A Note: Global Warming Threads

[iceaura]

So given both of those facts, the conclusion it quite simple, changes that would resemble in any way the Venusian Catastrophe, could not possibly happen in several hundred years.

Lessee - the argument is that we can't get into an uncontrolled methane release loop without melting the Antarctic ice cover completely, first?

I'm not quite sure the probability of that being true is 1.

The normal argument is more often the other way around - that we can't melt the entire Antarctic ice sheet without first getting into something like an uncontrolled methane release loop.

Either way, the positing of something like the influence of the Antarctic ice cap being the major obstacle to a Venusian catastrophe illustrates my observation: we appear to be in some reasonable danger of touching off a methane feedback loop - of possibly having done so already, even. And the factor responsible was and is the anthro CO2 buildup.

 

[Trippy]

OK: your point there simply advances a mechanism by which the new plateau would be established - the oxidation of the methane itself producing some water at the appropriate altitudes and curbing its own further increase, etc.

Ozone, not water.
Ozone is the critical component in the production of Hydroxyl radicals.
My suggestion is that to some extent the atmosphere is capable of buffering emissions, and that there's some critical value they need to exceed before the increase registers as an increase in the levels of atmospheric methane. And that this property, especially when combined with observations such as the draining of wetlands, and the change in attitude of the oil industry to methane etc etc, is sufficient to explain the levelling out.

But a methane greenhouse "disaster" - from the increased water vapor assumed, the extra CO2 produced, the boosted methane concentration established, and so forth - is a real and present concern: correct?

Define disaster.
No, seriously, go ahead.
My assertion is that Billy T's scenario is impossible - Billy T and I have previously discussed this elsewhere.
My position is what it is because as similar as earth and venus are, there are also some very fundamental differences, and those fundamental differences are, according to the research I have managed to do on the issue, generally considered sufficient to explain the obsereved modern differences, and doing so becomes much easier if you're willing to accept the giant impact hypothesis of Lunar Genesis.
Sure, an abrupt release of methane might make things unpleasant for Humans, but even if we burn all the coal and oil, and vent all the clathrates into the atmosphere the worst we'd be looking at is an end to civilization as we know it. In as little as 200,000 years the oceans will have scrubbed the excess CO[sub]2[/sub] out of the atmosphere resulting in maybe a 10% increase in atmospheric CO[sub]2[/SUB] as a new equilibrium level is established.

Even the authors of the Clathrate Gun Hypothesis suggested that an abrupt release of methane could trigger an ice age rather than a period of warming - through ignition and conflagration (which would also cause regional extinctions).

The simple fact of the matter is that even if we admit the Clathrate gun hypothesis, and even if we admit the idea of the CGH causing the Permian-Triassic extinction (generally considered implausable) or the PETM as being caused by it, then the scenario of switching to venusian hot state is still implausable (rather than improbable).

 

[iceaura]

Ozone, not water.
Ozone is the critical component in the production of Hydroxyl radicals.

Irrelevant to my comment. Methane oxidizes, eventually, to water and CO2 - according to your and adoucette's links - both of which are greenhouse gasses.

My suggestion is that to some extent the atmosphere is capable of buffering emissions, and that there's some critical value they need to exceed before the increase registers as an increase in the levels of atmospheric methane.

And I agree. Hence my arguments and observations.

Define disaster.
No, seriously, go ahead.
- - -
Sure, an abrupt release of methane might make things unpleasant for Humans, but even if we burn all the coal and oil, and vent all the clathrates into the atmosphere the worst we'd be looking at is an end to civilization as we know it.
- - -
Even the authors of the Clathrate Gun Hypothesis suggested that an abrupt release of methane could trigger an ice age rather than a period of warming - through ignition and conflagration (which would also cause regional extinctions).

I'm willing to accept the common understanding of "disaster", whatever it may be. It's far short of the end fo civilization as we know it, etc - a much smaller and more quickly plateaued methane loop than that would qualify, certainly.

 

[adoucette]

Lessee - the argument is that we can't get into an uncontrolled methane release loop without melting the Antarctic ice cover completely, first?

No ice, quit moving the goalposts, that's not the arguement, you are leaving out the part about it would take 10,000 years at 20+ C to do so and 20+ C is far higher than any plausible climatic change, so given ALL of that info the conclusion is a Venusian catastrophe in that time frame is also not possible.

So to repeat myself for the umpteenth time, find a reputable scientific study that shows that it is plausible that such a drastic change could occur on the earth within the next 10,000 years and I'll concede the point.

