[another_someone]

quote:Originally posted by crandles
The figure for photosynthesis is 121.3. That figure is for the carbon cycle and the units are Gigatonnes of carbon per year. To convert to weight of CO2 you would multiply by 44/12.

I see where the figure of 121.3 is shown, but is that total photosynthesis.  The image seems to indicate the number of gigatonnes absorbed by trees.  It is not even clear if that is the figure including all land plants (grasses, mosses, etc.), let alone marine vegetation (including algae).

quote:
A reason I introduced the pic was to show the different timescales involved. For carbon in the atmosphere only lasts 750/(121.3+.5+90) = 3.5 years.

Do I understand from this statement that within 3.5 years all of the CO2 in the atmosphere (at present levels) will be turned over (i.e. mostly converted to O2, or to carbonates, or to carbonic acid) ?

quote:
A similar calculation can be done for oxygen and I now think it looks like about 10,000 years (not millions as I said earlier sorry).

Given the much greater amount of O2 in the atmosphere than CO2, I would expect it to take longer to turn over (if that is what your figure is trying to say), although I am surprised if takes almost 3000 times as long to turn over 550 times as much O2 as there is CO2.  You may suggest that this indicates that only 18% of the CO2 cycle actually is part of the O2 cycle, and thus 82% of the CO2 cycle would be through other pathways, but I will need convincing that these figures are complete enough to make this claim.  How are these lifetimes measured?
Nonetheless, even if the photosynthesis path only accounts for 18% of CO2 in the atmosphere, it cannot be ignored as insignificant, even if it is the lesser proportion.  Since the figures seem to suggest that human input of carbon into the atmosphere amounts to only 0.7% of the carbon already in the atmosphere (even if that figure is slightly higher now, it has not changed by orders of magnitude), the 18% of turnover that is caused by photosynthesis can be enough that a slight change in that figure can have a sufficient impact to absorb the output created by humans.

George

[crandles]

quote:Originally posted by another_someone
I see where the figure of 121.3 is shown, but is that total photosynthesis.  The image seems to indicate the number of gigatonnes absorbed by trees.  It is not even clear if that is the figure including all land plants (grasses, mosses, etc.), let alone marine vegetation (including algae).

I think it includes all land plants. I am unsure of the extent which marine vegitation uses dissolved CO2. If 100% dissolved CO2 then I think you can take the 50 as being marine photosynthesis.

quote:
Do I understand from this statement that within 3.5 years all of the CO2 in the atmosphere (at present levels) will be turned over (i.e. mostly converted to O2, or to carbonates, or to carbonic acid) ?

Depends what you mean by all. If you really mean 'all' then no lots persists for decades. If by all you mean the same total amount then yes. Clearly some is turned over a few times within 3.5 years and lots are not removed within 3.5 years.

quote:

Given the much greater amount of O2 in the atmosphere than CO2, I would expect it to take longer to turn over (if that is what your figure is trying to say), although I am surprised if takes almost 3000 times as long to turn over 550 times as much O2 as there is CO2.  You may suggest that this indicates that only 18% of the CO2 cycle actually is part of the O2 cycle, and thus 82% of the CO2 cycle would be through other pathways, but I will need convincing that these figures are complete enough to make this claim.  How are these lifetimes measured?

Nonetheless, even if the photosynthesis path only accounts for 18% of CO2 in the atmosphere, it cannot be ignored as insignificant, even if it is the lesser proportion.  Since the figures seem to suggest that human input of carbon into the atmosphere amounts to only 0.7% of the carbon already in the atmosphere (even if that figure is slightly higher now, it has not changed by orders of magnitude), the 18% of turnover that is caused by photosynthesis can be enough that a slight change in that figure can have a sufficient impact to absorb the output created by humans.

Edited out some rubbish, yes my 10,000 is wrong again. Oops sorry.

All I was trying to show was that the average times were very different. To me this makes saying 'but equally, one has to ask where did the oxygen come from' rather curious and made me ask what you meant but I don't seem to be getting anywhere.

That 0.7% figure you mentioned (5.5/750) is the amount per year not in total. The CO2 level is 30% higher as you mentioned earlier.

For better figures we are putting 7gigatonnes of carbon into the atmosphere but when we measure the atmosphere only 4 gigatonnes is turning up. So there is a natural reaction of the system to try to restore the balance by absorbing 3gigatones. You would expect the 90 and 92 figures to be equal if the system was in equilibrium. By boosting the CO2 in the atmosphere by 30% you would expect more CO2 to be dissolved than released. Similarly the land is taking up some of the carbon (121.3+.5>60+60+1.6) However there are limits to how much carbon the land can take up before it gets back in balance and it is expected the land could soon become an net emitter rather than a sink.

Yes 'a slight change in [photosynethis] could have a sufficient impact to absorb the output created by humans'. However, it doesn't look likely - why hasn't it happened so far? A more reasonable interpretation is that the natural reaction is only 3 gigatonnes and we are currently overwhelming this with 7 gigatonnes of carbon. It may seem reasonable to suggest that the 3GT could grow as we move more than 30% above CO2 levels of 100 years ago, but there are suggestions that the land will become a net emitter soon. There are also limits to ocean absorbtion - how much can be absorbed before the buffering ability of the ocean is exhausted and it start to become more acidic more rapidly?

[another_someone]

quote:Originally posted by crandles
Depends what you mean by all. If you really mean 'all' then no lots persists for decades. If by all you mean the same total amount then yes. Clearly some is turned over a few times within 3.5 years and lots are not removed within 3.5 years.

OK, I accept (and was aware at the time) that the 3.5 years was an average – and as such reflected only about 50% of the total – but as you say, for the purposes of the comparison it was sufficient.  Sorry abut the loose use of words.

quote:

quote:Originally posted by another_someone
Given the much greater amount of O2 in the atmosphere than CO2, I would expect it to take longer to turn over (if that is what your figure is trying to say), although I am surprised if takes almost 3000 times as long to turn over 550 times as much O2 as there is CO2.

Not sure where your 550 came from. 20% of the atmosphere compared to 380ppm is a ratio of around 50,000 not 550. Then you have got to mess about with the weight per volume/mole. My 10,000 could easily be wrong again.

