[Al_U_Card]

This just in from the "settled science" department...

Peer-reviewed survey concerning attribution

Interesting, considering the bona fides of the surveyors and the respondants.

In March – April 2012 the PBL Netherlands Climate Assessment Agency, with several other scientists, conducted a survey of approximately 6,550 scientists studying climate change. It was published as “Scientists’ Views about Attribution of Global Warming” by Bart Verheggen et al in the 19 Aug 2014 issue of Environmental Science and Technology (peer-reviewed). In April 2015 they published a more detailed report (used in this post).



The conclusions deride the consensus-oriented approach of the IPCC and demonstrate much more uncertainty than is presented in the SPM of AR5.

[hrothgar]

Al_U_Card, on 2015-July-30, 10:17, said:

The conclusions deride the consensus-oriented approach of the IPCC and demonstrate much more uncertainty than is presented in the SPM of AR5.

Once again the only thing that ***** for brains Al_U-Card is demonstrating is the danger of blindly quoting other web sites without doing a bit of background research into the topic at hand.

The PBL Netherlands Environment Assessment Agency has very conveniently provided an FAQ which directly contradicts the assert that Al is making.
http://www.pbl.nl/en...-global-warming

Here's a relevant quote from the FAQ

Quote

Conclusions
How does the PBL-study compare to the often-quoted 97% consensus?

The results presented in the PBL-study are consistent with similar studies, which all find high levels of consensus among scientists, especially among scientists who publish more often in the peer-reviewed climate literature.

Cook et al. (2013) found that 97% of papers that characterized the cause of recent warming indicated that it is due to human activities. John Cook, the lead author of that analysis, is co-author on this current article. Similarly, a randomized literature review found zero papers that called human-induced climate change into question (Oreskes, 2004).

...

In the PBL-study, among respondents with more than 10 peer-reviewed publications (half of total respondents), 90% agree that greenhouse gases are the largest – or tied for largest - contributor to recent warming. The level of agreement is ~85% for all respondents.

While these findings are consistent with other surveys, several factors could explain the slight differences we found:

Surveys like ours focus on opinions of individual scientists, whereas in a literature analyses the statements in individual abstracts are tallied. Literature analyses have generally found higher levels of consensus than opinion surveys, since the consensus is stronger amongst more heavily published scientists.

This study sets a more specific and arguably higher standard for what constitutes the consensus position than other studies. For instance, Doran and Kendall-Zimmermann (2009) asked about human activity being a “significant contributor” to global warming, and Anderegg et al. (2010) investigated signatories of public statements, while the authors of the current study asked specifically about the degree to which greenhouse gases are contributing to climate change in comparison with other potential factors.

Contrarian viewpoints are somewhat overrepresented in our survey and they may have overestimated their self-declared level of expertise (see question 9).

[PassedOut]

Daniel1960, on 2015-July-28, 05:55, said:

"Climate models cannot currently reproduce trends in Antarctic sea ice variability. Virtually all equilibrium climate models simulate a strong decrease in the area of sea ice."

http://www.antarctic...arctic-sea-ice/

Why did you pick (and edit) two sentences from one section of that reference? Let's take a look at that whole section (with my italics):

Quote

Climate model simulations of sea-ice trends

Climate models simulate a decline in ice extent, thickness and volume in Antarctica. Equilibrium models cannot currently reproduce trends in Antarctic sea ice variability [17]. Virtually all equilibrium climate models simulate a strong decrease in the area of sea ice [18]. This may be because global climate models do not currently incorporate ice-shelf / -sheet/ -climate interactions. Basal melt from ice shelves is therefore disregarded. These equilibrium models may give an idea of what may eventually happen. Simulations with models that do include these interactions, particularly simulating the effect of extra freshwater from melting glaciers and ice caps, do simulate growths in Antarctic sea ice [10, 12].

Transient climate models are more able to capture the transient response of sea ice to changes in the winds. A modeling study by Marshall et al. [19] showed that changes in the winds tend to push the ice edge northwards, increasing ice extent. These winds also push the ocean surface northwards too, which effectively brings warmer water to the surface and eventually counters the increasing sea ice trend after a few decades. These transient models show that not enough time has elapsed for the equilibrium response to be achieved. We may well see the trends reversing in a few decades.

