How Bad Is Global Warming?

[Ben D]

Yes,...

http://www.nature.com/scitable/knowledge/library/methane-hydrates-and-contemporary-climate-change-24314790

Methane Hydrates and Contemporary Climate Change

By: Carolyn D. Ruppel (U.S. Geological Survey, Woods Hole, MA)

Conclusions
Catastrophic, widespread dissociation of methane gas hydrates will not be triggered by continued climate warming at contemporary rates (0.2ºC per decade; IPCC 2007) over timescales of a few hundred years. Most of Earth's gas hydrates occur at low saturations and in sediments at such great depths below the seafloor or onshore permafrost that they will barely be affected by warming over even 103 yr.

[Iamwhomiam]

Please note the date of publication

Potential for methane release
The potential for methane releases in the Arctic to cause runaway global warming

What are the chances of abrupt releases of, say, 1 Gt of methane in the Arctic? What would be the impact of such a release?

By Sam Carana, December 20, 2011, updated January 29, 2012

How much methane is there in the Arctic?

An often-used figure in estimates of the size of permafrost stores is 1672 Gt (or Pg, or billion tonnes) of Carbon. This figure relates to organic carbon and refers to terrestrial permafrost stores. (1)

This figure was recently updated to 1700 Gt of carbon, projected to result in emissions of 30 - 63 Gt of Carbon by 2040, reaching 232 - 380 Gt by 2100 and 549 - 865 Gt by 2300. These figures are carbon dioxide equivalents, combining the effect of carbon released both as carbon dioxide (97.3%) and as methane (2.7%), with almost half the effect likely to be from methane. (2)

Shakhova et al. estimate the accumulated methane potential for the Eastern Siberian Arctic Shelf (ESAS, rectangle on image above) alone as follows:

- organic carbon in permafrost of about 500 Gt;
- about 1000 Gt in hydrate deposits; and
- about 700 Gt in free gas beneath the gas hydrate stability zone. (7)

The East Siberian Arctic Shelf covers about 25% of the Arctic Shelf (3) and additional stores are present in submarine areas elsewhere at high latitudes. Importantly, the hydrate and free gas stores contain virtually 100% methane, as opposed to the organic carbon which the above study (2) estimates will produce emissions in the ratio of 97.3% carbon dioxide and only 2.7% methane when decomposing.

How stable is this methane?

It does take time for heat to be transferred down sediments. What can take place much more rapidly, though, is for heat to be transferred down fluids in cracks and openings in the rock and sediment, called pingos.

In addition to these terrestrial stores, there is methane in the oceans and in sediments below the seafloor. There are methane hydrates and there is methane in the form of free gas. Hydrates contain primarily methane and exist within marine sediments particularly in the continental margins and within relic subsea permafrost of the Arctic margins. (3)

Hunter and Haywood estimate that globally between 4700 and 5030 Pg (Gt) of Carbon is locked up within subsea hydrate within the continental margins. This does not include subsea permafrost-hosted hydrates and so those of the shallow Arctic margin (<~300m) were not considered. (3)

Dallimore and Collett (1995) found high methane concentrations in ice-bonded sediments and gas releases suggest that pore-space hydrate may be found at depths as shallow as 119 m. (4) Recent studies indicate that hydrate formation can occur in upper gas-saturated horizons (up to 100-200 m) of permafrost. (5) Furthermore, methane hydrates have been found in Siberia at depths as shallow as 20 m. (6)

The image above, from Hovland et al., shows pingo-like sediment features, formed by local accumulation of hydrate (ice) below the sediment surface, and methane migrating upwards through conduits. (8)

A recent study by Serié describes geophysical signatures of different development stages associated with the formation and dissociation of shallow gas hydrate, as well as their link to deep-rooted plumbing systems that allow thermogenic fluid migration from several-kilometers-deep sedimentary basins. (9)

Paull et al. describe pingo-like-features on the Beaufort Sea Shelf, adding that a thermal pulse of more than 10 degrees Celsius is still propagating down into the submerged sediment and may be decomposing gas hydrate as well as permafrost. (10)

The sensitivity of gas hydrate stability to changes in local pressure-temperature conditions and their existence beneath relatively shallow marine environments mean that submarine hydrates are vulnerable to changes in bottom water conditions (i.e. changes in sea level and bottom water temperatures). Following dissociation of hydrates, sediments can become unconsolidated, and structural failure of the sediment column has the potential to trigger submarine landslides and further breakdown of hydrate. The potential geohazard presented to coastal regions by tsunami is obvious. (3)

Further shrinking of the Arctic ice-cap results in more open water, which not only absorbs more heat, but which also results in more clouds, increasing the potential for storms that can cause damage to the seafloor in coastal areas such as the East Siberian Arctic Shelf (ESAS, rectangle on image above), where the water is on average only 45 m deep. (11)

Much of the methane released from submarine stores is still broken down by bacteria before reaching the atmosphere. Over time, however, depletion of oxygen and trace elements required for bacteria to break down methane will cause more and more methane to rise to the surface unaffected. (12)

There are only a handful of locations in the Arctic where (flask) samples are taken to monitor the methane. Recently, two of these locations showed ominous levels of methane in the atmosphere (images below).

The danger is that large abrupt releases will overwhelm the system, not only causing much of the methane to reach the atmosphere unaffected, but also extending the lifetime of the methane in the atmosphere, due to hydroxyl depletion in the atmosphere.

Shakhova et al. consider release of up to 50 Gt of predicted amount of hydrate storage as highly possible for abrupt release at any time. (13)

What would be the impact of methane releases from hydrates in the Arctic?