209,460 ppmv / 381 ppmv  to my calculations comes to a ratio of 549.763 (i.e. approximately 550).

quote:
That 0.7% figure you mentioned (5.5/750) is the amount per year not in total. The CO2 level is 30% higher as you mentioned earlier.

I recognise the 0.7% was annual anthropogenic input; on the other hand, the 30% is not proven to be anthropogenic, or to what extent it may be anthropogenic.

quote:
For better figures we are putting 7gigatonnes of carbon into the atmosphere but when we measure the atmosphere only 4 gigatonnes is turning up. So there is a natural reaction of the system to try to restore the balance by absorbing 3gigatones.

Are you not jumping to conclusions?

Yes, we can say that we can measure 7 gigatonnes going in, and only 4 gigatonnes remaining in; but what can we say about how much would have been there if we had not put 7 gigatonnes in – we can say nothing.

We cannot say whether, if we had not pumped 7 gigatonnes of carbon into the atmosphere, the atmosphere may have actually had a reduction of 3 gigatonnes over what it had before; or whether if would have had an increase of 4 gigatonnes anyway, whether or not we had pumped the 7 gigatonnes in.

What we can reasonably say is that the processes that extract CO2 from the atmosphere cannot be directly aware of the amount of CO2 that humans have pumped into the atmosphere.

The only way these processes can respond to human input of CO2 into the atmosphere would be:

• They are impervious to any change humans make, and so in no way alter the amount of CO2 they annually remove from the atmosphere.  This clearly is not the case, since they are (as far as we can tell – and again, I am assuming, maybe erroneously, that other sources of CO2 have remained constant) removing 3 gigatonnes of CO2 more than they did before.
• They are sensitive to the actual amount of CO2 in the atmosphere (i.e. the actual vapour pressure).
• They are sensitive to the ratio of CO2 and some other gas (probably O2, since O2 is the output of photosynthesis, to which CO2 is the input, and most feedback relies on maintaining a balance between output and input) in the atmosphere.

If they are sensitive to the ratio of CO2 to some other gas, or susceptible to absolute vapour pressure, then what other factors may alter the balance point that effects this sensitivity?  Could the changes to CO2 levels in the atmosphere have more to do with other external factors (e.g. increases in temperature due to increases in temperature caused by increased solar output and reduced solar dimming) and much less to do with the actual amount of CO2 that humans create (which may be perfectly within the capacity of the system to absorb)?

quote:
 Yes 'a slight change in [photosynethis] could have a sufficient impact to absorb the output created by humans'. However, it doesn't look likely - why hasn't it happened so far? A more reasonable interpretation is that the natural reaction is only 3 gigatonnes and we are currently overwhelming this with 7 gigatonnes of carbon. It may seem reasonable to suggest that the 3GT could grow as we move more than 30% above CO2 levels of 100 years ago, but there are suggestions that the land will become a net emitter soon. There are also limits to ocean absorbtion - how much can be absorbed before the buffering ability of the ocean is exhausted and it start to become more acidic more rapidly?

If the issue is that the environmental system had enough slack to exactly absorb 3 gigatonnes of carbon in CO2 per year, and no more; it would seem a remarkably (to my view) unlikely scenario – why exactly 3 gigatonnes?  If it had just so much slack, then what we should see in the records is that each year, up until the point where human output exceeded 3 gigatonnes of carbon in CO2 there should have been zero increase in global CO2 levels, and each year subsequent to that point, we should have seen each tonne of additional anthropogenic CO2 reflected by exactly 1 tonne of additional CO2 in the atmosphere.  I am not aware that this is what has been observed.

George

[crandles]

Yes I was making a mess of my maths again.

quote:
I recognise the 0.7% was annual anthropogenic input; on the other hand, the 30% is not proven to be anthropogenic, or to what extent it may be anthropogenic.



Are you not jumping to conclusions?

Yes, we can say that we can measure 7 gigatonnes going in, and only 4 gigatonnes remaining in; but what can we say about how much would have been there if we had not put 7 gigatonnes in – we can say nothing.

We cannot say whether, if we had not pumped 7 gigatonnes of carbon into the atmosphere, the atmosphere may have actually had a reduction of 3 gigatonnes over what it had before; or whether if would have had an increase of 4 gigatonnes anyway, whether or not we had pumped the 7 gigatonnes in.

It is true that for a single year, we wouldn't know if new sources or sinks to the tune of 7 gigatonnes had just arisen.

However, we have record of CO2 from ice cores going back hundreds of thousands of years. From this we know that the changes we are seeing now: A change from 300 to 380ppmv (~180gigatonnes)within 100 years is extremely unusual. It makes sense for the natural reaction to such a large change to be that the land and ocean to take up carbon. So it is possible for new sources or sink to have arisen to the tune of 180 gigatonnes, but for this to have happened at just the right time would be a really remarkable coincidence.

Some likely ways the system will respond:

*If the CO2 in atmosphere increase the amount of CO2 being dissolved by the oceans will increase (and CO2 releassed decrease) until the balance is restored.

*Extra CO2 in atmosphere will cause increase in photosynethis as one of the imputs has been increased. However there are limits to how long this can last for as there is a limit to the amount of carbon that can be put into vegetation. At some point that increase in vegetation starts to die off and rot.

So we would expect the processes to be sensitive to the amount of CO2 and possibly ratio to other gasses.

quote:then what other factors may alter the balance point that effects this sensitivity?

There could be other things but we know from the ice core record that what is happening now is very unusual so to expect them to be significant at this time would be very odd.

quote:
If the issue is that the environmental system had enough slack to exactly absorb 3 gigatonnes of carbon in CO2 per year, and no more; it would seem a remarkably (to my view) unlikely scenario – why exactly 3 gigatonnes? If it had just so much slack, then what we should see in the records is that each year, up until the point where human output exceeded 3 gigatonnes of carbon in CO2 there should have been zero increase in global CO2 levels, and each year subsequent to that point, we should have seen each tonne of additional anthropogenic CO2 reflected by exactly 1 tonne of additional CO2 in the atmosphere. I am not aware that this is what has been observed.

I would expect that the amount has grown to 3gigatonnes per year slowly as the CO2 level has risen and the CO2 record is consistent with this. This is why I said "It may seem reasonable to suggest that the 3GT could grow as we move more than 30% above CO2 levels of 100 years ago"

I have pointed out why there are limits to the growth of that 3GT. I certainly don't think it is 'exactly 3 GT and no more'. Given the arguments for a limit to the growth of the 3GT I think it is foolishly optimistic to expect that 3GT to keep on growing so that we don't need to cut carbon emissions.