As the earth continues to warm, obviously a time will come when the Antarctic sea ice retreats. That has no bearing on the fact that global warming causes the increases in the sea ice extents now. And, I think, you must know that.

Here is an earlier section of that same reference, the one that you provided:

Quote

Changes to sea surface temperatures

As the glaciers and ice shelves melt on the Antarctic continent, freshwater is added to the oceans. This layer of cold, fresh water on the ocean surface freezes easily [10]. When combined with increased ocean stratification due to this enhanced run off [11], sea-surface temperatures are depressed, encouraging sea-ice formation.

A recent modeling study has shown that increases in fresh meltwater flux from melting glaciers and ice caps on Antarctica under various IPCC standardized global warming scenarios offsets the decline in sea-ice area and to even further encourage the increases in sea-ice extent, especially in winter (in summer, air temperatures are too high to support significant sea-ice growth) [12].

Increased stratification has further implications. Suppression of ocean circulation overturning decreases the ocean heat flux available to melt ice, leading to an increase in net ice production[13].

You had to read this section to get to the section that you misquoted. So why not simply admit the plain truth--that the increase in Antarctic sea ice is the result of global warming, rather than the opposite?

[Daniel1960]

PassedOut, on 2015-July-30, 11:45, said:

Why did you pick (and edit) two sentences from one section of that reference? Let's take a look at that whole section (with my italics):


As the earth continues to warm, obviously a time will come when the Antarctic sea ice retreats. That has no bearing on the fact that global warming causes the increases in the sea ice extents now. And, I think, you must know that.

Here is an earlier section of that same reference, the one that you provided:


You had to read this section to get to the section that you misquoted. So why not simply admit the plain truth--that the increase in Antarctic sea ice is the result of global warming, rather than the opposite?

Once again you cherry pick one possible explanation for the sea ice increase as proof that global warming is responsible for the increase. That was one of many possibilities stated in the article, which I am sure you know from reading it.

[PassedOut]

Daniel1960, on 2015-July-30, 18:53, said:

Once again you cherry pick one possible explanation for the sea ice increase as proof that global warming is responsible for the increase. That was one of many possibilities stated in the article, which I am sure you know from reading it.

If what you say were true, you would be able to list some of the "many possibilities stated in the article" for which global warming is not responsible. Actually, I see none. What are you including in the "many possibilities stated in the article" that are not caused by global warming?

[Daniel1960]

PassedOut, on 2015-July-31, 07:10, said:

If what you say were true, you would be able to list some of the "many possibilities stated in the article" for which global warming is not responsible. Actually, I see none. What are you including in the "many possibilities stated in the article" that are not caused by global warming?

Some of the possibilities include: decreased ocean temperatures, increased snowfall, wind variations, ozone forcing, atmospheric dynamics, and an increase in polynyas. The authors also list measurement error as a possibility. They did not eliminate global warming as a possible explanation, but insists that sea ice should decline over the long term - at least according to the models.

[PassedOut]

Daniel1960, on 2015-July-31, 10:06, said:

Some of the possibilities include: decreased ocean temperatures, increased snowfall, wind variations, ozone forcing, atmospheric dynamics, and an increase in polynyas. The authors also list measurement error as a possibility. They did not eliminate global warming as a possible explanation, but insists that sea ice should decline over the long term - at least according to the models.

I asked for a list of the "many possibilities stated in the article" for which global warming is not responsible. Let's look again at what the article that you want us all to read says about "decreased ocean temperatures."

Quote

Changes to sea surface temperatures

As the glaciers and ice shelves melt on the Antarctic continent, freshwater is added to the oceans. This layer of cold, fresh water on the ocean surface freezes easily [10]. When combined with increased ocean stratification due to this enhanced run off [11], sea-surface temperatures are depressed, encouraging sea-ice formation.

A recent modeling study has shown that increases in fresh meltwater flux from melting glaciers and ice caps on Antarctica under various IPCC standardized global warming scenarios offsets the decline in sea-ice area and to even further encourage the increases in sea-ice extent, especially in winter (in summer, air temperatures are too high to support significant sea-ice growth) [12].

Increased stratification has further implications. Suppression of ocean circulation overturning decreases the ocean heat flux available to melt ice, leading to an increase in net ice production[13].

