Climate Changes Both Ways

The title comes from a news event last week when President Trump reminded Prince Charles of a natural truism:  Climate change goes both ways.  A media freak out ensued, as shown by this example from Newsweek.  Excerpt in italics with my bolds.

President Donald Trump said Wednesday he believes there has been a change in the weather due to climate change, but that “it changes both ways.”

The president then explained his views on the climate. “Don’t forget, it used to be called global warming, that wasn’t working, then it was called climate change, now it’s actually called extreme weather because with extreme weather you can’t miss,” the president said.

Environmental watchdog groups now advocate calling the phenomenon “climate catastrophe.”

It seemed to me that Trump is learning from his briefings with William Happer, and is finding the weak spots in the alarmist house of cards.  It also reminded me of a previous post describing the complexity of tracking climate change.  That essay is reprinted below because it reminds us that not only does climate change both ways, but also the warming and cooling can happen concurrently in some times and places.

Concurrent Climate Warming and Cooling

This post highlights recent interesting findings regarding past climate change in NH, Scotland in particular. The purpose of the research was to better understand how glaciers could be retreating during the Younger Dryas Stadia (YDS), one of the coldest periods in our Holocene epoch.

The lead researcher is Gordon Bromley, and the field work was done on site of the last ice fields on the highlands of Scotland. 14C dating was used to estimate time of glacial events such as vegetation colonizing these places. Bromely explains in article Shells found in Scotland rewrite our understanding of climate change at siliconrepublic. Excerpts in italics with my bolds.

By analysing ancient shells found in Scotland, the team’s data challenges the idea that the period was an abrupt return to an ice age climate in the North Atlantic, by showing that the last glaciers there were actually decaying rapidly during that period.

The shells were found in glacial deposits, and one in particular was dated as being the first organic matter to colonise the newly ice-free landscape, helping to provide a minimum age for the glacial advance. While all of these shell species are still in existence in the North Atlantic, many are extinct in Scotland, where ocean temperatures are too warm.

This means that although winters in Britain and Ireland were extremely cold, summers were a lot warmer than previously thought, more in line with the seasonal climates of central Europe.

“There’s a lot of geologic evidence of these former glaciers, including deposits of rubble bulldozed up by the ice, but their age has not been well established,” said Dr Gordon Bromley, lead author of the study, from NUI Galway’s School of Geography and Archaeology.

“It has largely been assumed that these glaciers existed during the cold Younger Dryas period, since other climate records give the impression that it was a cold time.”

He continued: “This finding is controversial and, if we are correct, it helps rewrite our understanding of how abrupt climate change impacts our maritime region, both in the past and potentially into the future.”

The recent report is Interstadial Rise and Younger Dryas Demise of Scotland’s Last Ice Fields G. Bromley A. Putnam H. Borns Jr T. Lowell T. Sandford D. Barrell  First published: 26 April 2018.(my bolds)

Abstract

Establishing the atmospheric expression of abrupt climate change during the last glacial termination is key to understanding driving mechanisms. In this paper, we present a new 14C chronology of glacier behavior during late‐glacial time from the Scottish Highlands, located close to the overturning region of the North Atlantic Ocean. Our results indicate that the last pulse of glaciation culminated between ~12.8 and ~12.6 ka, during the earliest part of the Younger Dryas stadial and as much as a millennium earlier than several recent estimates. Comparison of our results with existing minimum‐limiting 14C data also suggests that the subsequent deglaciation of Scotland was rapid and occurred during full stadial conditions in the North Atlantic. We attribute this pattern of ice recession to enhanced summertime melting, despite severely cool winters, and propose that relatively warm summers are a fundamental characteristic of North Atlantic stadials.

Plain Language Summary

Geologic data reveal that Earth is capable of abrupt, high‐magnitude changes in both temperature and precipitation that can occur well within a human lifespan. Exactly what causes these potentially catastrophic climate‐change events, however, and their likelihood in the near future, remains frustratingly unclear due to uncertainty about how they are manifested on land and in the oceans. Our study sheds new light on the terrestrial impact of so‐called “stadial” events in the North Atlantic region, a key area in abrupt climate change. We reconstructed the behavior of Scotland’s last glaciers, which served as natural thermometers, to explore past changes in summertime temperature. Stadials have long been associated with extreme cooling of the North Atlantic and adjacent Europe and the most recent, the Younger Dryas stadial, is commonly invoked as an example of what might happen due to anthropogenic global warming. In contrast, our new glacial chronology suggests that the Younger Dryas was instead characterized by glacier retreat, which is indicative of climate warming. This finding is important because, rather than being defined by severe year‐round cooling, it indicates that abrupt climate change is instead characterized by extreme seasonality in the North Atlantic region, with cold winters yet anomalously warm summers.

The complete report is behind a paywall, but a 2014 paper by Bromley discusses the evidence and analysis in reaching these conclusions. Younger Dryas deglaciation of Scotland driven by warming summers  Excerpts with my bolds.