[another_someone]

quote:Originally posted by crandles
It is true that for a single year, we wouldn't know if new sources or sinks to the tune of 7 gigatonnes had just arisen.

The issue is not whether a new source or sink had arisen, but how much variability exists within the existing sources and sinks.

quote:
However, we have record of CO2 from ice cores going back hundreds of thousands of years. From this we know that the changes we are seeing now: A change from 300 to 380ppmv (~180gigatonnes)within 100 years is extremely unusual.

While I am not saying that you are wrong, would you like to be more explicit.  Exactly how unusual?  How precise are our long term historic measurements?  Can we say that over a 60 million years or more that we know with precision exactly what happened from one century to the next (in fact, as far as I can see, most of our more precise data is over less than ½ million year period, a very short period over the history of the Earth, and it is not clear to me that even over that period we have the kind of precision that would tell us what was happening within any given century)?

quote:
It makes sense for the natural reaction to such a large change to be that the land and ocean to take up carbon. So it is possible for new sources or sink to have arisen to the tune of 180 gigatonnes, but for this to have happened at just the right time would be a really remarkable coincidence.

Some likely ways the system will respond:

*If the CO2 in atmosphere increase the amount of CO2 being dissolved by the oceans will increase (and CO2 releassed decrease) until the balance is restored.

*Extra CO2 in atmosphere will cause increase in photosynethis as one of the imputs has been increased. However there are limits to how long this can last for as there is a limit to the amount of carbon that can be put into vegetation. At some point that increase in vegetation starts to die off and rot.

So we would expect the processes to be sensitive to the amount of CO2 and possibly ratio to other gasses.

Direct solution into the oceans is unlikely to really provide an adequate response, particularly since any warming influence (whether as a consequence of greenhouse gases, or as a consequence of increased solar input – the latter of which we know we have been experiencing in recent centuries – would actually cause less CO2 to be dissolved into the oceans).

The real issue has to be, to my mind, around how vegetation (including single celled photosynthesising organisms) respond.  As you say, after a while these organisms will die, but what happens to them when they die?

Forests are fairly hopeless as sinks because they do indeed either get quickly eaten by bacteria, fungi, or animals.  Peat bogs are certainly better, since they are anaerobic and will not convert back to CO2.  The question then has to be what happens within the oceans?  If the dead vegetation can reach anaerobic conditions (i.e. fall into the depths of the ocean), then it is still possible they can avoid being converted back to CO2.  Similarly, if the about of animals that create carbonate shells increases, and these then fall to the depths, then that will remove carbon from the system.

All of the above do not assume any increase in photosynthesis, but simply a change in the context of the photosynthesis, and a reduction in the processes that convert the carbon back to CO2.  This may even happen simply because of the death of many organisms that would generate CO2 (e.g. a reduction in the number of plant eating animals).  It is certainly true that as humans grow vegetation for their own purposes, they do deliberately try and prevent other wildlife from consuming it (unlike when humans create forests and nature reserves, where they deliberately encourage wild life to eat the vegetation).

quote:
I would expect that the amount has grown to 3gigatonnes per year slowly as the CO2 level has risen and the CO2 record is consistent with this. This is why I said "It may seem reasonable to suggest that the 3GT could grow as we move more than 30% above CO2 levels of 100 years ago"

I have pointed out why there are limits to the growth of that 3GT. I certainly don't think it is 'exactly 3 GT and no more'. Given the arguments for a limit to the growth of the 3GT I think it is foolishly optimistic to expect that 3GT to keep on growing so that we don't need to cut carbon emissions.

But it still seems like an arbitrary assumption.

George

[crandles]

quote:Originally posted by another_someone

quote:Originally posted by crandles
It is true that for a single year, we wouldn't know if new sources or sinks to the tune of 7 gigatonnes had just arisen.

The issue is not whether a new source or sink had arisen, but how much variability exists within the existing sources and sinks.

Or either or a combination.

quote:

quote:
However, we have record of CO2 from ice cores going back hundreds of thousands of years. From this we know that the changes we are seeing now: A change from 300 to 380ppmv (~180gigatonnes)within 100 years is extremely unusual.

While I am not saying that you are wrong, would you like to be more explicit.  Exactly how unusual?  How precise are our long term historic measurements?  Can we say that over a 60 million years or more that we know with precision exactly what happened from one century to the next (in fact, as far as I can see, most of our more precise data is over less than ½ million year period, a very short period over the history of the Earth, and it is not clear to me that even over that period we have the kind of precision that would tell us what was happening within any given century)?

Looking at



Lets be generous and say 4 similar sized spikes in 400,000 years. So the chances of one of those spikes starting within a 100 year period would seem to be in the region of 1000:1 against.

Saying 4 is generous because

http://en.wikipedia.org/wiki/Image:Carbon_Dioxide_400kyr.png

quote:
Throughout most of the record, the largest changes can be related to glacial/interglacial cycles within the current ice age.

quote:

Direct solution into the oceans is unlikely to really provide an adequate response, particularly since any warming influence (whether as a consequence of greenhouse gases, or as a consequence of increased solar input – the latter of which we know we have been experiencing in recent centuries – would actually cause less CO2 to be dissolved into the oceans).

The real issue has to be, to my mind, around how vegetation (including single celled photosynthesising organisms) respond.  As you say, after a while these organisms will die, but what happens to them when they die?

Forests are fairly hopeless as sinks because they do indeed either get quickly eaten by bacteria, fungi, or animals.  Peat bogs are certainly better, since they are anaerobic and will not convert back to CO2.  The question then has to be what happens within the oceans?  If the dead vegetation can reach anaerobic conditions (i.e. fall into the depths of the ocean), then it is still possible they can avoid being converted back to CO2.  Similarly, if the about of animals that create carbonate shells increases, and these then fall to the depths, then that will remove carbon from the system.

All of the above do not assume any increase in photosynthesis, but simply a change in the context of the photosynthesis, and a reduction in the processes that convert the carbon back to CO2.  This may even happen simply because of the death of many organisms that would generate CO2 (e.g. a reduction in the number of plant eating animals).  It is certainly true that as humans grow vegetation for their own purposes, they do deliberately try and prevent other wildlife from consuming it (unlike when humans create forests and nature reserves, where they deliberately encourage wild life to eat the vegetation).