As global warming accelerates the freshwater melt from Antarctic glaciers, the resulting decrease in ocean temperatures (along with the lower salinity of the glacial melt) expands the surrounding sea ice. It has always been understood that this would happen on the way to equilibrium but, until the past few years, had been considered too obvious to point out.

What about "increased snowfall?"

Quote

Increased precipitation

Warmer air holds more moisture, and so precipitation is increasing around Antarctica [13]. Strong warming in the middle latitudes of the Southern Ocean can lead to an enhanced hydrological cycle, with enhanced evaporation and moisture content in the lower troposphere [14]. This additional moisture is transported poleward, where it results in increased precipitation. Increases in snow and rain falling onto the ocean contribute to the freshening of the ocean surface in the high latitudes of the Southern Ocean. Fresher, colder water freezes more easily, so this mechanism may contribute to the growth in area of Antarctic sea ice.

Furthermore, the increased weight of snow on the sea ice may force it deeper into the water, forming thicker sea ice when the snow refreezes. Deeper snow also insulates the ice, protecting it from melting [15].

As global warming produces more moisture-laden air, the Antarctic snowfall increases.

But what about "wind variations, ozone forcing, atmospheric dynamics, and an increase in polynyas?"

Quote

Wind and movement

Changes in atmospheric dynamics and winds are an important driver of regional sea-ice trends. Ozone and greenhouse forcings cool the Antarctic stratosphere, which increases the stratospheric vortex and tropospheric zonal winds. This results in an increase in the Southern Annular Mode [6]. Increases in the Southern Annular Mode (SAM) signify increased westerly winds [7] and a rigorous isolation and cooling of parts of the Antarctic continent [6].

Because the Arctic is a semi-enclosed ocean, there is little scope for sea ice movement. Ice in the Arctic is thicker as a result of collisions, which means that the ice will last longer. This means that much of the Arctic sea ice lasts for several seasons, leading to permanent ice cover at the pole. However, in the Antarctic, there are far fewer such constraints. The sea ice is able to move around far more freely. It floats northwards to warmer waters, where it melts away almost entirely. Changes in the winds around Antarctica therefore change ice-concentration trends around Antarctica [8] by influencing sea-ice production and melt rates [9]. The pattern of wind change is complex, but variations in winds can help to explain some of the regional patterns in sea-ice formation [8]. Where the wind blows to the north, the sea ice is blown north where it melts, resulting in increased sea-ice extent. Where the winds blow south, the sea ice is blown towards the continent, resulting in decreased sea-ice concentrations.

Polynyas are areas of persistently open water in regions where sea ice is usual. The water remains unfrozen as a result of processes that either prevent ice from forming or that move ice out of the area. Polynyas are therefore an important part of sea-ice production. An increase in the extent of polynyas in the Ross Sea from 1978 to 2008 contributed to sea ice production [2]. The resulting increased ice export accounts for a large proportion of the increased trend in ice production. Changes in wind circulation alter ice production and export in and from these polynyas.

Greenhouse forcing (which you "accidentally" left out) and ozone forcing are types of radiative forcing, the name for the "heating effect caused by greenhouse gases in the atmosphere." See Climate Change Indicators in the United States. And radiative forcing, as the article you want us all to read points out, does lead to changes in wind and ice movement. However, one can't maintain (with a straight face) that the article even hints that the changes caused by radiative forcing are not the result of global warming.

I'm pretty sure that everyone understands that as global warming continues, the ice sheets will decline over the long term. Over the short term, as the article points out, global warming is causing the increase in Antarctic sea ice in several ways. Predominant, though, is the accelerating ice melt from Antarctic glaciers.

[Daniel1960]

PassedOut, on 2015-July-31, 11:57, said:

I asked for a list of the "many possibilities stated in the article" for which global warming is not responsible. Let's look again at what the article that you want us all to read says about "decreased ocean temperatures."


As global warming accelerates the freshwater melt from Antarctic glaciers, the resulting decrease in ocean temperatures (along with the lower salinity of the glacial melt) expands the surrounding sea ice. It has always been understood that this would happen on the way to equilibrium but, until the past few years, had been considered too obvious to point out.

What about "increased snowfall?"


As global warming produces more moisture-laden air, the Antarctic snowfall increases.