Significance: As a principal component of global heat transport, the North Atlantic Ocean also is susceptible to rapid disruptions of meridional overturning circulation and thus widely invoked as a cause of abrupt climate variability in the Northern Hemisphere. We assess the impact of one such North Atlantic cold event—the Younger Dryas Stadial—on an adjacent ice mass and show that, rather than instigating a return to glacial conditions, this abrupt climate event was characterized by deglaciation. We suggest this pattern indicates summertime warming during the Younger Dryas, potentially as a function of enhanced seasonality in the North Atlantic.

Surface temperatures range from -30C to +30C

Fig. 1. Surface temperature and heat transport in the North Atlantic Ocean.  The relatively mild European climate is sustained by warm sea-surface temperatures and prevailing southwesterly airflow in the North Atlantic Ocean (NAO), with this ameliorating effect being strongest in maritime regions such as Scotland. Mean annual temperature (1979 to present) at 2 m above surface (image obtained using University of Maine Climate Reanalyzer, http://www.cci-reanalyzer.org). Locations of Rannoch Moor and the GISP2 ice core are indicated (yellow and red dots).

Thus the Scottish glacial record is ideal for reconstructing late glacial variability in North Atlantic temperature (Fig. 1). The last glacier resurgence in Scotland—the “Loch Lomond Advance” (LLA)—culminated in a ∼9,500-km2 ice cap centered over Rannoch Moor (Fig. 2A) and surrounded by smaller ice fields and cirque glaciers.

Fig. 2. Extent of the LLA ice cap in Scotland and glacial geomorphology of western Rannoch Moor. (A) Maximum extent of the ∼9,500 km2 LLA ice cap and larger satellite ice masses, indicating the central location of Rannoch Moor. Nunataks are not shown. (B) Glacial-geomorphic map of western Rannoch Moor. Distinct moraine ridges mark the northward active retreat of the glacier margin (indicated by arrow) across this sector of the moor, whereas chaotic moraines near Lochan Meall a’ Phuill (LMP) mark final stagnation of ice. Core sites are shown, including those (K1–K3) of previous investigations (14, 15).

When did the LLA itself occur? We consider two possible resolutions to the paradox of deglaciation during the YDS. First, declining precipitation over Scotland due to gradually increasing North Atlantic sea-ice extent has been invoked to explain the reported shrinkage of glaciers in the latter half of the YDS (18). However, this course of events conflicts with recent data depicting rapid, widespread imposition of winter sea-ice cover at the onset of the YDS (9), rather than progressive expansion throughout the stadial.

Loch Lomond

Furthermore, considering the gradual active retreat of LLA glaciers indicated by the geomorphic record, our chronology suggests that deglaciation began considerably earlier than the mid-YDS, when precipitation reportedly began to decline (18). Finally, our cores contain lacustrine sediments deposited throughout the latter part of the YDS, indicating that the water table was not substantially different from that of today. Indeed, some reconstructions suggest enhanced YDS precipitation in Scotland (24, 25), which is inconsistent with the explanation that precipitation starvation drove deglaciation (26).

We prefer an alternative scenario in which glacier recession was driven by summertime warming and snowline rise. We suggest that amplified seasonality, driven by greatly expanded winter sea ice, resulted in a relatively continental YDS climate for western Europe, both in winter and in summer. Although sea-ice formation prevented ocean–atmosphere heat transfer during the winter months (10), summertime melting of sea ice would have imposed an extensive freshwater cap on the ocean surface (27), resulting in a buoyancy-stratified North Atlantic. In the absence of deep vertical mixing, summertime heating would be concentrated at the ocean surface, thereby increasing both North Atlantic summer sea-surface temperatures (SSTs) and downwind air temperatures. Such a scenario is analogous to modern conditions in the Sea of Okhotsk (28) and the North Pacific Ocean (29), where buoyancy stratification maintains considerable seasonal contrasts in SSTs. Indeed, Haug et al. (30) reported higher summer SSTs in the North Pacific following the onset of stratification than previously under destratified conditions, despite the growing presence of northern ice sheets and an overall reduction in annual SST. A similar pattern is evident in a new SST record from the northeastern North Atlantic, which shows higher summer temperatures during stadial periods (e.g., Heinrich stadials 1 and 2) than during interstadials on account of amplified seasonality (30).

Our interpretation of the Rannoch Moor data, involving the summer (winter) heating (cooling) effects of a shallow North Atlantic mixed layer, reconciles full stadial conditions in the North Atlantic with YDS deglaciation in Scotland. This scenario might also account for the absence of YDS-age moraines at several higher-latitude locations (12, 36–38) and for evidence of mild summer temperatures in southern Greenland (11). Crucially, our chronology challenges the traditional view of renewed glaciation in the Northern Hemisphere during the YDS, particularly in the circum-North Atlantic, and highlights our as yet incomplete understanding of abrupt climate change.