Such things may indeed happen. So could other things that make things worse. For example the oceans are becoming more acidic and this may make it harder to create carbonate shells. So there may become less such organisms thereby decreasing the carbon transferred to the deep ocean.

It is more complex than I can hope to reason my way through. So I feel I have to rely on carbon cycle models built by experts. These suggest that the land will soon become a net emitter and the ocean will continue to only take up a proportion of the carbon released to the atmosphere.

[VAlibrarian]

I have to point out that 95% of climatologists agree with Crandles on this issue. We are not in any immediate danger of an ice age, but we are in immediate (100 to 200 years) danger of melting the Greenland and Antarctica ice sheets and saying goodbye to Bangladesh and part of Florida. Why would you assume that eventually doubling the amount of CO2 in the atmosphere would somehow improve the world climate?
I get baffled by you guys after a while. I am forced to conclude that you have made a decision to disagree with the prevailing conclusion on global warming because you do not like to agree with a scientific consensus. Why is that? Clearly it is not due to religious convictions. Maybe you enjoy feeling superior, and agreeing with others does not provide you that feeling?

I am sorry if this sounds a bit personal. But really, they pay these climatologists to figure things out. Why do you think you know science better than they do?

chris wiegard

[VAlibrarian]

Oh yes, i also needed to address the original posting. On a day like this one, I sympathize with the goal of drastically reducing the size of the human race. Since I had my vasectomy operation, I also have believed that sterilization (VOLUNTARY ONLY) can be a good thing, especially after having one or two kids (I have 2).

But really, most women in the third world would be thrilled to have fewer children. It's just that they have no access to free contraceptives and their husbands would rather lose them in childbirth than have smaller families. The only thing that needs to change is improved access despite the obstinate husbands.
I have despised George W. Bush for the past six years because his first act as president was to eliminate all funding for international family planning. Stupid. We expect ourselves in the  United States of America to solve all the world's problems, then we immediately refuse to help address the most serious problem of all. Far cheaper to prevent the conception of a human being than to feed, clothe, educate, combat, imprison, etc. the resulting person.

chris wiegard

[another_someone]

quote:Originally posted by VAlibrarian
But really, most women in the third world would be thrilled to have fewer children.

Upon what evidence do you base this assertion?

I would argue that this is not by any means the case.  What I would agree with is that most educated women (i.e. the women you will probably get to talk to over the Internet, or by other means of modern communication) would love to have fewer children, and many do achieve this.

Human beings (women as well as men) like to feel they have achieved something.  For many uneducated rural women, they have little opportunity to achieve except by having children, so that is the achievement they seek.

It must also be said that children represent an old age pension – another reason why children are so important in communities that have no other way of looking after their elderly (in fact, at a communal level, even in the rich Western world, we still depend upon our young to look after our elderly, but this is at a communal level and not at a personal level, so individuals (like myself) can choose to opt out of having children, while hoping that other people's children may look after me in my old age).

George

[another_someone]

quote:Originally posted by VAlibrarian
I have to point out that 95% of climatologists agree with Crandles on this issue. We are not in any immediate danger of an ice age, but we are in immediate (100 to 200 years) danger of melting the Greenland and Antarctica ice sheets and saying goodbye to Bangladesh and part of Florida.

But true science (unlike much of environmentalism) is meritocratic, not democratic.

That environmentalism (inevitably so, as it is an 'ism') is more about politics than about science, and so understandably the argument that 95% of climatologists believe one theory over another (they are only theories) does carry political weight.

quote:
 Why would you assume that eventually doubling the amount of CO2 in the atmosphere would somehow improve the world climate?

This is the difference between us that you seem to find so difficult to comprehend – that I do not believe that in the grand scheme of things there can ever be in any absolute sense 'good' or 'bad', or 'better' or 'worse' climate.  Good and bad are ethical judgements, and how do you make ethical judgements about climate?  Climate is as it is, and it has never stood still, so why should it now?

Was the mini-ice age in the middle of the 17th a better or a worse climate than we have today?  Was the medieval warm period that preceded it a better or worse climate than that of the mini ice age?

Do you really think that as the climate cooled between the 11th to the 17th century, people did not suffer; or that as the climate warmed since then, that people did not suffer?  Do you really believe we can ever create a world where the climate does not change, or where that change will not present challenges?

Just look at the stories of floods in the bible (and while I am no great believer in the bible, it does seem very plausible that those floods mentioned are probably folk memories of real floods that happened).  Ofcourse, in the bible, the population believes the floods came about because they had displeased God in some way, so too the environmentalists believe that modern floods happen because we have displeased nature in some way.  The reality is that floods happen even in the absence of humanity, so it is not all our fault.

I am not saying that I am being totally nonchalant about the suffering of people, but the best way of addressing the suffering of people is to give them the means to survive adverse weather, and not by vainly  (and insanely) trying to prevent adverse weather.  Back to the biblical example – it does not suggest that Noah tried to argue with God not to send the floods, but that he went about building an ark to save himself and his family from the unavoidable climate change.  OK, as I said, I am no promoter of the bible, but that is one example that I agree with wholeheartedly.

quote:
I get baffled by you guys after a while. I am forced to conclude that you have made a decision to disagree with the prevailing conclusion on global warming because you do not like to agree with a scientific consensus. Why is that? Clearly it is not due to religious convictions. Maybe you enjoy feeling superior, and agreeing with others does not provide you that feeling?

I am sorry if this sounds a bit personal. But really, they pay these climatologists to figure things out. Why do you think you know science better than they do?

They pay politicians to make decisions on our behalf – does that mean we are obliged always to defer to political consensus?

There are two possible ways of looking at this.  One way would be to say that I am not a qualified scientists, and therefore have no opinion about scientific matters (in which case, what am I doing on a forum such as this?).

The other option is to say that I think for myself. I will listen to scientific opinion by all those who choose to give me their opinion (and this includes your good self, even if I choose to disagree with you), but ultimately my opinion must be that which makes sense to me, and I do simply act out of mere deference to someone else's wage packet.

