A Note: Global Warming Threads

[arfa brane]

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.

And when you live in a world which is getting warmer, you of course expect that sea level will start to rise faster, after slowing down. You also expect that any ice remaining from the last ice age will eventually melt, if the world continues to get warmer (for whatever reason).

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?

You can't find this yourself? I thought you were an avid reader of IPCC reports.

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.

Well, perhaps you should read more about what happens when floodwaters don't recede.

Do you think a 1 metre sealevel rise will affect cities like London or New York? These places should be safe from storm surges and the like?

 

[adoucette]

And when you live in a world which is getting warmer, you of course expect that sea level will start to rise faster, after slowing down. You also expect that any ice remaining from the last ice age will eventually melt, if the world continues to get warmer (for whatever reason).

Yes, and that's what the sophisticated modeling done for the IPCC report took into consideration to come up with the .3 to .6 m rise this century. You simply ignore the IPCC report and suggest much higher rates simply because they have happened before.

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

What the IPCC report ACTUALLY says:

This analysis showed that much of the population of these 40 deltas is at risk through coastal erosion and land loss, primarily as a result of decreased sediment delivery by the rivers, but also through accentuated rates of sea-level rise. They estimate, using a coarse digital terrain model and global population distribution data, that more than 1 million people will be directly affected by 2050 in three megadeltas: the Ganges-Brahmaputra delta in Bangladesh, the Mekong delta in Vietnam and the Nile delta in Egypt. More than 50,000 people are likely to be directly impacted in each of a further 9 deltas, and more than 5,000 in each of a further 12 deltas

(bolding mine)

So the IPCC report, when not taken out of context, explains that the problem for these river deltas if PRIMARILY decreased sediment delivery by the river systems that rebuild the land which is the same problem we have with the New Orleans area.

The size of the area and the number of people affected is also much lower, and finally, this is the estimate of the number of people who are affected without regard to any Adaption strategies, and in areas like this that will be one of the key strategies people will use to adapt the land and the infrastructure to deal with ~6" of ocean rise over the next 40 years, so that a million or so people don't have to actually relocate.

Arthur

 

[arfa brane]

Yes, and that's what the sophisticated modeling done for the IPCC report took into consideration to come up with the .3 to .6 m rise this century. You simply ignore the IPCC report and suggest much higher rates simply because they have happened before.

The .3 to .6 metre rise this century--has the IPCC carved this in stone? You appear to believe this is what the report is saying, that sealevel will NOT rise any higher.
What brought you to this conclusion? Does the IPCC, or do any of its members, say that sealevel is NOT going to rise by more than .6 metres? Are there any uncertainties in the prediction? Why isn't ice stream dynamics included in the model?
Are you the one who is simply ignoring other reports, because they consider the possibility that sealevel rise could be higher than 1 metre, perhaps several metres, over the next century?

The IPCC report states that "more than 1 million people" will be affected. Other reports, not from the IPCC, state that hundreds of millions could be affected. This includes people living within 100km of a coastline. You seem to be unaware that the IPCC uses conservative models and makes conservative estimates; other groups consider effects that the IPCC reports intentionally leave out.

I expect you will now deny that people who are 100km from the sea could possibly be affected by storms, salination, high tides, etc.
Oh, perhaps except for those people who live in river delta regions, or the Netherlands, huh?

 

[adoucette]

Actually I've been doing all my discussions based on the sea level being on the TOP END of the IPCC projections, even though the actual trend continues to be for the LOW END of the projections.

I thought I explained in post 693 why I choose to go with the IPCC numbers.
The data there supposedly reflects a reasonable scientific concensus of the information we have to work with.

No, I don't think distance from the sea is the issue, it has to do with Topography. Which is what the IPCC used to figure out where the risks were and where ADAPTIVE strategies are needed.

Again, I'm NOT denying that the sea level is rising.
I believe the IPCC estimates are reasonable and I think we need to prepare for slightly higher than the high end of the estimates.

What I am saying is that when you look at the rest of this century we will be forced to do a lot of Adaption to allow for this rising sea level, and that is something that man has done for hundreds of years, and we will continue to do so, but we are better at it today and the rate of sea level rise is such that for most areas, with Adaptive techniques, it is not an insurmountable problem.

When you say 100s of millions will be affected what you are leaving out is that this is happening NOW and it has almost nothing to do with sea level rise.

To put this in perspective, there was a total loss of 15,845 km2 of deltaic wetlands over the past 14 years (ending in 2005) and yet in that time sea level went up less than 2 inches, so the loss was almost entirely to other forms of human induced coastal erosion.

