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Fram
2005-Oct-06, 01:32 PM
Because the (Apocalyptic) Anthropogenic Global Warming ((A)AGW) debate covers way too much topics, I would like to propose a discussion of some selected parts. These will not on their own prove or disprove AGW (assuming we reach a consensus on any one point of course), but they will help to get the discussion focused and the current data and arguments from both sides collected.

I would like to use this thread to discuss if there is for the moment Global Warming (GW), without looking at the causes at first (perhaps this will follow automatically). So no discussion of CO2, solar cycles, 800 year gaps... if possible. I would also like to start this thread as if we have said nothing about GW yet on this board, so we can start afresh.
Example questions are: for what periods do we have reliable data, globally and/or locally, and for what periods do we have useful but perhaps less reliable or complete data? Are these data filtered to exclude local features and give a more global view? Are there regions which clearly differ from the trend (like Antarctica or so, or oceans versus land masses)? Discussion of the evidence used for making these statistics is welcome as well, so we can better judge their value.
This discussion will of course talk about the Hockeystick Graph, but I would like it to be not exclusively about it. I would like if possible a comparison of short-time temperatures (the last 15 decades or so), mid-range (the last ten or twenty centuries), and long range (the last few million years or so), if at all possible.

A good summary of global temperature research in the last 100 years can be found here (http://www.aip.org/history/climate/20ctrend.htm), from the American Institute of Physics. I don't claim that it's perfectly neutral (no text on global warming is, it seems), but I think it can be used as a starting point, and it offers a lot of references and links.

Conclusions from it (if I am allowed some conclusions in the very first post of the debate :) ) seem to be that we are having currently a very warm period if we look at the last 150 years (since 1861), with the five warmest years of this period occurring in the last 7 years; that the hockeystick, while not necessarily incorrect, was certainly misleading in the emphasis it laid on the average temperature of the last 1000 years, while just giving the range (and the uncertainty) would have been better and more honest; and that in the hockeystick and in other, more recent studies of the global average temperature of the last thousand years, the last decade is as warm or warmer than any period in the millennium.

I guess that especially the last ones will be debated, but that's the purpose.

peteshimmon
2005-Oct-06, 07:00 PM
I will start with my two pence worth. I have
managed to find out that approx half of
emmited CO2 is absorbed by natural processes.
There is the 50 year old graph of increasing
CO2 in the atmosphere. I wonder if the increase
of shipping over the period causes a small but
finite increase of damage to sea plankton which
could lead to the increase. This is at least
a factor that can accurately be quantised.
Secondly, is it possible a lone but well
calibrated anemometer in a rocky location may
show a definite increase in weather "energy"
over the years.

Glom
2005-Oct-06, 09:24 PM
No peace for the wicked.

Taks
2005-Oct-07, 12:33 AM
yes, i've been attempting peace lately. i'm debated out. not in a very good mood due to pressures at work (due to a lack of work, actually). don't worry, i'm still with it all. we'll have discussions, it just may be a day or so before i'm up to snuff.

taks

Fram
2005-Oct-07, 09:15 AM
Take your time! I'ld rather have a debate when everyone is in a good mood, actually :-)
And I don't have the time as well to always reply and research immediately.

Argos
2005-Oct-07, 02:04 PM
The GW debate is exhaustive. Im regrouping for another charge. Ill be back. :)

dgruss23
2005-Oct-07, 02:28 PM
Hey, this is pretty cool. We're all at the same place with this debate - in need of a breather. I think I can say this is the first time I've seen this happen on this forum.

Your questions are good Fram. I'll try to find some time to put together some references on that. But I'm probably going to be gone from BAUT for about 3-4 months due to a new upcoming responsibility.

peteshimmon
2005-Oct-07, 05:21 PM
Well OK then, in your own time! I think the
suggestions I have made are sensible and any
answers will clarify things for many. In the
meantime I suggest time for thinking can be
combined with collecting various tree seeds
and planting in likely locations where they
might be allowed to grow. If you succeed you
can say you have sequested your own CO2:)

Fram
2005-Oct-07, 07:36 PM
All right, time out!