Some people are by nature of the type that pay deference, and choose not to make judgements for themselves.  I am not of that creed.  That I am not of that creed makes it inevitable that there will be times when my own opinion contravenes democratic consensus.  But then, what value would there be in democratic consensus if everyone had the same opinion?

In fact, if it is your assertion that only professional climatologists have a right to an opinion on climate, then unless you are yourself a climatologist, that would in effect deny you the right to an opinion on the matter also.  This in effect would mean that you do not express your own opinion at all, but merely become a messenger for the opinion of others.

George

[crandles]

quote:Originally posted by another_someone

This is the difference between us that you seem to find so difficult to comprehend – that I do not believe that in the grand scheme of things there can ever be in any absolute sense 'good' or 'bad', or 'better' or 'worse' climate.  Good and bad are ethical judgements, and how do you make ethical judgements about climate?  Climate is as it is, and it has never stood still, so why should it now?

Was the mini-ice age in the middle of the 17th a better or a worse climate than we have today?  Was the medieval warm period that preceded it a better or worse climate than that of the mini ice age?

Do you really think that as the climate cooled between the 11th to the 17th century, people did not suffer; or that as the climate warmed since then, that people did not suffer?  Do you really believe we can ever create a world where the climate does not change, or where that change will not present challenges?

No, we cannot create a world where the climate does not change, or where that change will not present challenges. However this does [size=18]not[/size=18] mean do nothing.

A cooling world would be worse than a warming world, so we should be thankful that it isn't cooling at the same rate that it is warming. The problem is the rate of change - it is high and likely to remain high if we do nothing. The more change there is over a short period the less likely that infrastructure will cope. There are plenty of examples of civilisations collapsing due to climate change.

Do you really think that we cannot make judgements like a fast rate of change is worse than a slow rate of change?

[another_someone]

quote:Originally posted by crandles
Do you really think that we cannot make judgements like a fast rate of change is worse than a slow rate of change?

In an absolute sense, no I don't think we can make that judgements.

As a qualified statement, to say that that this or that is worse for a particular outcome, yes – but first you have to decide what that outcome you desire is, and somehow to justify that outcome.

Interestingly, since the start of this thread commences with the statement that some people consider further expansion or even stability of human population is undesirable, thus we were to accept this, must remove maximising human population success as a goal.

George

[crandles]

I think that is just weird (and I say that to try to keep within the limits of what I can say to a moderator). There are lots of things that are clearly bad about a fast rate of change.

The opening post also said

quote:The extinction of any species by our hands is a crime beyond all other
crimes

To take things to the extreme, I don't think it is hard to say we don't want a process like:  

global warming >> ocean anoxia >> H2S outgassing process >> Ozone destruction
and each/each combination resulting in mass extinctions.

See http://www.sciam.com/article.cfm?chanID=sa006&articleID=00037A5D-A938-150E-A93883414B7F0000&pageNumber=1&catID=2

[VAlibrarian]

As far as I can see, global warming has the potential to increae human mortality as well as the extinctions of other species. I am not open minded enough to accept this prospect with equanimity.

If you think of the human race as just a species like amoebas or rattlesnakes, it does not matter much if there are 6 billion of us or only say 2 billion. But as a member of the human race I have a certain feeling of loyalty and it is disturbing to me that global warming could put downward pressure on our population. It also disturbs me that conditions may eventually result (according to Edward O. Wilson of Harvard University in his book The Creation) in half of the other species of our planet disappearing. I disagree with those who say the survival of other species is not our business.

chris wiegard

[another_someone]

quote:Originally posted by crandles
I think that is just weird (and I say that to try to keep within the limits of what I can say to a moderator). There are lots of things that are clearly bad about a fast rate of change.

The opening post also said

quote:The extinction of any species by our hands is a crime beyond all other
crimes

To take things to the extreme, I don't think it is hard to say we don't want a process like:  

global warming >> ocean anoxia >> H2S outgassing process >> Ozone destruction
and each/each combination resulting in mass extinctions.

See http://www.sciam.com/article.cfm?chanID=sa006&articleID=00037A5D-A938-150E-A93883414B7F0000&pageNumber=1&catID=2

There is a difference between saying you don't want something, and saying that it is in some absolute sense 'bad'.  All I said was that one cannot talk in absolute terms about 'good' or 'bad', but only in relative terms by saying that you desire a particular outcome, and something will help or hinder that outcome.  I was merely arguing  against the unqualified use of the terms 'worse' or 'better', in that you did not say what the objective was that you felt these things were better or worse for, thus making it difficult to agree or disagree as to whether it would be better or worse for such an outcome.

One interesting aspect of the article is that it seems to make very different assumptions to the ones you have made earlier.  The article uses C12/C13 atmospheric ratios as an indication of the amount of photosynthesis – the assumption being that there is a constant amount of carbon that is shared between living organisms and the atmosphere, and thus the less C12 in relation to C13 in the atmosphere can be regarded as a direct measure of the amount of C12 taken up by living organisms.  This seems to contradict your earlier argument that the amount of carbon taken out of the atmosphere by photosynthesis is negligible, and that the dominant means of extracting carbon from the atmosphere is inorganic (which would affect the C12/C13 ratios differently and would likely confuse any measurement that ignored those factors).

What is also interesting (as you have yourself now mention) is the issue of anoxia – but this again contradicts your earlier insistence that we can ignore the oxygen levels in the atmosphere as telling us nothing useful regarding the carbon cycle (on the assumption that most of the carbon cycle had little to do with photosynthesis).  Then again, if O2 levels dropped so far as to allow anaerobic life to exist in most of the ocean, then we are talking about levels of CO2 that would be well above the most extreme that anyone has talked of coming about from industrial output (in fact, humans would be incapable of pushing CO2 levels to that extreme since the lack of atmospheric oxygen would make combustion extremely difficult, aside from the requirements for humans themselves).

In fact, as far as I can see, the scenario the article is talking about came about not so much directly by the increase of CO2, as by the reduction of O2 that allowed the growth of anaerobic bacteria.

Ofcourse, you might argue that the other factor that would have an effect is global warming (not CO2 necessarily, but any cause that would increase water temperatures).  The only thing to be said about that is that even with the present climate being warmer than any time since the middle ages, it is still very much cooler than at many other times when mass extinctions did not take place.