Arthur

 

[arfa brane]

No, I don't think distance from the sea is the issue, it has to do with Topography. ...

Topography has to do with distance from the coast, though. That's where the sea is, at the coast.

When you say 100s of millions will be affected what you are leaving out is that this is happening NOW and it has almost nothing to do with sea level rise.

To put this in perspective, there was a total loss of 15,845 km2 of deltaic wetlands over the past 14 years (ending in 2005) and yet in that time sea level went up less than 2 inches, so the loss was almost entirely to other forms of human induced coastal erosion.

I'll assume you've intentionally left out New Orleans, the Maldives, and several Pacific attols from your "almost entirely due to human induced coastal erosion".

 

[adoucette]

Topography has to do with distance from the coast, though. That's where the sea is, at the coast.

You again missed the point.

You said "I expect you will now deny that people who are 100km from the sea could possibly be affected by storms, salination, high tides, etc" but the issue isn't DISTANCE from the sea, it's ELEVATION above sea level, and while that does tend to rise as you move away from the coast, different areas have different topographies and some areas like Bangladesh have wide delta plains where you have to go a long way from the coast to get any significant elevation. So the key to the effect of rising waters is NOT distance, but topography. Think of it this way, the houses 100 yards in from the cliffs of Dover have NOTHING to worry about, even if every piece of ice on the planet melts.

I'll assume you've intentionally left out New Orleans, the Maldives, and several Pacific attols from your "almost entirely due to human induced coastal erosion".

No, the people on the Maldives are pretty much destined to have to move. Everyone knows that since they are not actually living on land, but the remains of a coral reef that used to be underwater and it was always clear that if our present interstitial lasts, the Maldives were destined to be underwater again.

Yes, the increase in sea level rise from AGW is slightly speeding up the inevitable, but even at the natural rate of sea level rise much of the Maldives were going to be reclaimed by the ocean, though where most of the people live they probably have several centuries before having to relocate if they can't bring in enough material to keep above the rising water (which is what I think they will do (via dredging)).

the Maldives is the lowest country in the world, with a maximum natural ground level of only 2.3 metres (7 ft 7 in), with the average being only 1.5 metres (4 ft 11 in) above sea level, although in areas where construction exists, this has been increased to several metres. More than 80 per cent of the country's land, composed of coral islands scattered over an area about 850 km across the equator, is less than one metre above sea level.

So since most people live on the higher areas, most of the ~400,000 people in the Maldives still have plenty of time this century to either relocate or mine/build up their island, the latter being the most likely solution.

As to New Orleans, totally different issue, but like most Deltas the issues are not primarily due to rising sea levels.

Mississippi Delta subsidence primarily caused by compaction of Holocene strata

We find that millennial-scale compaction rates primarily associated with peat can reach 5mm per year, values that exceed recent model
predictions. Locally and on timescales of decades to centuries, rates are likely to be 10mm or more per year. We conclude that compaction of Holocene strata contributes significantly to the exceptionally high rates of relative sea-level rise and coastal wetland loss in the Mississippi Delta, and is likely to cause subsidence in other organic-rich and often densely populated
coastal plains.

http://www.tulane.edu/~tor/documents/NG2008.pdf

Glacial Sediments Add to Louisiana Coastal Subsidence
The Weight they Add to the Mississippi River Delta Contributes to the Sinking

A study by NASA and Louisiana State University scientists finds that sediments deposited into the Mississippi River Delta thousands of years ago when North America's glaciers retreated are contributing to the ongoing sinking of Louisiana's coastline. The weight of these sediments is causing a large section of Earth's crust to sag at a rate of 0.1 to 0.8 centimeters (0.04 to 0.3 inches) a year.

http://geology.com/nasa/louisiana-coastal-subsidence.shtml

Then there is the system of levees on the Mississippi that is starving the many lobes of the Delta system of the silt that is needed to keep them from disappearing

Currently, most of the flow of the Mississippi is forced to stay in one channel, so nearly all of the river’s sediment load is discharged into deep water. The result: As the delta subsides (mostly natural) there is no fresh sediment deposition to compensate.

(pg 33)

http://www.mrcmekong.org/download/P...dolf_Role of Sediments in Fluvial Systems.pdf

Coastal land loss has been accelerating since 1950 in the Mississippi Delta. Annual sediment volume averaged ~440 million tons/yr prior to 1950
Since 1950, the average sediment load of the Mississippi River has been reduced to about ~215 million tons per year, But, most of this 215 mty is lost out the jetties.

