compared to natural sources, our contribution is
small indeed. Yet, the seemingly small human-made or `anthropogenic'
input is enough to disturb the delicate balance. "Anthropogenic CO2
is a biogeochemical perturbation of truly geologic proportions"
[Sundquist] and has caused a steep rise of atmospheric CO2.

The vexing thing is that, in the global carbon cycle, the rising level
of atmospheric CO2 and the human origin of this rise are about the only
two things that are known with high certainty. Natural CO2 fluxes
into and out of the atmosphere exceed the human contribution by more
than an order of magnitude. The sizes of the natural carbon fluxes
are only approximately known, because they are much harder to measure
than atmospheric CO2 and than the features pointing to a human origin
of the CO2 rise.

>From its preindustrial level of about 280 ppmv (parts per million
by volume) around the year 1800, atmospheric carbon dioxide rose to
315 ppmv in 1958 and to about 358 ppmv in 1994 [Battle] [C.Keeling]
[Schimel 94, p 43-44]. All the signs are that the CO2 rise is
human-made:

* Ice cores show that during the past 1000 years until about the year
1800, atmospheric CO2 was fairly stable at levels between 270 and
290 ppmv. The 1994 value of 358 ppmv is higher than any CO2 level
observed over the past 220,000 years. In the Vostok and Byrd ice
cores, CO2 does not exceed 300 ppmv. A more detailed record from
peat suggests a temporary peak of ~315 ppmv about 4,700 years ago,
but this needs further confirmation. [Figge, figure 3] [Schimel 94,
p 44-45] [White]

* The rise of atmospheric CO2 closely parallels the emissions history
from fossil fuels and land use changes [Schimel 94, p 46-47].

* The rise of airborne CO2 falls short of the human-made CO2 emissions.
Taken together, the ocean and the terrestrial vegetation and soils
must currently be a net sink of CO2 rather than a source [Melillo,
p 454] [Schimel 94, p 47, 55] [Schimel 95, p 79] [Siegenthaler].

* Most "new" CO2 comes from the Northern Hemisphere. Measurements
in Antarctica show that Southern Hemisphere CO2 level lags behind
by 1 to 2 years, which reflects the interhemispheric mixing time.
The ppmv-amount of the lag at a given time has increased according
to increasing anthropogenic CO2 emissions. [Schimel 94, p 43]
[Siegenthaler]

* Fossil fuels contain practically no carbon 14 (14C) and less carbon
13 (13C) than air. CO2 coming from fossil fuels should show up in
the trends of 13C and 14C. Indeed, the observed isotopic trends
fit CO2 emissions from fossil fuels. The trends are not compatible
with a dominant CO2 source in the terrestrial biosphere or in the
ocean. If you shun details, please skip the next two paragraphs.

* The unstable carbon isotope 14C or radiocarbon makes up for roughly
1 in 10**12 carbon atoms in earth's atmosphere. 14C has a half-life
of about 5700 years. The stock is replenished in the upper atmosphere
by a nuclear reaction involving cosmic rays and 14N [Butcher,
p 240-241]. Fossil fuels contain no 14C, as it decayed long ago.
Burning fossil fuels should lower the atmospheric 14C fraction (the
`Suess effect'). Indeed, atmospheric 14C, measured on tree rings,
dropped by 2 to 2.5 % from about 1850 to 1954, when nuclear bomb
tests started to inject 14C into the atmosphere [Butcher, p 256-257]
[Schimel 95, p 82]. This 14C decline cannot be explained by a CO2
source in the terrestrial vegetation or soils.

* The stable isotope 13C amounts to a bit over 1 % of earth's carbon,
almost 99 % is ordinary 12C [Butcher, p 240]. Fossil fuels contain
less 13C than air, because plants, which once produced the precursors
of the fossilized organic carbon compounds, prefer 12C over 13C in
photosynthesis (rather, they prefer CO2 which contains a 12C atom)
[Butcher, p 86]. Indeed, the 13C fractions in the atmosphere and
ocean surface waters declined over the past decades [Butcher, p 257]
[C.Keeling] [Quay] [Schimel 94, p 42]. This fits a fossil fuel CO2
source and argues against a dominant oceanic CO2 source. Oceanic
carbon has a trifle more 13C than atmospheric carbon, but 13CO2 is
heavier and less volatile than 12CO2, thus CO2 degassed from the
ocean has a 13C fraction close to that of atmospheric CO2 [Butcher,
p 86] [Heimann]. How then should an oceanic CO2 source cause
a simultaneous drop of 13C in both the atmosphere and ocean ?