Taks
2005-Oct-07, 08:14 PM
sounds like russ is about to be bambinoed! :)

taks

peteshimmon
2005-Oct-13, 02:46 PM
Right you have had a rest! Might there be an answer to my point that
lots of propellors may be damaging plankton reducing the capacity of the
oceans to be a carbon sink?

Taks
2005-Oct-14, 06:04 AM
as soon as i can breathe, and think, i'll respond. i have a code in my node. ugh.

taks

dgruss23
2005-Oct-15, 02:47 PM
Right you have had a rest! Might there be an answer to my point that
lots of propellors may be damaging plankton reducing the capacity of the
oceans to be a carbon sink?

I would expect that there's no research to present in response to your idea because its not a realistic scenario. First, you'd have to have some evidence that the motion of propellors would damage plankton - specifically phytoplankton. Now by defintion the phytoplankton are quite small. Imagine putting a boat engine into a swimming pool and then putting in some rice. How much of the rice is actually going to get hacked up by the propellor? Now consider that phytoplankton is generally much smaller than the rice. Its probably going to be a rare cell of algae that is unfortunate enough to get hacked.

But now expand this to the scale of the ocean. What is the distribution of phytoplankton with depth? Obviously phytoplankton in the Euphototic zone, but below the depth of ship propellors will be safe.

What % of the ocean is covered by ship travel? Not much - considering they're 70% of the surface and that there are shipping lanes of high boat travel. If anything your scenario is a good example of why we must be careful not to overestimate the impact we can have upon this planet.

peteshimmon
2005-Oct-15, 10:18 PM
I am not sure how large a carbon sink the
oceans are but I have got the idea the
creatures grow carbonate shells which fall to
the ocean bottom on death. So Wow! this must
be important for removing CO2. And I do not
think the creatures get off lightly when
the props of a supertanker or freightliner
pass. Think of the forces involved in moving
such masses against their drag in the water!
Surely this question has been looked at
quantitivly.

dgruss23
2005-Oct-15, 10:51 PM
I am not sure how large a carbon sink the
oceans are but I have got the idea the
creatures grow carbonate shells which fall to
the ocean bottom on death. So Wow! this must
be important for removing CO2. And I do not
think the creatures get off lightly when
the props of a supertanker or freightliner
pass. Think of the forces involved in moving
such masses against their drag in the water!
Surely this question has been looked at
quantitivly.

But think about what you're proposing. I'm not even going to try to go into this in the typical style of providing references that I normally use. Lets just stick with the hypothetical format you've proposed this in. What makes you think that phytoplankton can be damaged by props? Why wouldn't they just get twisted around as the props rotate through the water. You're talking about objects that exist on two totally different scales.

Think of it this way - put a styrofoam cup in a bucket of water and hack at it with a butter knife. Or course that will damage it. Now grind another cup into little pieces and sprinkle them in the water. Will any significant fraction of the little pieces be damages further by the knife?
That's the case you'll need to make. And then you'd have to show that a significant fraction of the world's oceans are affected.

peteshimmon
2005-Oct-15, 11:15 PM
Well I have made the suggestion this is an
important factor. I do not know for sure
but it certainly should be researched in my
opinion!

Glom
2005-Oct-15, 11:33 PM
Tunga did suggest a drop in phytoplankton from shipping but not props slicing and dicing, rather plankton wars as foreign kinds get moved around by the ships.

Ken G
2005-Oct-16, 01:00 AM
It seems the answer would require observing plankton populations, and even though I personally find it hard to picture that propellers would do it (more likely oceanic pollutants, I should think) it is an interesting idea to look not just at the rates of CO2 emission but also at the rates of removal. Can we all agree the CO2 is increasing? This means we are not in equilibrium, and unless something is done either at the emission end or the removal end, we won't be in equilibrium any time soon. But I thought the purpose of the thread was to debate if there is in fact GW, not why?

Glom
2005-Oct-16, 11:06 AM
But the rate of increase is not changing much.

dgruss23
2005-Oct-16, 12:47 PM
Can we all agree the CO2 is increasing? This means we are not in equilibrium, and unless something is done either at the emission end or the removal end, we won't be in equilibrium any time soon.