(page 37)

http://www.laseagrant.org/floodprotection/ppts/3b-Rogers3.pdf

Finally:

Using water-level measurements, core samples, isotopic analyses, aerial photographs, and satellite imagery, they documented areas and rates of wetland loss and identified subsidence—the gradual settling or sudden sinking of the Earth's surface relative to sea level—as the main cause of wetland loss in the studied areas. What's more, they showed that the highest rates of wetland loss correlate significantly with periods of peak extraction of subsurface oil, gas, and water from below ground: their results document a rapid increase in land loss in the late 1960s and early 1970s, followed by a decrease in land-loss rates from the 1980s to the 1990s. This pattern corresponds to the region's history of underground-fluid extraction, which also peaked in the late 1960s and early 1970s and subsequently declined

So yes, it most definately has to do with human influences.

Arthur

 

[arfa brane]

So yes, it most definately has to do with human influences.

Sure, there are a lot of factors involved, including erosion due to extraction of oil, gas, water, unforseen consequences of building tidal barriers, etc.
The biggest human influence is definitely the CO2 loading, though.

The big elephant is the uncertainty; we simply don't have enough information to predict the outcome of this accurately. We don't have many plans either, to deal with potential future scenarios despite your belief that humans have dealt with gradual rises in sealevel. We might have to "deal" with rapid rises in sealevel.

You can discount this possibility as much as you want, it will remain true that we simply don't know enough to conclude it won't happen. Given the material response to the dangers of global warming to date, which amount to almost nothing, I would say rapid changes are looking more and more likely.

We would need to stop using fossil fuels in say, less than 10 years (highly unlikely), and even then there will be a long "tail" of CO2 buildup for future generations to deal with, lasting thousands of years.
We can't even say with much confidence how much longer we can just keep putting CO2 into the atmosphere, before some point of no return is reached--a tipping point.

 

[adoucette]

Sure, there are a lot of factors involved, including erosion due to extraction of oil, gas, water, unforseen consequences of building tidal barriers, etc.
The biggest human influence is definitely the CO2 loading, though.

No it's not.
Did you bother to even read the sources?

Sea level rise is 3 mm per year, but peat compaction alone is ~10 mm per year, three times as much.

Weight from the sediments deposited thousands of years ago is causing crustal subsidence at a rate of 1 to 8 mm per year on top of that.

Then there is the removal of oil/gas and then there is the lack of new sediment.

So the change in Relative Sea Level of the Delta is FAR GREATER than the relatively modest amount of sea level rise so far and even far into the future.
The rise in sea level doesn't help, but if the sea stopped rising tomorrow the delta would still be eroding at a high rate for all the factors mentioned.

The big elephant is the uncertainty; we simply don't have enough information to predict the outcome of this accurately. We don't have many plans either, to deal with potential future scenarios despite your belief that humans have dealt with gradual rises in sealevel. We might have to "deal" with rapid rises in sealevel. You can discount this possibility as much as you want, it will remain true that we simply don't know enough to conclude it won't happen. Given the material response to the dangers of global warming to date, which amount to almost nothing, I would say rapid changes are looking more and more likely.

And yet you have posted nothing to support these assertions.

We would need to stop using fossil fuels in say, less than 10 years (highly unlikely), and even then there will be a long "tail" of CO2 buildup for future generations to deal with, lasting thousands of years.
We can't even say with much confidence how much longer we can just keep putting CO2 into the atmosphere, before some point of no return is reached--a tipping point.

What's your point?

Arthur

 

[arfa brane]

No it's not.

Yes it is. Denying it won't make any difference.

Sea level rise is 3 mm per year, but peat compaction alone is ~10 mm per year, three times as much.

The seas have risen by an average of 3mm per year since the satellite monitoring era began.
What evidence is there that this 3mm rate will stay constant for the foreseeable future?

And yet you have posted nothing to support these assertions.

I don't need to post anything, there is plenty of support for the assertions. There is a large enough uncertainty that several scenarios remain "possible". You, or anyone, can verify this using google with words like "sea level", "arctic melting", and so on.

Or you could look for articles that support your personal point of view.

What's your point?

What's yours?

 

[adoucette]

I posted many reports that showed that the subsidence of the delta outside New Orleans was dominated by man made forces and not sea level rise.
You don't like to accept the facts, but so what else is new?

Actually, to get to the .6 meter rise that I've been using as the expected amount this century, the annual rise has to double to get to OVER 6 mm per year. So far the level of rise continues to track on the LOW end of the projected rise, or .3 meters, but STILL, I've been accepting that it will eventually increase to two or more times what it has been.


As to you not having to post anything to support your position, what a JOKE.
It's so friggin obvious that you are just making this up and resorting to cherry picking since when challenged your answer invariably comes down to telling me to "google it".