Overall, a natural disturbance causing the recent CO2 rise is
extremely unlikely.



2. Carbon fluxes and reservoirs

First we look at natural carbon fluxes, next at fluxes of anthropogenic
carbon, and finally at carbon reservoirs. Carbon enters and leaves the
atmosphere largely as CO2. The remaining carbon fluxes involve various
organic and inorganic carbon compounds.

Unless stated otherwise, the following figures are adapted from [Schimel
95, p 77, 79]. Natural carbon fluxes and, except for the atmosphere,
carbon reservoirs are hard to measure, their estimates vary somewhat
across the literature. We omit many details like, for instance, atmo-
spheric carbon monoxide with a lifetime of about 2 months [Novelli],
or methane with a lifespan of 10+ years. Their roles as atmospheric
carbon reservoirs are minor, both eventually end up largely as CO2
[Prather 94/95]. For more on the carbon cycle see [Butcher] [Denman]
[Melillo] [Schimel 94/95] [Siegenthaler] [Sundquist].

Gt = gigatonne = 10^9 metric tonnes, which is the mass
of one cubic kilometre of water. Instead of Gt, some
authors use Pg = petagram = 10^15 grams
1 GtC corresponds to ~3.67 Gt CO2
2.12 GtC or ~7.8 Gt CO2 correspond to 1 ppmv CO2 in the
atmosphere. ppmv = parts per million by volume



2.1 Natural carbon fluxes

GtC / year

Atmosphere --> terrestrial vegetation 120 Photosynthesis
Terrestrial vegetation --> atmosphere 60 Respiration
Terrestrial vegetation --> soils & detritus 60
Soils & detritus --> atmosphere 60 Respiration

Atmosphere --> surface ocean 90
Surface ocean --> atmosphere 90

Surface ocean --> deep ocean 90 Inorganic carbon
Surface ocean --> deep ocean 10 Organic carbon
Deep ocean --> surface ocean 100 Mostly inorganic


These fluxes are averages for 1980-1989, with anthropogenic carbon
omitted. Fluxes can vary from year to year. The above irreverently
lumps land animals with soils and detritus, and it skips many other
details as well. For instance, both volcanic CO2 and CO2 removal via
silicate weathering are in the order of 0.1 GtC/year and play a role
on geologic time scales only [Butcher, chapter 11] [Sundquist].

Some, like [Schimel 95, p 77], condense the first four of the above
carbon fluxes into a shorthand (in GtC/year):

Atmosphere --> terrestrial vegetation 60 Net primary production
Soils & detritus --> atmosphere 60 Respiration

Net primary production is "total photosynthesis minus respiration"
of the photosynthesizing biota. For terrestrial vegetation, net
primary production is roughly half of total photosynthesis. The
shorthand omits about 60 GtC/year which plants first take up via
photosynthesis and then return to the air via respiration. The
60 GtC/year estimate for terrestrial net primary production is
based on a reassessment of earlier estimates ranging from 45.5 to
78 GtC/year. [Butcher, p 250-251] [Melillo, p 452]

Organic carbon compounds stemming from terrestrial net primary
production are ultimately decomposed via respiration by micro-
organisms and animals [Butcher, p 46]. Microorganisms are likely
to do the lion's share, yet an estimate of the respiratory carbon
flux from land animals would be interesting (I couldn't spot one).
While the biomass of animals contains only perhaps 1 or 2 GtC
[Schneider, p 102], some, and not only warm-blooded, animals spend
much more energy in respiration than for growth [Butcher, p 48].
(True, not all fungi are microorganisms. But you have to stop
somewhere



2.2 Anthropogenic carbon fluxes

Carbon dioxide sources GtC / year

Fossil fuel burning, cement production 5.5 (5.0-6.0)
Changes in tropical land use 1.6 (0.6-2.6)

Total anthropogenic emissions 7.1 (6.0-8.2)

Partitioning among reservoirs GtC / year

Storage in the atmosphere 3.3 (3.1-3.5)
Oceanic uptake 2.0 (1.2-2.
Uptake by Northern Hemisphere forest
regrowth 0.5 (0.0-1.0)
Additional terrestrial sinks: CO2 fer-
tilization, nitrogen fertilization,
climatic effects 1.3 (-0.2-2.