The climate is never in equilibrium. Just in the last 1000 years we've had the Medieval maximum, the Little ice age, and now we're in a warming cycle again. On larger time scales you have major ice ages and interglacial warms. Evidence is increasingly showing solar activity is correlated with these changes.

Ken G
2005-Oct-16, 01:59 PM
On the contrary, those all sound like equilibrium configurations to me, in the sense of the temperature being set by a balance between energy inputs and energy responses. I misspoke that rising CO2 levels would imply we are out of equilibrium, what I meant was that they have the potential to knock us out the equilibrium we are in. The fact that temperature on the Moon varies so fast shows conclusively that terrestrial planets find thermal equilibrium on timescales of a year or so! (Yes it would be longer for Earth than the Moon, we're bigger and have lots of water, but I doubt that much longer). The only way to actually go out of equilibrium in any significant way is to bifurcate from one equilibrium solution to another (i.e., Venus). But realistically, we are not likely to see a bifurcation like that any time soon.
So really, what I meant was that we already know the timescales on which the Sun can cause temperature variations on Earth, and they are probably managable for humanity. What we have no idea about is the timescales on which human intervention can alter the climate. If your arguments hold sway on the policymakers, we may find out. That's really what I meant about losing equilibrium, it was not well stated.

dgruss23
2005-Oct-16, 03:49 PM
On the contrary, those all sound like equilibrium configurations to me, in the sense of the temperature being set by a balance between energy inputs and energy responses. I misspoke that rising CO2 levels would imply we are out of equilibrium, what I meant was that they have the potential to knock us out the equilibrium we are in.

By definition equilibrium means an unchanging balance in a system. The climate is never in equilibrium. It is always changing. Sometimes the changes are small, sometimes they are big. Equilibrium has nothing to do with this. Climate change is the issue and whether or not the CO2 increases are causing change .


The fact that temperature on the Moon varies so fast shows conclusively that terrestrial planets find thermal equilibrium on timescales of a year or so! (Yes it would be longer for Earth than the Moon, we're bigger and have lots of water, but I doubt that much longer).

I think you're underestimating the influence of both the ocean and the atmosphere.


So really, what I meant was that we already know the timescales on which the Sun can cause temperature variations on Earth, and they are probably managable for humanity.

We are still coming to understand the full range of scales over which the Sun influences climate. See for example this (http://www.sciencedaily.com/releases/2002/06/020607073439.htm) recent result.


What we have no idea about is the timescales on which human intervention can alter the climate.

Actually its even more fundamental than that. We are not sure that our changes in CO2 levels constitutes a climate "intervention" at all.

Ken G
2005-Oct-16, 09:35 PM
By definition equilibrium means an unchanging balance in a system.
Your literal definition of equilibrium equates it with a completely null set. The working definition is one of comparing driving timescales to response timescales. But it's a semantic point that is not relevant, I tried to explain what I meant by the term and I regret having used it at all.


I think you're underestimating the influence of both the ocean and the atmosphere.

You may be right there, certainly it would be interesting to know the fundamental response timescales of the Earth's climate.



We are still coming to understand the full range of scales over which the Sun influences climate. See for example this (http://www.sciencedaily.com/releases/2002/06/020607073439.htm) recent result.

Thanks for the link, interesting stuff, but of course AGW has nothing to do with 100,000 year timescales, it's three orders of magnitude shorter.

Let me ask you this: what do you think is the current probability that human intervention is causing the CO2 rise, and that this could lead to climate change? Also, what type of new evidence would you need to hear to raise your estimate to 50/50?

peteshimmon
2005-Oct-17, 07:26 PM
One more point about propellors and plankton.
I suspect the blades slicing through the water
create a pressure pulse and cell based
organisms may go "pop". Needs looking at I say.
I think I unwittingly hijacked this thread but
they decided they wanted a rest anyway. When
they start there is the other suggestion that
lone measurements of windspeed might show a
signal of increasing energy in the atmosphere.

dgruss23
2005-Oct-18, 03:00 AM
Your literal definition of equilibrium equates it with a completely null set. The working definition is one of comparing driving timescales to response timescales. But it's a semantic point that is not relevant, I tried to explain what I meant by the term and I regret having used it at all.