If an amount of, say, 1 Gt of methane from hydrates in the Arctic would abruptly enter the atmosphere, what would be the impact?

Methane's global warming potential (GWP) depends on many variables, such as methane's lifetime, which changes with the size of emissions and the location of emissions (hydroxyl depletion already is a big problem in the Arctic atmosphere), the wind, the time of year (when it's winter, there can be little or no sunshine in the Arctic, so there's less greenhouse effect), etc. One of the variables is the indirect effect of large emissions and what's often overlooked is that large emissions will trigger further emissions of methane, thus further extending the lifetime of both the new and the earlier-emitted methane, which can make the methane persist locally for decades.

The IPCC (2007) gives methane a lifetime of 12 years, and a GWP of 25 as much as carbon dioxide over 100 years and 72 as much as carbon dioxide over 20 years. (14)

The image by Dessus (2008) below illustrates how methane's GWP depends on the horizon over which its impact is calculated. (15)

Drew Shindell (2009) points out that the IPCC figures do not include direct+indirect radiative effects of aerosol responses to methane releases that increase methane's GWP to 105 over 20 years when included. (16)

Using the IPCC figures, applying a GWP of 72 times carbon dioxide would give 1 Gt of methane a greenhouse effect equivalent to 72 Pg of carbon dioxide over 20 years. Applying a GWP of 105 times carbon dioxide would give 1 Gt of methane a greenhouse effect equivalent to 105 Pg of carbon dioxide over 20 years.

By comparison, atmospheric carbon dioxide levels rose from 288 ppmv in 1850 to 369.5 ppmv in 2000, for an increase of 81.5 ppmv, or 174 Pg C. (17)

Note that this 174 Pg C should be multiplied by 3.667 to get units of carbon dioxide, as in above graph.

http://3.bp.blogspot.com/-8QVxqIP08_U/T ... 758-14.jpg

The image above shows the impact of 1 Gt of methane, compared with annual fluxes of carbon dioxide based on the NOAA carbon tracker. (18)

Globally, 9.139 Pg C was emitted from fossil-fuel combustion and cement manufacture in 2010. Converted to carbon dioxide, so as to include the mass of the oxygen molecules, this amounts to over 33.5 Gt of carbon dioxide. (19)

Fossil fuel and fires have been adding an annual flux of just under 10 Pg C since 2000 and a good part of this is still being absorbed by land and ocean sinks.

In other words, the total burden of all carbon dioxide emitted by people since the start of the industrial revolution has been partly mitigated by sinks, since it was released over a long period of time.

Furthermore, the carbon dioxide was emitted (and partly absorbed) all over the globe, whereas methane from such abrupt releases in the Arctic would - at least initially - be concentrated in a relatively small area, and likely cause oxygen depletion in the water and hydroxyl depletion in the atmosphere, extending methane's lifetime, while triggering further releases from hydrates in the Arctic.

This makes it appropriate to expect a high initial impact from an abrupt 1 Gt methane release, i.e. at a GWP of well over 100 times the greenhouse effect of carbon dioxide, which will last for decades.

Even more terrifying is the prospect that this would trigger further methane releases. Given that there already is ~5 Gt in the atmosphere, the impact of this initial 1 Gt combined with further releases of, say, 4 Gt of methane would result in a burden of 10 Gt of methane. When applying a GWP of 105 times carbon dioxide, this would result in a greenhouse effect equivalent to 1050 Pg of carbon dioxide over 20 years.

In conclusion, a release of 1 Gt of methane in the Arctic would be catastrophic and the methane wouldn't go away quickly either, since this would be likely to keep triggering further releases. While some models project rapid decay of the methane, those models often use global decay values and long periods, which is not applicable in case of such abrupt releases in the Arctic.

Instead, the methane is likely to stay active in the Arctic for decades at a very high warming potential, due to depletion of hydroxyl and oxygen, while the resulting summer warming (when the sun doesn't set) is likely to keep triggering further releases in the Arctic.

Continued at: Warming in the Arctic

References

1. Soil organic carbon pools in the northern circumpolar permafrost region
Tarnocai, Canadell, Schuur, Kuhry, Mazhitova and Zimov (2009)
http://www.agu.org/pubs/crossref/2009/2008GB003327.shtml
http://www.lter.uaf.edu/dev2009/pdf/1350_Tarnocai_Canadell_2009.pdf

2. Climate change: High risk of permafrost thaw
Schuur et al. (2011)
Nature 480, 32–33 (1 December 2011) doi:10.1038/480032a
http://www.nature.com/nature/journal/v480/n7375/full/480032a.html
http://www.lter.uaf.edu/pdf/1562_Schuur_Abbott_2011.pdf

3. Science Blog: Submarine Methane Hydrate: A threat under anthropogenic climate change?
Stephen Hunter and Alan Haywood (2011)
http://climate.ncas.ac.uk/ncas-science-blog/241-science-blog-submarine-methane-hydrate-a-threat-under-anthropogenic-climate-change

4. The Cryosphere: Changes and Their Impacts
IPCC SAR Chapter 7 (2007)
http://www.ipcc-wg2.gov/publications/SAR/SAR_Chapter%207.pdf

5. Investigation of gas hydrate formation in frozen and thawing gas saturated sediments
Chuvilin et al. (2011)
http://www.cost-pergamon.eu/Administrative-doc/PERGAMON-INFO/ARTICLES/chuvilin5.pdf

6. Arctic Methane outgassing on the East Siberian Arctic Shelf
John Mason (2012)
http://www.skepticalscience.com/arctic-methane-outgassing-e-siberian-shelf-part2.html