But what about "wind variations, ozone forcing, atmospheric dynamics, and an increase in polynyas?"


Greenhouse forcing (which you "accidentally" left out) and ozone forcing are types of radiative forcing, the name for the "heating effect caused by greenhouse gases in the atmosphere." See Climate Change Indicators in the United States. And radiative forcing, as the article you want us all to read points out, does lead to changes in wind and ice movement. However, one can't maintain (with a straight face) that the article even hints that the changes caused by radiative forcing are not the result of global warming.

I'm pretty sure that everyone understands that as global warming continues, the ice sheets will decline over the long term. Over the short term, as the article points out, global warming is causing the increase in Antarctic sea ice in several ways. Predominant, though, is the accelerating ice melt from Antarctic glaciers.

No. The authors gave "possible" explanations as to how global warming could have caused many of their possibilities. Natural changes could have also been the cause of every one of those possibilities. I did not
leave out greenhouse forcings, I simply referred to it as global warming - to keep our conversation consistent. Nowhere did the authors state that accelerated ice melt from receding glaciers was the predominant cause. Ice melt from increased snowfall or advancing glaciers is possible also.

Some people see global warming in everything, and close their eyes to natural fluctuations. You seem to want to fit the data into the global warming theory, instead of formulating a theory to fit the data. Political activism vs Science.

[PassedOut]

Daniel1960, on 2015-July-31, 12:25, said:

Natural changes could have also been the cause of every one of those possibilities.

There is nothing unnatural about the effects of global warming. When you increase heat, you naturally get the predictable effects. The predictable effects of global warming include an increase in Antarctic sea ice until equilibrium is reached. Given that we are continuing to increase greenhouse gases, what would be "unnatural" at this point would be the failure of the Antarctic sea ice to increase, given the simple physics of the situation.

[Daniel1960]

There was nothing "predictable" about the increasing Antarctic sea ice. Scientists are scrambling now to determine the cause(s). Some are trying to see how they can blame global warming. Others are looking more scientifically as to what is happening. Simple physics states that warmer temperatures lead to less ice, as witnessed around the rest of the globe. Antarctica should be no different.

[PassedOut]

Daniel1960, on 2015-July-31, 14:12, said:

There was nothing "predictable" about the increasing Antarctic sea ice. Scientists are scrambling now to determine the cause(s). Some are trying to see how they can blame global warming. Others are looking more scientifically as to what is happening. Simple physics states that warmer temperatures lead to less ice, as witnessed around the rest of the globe. Antarctica should be no different.

This is simply not true, and is insulting to scientists that I know and respect. I'd be surprised if you can find even one climate scientist who is surprised by the fact that Antarctic ice sheets are expanding because of global warming before they begin to retreat.

It's true that there has been (and is) uncertainty about the rate of that expansion and the point at which the retreat will begin. There has also been uncertainty about how much of the expansion results from changes in the wind and currents caused by global warming, how much results from the additional moisture held by the warming air, and how much results from the accelerating freshwater melt from the Antarctic glaciers. In particular, more accurate and recent measurements show a faster acceleration of the glacial melt than had been expected.

But the notion that "scientists are scrambling now to determine the causes" is pure rubbish. For example, here is an article in Nature GeoScience from March, 2013:

Quote

Specifically, we present observations indicating that melt water from Antarctica’s ice shelves accumulates in a cool and fresh surface layer that shields the surface ocean from the warmer deeper waters that are melting the ice shelves. Simulating these processes in a coupled climate model we find that cool and fresh surface water from ice-shelf melt indeed leads to expanding sea ice in austral autumn and winter. This powerful negative feedback counteracts Southern Hemispheric atmospheric warming. Although changes in atmospheric dynamics most likely govern regional sea-ice trends, our analyses indicate that the overall sea-ice trend is dominated by increased ice-shelf melt. We suggest that cool sea surface temperatures around Antarctica could offset projected snowfall increases in Antarctica, with implications for estimates of future sea-level rise.

I don't mind your holding and advocating for your very extreme views, but I'd prefer that you avoid insulting the scientists doing serious work on climate change.

[Daniel1960]

PassedOut, on 2015-July-31, 15:09, said:

This is simply not true, and is insulting to scientists that I know and respect. I'd be surprised if you can find even one climate scientist who is surprised by the fact that Antarctic ice sheets are expanding because of global warming before they begin to retreat.