In any case, if one's main concern is the H2S that may be produced by anaerobic bacteria in the ocean, this could be addressed directly by seeking to control the growth of that bacteria in other ways (although the assumption seems to be that this would at most be only a threat some centuries hence, and direct intervention could be very much faster and more manageable that trying to manipulate atmospheric O2 and CO2 levels).

Ofcourse, the other interesting issue that was totally omitted within the article, which sought only to demonstrate why so much of aerobic life died, is why so much survived.  We have a continuity of species through the extinction events (most recently, although the extinction event of 65 million years ago may have killed T. Rex and all the large dinosaurs, it did not kill all dinosaurs for they became birds, let alone insects and crocodiles and early mammals and  many other species).  If we are looking to human survival as an objective, then we must understand why things survive just as much as understand why they die.  If we constantly only look at doomsday scenarios, and accept with defeatism that any seriously challenging environmental condition will automatically spell death for the human species, then we start with a disadvantage in trying to meet the inevitable challenges that are unavoidable.  We cannot stop environmental change, any more than our predecessors could, but we can learn how to adapt to it, as some of them did, while others did not.

George

[crandles]

quote:Originally posted by another_someone

There is a difference between saying you don't want something, and saying that it is in some absolute sense 'bad'.  All I said was that one cannot talk in absolute terms about 'good' or 'bad', but only in relative terms by saying that you desire a particular outcome, and something will help or hinder that outcome.  I was merely arguing  against the unqualified use of the terms 'worse' or 'better', in that you did not say what the objective was that you felt these things were better or worse for, thus making it difficult to agree or disagree as to whether it would be better or worse for such an outcome.

There is a difference between absolute and relative but in this case it is so obvious as to not really make any practical difference.

quote:
One interesting aspect of the article is that it seems to make very different assumptions to the ones you have made earlier.  The article uses C12/C13 atmospheric ratios as an indication of the amount of photosynthesis – the assumption being that there is a constant amount of carbon that is shared between living organisms and the atmosphere, and thus the less C12 in relation to C13 in the atmosphere can be regarded as a direct measure of the amount of C12 taken up by living organisms.  This seems to contradict your earlier argument that the amount of carbon taken out of the atmosphere by photosynthesis is negligible, and that the dominant means of extracting carbon from the atmosphere is inorganic (which would affect the C12/C13 ratios differently and would likely confuse any measurement that ignored those factors).

Different techniques for different purposes and even different time periods can be appropriate.

Earlier we wanted to compare the 7 gigatonnes of carbon from fossil fuels to the net difference 121.3+.5-60-60-1.6=0.2 For this we didn't really care much what the 121.3 figure was exactly because there was more uncertainty in the 60 figures. We only wanted the change in the level of carbon in soil and vegetation and to consider how that was likely to change with time.

If you do want to know the 121.8 figure then using the C12/C13 ratio is appropriate.

quote:
What is also interesting (as you have yourself now mention) is the issue of anoxia – but this again contradicts your earlier insistence that we can ignore the oxygen levels in the atmosphere as telling us nothing useful regarding the carbon cycle (on the assumption that most of the carbon cycle had little to do with photosynthesis).  Then again, if O2 levels dropped so far as to allow anaerobic life to exist in most of the ocean, then we are talking about levels of CO2 that would be well above the most extreme that anyone has talked of coming about from industrial output (in fact, humans would be incapable of pushing CO2 levels to that extreme since the lack of atmospheric oxygen would make combustion extremely difficult, aside from the requirements for humans themselves).

Not really sure where I was insisting we can ignore the oxygen levels but it is quite possible I have said something either to that effect or has been misinterpreted. If you can go about measuring something in at least two different ways, then it can be sensible to use the method with a low margin of error (measuring the carbon)rather than a method with a high margin of error(measuring the oxygen). This is not the same as saying ignore the oxygen level for all purposes!

For considering anoxia you are going to consider the oxygen level.

quote:
In fact, as far as I can see, the scenario the article is talking about came about not so much directly by the increase of CO2, as by the reduction of O2 that allowed the growth of anaerobic bacteria.

I suspect the article made a rather dubious attempt to make it seem relevant to what was happening today. I also very much doubt greenhouse warming alone could cause such a scenario.

quote:
Of course, you might argue that the other factor that would have an effect is global warming (not CO2 necessarily, but any cause that would increase water temperatures).  The only thing to be said about that is that even with the present climate being warmer than any time since the middle ages, it is still very much cooler than at many other times when mass extinctions did not take place.

Yes it is a very extreme possibility which isn't likely. Trying to slip in 'warmer than any time since the middle ages'? There are lots of reconstructions and their best estimates all show a temperature for the medieval warm period cooler than today.


 

quote:
In any case, if one's main concern is the H2S that may be produced by anaerobic bacteria in the ocean, this could be addressed directly by seeking to control the growth of that bacteria in other ways (although the assumption seems to be that this would at most be only a threat some centuries hence, and direct intervention could be very much faster and more manageable that trying to manipulate atmospheric O2 and CO2 levels).

Certainly not my main concern; I did say it was an extreme when I introduced it. I felt it showed that it was easy to say a fast rate of change was bad and this was so self evident that it didn't need an excercise in deciding what was bad.

[another_someone]

quote:Originally posted by crandles
There is a difference between absolute and relative but in this case it is so obvious as to not really make any practical difference.

I suppose I still have a preference to making sure the terms of the debate are overt and not merely assumed, and each side assuming the other side is making exactly the same assumptions as itself.

quote:
Different techniques for different purposes and even different time periods can be appropriate.

Earlier we wanted to compare the 7 gigatonnes of carbon from fossil fuels to the net difference 121.3+.5-60-60-1.6=0.2 For this we didn't really care much what the 121.3 figure was exactly because there was more uncertainty in the 60 figures. We only wanted the change in the level of carbon in soil and vegetation and to consider how that was likely to change with time.

If you do want to know the 121.8 figure then using the C12/C13 ratio is appropriate.

And what about the 90/92 gigatonne exchange with the oceans, the 38 teratonnes of carbon stored in the deep oceans, or the (up to) 700 gigatonnes of organic carbon in the oceans.

There are so many variable, and I doubt that any are well known (we don't actually know very much about the deep oceans at all).