7. Methane release from the East Siberian Arctic Shelf and the Potential for Abrupt Climate Change
Natalia Shakhova and Igor Semiletov (2010)
http://symposium2010.serdp-estcp.org/content/download/8914/107496/version/3/file/1A_Shakhova_Final.pdf

8. Submarine pingoes: Indicators of shallow gas hydrates in a pockmark at Nyegga, Norwegian Sea
Hovland et al., Marine Geology 228 (2006) 15–23
http://www.sciencedirect.com/science/article/pii/S0025322705003968

9. Gas hydrate pingoes: Deep seafloor evidence of focused fluid flow on continental margins
Christophe Serié, et al. (2012)
http://geology.gsapubs.org/content/early/2012/01/23/G32690.1.abstract

10. Origin of pingo-like features on the Beaufort Sea shelf and their possible relationship to decomposing methane gas hydrates
Paull, et al., Geophysical Research Letters, 34, L01603 (2007)
http://www.agu.org/pubs/crossref/2007/2006GL027977.shtml

11. Extensive Methane Venting to the Atmosphere from Sediments of the East Siberian Arctic Shelf
Shakhova et al. (2010)
http://www.sciencemag.org/content/327/5970/1246.abstract

12. Berkeley Lab and Los Alamos National Laboratory (2011)
http://newscenter.lbl.gov/feature-stories/2011/05/04/methane-arctic/
https://www.mcgill.ca/newsroom/news/item/?item_id=212872

13. Anomalies of methane in the atmosphere over the East Siberian shelf: Is there any sign of methane leakage from shallow shelf hydrates?
Shakhova, Semiletov, Salyuk and Kosmach (2008)
http://www.cosis.net/abstracts/EGU2008/01526/EGU2008-A-01526.pdf

14. Global Warming Potential
Intergovernmental Panel on Climate Change (IPCC, 2007)
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2s2-10-2.html#table-2-14

15. Global warming: the significance of methane Benjamin DESSUS, Bernard LAPONCHE, Hervé LE TREUT (January 28, 2008)
http://www.endseurope.com/docs/report3.doc

16. Improved Attribution of Climate Forcing to Emissions
Drew Shindell (2009)
http://www.sciencemag.org/content/326/5953/716.full

17. Runaway global warming
Sam Carana (2011)
http://geo-engineering.blogspot.com/2011/04/runaway-global-warming.html

18. Carbon Tracker 2010 - Flux Time Series - CT2010 - Earth System Research Laboratory
U.S. Department of Commerce | National Oceanic & Atmospheric Administration (NOAA)
http://www.esrl.noaa.gov/gmd/ccgg/carbontracker/fluxtimeseries.php?region=All_Land#imagetable

19. Global Carbon Dioxide Emissions from fossil-fuel combustion and cement manufacture
Carbon Dioxide In formation Analysis Center (CDIAC)
http://cdiac.ornl.gov/trends/emis/perlim_2009_2010_estimates.html

20. On carbon transport and fate in the East Siberian Arctic land–shelf–atmosphere system
Semiletov et al. (2012)
http://iopscience.iop.org/1748-9326/7/1/015201

http://arctic-news.blogspot.com/p/potential-for-methane-release.html

[Iamwhomiam]

excerpted from what BenD wrote,
...that they will barely be affected by warming over even 103 yr.

Seems to me they've been severely affected by warming over the past 103 years, or are all those scientists imagining methane's escaping from holes in ice floating in the Arctic and from thawing permafrost all around the world. CGI is quite good these days, I know, but really, Ben, what has caused our planet's warming, our warming oceans and is responsible for melting Polar Ice Caps?

Do you believe global warming is a myth and that none of the observed effects from warming are actually occurring? If yes, for what purpose would such a myth be propagated and whom would it be that you believe instigated such a fraud?

I recall once before asking you if you believed in global warming (0.8C) and believe I recall your saying you did, but disputed its cause to be something other than anthopogenic. So, if no to my question above, what is causing Earth's air, lands and waters to warm and our permafrost, glaciers and ice caps to melt?

[Iamwhomiam]

Ben, the Nature .com article was published in 2011, four years after the IPCC Assessment, which was amended nearly immediately to correct for unaccounted warming we both mentioned earlier, to reflect the warming potential of CH4 to be 105 times as great as CO2 over a twenty year period. That changes much of her calculation.

"Yes, AND, the values you provide for methane’s Global Warming Potential (GWP), or 25 times CO2 over 100 years and 72 over 20 years, is from the 2007 IPCC Fourth Assessment. Subsequent to the development of that data, NASA has updated methane’s GWP to account for indirect aerosol effects. The current methane GWP, accounting for aerosols, is 33 times CO2 over 100 years and 105 times over 20 years. See Drew Shindell, “Improved Attribution of Climate Forcing Emissions,” 326 Science 716 (2009). The implications are exceedingly disturbing."

However, I do not believe anyone, certainly no scientist worthy of that title would be under an impression that all of the earth's methane hydrates would or could suddenly and simultaneously burst forth from the incredible pressures that exist in deep sea floor sediments.

However, in formerly cold shallow seas this could occur. And permafrost is warming and releasing methane too. With permafrost, some running nearly 5000 feet deep, the greatest concern is with what lies just below the 13 foot active layer will begin thawing. And that's what's happening all around the world today.

We don't need to be concerned for all ice and earthbound methane being suddenly released, we do need to be concerned that methane releases are increasing. And industrialization with all its new sources of carbon spitting pollution is proceeding at a greater pace than ever before.

The greed of few will kill us all.