Arthur

 

[arfa brane]

On the subject of implausible scenarios:

How likely is the scenario that humans will reduce their carbon output over the next 10 years (or n years), so that methane from permafrost thawing won't lead to a runaway effect?

Here, "runaway effect" can mean anything from sea level rise that creates millions or billions of refugees, to loss of arable land due to drought, say. But it might include a number of unforseen effects--for instance the Gulf Stream could shut down, or large regions of the ocean become lifeless for thousands of years. Whatever, the effect on civilisation as we know it is that it ceases to exist--there are no large cities or ports, no global trade, no political systems. No biggie, humans will no doubt survive.

Are the required reductions too big to make for us, in our current situation? Is the fossil fuel industry too big to fail--we need it too much?
What are the predictions for global reductions? Are there any? How many years is n years?

 

[adoucette]

On the subject of implausible scenarios:

How likely is the scenario that humans will reduce their carbon output over the next 10 years (or n years), so that methane from permafrost thawing won't lead to a runaway effect?

I'd say it's highly unlikely than humans will reduce their carbon output over the next 10 years, but on the other hand you have not shown that not reducing our carbon output within the next 10 years will lead to any "runaway effect".

Here, "runaway effect" can mean anything from sea level rise that creates millions or billions of refugees, to loss of arable land due to drought, say. But it might include a number of unforseen effects--for instance the Gulf Stream could shut down, or large regions of the ocean become lifeless for thousands of years. Whatever, the effect on civilisation as we know it is that it ceases to exist--there are no large cities or ports, no global trade, no political systems. No biggie, humans will no doubt survive.

Except there is no conceivable way for the sea level to rise within the next 100 yeas that could possibly create millions, let alone billions of refugees.
As to drought, sure that's possible, but in general a warmer world tends to be a wetter world, in any case, we've seen no evidence that a larger percent of the globe is becoming desert, in fact the opposite appears to be occuring.

Do you have any reputable scientific studies that show that the "end of civilization as we know it" is a plausible outcome this century due to climate change?

Are the required reductions too big to make for us, in our current situation? Is the fossil fuel industry too big to fail--we need it too much?
What are the predictions for global reductions? Are there any? How many years is n years?

There are, as far as I know, no government of industry predictions for reductions in fossil fuel use in the next 50 years.

Arthur

 

[arfa brane]

you have not shown that not reducing our carbon output within the next 10 years will lead to any "runaway effect".

Well, suppose I conjecture that warming could lead to a positive feedback and increase thawing of permafrost. Once the feedback starts it won't be "reversible", even if we stop using fossil fuels altogether.

Since there are no govenment or industry predictions of reductions, or total abstinence, what possible mechanism is there to prevent positive feedback?
How many years are there before an irreversible feedback cycle begins?

there is no conceivable way for the sea level to rise within the next 100 yeas that could possibly create millions, let alone billions of refugees.

But sea levels have been that high in the past, so there is a conceivable way for it to happen in the next n years. Like I asked, how many years is n years?

Will nature "play ball" and follow this n year scenario? Is that plausible?

 

[Trippy]

Irrelevant to my comment. Methane oxidizes, eventually, to water and CO2 - according to your and adoucette's links - both of which are greenhouse gasses.

Then be more precise with your language, and you will find yourself in fewer misunderstandings. One of the reasons why I generally endeavour to be as precise in my statements as I can, to the point where I'm known for my pedantism in my social circles.

What you meant was:
"...the oxidation of the methane itself producing some water (a greenhouse gas) at the appropriate altitudes and curbing its own further increase, etc..."

Rather than what you said which was suggestive that you were talking about the chemistry.

The fact that water is produced is wholly irrelevant for two reasons.
1. Water absorption bands are pretty much saturated, so any additional radiative forcing from them is going to be minimal.
2. The water is Catalytic - the reaction starts when one molecule of Ozone reacts with one molecule of water to produce a hydroxyl radical, and then later a molecule of water is produced as a reaction product.

There is no net production of water in the oxidation process.

And as far as the carbon dioxide goes, it has a lower potential than methane, so it's a good thing over all, and the carbon dioxide will be sequestered, eventually, along with all the other carbon dioxide.
And I agree. Hence my arguments and observations.

I'm willing to accept the common understanding of "disaster", whatever it may be. It's far short of the end fo civilization as we know it, etc - a much smaller and more quickly plateaued methane loop than that would qualify, certainly.