It's true that there has been (and is) uncertainty about the rate of that expansion and the point at which the retreat will begin. There has also been uncertainty about how much of the expansion results from changes in the wind and currents caused by global warming, how much results from the additional moisture held by the warming air, and how much results from the accelerating freshwater melt from the Antarctic glaciers. In particular, more accurate and recent measurements show a faster acceleration of the glacial melt than had been expected.

But the notion that "scientists are scrambling now to determine the causes" is pure rubbish. For example, here is an article in Nature GeoScience from March, 2013:


I don't mind your holding and advocating for your very extreme views, but I'd prefer that you avoid insulting the scientists doing serious work on climate change.

I do not mind that you hold to your extreme views either. However, do not assume that the scientists agree with you. Here are a few assessment of the climate models:

http://www.the-cryos...-9-399-2015.pdf

http://journals.amet...LI-D-12-00068.1

http://onlinelibrary.../jgrd.50443/pdf

Here are some IPCC predictions for Antarctic sea ice:

https://www.ipcc.ch/...0s10-3-2-4.html

http://www.ipcc.ch/i...dex.php?idp=593

This explanation is from another website that I frequent, which was started by Gavin Schmidt, a strong global warming proponent:

http://www.realclima...arctic-sea-ice/

Let me quote, "The average expansion of Antarctic sea ice was not anticipated, but it hardly represents any sort of existential threat to our fundamental understanding of the climate system as a whole. It’s merely an interesting scientific challenge."

http://www.realclima...arctic-sea-ice/

I would like to know who you think predicted 10 or 20 years ago that Antarctic sea ice would increase. I would be surprised if you can find even one climate scientists who made this prediction.

[PassedOut]

Daniel1960, on 2015-July-31, 17:04, said:

I would like to know who you think predicted 10 or 20 years ago that Antarctic sea ice would increase. I would be surprised if you can find even one climate scientists who made this prediction.

It is true that climate scientists expected the Antarctic glaciers to be much more stable than they turned out to be, so the earlier predictions did not include the effect of the unanticipated freshwater melt. Without that melt, models predicted that rising ocean temperatures would dominate the opposing effects of increased snowfall from the warmer air and of the wind shifts due to radiant forcing.

Climate scientists did understand that freshwater is lighter and freezes more quickly than saltwater. And climate scientists did realize that Antarctic freshwater melt would oppose the effect of rising ocean temperatures. Climate scientists simply expected the freshwater melt to be insignificant to the calculations. When that expectation turned out to be wrong, climate scientists reacted appropriately and modeled the effects of the accelerating freshwater melt.

This reality is a far cry from your description here:

Daniel1960, on 2015-July-31, 14:12, said:

There was nothing "predictable" about the increasing Antarctic sea ice. Scientists are scrambling now to determine the cause(s). Some are trying to see how they can blame global warming. Others are looking more scientifically as to what is happening. Simple physics states that warmer temperatures lead to less ice, as witnessed around the rest of the globe. Antarctica should be no different.

No one is "trying to see how they can blame global warming." The vast majority of climate scientists are honest, competent people measuring and explaining complex interactions as objectively and precisely as they can.

And it's definitely not the case that the expanding sea ice around Antarctica suggests greater stability of the Antarctic ice sheets, nor does any competent climate scientist believe that. On the contrary.

[Daniel1960]

PassedOut, on 2015-August-01, 05:36, said:

It is true that climate scientists expected the Antarctic glaciers to be much more stable than they turned out to be, so the earlier predictions did not include the effect of the unanticipated freshwater melt. Without that melt, models predicted that rising ocean temperatures would dominate the opposing effects of increased snowfall from the warmer air and of the wind shifts due to radiant forcing.

Climate scientists did understand that freshwater is lighter and freezes more quickly than saltwater. And climate scientists did realize that Antarctic freshwater melt would oppose the effect of rising ocean temperatures. Climate scientists simply expected the freshwater melt to be insignificant to the calculations. When that expectation turned out to be wrong, climate scientists reacted appropriately and modeled the effects of the accelerating freshwater melt.