[Ben D]

Do you believe global warming is a myth and that none of the observed effects from warming are actually occurring? If yes, for what purpose would such a myth be propagated and whom would it be that you believe instigated such a fraud?

I recall once before asking you if you believed in global warming (0.8C) and believe I recall your saying you did, but disputed its cause to be something other than anthopogenic. So, if no to my question above, what is causing Earth's air, lands and waters to warm and our permafrost, glaciers and ice caps to melt?

You understand correctly, it is not a myth, the planet has warmed about 0.8C from 1880 to 1997, and due to the pause in warming, in 2013 it is still at 0.8C. And yes, this 0.8C warming is not primarily caused by the activities of man, but by natural climate change, the climate is after all between ice ages.

Iam, I have followed the debate between the AGW scientists and the skeptical scientists since that late 1990s, and in that time, over 16 years, there has been no further increase in global temperature. But during that same time, over 16 years, 25% of all human caused CO2 produced since 1880 has been added to the atmosphere with no measurable change in temperature.

Iam, how long do I have to wait before you concede that climate change is not primarily due to the activities of man, 20 years with no warming with continued ever higher record human caused CO2 levels being added to the atmosphere? 30 years?

[brainpanhandler]

Iam, I have followed the debate between the AGW scientists and the skeptical scientists since that late 1990s, and in that time, over 16 years, there has been no further increase in global temperature. But during that same time, over 16 years, 25% of all human caused CO2 produced since 1880 has been added to the atmosphere with no measurable change in temperature.

And to think that you deride climate scientists for the inadequacy of their climate modeling. Tsk, tsk ben.

As I am sure you are aware 1998 was a super El Niño year. Starting there obviously skews the picture.

Additionally fluctuations in atmospheric aerosols, both from combustion of coal and from smaller volcanic eruptions once thought to be unable to significantly effect the earth's albedo, have played a role in the global warming pause as well as Solar irradiance variation, as you well know. And then there is the ocean warming to consider.

It's not as simple as increasing human produced CO2 = increased global warming. No wonder you are a skeptic. Did you think climate scientists were that stupid or are you that stupid?

[Ben D]

Iam, I have followed the debate between the AGW scientists and the skeptical scientists since that late 1990s, and in that time, over 16 years, there has been no further increase in global temperature. But during that same time, over 16 years, 25% of all human caused CO2 produced since 1880 has been added to the atmosphere with no measurable change in temperature.

And to think that you deride climate scientists for the inadequacy of their climate modeling. Tsk, tsk ben.

As I am sure you are aware 1998 was a super El Niño year. Starting there obviously skews the picture.

Additionally fluctuations in atmospheric aerosols, both from combustion of coal and from smaller volcanic eruptions once thought to be unable to significantly effect the earth's albedo, have played a role in the global warming pause as well as Solar irradiance variation, as you well know. And then there is the ocean warming to consider.

It's not as simple as increasing human produced CO2 = increased global warming. No wonder you are a skeptic. Did you think climate scientists were that stupid or are you that stupid?

Yes, of course I'm aware, but the fact that 1998 was a super El Nino year doesn't alter the facts, the global warming anomaly since 1880 of approx. 0.8C was reached then and now in 2013, it is still 0.8C,...over 16 years without further warming.

So bph, if it's not as simple as increasing human produced CO2 = increased global warming, please explain the complexities. I hope you are not just going to tell me that the pause in warming over the last 16/17 years is because natural cooling is masking the human derived CO2 GHG factor, because I've already factored that into my question to Iam as to how long do I have to wait without further warming before that proposed reason is no longer credible,..20 years, 30 years?

[brainpanhandler]

Iam, I have followed the debate between the AGW scientists and the skeptical scientists since that late 1990s, and in that time, over 16 years, there has been no further increase in global temperature. But during that same time, over 16 years, 25% of all human caused CO2 produced since 1880 has been added to the atmosphere with no measurable change in temperature.

And to think that you deride climate scientists for the inadequacy of their climate modeling. Tsk, tsk ben.

As I am sure you are aware 1998 was a super El Niño year. Starting there obviously skews the picture.

Additionally fluctuations in atmospheric aerosols, both from combustion of coal and from smaller volcanic eruptions once thought to be unable to significantly effect the earth's albedo, have played a role in the global warming pause as well as Solar irradiance variation, as you well know. And then there is the ocean warming to consider.

It's not as simple as increasing human produced CO2 = increased global warming. No wonder you are a skeptic. Did you think climate scientists were that stupid or are you that stupid?

Yes, of course I'm aware, but the fact that 1998 was a super El Nino year doesn't alter the facts, the global warming anomaly since 1880 of approx. 0.8C was reached then and now in 2013, it is still 0.8C,...over 16 years without further warming.

So bph, if it's not as simple as increasing human produced CO2 = increased global warming, please explain the complexities. I hope you are not just going to tell me that the pause in warming over the last 16/17 years is because natural cooling is masking the human derived CO2 GHG factor, because I've already factored that into my question to Iam as to how long do I have to wait without further warming before that proposed reason is no longer credible,..20 years, 30 years?

Ben, I've already provided you with a number of potential factors which could produce the pause in warming when I wrote, "fluctuations in atmospheric aerosols, both from combustion of coal and from smaller volcanic eruptions once thought to be unable to significantly effect the earth's albedo, have played a role in the global warming pause as well as Solar irradiance variation, as you well know. And then there is the ocean warming to consider."

I am not a climate scientist. OK? But even if I was the question of what has caused the pause is not in my reading answered as of yet. It is an open ended question. A fair question. A question that climate scientists are honestly asking themselves and each other.

I will do some more googling for you after you clarify your position.