These are average annual fluxes for 1980 through 1989. The ranges
in parentheses are 90 %-confidence intervals, meaning the authors
estimate a 90 % chance that a given range encloses the true value
of the respective flux [Schimel 95, p 79].

CO2 fertilization, N fertilization, northern forest regrowth, and
climatic effects are hard to separate, their relative roles are not
well known [Goulden] [Melillo, p 449, 451-57] [Schimel 95, p 78-82].
For the ocean, a tentative estimate is that roughly 0.4 GtC/year of
anthropogenic carbon stay in the surface layer, while (1-) 1.6 (-2)
GtC/year go to the intermediate and deep ocean [Denman, p 495-496]
[Schimel 95, p 77] [Siegenthaler].

Today, about 45 % of the anthropogenic CO2 stays aloft. It is open,
whether and how this may change in future. A host of processes
in the terrestrial biosphere and in the ocean may eventually affect
the airborne fraction [Denman] [Melillo] [Schimel 94, p 51-58].



2.3 Carbon reservoirs (in GtC)

Atmosphere (1990) 750 Surface ocean 1020
Terrestrial vegetation 610 Marine biota 3
Soils & detritus 1580 Dissolved organic carbon 700
Deep ocean 38100

Coal, oil [Butcher, p 256, 259] ~5000 to ~10000
Coal, oil, gas [IPCC 95/II, p 80, 87] at least ~20000

The mass of the marine biota is small, their turnover is huge.
Estimates for oceanic primary production range from 15 to 126
GtC/year, with a best guess of 50 GtC/year. Phytoplankton carries
out the photosynthesis. Other organisms recycle most of the resulting
organic carbon compounds on the spot, in the sunlit surface layer
of the ocean. Detritus and dissolved organic carbon compounds
containing roughly 10 GtC/year go to the intermediate and deep ocean
(the so-called biological carbon pump). This carbon flux is balanced
mostly by upwelling of deep water enriched in inorganic carbon from
decomposition of the organic remnants. Current thinking is that the
biological pump was roughly in steady state during the past century.
If so, then the anthropogenic CO2 currently absorbed by the ocean
would mainly take the "inorganic path". [Butcher, p 252-253] [Denman]
[Siegenthaler]



3. Fluctuations of the CO2 rise

The average annual increase of CO2 went up from about 0.9 ppmv/year
during the 1960s to about 1.5 ppmv/year during the 1980s. The annual
CO2 growth rate has kept fluctuating since the start of direct
measurements in 1958. Many fluctuations appear to be related to
El Nino-Southern Oscillation (ENSO) events. The drop of the CO2
growth rate between late 1991 and late 1993, however, cannot be
directly linked to an ENSO event. The rise of atmospheric methane
and of nitrous oxide temporarily slowed down at about the same time.
Mt. Pinatubo's 1991 eruption may have played a role, but the matter
is not settled. [Heimann] [IPCC 95, p 75-6] [Prather 95, p 87-8]
[Schimel 95, p 80-2]

The oceanic and, presumably even more, the terrestrial net CO2 uptake
appear to vary by a few GtC from year to year, probably in response
to climatic variations [Bender] [C.Keeling] [R.Keeling] [Melillo,
p 456-457]. Elucidating climatic effects on terrestrial CO2 fluxes
requires, as a minimum, long-term monitoring of vegetation in all
major climatic regions. In a forest, for instance, the net CO2 flux
depends on net photosynthesis (net primary production) and on soil
respiration. These in turn may depend, among others, on the length
of the growing season and on the timing and amount of rain, snow,
drought and cloud cover. [Goulden] [Melillo, p 452-454]