In contrast I post link after link after link of reputable scientific reports supporting my position, you always show up empty handed or with quotes taken out of context.

Typical CRANK behavior.

LOL

Arthur

 

[Trippy]

Perhaps someone would like to accuse Chucky D of being a denialist (for suggesting that Atoll's subside).
http://darwin-online.org.uk/content/frameset?viewtype=text&itemID=F271&pageseq=1

(Image courtosey of USGS).

However, I'm sorry to point out (to Arthur) that AGW does have the capacity to (directly) increase the rate of subsidence of a coral atoll (as well as inundation by sea level rise).

The rate at which an Atoll subsides (or grows, as the case may be) is the difference between the rate at which the underlying land subsides, and the rate at which the coral grows. The point being that if AGW begins to influence the health of coral reefs, then the 'Darwin Point' is going to shift (geographicaly, and or bathymetricaly) so that reefs that are currently growing, and potentially growing faster than sea level rise may begin to be inundated.

There are examples of this having happened - Guyots north west of the Hawiian acrhipeligo, and a number of drowned reefs (as a result of the Last Glacial Maximum).

 

[adoucette]

However, I'm sorry to point out (to Arthur) that AGW does have the capacity to (directly) increase the rate of subsidence of a coral atoll (as well as inundation by sea level rise).

I didn't say it didn't.
Indeed I said that it DID speed up the process.
Several times in fact.

Arthur

 

[arfa brane]

As to you not having to post anything to support your position, what a JOKE.
It's so friggin obvious that you are just making this up and resorting to cherry picking since when challenged your answer invariably comes down to telling me to "google it".

It isn't a googling competition. As I said, you can look for articles that support your position if you want. And look at you.

In contrast I post link after link after link of reputable scientific reports supporting my position, you always show up empty handed or with quotes taken out of context.

Typical CRANK behavior.

It won't make the slightest difference to your point of view if I post links, will it?
Therefore the suggestion that you try a few more words in the search bar (than you apparently have so far).

Again, anyone can use google, anyone can type certain words into the search bar. If you try "permafrost thawing", say, you get a lot of newspaper articles, but also quite a few scientific articles. And you will discover that there is little consensus on how many people will be affected over the next century by rising seas. Some are saying hundreds of millions could be affected, the IPCC says more than a million, so who knows?

But most of the world's population is expected to be living in urban areas when or if things get "bad". So how many of the world's cities are situated at low elevations, or are within 100km of a coastline?

 

[adoucette]

What you seem to be missing is that when you see reports about hundreds of millions being affected, that doesn't mean that they all have to move, just that they have to do something.

You know, for most it will be building seawalls and/or dikes.

The much more rational view is the vast majority of people, towns and cities near the coast will utilize long proven adaption strategies to cope with the slowly rising waters.

Arthur

 

[arfa brane]

What you seem to be missing is that when you see reports about hundreds of millions being affected, that doesn't mean that they all have to move, just that they have to do something.

Learn how to swim?

You know, for most it will be building seawalls and/or dikes.

The much more rational view is the vast majority of people, towns and cities near the coast will utilize long proven adaption strategies to cope with the slowly rising waters.

Building seawalls and dykes has been the approach in the Netherlands, for example. How much higher should they be built, and how quickly? What if, instead of slowly rising waters, you start to get quickly rising waters, maybe over the next 50 years? Are any governments considering this possibility, is the Netherlands?

I know how difficult that last scenario is for you to think about, but it would be rather presumptuous of the Netherlands government to dismiss the possibility, wouldn't it? Seeing how many people live on reclaimed land or are expected to be living there.

I'd say there are two options for the Netherlands (but, I'm quite sure I'm not the only one saying it), which are relocation and adaptation. Adapting by building higher seawalls will be costly, but so will relocating a lot of people. Say we run out of oil in the next 100 years, then having the money to adapt or relocate will also be a problem. Unless there is by then a new source of cheap energy like oil, this will be another problem for governments who have to deal with inundation of low-lying areas.

Doing something now will be less costly, but still a significant burden on any country.
I suppose that's why governments have "plans" but haven't really done much about implementing them.

 

[iceaura]

I called nothing a denialist essay.
”
So then... This isn't your post?

That is part of my post, in the whole of which I point out that adoucette's selective quoting of an article he has not actually read is in service of his agenda here - cherry picking congenial vocabulary, with the standard use of Foxvoc "interesting", in an attempt to support his argument here with an article that does not actually support it - and call him on it.