The problem here is that there is no compelling evidence that CO2 is capable of driving climate change on any timescales.



Thanks for the link, interesting stuff, but of course AGW has nothing to do with 100,000 year timescales, it's three orders of magnitude shorter.

The point is that the solar influence on climate is observed from the smaller decade length time scales on up through the 10^5 year timescales.

The whole AAGW claim hinges on the assumption that CO2 is capable of forcing climate change. The ice cores contradict this notion as does the 20th century temperature records in ways that I've discussed on the other thread I pointed you to.


Let me ask you this: what do you think is the current probability that human intervention is causing the CO2 rise,

Pretty good.


and that this could lead to climate change?

The evidence contradicts the notion that CO2 is a climate forcer. I've discussed that in the other thread ("Animosity" thread).


Also, what type of new evidence would you need to hear to raise your estimate to 50/50?

In the next 30 years if the solar cycle weakened but the climate warmed by a few tenths of a degree, then I would take that as evidence that other influences are overwhelming the solar influence. At that point CO2 increases would become a strong candidate.

As it is right now I've cited the Shaviv paper that finds 2/3 of the observed warming can be accounted for by direct and indirect solar influences.

If you read that thread I linked you'll see that all these questions are answered there.

Ken G
2005-Oct-18, 07:53 AM
The evidence contradicts the notion that CO2 is a climate forcer.

I must apologize for not being up on all your arguments in this vein, and I would not ask you to repeat them here. But my question was what is your estimate of the *probability* (a rough guess, of course, if you feel it possible) that CO2 might be a climate factor, not your opinion of the majority likelihood. The latter is already clear.



In the next 30 years if the solar cycle weakened but the climate warmed by a few tenths of a degree, then I would take that as evidence that other influences are overwhelming the solar influence. At that point CO2 increases would become a strong candidate.
OK, this is a constructive issue toward reaching consensus. But note that you must also consider a criteria in the presence of solar cycle strengthening or staying the same, or else you are saying you cannot be convinced unless the Sun does something particular. You would be hamstrung to reach a conclusion half the time if the Sun's influence was actually of minimal importance.


As it is right now I've cited the Shaviv paper that finds 2/3 of the observed warming can be accounted for by direct and indirect solar influences.

Yes, and what I am wondering is, what is the probability that the uncertainties in the analysis could result in the true answer being only 1/3, or 1/6? You see, when one is using science to make policy, it is not enough to cite the majority likelihood. That would be like going to the surgeon and being told that "2/3 of the time the surgery we are proposing will be beneficial to you, so you should have it". Would you go to such a doctor? It depends on the price of being wrong, and that's not a part of any internally scientific calculation.
We can all agree it is frustratingly hard to use science to set policy when the science is in its infancy. Under those circumstances, the greatest strength of science, it's own tolerance for being wrong, becomes its greatest weakness. To me, the fact that CO2 level rise is caused by human intervention, and the fact that it has a potential mechanism for climate change even if unproven, is worthy of attention. What it does is to give us a good reason to sit down and actually come up with a worldwide fossil-fuel energy policy, which we're going to need anyway as fossil fuels become less abundant, although that's equally much an issue of greed versus fairness. Your claim that this is a purely scientific question is an internally inconsistent position, because science in its purest form has no rules for interfacing with public policy. The AGW debate is inherently something a little different from science, because we're not allowed to be wrong here, if one cares about stewardship. It is much closer to the relationship that a doctor has with his/her patient, and we do well to remember their highest mission: do no harm.

dgruss23
2005-Oct-18, 11:56 AM
I must apologize for not being up on all your arguments in this vein, and I would not ask you to repeat them here. But my question was what is your estimate of the *probability* (a rough guess, of course, if you feel it possible) that CO2 might be a climate factor, not your opinion of the majority likelihood. The latter is already clear.

There is no evidence that CO2 is a forcer of climate change. If there was solid evidence that CO2 is a climate forcer, then the probability would be 100%. In the absense of any good evidence for CO2 as a climate forcer a rough guess is not possible. Should I estimate 10^-1, 10^-3, 10^-6? What is the value of rough probability estimate? Either you have the data needed to calculate a probability or you don't.