Are you suggesting that the pause in global warming (oceans aside for the moment) despite increasing human sourced CO2 emissions means that global warming cannot be attributed to human causes?

Or in other words is your climate model as simple as increasing human produced CO2 = increased global warming, no increased global warming = no anthropogenic cause of global warming?

[Ben D]

Ben, I've already provided you with a number of potential factors which could produce the pause in warming when I wrote, "fluctuations in atmospheric aerosols, both from combustion of coal and from smaller volcanic eruptions once thought to be unable to significantly effect the earth's albedo, have played a role in the global warming pause as well as Solar irradiance variation, as you well know. And then there is the ocean warming to consider."

I am not a climate scientist. OK? But even if I was the question of what has caused the pause is not in my reading answered as of yet. It is an open ended question. A fair question. A question that climate scientists are honestly asking themselves and each other.

I will do some more googling for you after you clarify your position.

Are you suggesting that the pause in global warming (oceans aside for the moment) despite increasing human sourced CO2 emissions means that global warming cannot be attributed to human causes?

Bph, the whole AGW argument is based on the warming due to human GHG emissions, of which CO2 is the most important based on the ever increasing amounts pumped into the atmosphere. If there is a pause in warming for 16/17 years, the question of why the warming has paused naturally arises.

What has changed to cause the pause? Obviously the climate has changed, the increase in warming has paused, while man's GHG emissions have grown. It therefore seems to me that either human causes are not the primary cause, or some natural cooling, not present in the latter part of the 20th century, has cut in to neutralize the man derived CO2/GHG emissions warming.

That's how I see it it at this time. If it was natural cooling that cut in 17 years ago, how do we know what caused it? Wrt those things you mentioned as a possible cause for the pause, volcanic activity is a known, but clean air improvements in the developed nations may have increased the warming **. If it is that the anthropogenic factor of AGW was greatly exaggerated/over estimated, how do we know? If it is a combination of both natural climate change cooling and exaggerated anthropogenic factor, then that also is possible, but the science is not settled so how do we know?

** Wrt man produced atmospheric carbon and aerosols, apparently it is the reduction in aerosols that lead to warming, here is the abstract of a new paper from the National University of Ireland presented this summer at the 19th International Conference on Nucleation and Atmospheric Aerosols that suggests clean air laws put in place in the 1970′s and 80′s have resulted in an increase in sunlight impacting the surface of the Earth, and thus have increased surface temperatures as a result.. What do you think of that?

http://proceedings.aip.org/resource/2/apcpcs/1527/1/579_1?isAuthorized=no

[brainpanhandler]

Ben, I've already provided you with a number of potential factors which could produce the pause in warming when I wrote, "fluctuations in atmospheric aerosols, both from combustion of coal and from smaller volcanic eruptions once thought to be unable to significantly effect the earth's albedo, have played a role in the global warming pause as well as Solar irradiance variation, as you well know. And then there is the ocean warming to consider."

I am not a climate scientist. OK? But even if I was the question of what has caused the pause is not in my reading answered as of yet. It is an open ended question. A fair question. A question that climate scientists are honestly asking themselves and each other.

I will do some more googling for you after you clarify your position.

Are you suggesting that the pause in global warming (oceans aside for the moment) despite increasing human sourced CO2 emissions means that global warming cannot be attributed to human causes?

Bph, the whole AGW argument is based on the warming due to human GHG emissions, of which CO2 is the most important based on the ever increasing amounts pumped into the atmosphere. If there is a pause in warming for 16/17 years, the question of why the warming has paused naturally arises.

Correct. Which is why climate scientists are examining that question.

What has changed to cause the pause? Obviously the climate has changed, the increase in warming has paused, while man's GHG emissions have grown. It therefore seems to me that either human causes are not the primary cause, or some natural cooling, not present in the latter part of the 20th century, has cut in to neutralize the man derived CO2/GHG emissions warming.

False dichotomy.

If it was natural cooling that cut in 17 years ago, how do we know what caused it?

That's what science is for.

Wrt those things you mentioned as a possible cause for the pause, volcanic activity is a known, but clean air improvements in the developed nations may have increased the warming **.

Indeed, therefore if human sourced atmospheric aerosols were to increase, think china burning coal, then that might contribute to cooling. It is as yet unclear what effect if any china burning coal might be having on global temperatures. As an aside, an increase in human sourced atmospheric aerosols is not "natural cooling". And why saying this: "volcanic activity is a known" makes it less important in the discussion is unclear to me. I am also unclear what this means: "I hope you are not just going to tell me that the pause in warming over the last 16/17 years is because natural cooling is masking the human derived CO2 GHG factor, because I've already factored that into my question to Iam as to how long do I have to wait without further warming before that proposed reason is no longer credible,..20 years, 30 years?"

How did you "factor" that into your question?

If it is that the anthropogenic factor of AGW was greatly exaggerated/over estimated, how do we know?

It's called science Ben.

If it is a combination of both natural climate change cooling and exaggerated anthropogenic factor, then that also is possible, but the science is not settled so how do we know?

I think we do know that there are more variables than "natural climate change cooling and exaggerated anthropogenic factor'. But to play your game,

Maybe it is a combination of a well established anthropogenic factor offset by both natural and unnatural factors contributing to climate cooling.

See what I did there?