As far as Archer's article, it would be interesting - in the real sense - to discuss here if the posts involved would be allowed to remain this time ?

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.

That's very rapid by any geologist's yardstick, and would have serious implications for human beings within the century.

"This crap again. Didn't we go through that with the CO2?
”
Different issue.
Water absorption bands are actually saturated.
This is basically dishonest.
- - -
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 -
- - -
"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.

As I do not wish to get banned any more, or have my sides of discussions with you deleted while yours remain, I cannot respond to any of that. Since inability to respond prevents actual discussion, may I ask you politely to simply ignore what I post here in response to others? I'm sure they can deal with my various errors, etc, on their own.

 

[Trippy]

As far as Archer's article, it would be interesting - in the real sense - to discuss here if the posts involved would be allowed to remain this time ?

Nothing's stopping you from discussing it.

As I do not wish to get banned any more...

Then simply refrain from telling me to "Fuck off and leave [you] alone" in the forum that I voluntarily moderate.

or have my sides of discussions with you deleted while yours remain, I cannot respond to any of that. Since inability to respond prevents actual discussion, may I ask you politely to simply ignore what I post here in response to others? I'm sure they can deal with my various errors, etc, on their own.

You're going to have to substantiate this.
I've been back through 18 pages of posts, and aside from an off topic discussion between Me-Ki-Gal and Chimpkin regarding predation, I can find one post (of Me-Ki-Gals) that I have deleted (as offtopic).

I have not deleted anything of yours, let alone anything you have said to me.

 

[iceaura]

or have my sides of discussions with you deleted while yours remain, I cannot respond to any of that. Since inability to respond prevents actual discussion, may I ask you politely to simply ignore what I post here in response to others? I'm sure they can deal with my various errors, etc, on their own.
”

You're going to have to substantiate this.

Whoa, there they are - in my earlier trip through, I couldn't find the ones that got me banned. Twice. Odd - at any rate, I can't substantiate something false and wrong, and can only apologize for the response - I was pretty irritated about that.

As far as Archer's article, it would be interesting - in the real sense - to discuss here if the posts involved would be allowed to remain this time ?
”
Nothing's stopping you from discussing it.

In which case, discussion begun.

Then simply refrain from telling me to "Fuck off and mind (my) own business" in the forum that I voluntarily moderate.

Please also refrain from putting quote marks around things that are not quotes.

 

[Trippy]

Please also refrain from putting quote marks around things that are not quotes.

Amended.

 

[adoucette]

That is part of my post, in the whole of which I point out that adoucette's selective quoting of an article he has not actually read is in service of his agenda here

I'm tired of your trying to turn this discussion into something that it is not.
Just because I might disagree with you doesn't mean I have an agenda.

So stick to the Science and quit with the personal attacks.

All my quotes came from the section RISKS FOR THE FUTURE which is what we were discussing.

I chose 3 of the sections,

4.1 Capacity for doomsday
Fortunately, most of the hydrate reservoir seems insolated from the climate of the Earth’s surface, so that any melting response will take place on time scales of millennia or longer.

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

4.5 Century-timescale response
On the timescale of the coming century, it appears that most of the hydrate reservoir will be insulated from anthropogenic climate change. The exceptions are hydrate in permafrost soils, especially those coastal areas, and in shallow ocean sediments where methane gas is focused by subsurface migration.
The most likely response of these deposits to anthropogenic climate change is an increased background rate of chronic methane release, rather than an abrupt release.

And none of those quotes are out of context with their headings and did in fact pertain to our discussion.
I skim read the entire report at the time but I closely read the pertinent section on Risks, and though I didn't quote from all the sections they too were in basic agreement with what I posted:

4.3 Structural Deposits
Surface warming is expected to take order a century to reach these depths. Presumably any melting response to this gradual warming would be gradual as well, slower than the atmospheric lifetime of methane and therefore by our definition a chronic methane release rather than a catastrophic one.

4.4 Stratigraphic deposits
Most of the hydrate deposits on Earth are of the stratigraphic type,
…. Warming of the ocean can propagate into the sediment column, but this thick layer of thermal insulation guarantees that most of the anthropogenic effect on temperature will take thousands of years.

A landslide methane release would certainly be abrupt, but it would not be climatically catastrophic because the amount of methane in any given landslide could only be a tiny fraction of the global methane inventory.

4.6 Geological-timescale response
In a worst-case scenario, after thousands or hundreds of thousands of years, the methane hydrate reservoir could release as much carbon as fossil fuel emissions.

And they do discuss a feedback scenario and that's the worst case in 4.6, but the shortest time frame mentioned is in THOUSANDS of years.

Arthur