You say the O2 cycle and C12/C13 ratios are only appropriate for the 121.3 (I assume your 121.8 was a mistype), but by your own admission, you do not know if this takes into account what is going on in the oceans.  I am not even sure that it accurately monitors what is going on on the land, since I cannot imagine it can accurately monitor in any direct way the total amount of moss, grass, and other vegetation that lives in every nook and cranny on the surface of the Earth – the only measurements you can take are the indirect.

quote:
Not really sure where I was insisting we can ignore the oxygen levels but it is quite possible I have said something either to that effect or has been misinterpreted. If you can go about measuring something in at least two different ways, then it can be sensible to use the method with a low margin of error (measuring the carbon)rather than a method with a high margin of error(measuring the oxygen). This is not the same as saying ignore the oxygen level for all purposes!

But the point is that I cannot see how one can accurately measure the amount of carbon extracted from the atmosphere.  We can measure the amount of carbon remaining in the atmosphere, but to measure the amount of carbon removed from the atmosphere one has to find ways of determining how much carbon might otherwise be in the atmosphere.  Since O2 is a residue created when carbon is removed from the atmosphere, it seems about the best indicator (as imperfect as it is) for indicating how much carbon would have been in the atmosphere, and thus give some indication of the capacity of the environment to absorb carbon from the atmosphere.

quote:
Trying to slip in 'warmer than any time since the middle ages'? There are lots of reconstructions and their best estimates all show a temperature for the medieval warm period cooler than today.

The black line shows direct measurements that were taken since 1856.  These may be more accurate than the other colours, but it is not at all comparable to any of the historic indirect measurements.  All of the like for like measurements show a far greater ambiguity concerning the relative temperature between the middle ages and today.  That having been said, I accept that the red line, which seems to be based on tree ring data, stops at 1990, and so does not include the last 16 years.  Whether the last 16 years is sufficient basis for extrapolating a new trend, let alone a trend for which we have no comparable historic data, is another matter.

quote:
I did say it was an extreme when I introduced it. I felt it showed that it was easy to say a fast rate of change was bad and this was so self evident that it didn't need an excercise in deciding what was bad.

On the contrary.

http://www.sciam.com/article.cfm?chanID=sa006&articleID=00037A5D-A938-150E-A93883414B7F0000&pageNumber=2&catID=2

quote:
As researchers continued to probe the data in recent years, however, they found that some things did not add up. New fossil analyses indicated that the Permian and Triassic extinctions were drawn-out processes spanning hundreds of thousands of years. And newly obtained evidence of the rise and fall of atmospheric carbon, known as carbon cycling, also seemed to suggest that the biosphere suffered a long-running series of environmental insults rather than a single, catastrophic strike.

This article does not seem to believe that a rapid change caused the extinctions, but rather that a persistent change (whether rapid or slow in origin) caused the extinctions events.

I am not saying that rate of change is insignificant, but that rate of change cannot alone tell us about outcome.

In any event, as I said before, these extinction events did not kill off all living organisms, and if our concern is for the survival of the human species (ofcourse, this is an arbitrary objective – which is why I was trying to be explicit above in indicating that we cannot judge 'good' and 'bad' until we decide what our objectives are), then we have to be more specific than merely to say that many species died – we need to know precisely how our own species would respond to a particular change.

George

[another_someone]

http://www.pacificresearch.org/pub/sab/enviro/05_enviroindex/18_climate_change.html

• Dispute continues over Michael Mann’s “hockey stick” graph, which purports to prove that the last 25 years have been the warmest in the last 1,000 years. Scientists have shown that a key step in the process used to generate Mann's graph is strongly biased in favour of finding hockey stick patterns even in lists of random numbers. One internationally renowned expert has called the graph “methodologically wrong” and “rubbish.”
• July 2004 was the coolest July in the last four years. Perhaps that’s partly because the annual rate of increase in the concentration of CO2 in the atmosphere is only about half of what is expected based on man-made emissions. Scientists believe the oceans are absorbing the missing half.
• The arctic today, though warmer than it was in 1970, is colder than it was in 1930. In fact, temperatures in Greenland have fallen over the last 15 years. That is leading some scientists to believe that shifts in the wind, rather than temperature change, are responsible for any retreating of the arctic ice.

It is hard to settle on a results-oriented metric for what is happening with climate change in the United States or around the world. And it’s even harder to settle on one for the ongoing dispute about policy responses.

The best metric would be temperature. Everyone agrees that global temperatures have risen about 0.6 degrees celsius over the last century.1 But controversy remains about the accuracy of our recent measurements and the pace of warming. In 2004, there were more attempts to square one of the leading anomalies of climate measurement.

Ground-based temperature readings show a warming trend over the last 25 years. Satellite temperature measurements of the lower atmosphere (or troposphere) show only about half as much warming, even though most climate models suggest the lower atmosphere should warm even more than ground level. To understand this controversy, keep in mind that ground-level temperatures are taken the old fashioned way—with thermometers. They are then corrected for the “urban heat island effect,” i.e. the fact that most temperature readings are taken near cities and other human-altered areas where temperatures are higher than the average atmospheric temperatures for the planet as a whole.

Satellite temperature readings, by contrast, come from microwave readings rather than direct measurement. They require statistical interpretation because microwave readings yield different temperatures at varying elevations from the earth’s surface. Any data that can be interpreted statistically can be re-interpreted statistically to get a different result. This is exactly what a team led by Qiang Fu at the University of Washington did in a study published in Nature last May.2

By “correcting” for the cooling effect of the stratosphere (the next layer of the atmosphere above the troposphere), the satellite results can be brought into line with the surface thermometer readings. Case closed? Probably not. John Christy, director of the Earth System Science Center at the University of Alabama/Huntsville, disputes the Fu findings, and argues that the Fu team has over-corrected for stratospheric cooling and introduced new statistical errors into the analysis. Christy was one of the designers of the satellite observation system, and the first to point out, more than a decade ago, the discrepancy between satellite and surface temperature readings.

This is not the first attempt to reconcile the clashing temperature findings with statistical re-analysis, and it is unlikely to be the last. Another major statistical controversy over temperature readings erupted during the last two years.

As sports-minded readers know, the entire National Hockey League season was called off in 2004 on account of labor difficulties. While it is certainly coincidental, we can’t help but notice that the famous “hockey stick” graph that was supposed to be the “smoking gun” of global warming has quit working too. The dispute about Michael Mann’s “hockey stick” graph, which purports to prove that the last 25 years have been the warmest in the last 1,000 years, has intensified in recent months. Criticisms are rolling in from more scientists and statisticians.