** Wrt man produced atmospheric carbon and aerosols, apparently it is the reduction in aerosols that lead to warming, here is the abstract of a new paper from the National University of Ireland presented this summer at the 19th International Conference on Nucleation and Atmospheric Aerosols that suggests clean air laws put in place in the 1970′s and 80′s have resulted in an increase in sunlight impacting the surface of the Earth, and thus have increased surface temperatures as a result.. What do you think of that?

http://proceedings.aip.org/resource/2/apcpcs/1527/1/579_1?isAuthorized=no

Let me fix that for you:

Wrt man produced atmospheric carbon and aerosols, apparently a reduction in aerosols contributed to warming, here is the abstract of a new paper from the National University of Ireland presented this summer at the 19th International Conference on Nucleation and Atmospheric Aerosols that suggests clean air laws put in place in the 1970′s and 80′s have resulted in an increase in sunlight impacting the surface of the Earth, and thus have increased surface temperatures as a result.

[Iamwhomiam]

Ben wrote:
Iam, how long do I have to wait before you concede that climate change is not primarily due to the activities of man, 20 years with no warming with continued ever higher record human caused CO2 levels being added to the atmosphere? 30 years?

Perhaps only 30 years, 72 days, 2 hours and 20 minutes. By then I'll be either 100 and won't care or I'll be long dead.

I have never once claimed that global warming was primarily caused by man, only that man's pollutants, like the chemical sulfuryl fluoride, with 4300 times the warming potential of C. contribute to warming our climate. Personally, I have no idea why there's been a momentary pause in the ever-climbing Red Line. I doubt we're entering the next Ice Age, though that was the expectation, with AGW being the only observable reason for warming during what had been predicted to be a cooling-off period. And those models have convincingly shown, flawed as they've been, that Man's pollutants were the cause for warming during what was predicted to be a cooling-off period. (And let's not bring the old, long outdated models that predicted cooling into this conversation, for time and observation have shown they were also severely flawed.

I've only ever asked you to confirm that man-made pollutants contributed to observed warming.

You wrote to bph: "...the global warming anomaly since 1880 of approx. 0.8C was reached then (1998) and now in 2013, it is still 0.8C,...over 16 years without further warming." and this, "I hope you are not just going to tell me that the pause in warming over the last 16/17 years is because natural cooling is masking the human derived CO2 GHG factor, because I've already factored that into my question to Iam as to how long do I have to wait without further warming before that proposed reason is no longer credible,..20 years, 30 years?"

Ben, how about you explain for us "the global warming anomaly" that began in 1880 and lasted until 1998? We were then supposed to be entering a time of planetary cooling, but yet the earth's warmed 0.8C over that time, so whats caused those 13 decades of warming?

You seem to want us to ignore this astounding anomaly that we and thousands of scientists agree was caused certainly in part by man's unnatural input over 130 years. If you're about to blame the warming on the Sun, you also cannot blame the maunder minimum, a 75 year long period, for momentary pause in warming over 16 years. You'll have to await 59 more years to determine if cooling continued that long.

But I would say from all the research I've read that it is extremely unlikely a true reversal in warming will continue much longer before spiking upwards once again.

[justdrew]

the "pause" is caused by heat going into the deep oceans and melting ice. It's not rocket science to figure this out. If we were able to actually measure the heat in the ENTIRE system rather than just atmospheric, it would be obvious that no 'pause' has occurred.

[seemslikeadream]

Will the American Right Kill Us All?
August 20, 2013

Exclusive: By wallowing in a world of scientific denial and historical fabrication, the Republican Right and its Tea Party allies have prevented the U.S. government from responding aggressively to the existential emergency from global warming, writes Robert Parry.

By Robert Parry

It is a touchstone of the American Right that the Framers drafted the U.S. Constitution in 1787 to tightly constrain the federal government and to promote states’ rights – and that this supposed “originalism” is inviolable regardless of the perceived needs of the nation or the dangers implicit in this so-called “strict construction.”

For various reasons – from the mainstream media’s timidity to the disdain some progressives feel for the Constitution’s compromises on slavery – this right-wing Founding Narrative rarely gets challenged, even though it is a demonstrable fiction. But this lazy tolerance of the Right’s made-up historynow is becoming an existential threat to mankind.

That is because the scientific consensus continues to solidify that human activity is causing global temperatures to increase dangerously, possibly causing a catastrophic rise of three feet in sea levels by the end of the century. Yet, right-wing obstructionism, which deems federal environmental activism unconstitutional, has hobbled any effort to enact a timely response to the emergency.

The scope of the impending environmental disaster is fast becoming incontestable among scientists.

“It is extremely likely that human influence on climate caused more than half of the observed increase in global average surface temperature from 1951 to 2010,” a draft report from the Intergovernmental Panel on Climate Change said, according to the New York Times. “There is high confidence that this has warmed the ocean, melted snow and ice, raised global mean sea level and changed some climate extremes in the second half of the 20th century.”

The consequences are expected to grow much worse in the coming decades, with many climate scientists seeing the probability of temperatures rising more than 5 degrees Fahrenheit if the present trend continues, the Times reported.

“Warming the entire planet by 5 degrees Fahrenheit would add a stupendous amount of energy to the climate system,” the Times wrote. “Scientists say the increase would be greater over land and might exceed 10 degrees at the poles. They add that such an increase would lead to widespread melting of land ice, extreme heat waves, difficulty growing food and massive changes in plant and animal life, probably including a wave of extinctions.”

The possibility of a three-foot rise in sea levels would threaten some of the world’s major cities, possibly displacing hundreds of millions of people. The mix of mass dislocations from flooding and the loss of traditional agricultural lands to drought could exacerbate geopolitical tensions and spark warfare among desperate countries facing steep declines in standards of living or even mass starvation.

Given the prevalence of nuclear weapons in the hands of rival nations where the impact of global warming might be particularly severe – from China, India and Pakistan to Great Britain, Israel and the United States – the threat to human existence is made even more acute.