:Sigh:
If you had bothered to read Arhcer 2007 rather than dismissing it as a denialist essay (because Adoucette quoted it) you would actually understand what you're talking about.
I'd also reccomend Archer 2005.
Archer 2007 deals with various release mechanisms, and assess their likely impacts, and such.
Archer 2005 largely deals with the impact on the Clathrate stability on the ocean floor, and the influences that anthropogenic warming might have. One of the scenarios considered is the release of 5000GT of Methane in 1k years.

Incidentally, next time, just answer the question rather than talking around it.

 

[adoucette]

Well, suppose I conjecture that warming could lead to a positive feedback

Conjecture anything you want, but as you have provided no scientific support for your conjecture it's worth nothing.

But sea levels have been that high in the past, so there is a conceivable way for it to happen in the next n years. Like I asked, how many years is n years?

As already discussed many times, the IPCC has stated that it would take 10,000 years to melt the East Antarctica Ice sheet, raising the sea level 60 meters IF the globe annual average temperature was +20C higher than present for that 10,000 years, BUT that there is no plausible mechanism for the climate to be 20+C over the next 10,000 years, so you do have some boundaries to work with.

The fact is sea level is expected to rise roughly half a meter over the next 100 years and that's about as good as anyone can plan for, and that level of sea level rise won't generate millions of refugees, indeed on a global perspective it will generate hardly any. The ones it does create were going to have to move anyway, they are just getting their oceanic eviction notice a few decades sooner than normal.

Arthur

 

[arfa brane]

Conjecture anything you want, but as you have provided no scientific support for your conjecture it's worth nothing.

Over the course of the twentieth century, the rate of sea level rise has roughly tripled in response to 0.8 °C global warming2. Since the beginning of satellite measurements, sea level has risen about 80 per cent faster, at 3.4 millimetres per year, than the average IPCC model projection of 1.9 millimetres per year. The difference between the semi-empirical estimates and the model-based estimates of the IPCC can be attributed largely to the response of continental ice to greenhouse warming. The IPCC range assumes a near-zero net contribution of the Greenland and Antarctic ice sheets to future sea level rise, on the basis that Antarctica is expected to gain mass from an increase in snowfall. Observations show, however, that both ice sheets have been losing mass at an accelerating rate over the past two decades.

A number of recent studies taking the semi-empirical approach have predicted much higher sea level rise for the twenty-first century than the IPCC, exceeding one metre if greenhouse gas emissions continue to escalate. These new results have found wide recognition in the scientific community, as recent broad-based assessments show. The question is: how plausible are the new estimates?

--http://www.nature.com/climate/2010/1004/full/climate.2010.29.html

The fact is sea level is expected to rise roughly half a meter over the next 100 years and that's about as good as anyone can plan for, and that level of sea level rise won't generate millions of refugees, indeed on a global perspective it will generate hardly any.

More wishful thinking. You're good at doing that.

 

[iceaura]

Then be more precise with your language, and you will find yourself in fewer misunderstandings.

It is impossible to be "precise" enough to prevent you from misreading. You would have to be willing to follow the argument in the first place.

If you had bothered to read Arhcer 2007 rather than dismissing it as a denialist essay (because Adoucette quoted it) you would actually understand what you're talking about.

I read it, Arthur didn't.

I told you I read it. Arthur told you he didn't read it.

I actually paid attention to it - it's a bit sloppy, in some suggestive ways, with its glossing over certain points, but overall one can see that it deals in the basic uncertainties as uncertainties. Fair enough. My point was the existence of uncertainties - the necessity of language like "presumably", and "most likely".

I called nothing a denialist essay. Arthur attempted to manipulate the discussion to support his denialist agenda. I responded to Arthur's actual argument, you didn't pay attention to either one of us. Pay attention now, or fuck off and leave me alone.

1. Water absorption bands are pretty much saturated, so any additional radiative forcing from them is going to be minimal

This crap again. Didn't we go through that with the CO2? Besides: water vapor concentration at various levels in the atmosphere varies widely, in time and space. It's not always saturated everywhere, eh?

Lessee - the argument is that we can't get into an uncontrolled methane release loop without melting the Antarctic ice cover completely, first?
”
No ice, quit moving the goalposts, that's not the arguement,

It is your argument - here you are making it again, immediately:

you are leaving out the part about it would take 10,000 years at 20+ C to do so and 20+ C is far higher than any plausible climatic change, so given ALL of that info the conclusion is a Venusian catastrophe in that time frame is also not possible.

Why this deflection, this irrelevant (and arguable, btw) claim presented as though it answered anything?

We are, some of us in attempt anyway, discussing the hazards of the anthro CO2 buildup and consequent heat trapping, most recently the possibility of touching off a run of positive feedback in methane release from cold storage.