As reported in last year’s edition, the Mann “hockey stick” graph would seem to negate what has always been referred to as the “medieval warm period” that preceded the “little ice age,” from roughly 1400 to 1850. New statistical critiques from Steven McIntyre and Ross McKitrick, the duo that raised the first questions about the hockey stick, have furthered doubts about the accuracy of the hockey stick. Other climate scientists, including several affiliated with the Intergovernmental Panel on Climate Change (IPCC), have reviewed the methodological dispute and come down on McIntyre and McKitrick’s side.

McIntyre and McKitrick have demonstrated that the computer algorithm used to generate the hockey stick graph is strongly biased in favor of finding hockey stick patterns even in lists of random numbers. Dr. Rob van Dorland, an IPCC lead author and climate scientist at the Dutch National Meteorological Agency, has said the controversy will “seriously damage the image of the IPCC.” Van Dorland added: “It is strange that the climate reconstruction of Mann passed both peer review rounds of the IPCC without anyone ever really having checked it.”

The most devastating critique comes from Hans von Storch, an IPCC contributing author and internationally-renowned expert in climate statistics at the Center for Coastal Research in Geesthacht, Germany. He has said the McIntyre-McKitrick critique is “entirely valid,” and that the hockey stick graph “contains assumptions that are not permissible. Methodologically it is wrong: rubbish.”

University of California physicist Richard Muller wrote in Technology Review that the hockey stick “turns out to be an artifact of poor mathematics.” Everyone, including McIntyre and McKitrick, is quick to qualify their criticisms by saying the debunking of the hockey stick does not mean global warming is not happening today; merely that we still cannot confidently tell from the available data the exact temperature history of the last millennium.3

This is a vital point, because whenever anomalies call into question our mastery of climate science, the defenders of urgent action immediately repair to the “consensus.” Critics of specific aspects of climate science are usually portrayed—if not demonized—as climate change “skeptics” or deniers, on par with Holocaust deniers.

Science magazine stirred a furor late in the year with “The Scientific Consensus on Climate Change,”4 an article by Naomi Oreskes. She analyzed nearly 1,000 articles on climate science in scientific journals, and found none dissented from the “consensus” position. Oreskes concludes that “there is a scientific consensus on the reality of anthropogenic climate change. Climate scientists have repeatedly tried to make this clear. It is time for the rest of us to listen.”

Roger Pielke of the University of Colorado pointed out on his website that Oreskes’s argument amounts to a poorly constructed straw man.5 Who, exactly, says the general consensus is wrong? Fred Singer, considered one of the leading “skeptics,” says: “In fact, the IPCC statement is in many ways a truism. There certainly must be a human influence on some features of the climate, locally if not globally.”

 Another leading “skeptic,” Pat Michaels, says: “It has been known since 1872 that water vapor and carbon dioxide are the principal ‘greenhouse’ gases in the atmosphere, and that increasing their concentration should elevate the temperature in the lower atmosphere. What has been a subject of contention ever since is the amount and character of the warming.” And Bjørn Lomborg has said: “There is no doubt that global warming is happening or that it is important. Carbon dioxide from burning fossil fuels will increase Earth’s temperature. That is likely to have an overall negative effect.”

This last statement from Lomborg is especially significant because he has raised the question in acute form of what should be done now about climate change relative to other current world problems. Even Oreskes herself admits that “Many details about climate interactions are not well understood, and there are ample grounds for continued research to provide a better basis for understanding climate dynamics. The question of what to do about climate change is also still open.” (Emphasis added.) Lomborg’s “Copenhagen Consensus” exercise last year ranked global warming low on a list of world priorities, for which he was roundly abused.

Dr. Rajendra Pachauri, the IPCC’s chairman, compared Lomborg to Hitler. “What is the difference between Lomborg’s view of humanity and Hitler’s?” Pachauri told a Danish newspaper. “If you were to accept Lomborg’s way of thinking, then maybe what Hitler did was the right thing.” Lomborg’s sin was merely to follow the consensus practice of economists in applying a discount to present costs for future benefits, and comparing the range of outcomes with other world problems alongside climate change.

It is hard to judge what is worse: Pachauri’s appalling judgment or his abysmal ignorance of basic economics. In either case, it is hard to have much confidence in the policy advice the IPCC might give. It might be added that when Pachauri compared Lomborg to Hitler, he ran afoul of what is known in the Internet blogosphere as “Godwin’s Law,” which holds that resorting to reductio ad Hitlerum is a sure sign that someone is losing an argument.

Are the “skeptical” questions about our mastery of climate science and its relation to the timing of policy very different from some of the caveats that appear in the “consensus” reports, such as the IPCC’s latest assessment? Consider, for example, this passage from the latest IPCC assessment report:

There is an increasing realization that natural circulation patterns such as 'El Nino-Southern Oscillation' and 'North Atlantic Oscillation' play a fundamental role in global climate science and its interannual and longer-term variability.6

Or this, from a different section of the IPCC report:

In climate research and modeling, we should recognize that we are dealing with a coupled non-linear chaotic system, and therefore that the long-term prediction of future climate states is not possible.7

To this can be added the judgment of the U.S. National Research Council, from whose 2001 report, “Climate Change Science: An Analysis of Some Key Questions,” one sentence was widely cited by climate-action enthusiasts: “The recent [climate] changes observed over the last several decades are likely mostly due to human activities.”

If, as keepers of the “consensus” view readily admit, “the question of what to do about climate change is still open,” then why this belabored attempt to bash a straw man, if not to build political pressure for the agenda of immediate carbon suppression? As the argument over our knowledge of climate science continues to go badly for alarmists, advocates of Kyoto-style carbon suppression are becoming increasingly shrill.

[rosy]

<quote>I think that is just weird (and I say that to try to keep within the limits of what I can say to a moderator). </quote>
As no-one's picked up on the above yet I will... There is no distinction between what you can say to a mod and what you can say to anyone else. None. The mods are among the most frequent users of the forum and will read most if not actually all new posts... so being abusive will get picked up on whoever you're talking to (even if you don't get actively reported by someone else). Also, the mods don't, or at all events positively try not to, treat people differently who are abusive to them than to anyone else.

... somewhat rambling but I hope you'll take my point.