The terrestrial biosphere was probably roughly in balance during
the late 1970s and the 1980s. Over this period, CO2 release
from tropical land-use changes and the average CO2 uptake by
the terrestrial biosphere seem to have almost cancelled, in spite
of year-to-year variations. From 1991 to 1993, the terrestrial
biosphere probably was a net CO2 sink, in 1994 the CO2 rise was
back to its usual pace. [Battle] [Bender] [C.Keeling] [R.Keeling]
[Schimel 95, figure 2.2]



4. References

[Battle] M. Battle, M. Bender, T. Sowers, P.P. Tans, 7 more authors,
Atmospheric gas concentrations over the past century measured in air
from firn at the South Pole. Nature 383 (1996), 231-235
[Bender] Michael Bender, A quickening on the uptake ?
Nature 381 (1996), 195-196
[Butcher] Samuel S. Butcher, Robert J. Charlson et al. (eds),
Global Biogeochemical Cycles. San Diego, CA, Academic Press 1992
[Denman] K. Denman, E. Hofmann, H. Marchant, Marine biotic
responses to environmental change and feedbacks to climate.
Pages 483-516 in [IPCC 95]
[Figge] Regina A. Figge and James W.C. White,
High-resolution Holocene and late glacial atmospheric CO2 record:
variability tied to changes in thermohaline circulation.
Global Biogeochemical Cycles 9 (1995), 391-403
[Goulden] Michael L. Goulden, J.William Munger, Song-Miao Fan,
Bruce C. Daube, Steven C. Wofsy, Exchange of carbon dioxide
by a deciduous forest: Response to interannual climate variability.
Science 271 (1996), 1576-1578
[Heimann] Martin Heimann, Dynamics of the carbon cycle.
Nature 375 (1995), 629-630
[IPCC 94] Climate Change 1994: Radiative Forcing of Climate Change
and An Evaluation of the IPCC IS92 Emission Scenarios.
J.T. Houghton, L.G. Meira Filho, J. Bruce, Hoesung Lee,
B.A. Callander, E. Haites, N. Harris and K. Maskell (eds),
Cambridge University Press 1995
[IPCC 95] Climate Change 1995: The Science of Climate Change.
J.T. Houghton, L.G. Meira Filho, B.A. Callander, N. Harris,
A. Kattenberg and K. Maskell (eds), Cambridge University Press 1996
[IPCC 95/II] Climate Change 1995: Impacts, Adaptations and
Mitigation of Climate Change: Scientific-Technical Analyses.
Robert T. Watson et al. (eds), Cambridge University Press 1996
[C.Keeling] C.D. Keeling, T.P. Whorf, M. Wahlen & J. van der Plicht,
Interannual extremes in the rate of rise of atmospheric carbon
dioxide since 1980. Nature 375 (1995), 666-670
[R.Keeling] Ralph F. Keeling, Stephen C. Piper & Martin Heimann,
Global and hemispheric CO2 sinks deduced from changes in atmospheric
O2 concentration. Nature 381 (1996), 218-221
[Melillo] J.M. Melillo, I.C. Prentice, G.D. Farquhar, E.-D. Schulze,
O.E. Sala, Terrestrial biotic responses to environmental change
and feedbacks to climate. Pages 445-481 in [IPCC 95]
[Novelli] Paul C. Novelli, Ken A. Masarie, Pieter P. Tans,
Patricia M. Lang, Recent changes in atmospheric carbon monoxide.
Science 263 (1994), 1587-1590
[Prather 94] M. Prather, R. Derwent, D. Ehhalt, P. Fraser,
E. Sanhueza, X. Zhou, Other trace gases and atmospheric chemistry.
Pages 73-126 in [IPCC 94]
[Prather 95] M. Prather, R. Derwent, D. Ehhalt, P. Fraser,
E. Sanhueza, X. Zhou. Other trace gases and atmospheric chemistry.
Pages 86-103 in [IPCC 95]
[Quay] P.D. Quay, B. Tilbrook, C.S. Wong, Oceanic uptake of fossil
fuel CO2: carbon-13 evidence. Science 256 (1992), 74-79
[Schimel 94] D. Schimel, I.G. Enting, M. Heimann, T.M.L. Wigley,
D. Raynaud, D. Alves, U. Siegenthaler, CO2 and the carbon cycle.
Pages 35-71 in [IPCC 94]
[Schimel 95] D. Schimel, D. Alves, I. Enting, M. Heimann, F. Joos,
D. Raynaud, T. Wigley, CO2 and the carbon cycle. Pages 76-86
in [IPCC 95]
[Schneider] Stephen H. Schneider, Global Warming: Are We Entering
the Greenhouse Century ? Vintage Books, New York 1990
[Siegenthaler] U. Siegenthaler & J.L. Sarmiento, Atmospheric
carbon dioxide and the ocean. Nature 365 (1993), 119-125
[Sundquist] Eric T. Sundquist, The global carbon dioxide budget.
Science 259 (1993), 934-941
[White] J.W.C. White, P. Ciais, R.A. Figge, R. Kenny &
V. Markgraf, A high-resolution record of atmospheric CO2 content
from carbon isotopes in peat. Nature 367 (1994), 153-156.
Discussion: Nature 371 (1994), 111-112