 

[Trippy]

I called nothing a denialist essay.

So then... This isn't your post?

- as here, in the typical weasel role that such qualifiers play in denialist essays:

No mechanism has been proposed whereby a significant
fraction of the Siberian permafrost hydrates could release
their methane catastrophically.

It is impossible to be "precise" enough to prevent you from misreading.

And yet, many others have no problem in communicating with me.

This crap again. Didn't we go through that with the CO2?

Different issue.
Water absorption bands are actually saturated.
This is basically dishonest. btw, because in this very thread I have argued against CO2 absorption bands being saturated, AND presented evidence to support that argument.

Besides: water vapor concentration at various levels in the atmosphere varies widely, in time and space. It's not always saturated everywhere, eh?

Deflection.
Even if we admit this argument, it is rendered irrelevant by the first part of my argument - that water is catalytic in this cycle, for every molecule of water produced, one is consumed.

There's a corrollary implicit with this, which makes the third part of my argument:
3. The water is produced in the same place that it is consumed (more or less).

We are, some of us in attempt anyway, discussing the hazards of the anthro CO2 buildup and consequent heat trapping, most recently the possibility of touching off a run of positive feedback in methane release from cold storage.

Recently? I've seen reference to Clathrate feedback mechanisms dating back to 1995.

 

[adoucette]

--http://www.nature.com/climate/2010/1004/full/climate.2010.29.html
More wishful thinking. You're good at doing that.

Not at all.

Instead:

Jason Lowe, a leading Met Office climate researcher, said: "These predictions of a rise in sea level potentially exceeding 6ft have got a huge amount of attention, but we think such a big rise by 2100 is actually incredibly unlikely. The mathematical approach used to calculate the rise is simplistic and unsatisfactory."

Another critic is Simon Holgate, a sea-level expert at the Proudman Oceanographic Laboratory, Merseyside. He has written to Science magazine, attacking Rahmstorf's work as "simplistic".

"Rahmstorf is very good at publishing extreme papers just before big conferences like Copenhagen when they are guaranteed attention," said Holgate. "The problem is that his methods are biased to generate large numbers for sea-level rise which cannot be justified but which attract headlines."

http://www.timesonline.co.uk/tol/news/environment/article6982299.ece

Which is why I prefer to stick to the IPCC reports, while keeping track of the science, so far I find that the IPCC reports in general tend not to be more scientific then sensationalistic.

The IPCC is actually projecting that the slope of this line will dramatically increase, to over 6 mm per year.

Arthur

 

[arfa brane]

Not at all.

You're deflecting. You were being optimistic about how many people live close enough to the coast they will need to relocate inland.
You think, rather wishfully, that not many people are living in threatened areas. To reiterate, you said:

sea level is expected to rise roughly half a meter over the next 100 years and that's about as good as anyone can plan for, and that level of sea level rise won't generate millions of refugees, indeed on a global perspective it will generate hardly any.

Which is what I was calling wishful thinking.

 

[adoucette]

Not at all.

Man is quite capable of dealing with slowly rising oceans and have done it over and over again, all over the world.

Which is why people gladly live very near the ocean even though it on occasion rises up and smites them.

The idea that half a meter of sea rise will create millions of refugees is not based on any rational analysis of the cost of the much lower cost of adaption vs relocation for most of the people on the globe. Nor does relocating inland make people into refugees, particularly when this relocation takes place over a century time frame.

Arthur

 

[arfa brane]

Man is quite capable of dealing with slowly rising oceans and have done it over and over again, all over the world.

How capable are we of dealing with rapidly rising oceans, since that's a definite posibility?

There are good reasons to believe that sea level rise will accelerate, in fact it has already since about 1990--ocean warming and ice sheet melting is linear in a certain model, but there are proxy records that indicate it won't stay linear.

How well will lots of people, and their governments, deal with relocating several times, like once every 10 years? Or should they relocate far away enough they won't need to move again for a century, and how far is that?

The idea that half a meter of sea rise will create millions of refugees is not based on any rational analysis of the cost of the much lower cost of adaption vs relocation for most of the people on the globe.

Does "most of the people on the globe" include the ones in Bangladesh and other low-lying regions of Asia and South-East Asia?

 

[Trippy]

Oh, and before anybody starts commenting on Archer as a source.
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch7.html
Please note, he a contributing author for the IPCC.

 

[adoucette]

How capable are we of dealing with rapidly rising oceans, since that's a definite posibility?

Says who?

Please show a study that suggests that the oceans will rise RAPIDLY.