This reality is a far cry from your description here:


No one is "trying to see how they can blame global warming." The vast majority of climate scientists are honest, competent people measuring and explaining complex interactions as objectively and precisely as they can.

And it's definitely not the case that the expanding sea ice around Antarctica suggests greater stability of the Antarctic ice sheets, nor does any competent climate scientist believe that. On the contrary.

I am not saying they are dishonest. Rather, they view global warming as the dominant forces, and try to model ever climactic event on that basis. This is not unique to climate scientists. Astrophysicists are convinced that solar and galactic forces dominate our weather and climate.

Just because they can model past observations based on specified inputs, does not prove accuracy. Astrophysicists have had similar results modelling past climate regimes bast on solar output. I am not confident that their recent modelling, showing significant cooling in the coming decades, will come to fruition.

Scientists tend to play to their strengths. In addition to astrophysicists, oceanographers point to ocean currents as the dominant weather forcing for our planet. Climatologists claim it is carbon dioxide. Each discipline has a certain amount of validity in their claims. However, selecting one as being correct, based on pre-tuned models, lacks significant scientific understanding. That does not necessarily dispute their accuracy. It just means that we are lacking in sufficient proof.

[WellSpyder]

PassedOut, on 2015-July-31, 12:54, said:

The predictable effects of global warming include an increase in Antarctic sea ice until equilibrium is reached.

You may think it was predictable, but I am not aware that it was predicted!

There is a big difference between being able to explain afterwards why something happened, and actually expecting it before it happened. (I am an economist by profession, a field where "experts" often seem to be on the wrong end of this comparison!)

I am not trying to argue that the failure to predict an increase in Antarctic sea ice invalidates global warming science, but it would certainly have been a more impressive validation of the science if this had been foreseen rather than being explained afterwards.

[PassedOut]

WellSpyder, on 2015-August-03, 03:46, said:

You may think it was predictable, but I am not aware that it was predicted!

There is a big difference between being able to explain afterwards why something happened, and actually expecting it before it happened. (I am an economist by profession, a field where "experts" often seem to be on the wrong end of this comparison!)

I am not trying to argue that the failure to predict an increase in Antarctic sea ice invalidates global warming science, but it would certainly have been a more impressive validation of the science if this had been foreseen rather than being explained afterwards.

Obviously.

But the reason that the increase was not predicted many years ago was not because scientists didn't understand that freshwater melt from Antarctic glaciers would increase the sea ice around Antarctica. It was because then they had no evidence that those glaciers were as unstable as they turned out to be, and therefore had no basis for predicting the increase in sea ice.

[Al_U_Card]

Glaciology and the mechanisms of glacial melt are pretty well understood and have been since well before the IPCC and its "GW causes-all" agenda.

The only wild card in the mix appears to be the volcanism under the WAIS that is producing melt greater than expected for the cooling of the locale (despite CAGW predictions of increased ice melt and higher temps). The hand-waving explanations associated with discrepancies between model projections and reality only serve to demonstrate just how far off the models are from what is actually occurring, thereby (further) invalidating their usefulness for scenarios of future global or especially regional climate conditions.

[y66]

For those of you who can't get to DC for Grandparents' Climate Action Days on September 9 and 10, there will be another event coinciding with Pope Francis' address to Congress on September 24th sponsored by Moral Action on Climate.

[Al_U_Card]

y66, on 2015-August-05, 11:16, said:

For those of you who can't get to DC for Grandparents' Climate Action Days on September 9 and 10, there will be another event coinciding with Pope Francis' address to Congress on September 24th sponsored by Moral Action on Climate.

I wonder about 2 things. First, how much "climate change" are they expecting to reverse/prevent?

Second, James Hansen is front and center in the first link and the Pope is in the second link. What do they have in common? Well, Hansen was molesting the Gisstemp data for years...

Seriously, the first is an appeal for donations (registration?) to support the eldersclimateaction organization. (Hopefully Passedout and WinstonM will contribute...)

The real question is will these elders and their organization turn off the A/C and lower the heating in winter? Stop jetting about to various sites to protest overuse of carbon-rich transportation? Give up on modern technology to ensure that our grandchildren have some woodchips to burn for heat? Calculate the net effect of their actions and realize that the whole thing is a scam on elders (and everyone else) and they should report it as such.

[y66]

#followfrancis