OK, this is a constructive issue toward reaching consensus.

Consensus is irrelevant.


But note that you must also consider a criteria in the presence of solar cycle strengthening or staying the same, or else you are saying you cannot be convinced unless the Sun does something particular. You would be hamstrung to reach a conclusion half the time if the Sun's influence was actually of minimal importance.

You asked for a criteria that would be compelling to me. You're right - if the solar cycle strengthens and warming occurs, then its going to be much harder to make a compelling case for CO2 induced warming. But you're not just facing the current crop if climate data in this issue. I've discussed in the other threads specific evidence in the climate record contradicting the notion of CO2 as a climate forcer. There is the 1940-1970 cooling trend that corresponds with a reduction in solar activity even as CO2 levels were increasing. There is also the 800 year gap between the increases in temperature and the increases in CO2 revealed in the ice cores with the CO2 increases lagging behind the temperature increases.
There is the growing body of evidence on all observable time scales that climate change has been directed by solar variations.


Yes, and what I am wondering is, what is the probability that the uncertainties in the analysis could result in the true answer being only 1/3, or 1/6?

If you will take the time to read the threads you will encounter the link, but I'll provide it again (http://arxiv.org/abs/physics/0409123). If you want to look at it those terms, the 1 sigma bounds on the warming and the model provide you with lower bound of 36% and upper bound >100% of the warming can be accounted for by solar influences.

Of course this study only accounts for direct solar irradiance changes as well as the cosmic ray influence. There is still a possibility that interstellar dust is modulated by the solar wind and provides another influence. So even the 2/3 estimate is possibly an incomplete accounting of the solar influence on climate.


We can all agree it is frustratingly hard to use science to set policy when the science is in its infancy. Under those circumstances, the greatest strength of science, it's own tolerance for being wrong, becomes its greatest weakness. To me, the fact that CO2 level rise is caused by human intervention, and the fact that it has a potential mechanism for climate change even if unproven, is worthy of attention.

No, its not just unproven, CO2 forcing is contradicted by evidence already published. Having evidence that contradicts a hypothesis is very different from simply lacking evidence that "proves" a hypothesis. We can dream up all sorts of mechanisms. Should we initiate public policy based upon every potential threat that someone invents?

Ebola originates in Africa. We know that people that travel there run a greater risk of being exposed to it. Should we stop all citizens from going there in order to prevent a worldwide outbreak? After all, it only takes one infected person on an airliner to tranport that disease.



What it does is to give us a good reason to sit down and actually come up with a worldwide fossil-fuel energy policy, which we're going to need anyway as fossil fuels become less abundant, although that's equally much an issue of greed versus fairness. Your claim that this is a purely scientific question is an internally inconsistent position, because science in its purest form has no rules for interfacing with public policy.

Can you show me where I claimed this is a purely scientific question? I specifically said I was not going to get into another pointless debate on economics. You're right, science has no rules for interfacing with public policy - which is why I don't see the point in talking public policy on this board. The science of AAGW is a matter of evidence and predictions that can be tested against that evidence. That is concrete within the uncertainty of the data.

Public policy is largely driven by political philosophy and belief. I'm not going to engage in those sorts of pointless discussion. I can engage in a discussion of the evidence - but why would I waste my time debating someone about their political philosophy.

Now how does the climate issue relate to public policy? The scientific evidence must first establish that there is a need for action. The points I find worth discussing involve that aspect. If it can be scientifically shown that the CO2 increases will in fact lead to catastrophic climate change and that there are plausible actions we could take to mitigate the threat, then its time to talk public policy.


The AGW debate is inherently something a little different from science, because we're not allowed to be wrong here, if one cares about stewardship. It is much closer to the relationship that a doctor has with his/her patient, and we do well to remember their highest mission: do no harm.

Which is why it must be scientifically established that harm is being done.

peteshimmon
2005-Nov-04, 03:54 PM
I think this thread is worth bumping up again with another question. What
were the effects of the great oil burning in Kuwait? I thought I noticed
an accelleration in CO2 levels from that time on a graph recently.