The current rate appears to be 3.1 mm per year, the IPCC says this will about double over this century, but that's still ~2 inches per decade, which is NOT rapid by anyone's yardstick.

There are good reasons to believe that sea level rise will accelerate, in fact it has already since about 1990--ocean warming and ice sheet melting is linear in a certain model, but there are proxy records that indicate it won't stay linear.

Yes, the IPCC says it will accelerate quite a bit, if it didn't the rise by the end of the Century would only be .3 meters, but the estimates are for about twice that.

How well will lots of people, and their governments, deal with relocating several times, like once every 10 years? Or should they relocate far away enough they won't need to move again for a century, and how far is that?

I doubt many will be relocated at all, very few poeple live THAT close to sea level who don't already deal with occasionally rising seas.
I suspect any people who are that close to the ocean that they have to move back are so close that they would have had to move back ANYWAY (since the NATURAL rise was about 2 mm per year), so maybe they have to move back a bit sooner, but so?

Does "most of the people on the globe" include the ones in Bangladesh and other low-lying regions of Asia and South-East Asia?

Sure it does

Here's Bangladesh

http://upload.wikimedia.org/wikiped...sh-en.svg/2000px-Map_of_Bangladesh-en.svg.png

Notice most of the towns are a decent way from the ocean.

Yes, some will have to do something, but they already deal with occasional high water TODAY if they live in those light green areas (1-10 m) and the next color (10-25 m), the vast majority of the area, obviously won't be affected.

You think there is some great mass of population somewhere which will have to move if the ocean goes up 1/2 a meter, then specifically, name the City that doesn't have the resources to protect itself from 1 meter of ocean rise over the next 100 years.

Arthur

 

[arfa brane]

Please show a study that suggests that the oceans will rise RAPIDLY.

There are plenty of studies that conclude sealevels have risen rapidly (more than 1 metre per century) several times during the current glaciation.

You think there is some great mass of population somewhere which will have to move if the ocean goes up 1/2 a meter

Yes, me and these guys:

The United Nations Intergovernmental Panel on Climate Change predicts rising sea levels will devour 17 per cent of Bangladesh by 2050, displacing at least 20 million people. More than 155 million people live in the country.

The Bangladesh non-governmental organisation Coastal Watch says an average of 11 Bangladeshis are losing their homes to rising waters every hour.

Professor Hazra predicts that 15 per cent of the Indian Sundarbans region on the northern shore of the Bay of Bengal will be submerged by 2020.

--http://www.smh.com.au/environment/c...vel-settles-border-dispute-20100324-qwum.html

 

[adoucette]

There are plenty of studies that conclude sealevels have risen rapidly (more than 1 metre per century) several times during the current glaciation.

Of course when there was a lot more low lying glaciers as we exited the last ice age one would of course expect that you start out with faster sea level rises and then you slow down.

http://en.wikipedia.org/wiki/File:Post-Glacial_Sea_Level.png

Yes, me and these guys:

--http://www.smh.com.au/environment/c...vel-settles-border-dispute-20100324-qwum.html

Gonna have to do better than that, let's see the actual section of the IPCC report that concludes that in the context of how it's presented. Is that without any Adaption efforts for instance?

Bangladesh is a country that routinely deals with long duration flooding, so I want to see the why someone thinks that so many are going to have to bail because of just 6" of ocean rise. What I've been reading on the area tends to be focused on effective ADAPTION strategies, not extensive relocation strategies.

Traditionally, the Bangladeshi poor people have learned to live with floods. Rural population no longer considers a moderate flood as a cause of concern. With limited institutional support, they have successfully coped with very high intensity floods in the recent past. Management of during- and post-flood situations in Bangladesh during the deluge of 1998 - an event that lasted for about 70 days, engulfing over two-thirds of the land and rendering
over 30 million people temporarily homeless - provides a glaring example of successful coping with floods.

http://www.bdresearch.org.bd/home/c...nge and Bangladesh Annotated Bibliography.pdf

By the way, I'm not saying that rising waters won't be an eventual problem, it's just that they are rising at a level that humans can cope with. And that's not to say that coping with rising waters isn't expensive, it is, but the money can be spent over long periods of time. Bangladesh is probably one of the places on the globe where the extent of the problem and the lack of funds to deal with it are at the greatest odds, and the world does need to help them out, but still, the idea that the world will see millions of refugees from rapidly rising waters isn't a realistic expectation either. Even in Bangladesh what you will see is a combination of adaption strategies and relocation of people over many decades to slightly higher ground.

Arthur