5. Acknowledgements. Administrivia

Acknowledgements: Many people helped with explanations and comments.
My wife Rosemarie pointed out several confusing points. Len Evens
spotted a particularly idiosyncratic outburst.

Caveat: This is not my field. Corrections and amendments, especially
by professionals, are welcomed. Students should not use this article
as a reference for school projects. They should instead use it as a
pointer to some of the published literature.

Copyright (c) 1996 by Jan Schloerer, all rights reserved. This article
may be posted to any USENET newsgroup, on-line service and BBS, as long
as it is posted in its entirety and includes this caveat and copyright
statement. However, please inform me, so I know where the article goes.
This article may not be distributed for financial gain, it may not be
included in commercial collections or compilations without the express
written permission of the author.

This file is archived at:
http://www.radix.net/~bobg/



Jan Schloerer jschloer@rzmain.rz.uni-ulm.de
As from 1997: jan.schloerer@medizin.uni-ulm.de
Uni Ulm Biometrie & Med.Dokumentation D-89070 Ulm, Germany
Climate Change Basics -- Jan Schloerer
Sea Level Change FAQ -- Robert Grumbine
Carbon Dioxide Rise Basics -- Jan Schloerer
Climate Change Reading -- Jan Schloerer
Models versus Climate reconstruction -- Jan Schloerer
Schools in Meteorology, Oceanography, and Related Sciences -- Robert Grumbine
Favorite objects for Amateur Astronomers -- Robert Grumbine
Icebergs -- Robert Grumbine
bobg Books home page -- Robert Grumbine
bobg Home Page -- Robert Grumbine



john

[Digit]

Morning John, if you had warned me I could have saved you the trouble of that post as I'm aware of the info.
Firstly, you seem to be under the impression that I believe man's activities do not matter, that is not so, and if you are under that impression I ask you to check my earlier posts.
I fear that you have missed the point of my argument so I'll try another approach.
If man was a non-technical animal what would the current global temp be?
If the current global temp is as a result of man will it crash like previous curves?
If you can start with answers to those questions I'll move on to further queries.

[Digit]

From todays Sun newspaper, no link I'm afraid.

A gaping hole in the Earth's surface has been found 2 miles down in the Atlantic. Covering thousands of square miles the mantle beneath is fully exposed.
The hole is where the North American and African plates meet according to Dr Chris McLeod of Cardiff University and could change theories on plate techtonics and global warming.

[Beagle]

http://news.bbc.co.uk/2/hi/uk_news/wales/6405667.stm

Here's a link Digit. Interesting story.

[Forum Monk]

Actually, John, I very much appreciate your link. I will need some time to examine it. Thanks.

[Digit]

Thanks Beag. Once again, just as they think they've got all the answers nature turns and bites.

[Digit]

And when you've studied it Monk please let us have your view. I perceive it as an honest assessment for one simple reason, for once the author is not telling me he has all the answers, in fact there are more caveats than I have seen in a paper in many years.