Politicizing Science

Aggressive action by the U.S. government, in particular, is required to avert this impending catastrophe, but today’s Right has politicized the near scientific certainty about global warming and the human role in its acceleration.

From the Tea Party to the “libertarians,” oil money from fossil-fuel energy tycoons, such as Charles and David Koch of Koch Industries. has fueled “populist” propaganda challenging the case for global warming, first by funding “scientists” who quibble with the research or who assert that the warming will be modest and manageable.

Beyond that, America’s political Right has added climate change to its list of perceived “statist” conspiracy theories, claiming that the scientific consensus is just a plot by Al Gore and “liberals” to find another excuse for overriding the supposed constitutional principles of a tightly constrained federal government.

And, since these alleged principles of “originalism” and “strict construction” are inviolable anyway, this thinking goes, there’s no legitimate case that can be made for expanding the federal government’s role in reducing U.S. emissions of the carbon dioxide and other global-warming chemicals.

That is why the emotional pull of the Right’s proclaimed Founding Principles must be addressed with sound historical research, even if some on the Left find it silly or irrelevant to ponder what Alexander Hamilton, James Madison and George Washington were thinking back in 1787.

It is dangerous to cede the historical reality to well-funded right-wing “historians” who are dispatched back in time by the Koch Brothers and their allies to cherry-pick a few quotes here and there to distort what the key Framers were actually doing with the Constitution, i.e. they were creating a vibrant federal government that would have the flexibility to address the country’s “general Welfare” then and in the future.

The Real Constitution

The historical reality of 1787 was nearly the opposite of how today’s Right portrays it. The Framers of the Constitution were intent on overthrowing a disastrous system from the Articles of Confederation, which had enshrined the 13 original states as “sovereign” and “independent” with the central government deemed only a “league of friendship” and lacking any significant power.

As the young nation descended into squabbling and insolvency in the mid-1780s, the advocates for a strong central government – led by Washington, Madison, Hamilton and Gouverneur Morris (who drafted the famous Preamble) – staged what amounted to a nonviolent coup d’etat against the old structure.

Meeting in secret in Philadelphia – and then circumventing the state legislatures by arranging special ratification conventions – the Framers pushed through a system that made federal law supreme and sought to make the states “subordinately useful,” in the words of James Madison.

This reality was recognized by political leaders who opposed what the Framers of the Constitution were doing. For instance, Pennsylvania delegates on the losing side of the Philadelphia debate explained their opposition, declaring: “We dissent … because the powers vested in Congress by this constitution, must necessarily annihilate and absorb the legislative, executive, and judicial powers of the several states, and produce from their ruins one consolidated government. …

“The new government will not be a confederacy of states, as it ought, but one consolidated government, founded upon the destruction of the several governments of the states. … The powers of Congress under the new constitution, are complete and unlimited over the purse and the sword, and are perfectly independent of, and supreme over, the state governments; whose intervention in these great points is entirely destroyed.”

The Pennsylvania dissenters noted that the state sovereignty language from the Articles of Confederation was stripped out of the Constitution and that national sovereignty was implicitly transferred to “We the People of the United States” in the Preamble. They pointed out that the Constitution’s Article Six made federal statutes and treaties “the supreme law of the land.”

“The legislative power vested in Congress … is so unlimited in its nature; may be so comprehensive and boundless [in] its exercise, that this alone would be amply sufficient to annihilate the state governments, and swallow them up in the grand vortex of general empire,” the Pennsylvania dissenters declared.

The Sweeping Powers

Those federal powers, listed in Article One, Section Eight, included “to provide for the common Defense and general Welfare of the United States” and “To make all Laws which shall be necessary and proper for carrying into Execution the foregoing Powers, and all other Powers vested by this Constitution in the Government of the United States.”

In other words, the Framers gave the U.S. Congress broad powers to act on behalf of the American people. But those powers were particularly unnerving to Southern Anti-Federalists, such as Virginia’s Patrick Henry, who warned the state’s plantation aristocracy that ratification would inexorably lead to the demise of slavery. “They’ll free your niggers!” Henry declared.

Despite losing the battle to block ratification, the Anti-Federalists did not go away. Behind the charismatic figure of Thomas Jefferson – and drawing important support from Southern slaveholders who feared federal encroachment on their investment in human chattel – the opponents of a strong central government set out to redefine what the Constitution meant. [See Consortiumnews.com’s “Rethinking Thomas Jefferson.”]

That was a political struggle that Jefferson and other Southern slaveholders won against the Federalists of Washington, Hamilton and Morris by the end of the 1790s, with Jefferson’s defeat of John Adams for the presidency in 1800. The victory of Jefferson’s Republicans, those supposed advocates of human freedom, relied on the extra votes that the Southern states got by counting their slaves as “three-fifths” of a person for the purpose of representation.

As the bitter political warfare of the 1790s played out, Madison was pulled from his original alliance with the Federalists into the political camp of his Virginia neighbor and fellow slaveholder Jefferson. In doing so – in becoming a political representative of Virginia’s plantation system – Madison repudiated many of his earlier constitutional positions.

Jefferson called his election a new “revolution” as he reinterpreted the Constitution to afford very limited power to the federal government and expanded authority for states, even to “nullify” federal law. This revisionist approach amounted to a radical change from what Washington, Hamilton, Morris and the earlier Madison had constructed in Philadelphia.

In other words, Jefferson’s view was not the “original” understanding of the Constitution. Yet, today’s Right pretends it was. Even Jefferson, after becoming the third U.S. President, abandoned his “strict constructionism” when it was useful for him to do so, such as when he and Secretary of State Madison negotiated the Louisiana Purchase in 1803.

The Ongoing Struggle

But the struggle between the original Federalist view of the Constitution and its later hijacking by some of its anti-federal opponents has continued throughout American history, most notably in the South’s resistance to Northern efforts to restrict the spread of slavery into new states and ultimately in the secession of Confederate states after Abraham Lincoln’s election in 1860.

Even after the South’s defeat in the Civil War and the end of slavery, the white Southern aristocracy did not surrender its insistence on a crimped view of the Constitution, often finding allies among the powerful Northern “robber barons” of the late Nineteenth Century and early Twentieth. Both the segregationist Southerners and the laissez-faire capitalists of Wall Street wanted the federal government to keep its nose out of their business.

However, with the Great Depression of the 1930s, President Franklin Roosevelt reached back to the original concept of the Constitution – that the federal government was empowered to act on behalf of “the general Welfare,” a principle embedded both in the Preamble and Article One, Section Eight.

Yet, when this federal activism began to encroach on the South’s racial separation in the 1950s and 1960s, the Right again moved to reassert its revisionist take on the Constitution, that it supposedly enshrined states’ rights as supreme.

Though the Right lost this battle to defend racial segregation – much as the Anti-Federalists lost the fight to block the Constitution – the political struggle was by no means over as Southern whites moved to the Republican Party of Richard Nixon and Ronald Reagan.

With Reagan’s victory in 1980, the stage was set for the ascendance again of right-wing revisionism on the Constitution, with Reagan and his Republican successors, George H.W. Bush and George W. Bush, installing on the U.S. Supreme Court right-wing ideologues who embraced the faux history that right-wing “scholars” had been busy assembling.

These ideological descendants of the South’s slaveholders and the later alliance between the Robber Barons and Jim Crow are now positioned to interpret the Constitution as they see fit. Plus, they have a dedicated political movement in the Tea Party and on the Republican Right that has absorbed the made-up Founding Narrative of why the Constitution was written.

This combination of factors now presents an existential threat to the world because the Right’s distortion of the Framers’ original intent precludes crucial U.S. government action to restrain the spewing of climate-changing chemicals into the atmosphere.

It is a case where history is not just history, it is the future of mankind.

[Iamwhomiam]

Haven't had time to digest the paper, but I have checked out a few of the authors' referenced works. Interesting that 4 of the 5 hail from the same school.

Excerpted from a report written by co-author Darius Ceburnis,

"There were many great presentations, but some of them should be highlighted. A keynote presentation on ozone from historical perspective and future challenges delivered by David Parrish was a delight. It was intriguing to learn that every rapidly developing country is going through the depressing atmospheric pollution phase when environmental issues are being neglected. Similar story of severe ozone pollution has been recorded in Los Angeles (1950), Mexico city (1970) and more recently Beijing and Shanghai following in their footsteps. All participants had a chance to observe an infamous pollution haze advecting into Chinese capital during the conference."

"An invited presentation given David Etheridge provided assured robust global warming evidence, emphasizing that the famous global warming hockey stick of temperature and greenhouse gases certainly survived scrutiny in ice core records. Franz Rohrer presented a new chemical coordinate system uncovering unknown self-cleansing capability of the atmosphere stabilised at it maximum efficiency."

"Many presentations from local Chinese colleagues addressed the infamous Chinese regional haze. Despite decreasing or stabilized PM, SO4 and NOx concentrations, however, not without the concern due to very high levels, ozone is one major pollutant which concentrations are sharply increasing. The haze is certainly a regional phenomenon and local policy measures, however, pleasing (with electrical motorcycles had completely replaced petrol ones in Beijing) are not a solution. More robust and sustainable policy is needed to address regional pollution."

I'm sure I'll find more from other authors you've cited, though it seems so far they do not support your argument that the sun is solely responsible for our warming of 0.8C over a century.

But thank for alerting me to the author of the hockey stick quote above. Considering you've referenced this author as a credible source supporting your claims, what do you have to say about his hockey stick comment I've quoted? Do you now have something along the way of an apology for beating us with it, while condemning it and the hacked emails and the so-called fraudulent research you've claimed to be conspiratorial, you know, to empower a one government ruled world, to control and exterminate the masses.

Someday I hope you'll realize that you've been duped by big industry, free market unregulated capitalism. Regulating pollution is not only a good thing but with greed and dishonesty ruling the day today, regulations of all sort are absolutely necessary to protect us from their excesses.

[Ben D]

And why saying this: "volcanic activity is a known" makes it less important in the discussion is unclear to me.

I am also unclear what this means: "I hope you are not just going to tell me that the pause in warming over the last 16/17 years is because natural cooling is masking the human derived CO2 GHG factor, because I've already factored that into my question to Iam as to how long do I have to wait without further warming before that proposed reason is no longer credible,..20 years, 30 years?"

How did you "factor" that into your question?

I think we do know that there are more variables than "natural climate change cooling and exaggerated anthropogenic factor'. But to play your game,

Maybe it is a combination of a well established anthropogenic factor offset by both natural and unnatural factors contributing to climate cooling.

See what I did there?

The cooling effect of any volcanic activity that may have occurred during the pause can be calculated and hence known.

Because if AGW scientists claim the cooling offset to the warming GHG during this 16/17 year pause is natural cooling, the question naturally arises as to their predicted end to the cooling and the resumption of warming due to human derived CO2. AGW GCMs have a target to meet to be scientifically credible, ie. continued increase in global warming into the 21st century, they just can't wait for another 5, 10, 15 years of pause by calling it natural cooling offsets.