Summary

Several things are illuminated by this study. For one thing, glaciers grow or recede because of multiple factors, not just air temperature. The study noted that glaciers require precipitation (snow) in order to grow, but also melt under warmer conditions. For background on the complexities of glacier dynamics see Glaciermania

Also, paleoclimatology relies on temperature proxies who respond to changes over multicentennial scales at best. C14 brings higher resolution to the table.

Finally, it is interesting to consider climate changing with respect to seasonality.  Bromley et al. observe that during Younger Dryas, Scotland shifted from a moderate maritime climate to one with more seasonal extremes like that of inland continental regions. In that light, what should we expect from cooler SSTs in the North Atlantic?

Note also that our modern warming period has been marked by the opposite pattern. Many NH temperature records show slight summer cooling along with somewhat stronger warming in winter, the net being the modest (fearful?) warming in estimates of global annual temperatures.

I’m with Trump on this one:  Climate shifts are not a matter of one-way warming, as we have been told.

 

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Blinded by Antarctica Reports

Special snow goggles for protection in polar landscapes.

Someone triggered Antarctica for this week’s media alarm blitz.

Antarctic ice loss increases to 200 billion tonnes a year – Climate Action

Antarctica is now melting three times faster than ever before – Euronews

Antarctica is shedding ice at an accelerating rate – Digital Journal

Al Gore Sounds the Alarm on 0.3 inches of Sea Level Rise from Ice Sheets– Daily Caller

Antarctica is losing an insane amount of ice. Nothing about this is good. – Fox News
Looks like it’s time yet again to play Climate Whack-A-Mole.  That means stepping back to get some perspective on the reports and the interpretations applied by those invested in alarmism.

Antarctic Basics

The Antarctic Ice Sheet extends almost 14 million square kilometers (5.4 million square miles), roughly the area of the contiguous United States and Mexico combined. The Antarctic Ice Sheet contains 30 million cubic kilometers (7.2 million cubic miles) of ice. (Source: NSIDC: Quick Facts Ice Sheets)

The Antarctic Ice Sheet covers an area larger than the U.S. and Mexico combined. This photo shows Mt. Erebus rising above the ice-covered continent. Credit: Ted Scambos & Rob Bauer, NSIDC

The study of ice sheet mass balance underwent two major advances, one during the early 1990s, and again early in the 2000s. At the beginning of the 1990s, scientists were unsure of the sign (positive or negative) of the mass balance of Greenland or Antarctica, and knew only that it could not be changing rapidly relative to the size of the ice sheet.

Advances in glacier ice flow mapping using repeat satellite images, and later using interferometric synthetic aperture radar SAR methods, facilitated the mass budget approach, although this still requires an estimate of snow input and a cross-section of the glacier as it flows out from the continent and becomes floating ice. Satellite radar altimetry mapping and change detection, developed in the early to mid-1990s allowed the research community to finally extract reliable quantitative information regarding the overall growth or reduction of the volume of the ice sheets.

By 2002, publications were able to report that both large ice sheets were losing mass (Rignot and Thomas 2002). Then in 2003 the launch of two new satellites, ICESat and GRACE, led to vast improvements in one of the methods for mass balance determination, volume change, and introduced the ability to conduct gravimetric measurements of ice sheet mass over time. The gravimetric method helped to resolve remaining questions about how and where the ice sheets were losing mass. With this third method, and with continued evolution of mass budget and geodetic methods it was shown that the ice sheets were in fact losing mass at an accelerating rate by the end of the 2000s (Veliconga 2009, Rignot et al. 2011b).

Contradictory Findings

NASA Study: Mass Gains of Antarctic Ice Sheet Greater than Losses

A new 2015 NASA study says that an increase in Antarctic snow accumulation that began 10,000 years ago is currently adding enough ice to the continent to outweigh the increased losses from its thinning glaciers.

The research challenges the conclusions of other studies, including the Intergovernmental Panel on Climate Change’s (IPCC) 2013 report, which says that Antarctica is overall losing land ice.

According to the new analysis of satellite data, the Antarctic ice sheet showed a net gain of 112 billion tons of ice a year from 1992 to 2001. That net gain slowed to 82 billion tons of ice per year between 2003 and 2008.

“We’re essentially in agreement with other studies that show an increase in ice discharge in the Antarctic Peninsula and the Thwaites and Pine Island region of West Antarctica,” said Jay Zwally, a glaciologist with NASA Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the study, which was published on Oct. 30 in the Journal of Glaciology. “Our main disagreement is for East Antarctica and the interior of West Antarctica – there, we see an ice gain that exceeds the losses in the other areas.” Zwally added that his team “measured small height changes over large areas, as well as the large changes observed over smaller areas.”

Scientists calculate how much the ice sheet is growing or shrinking from the changes in surface height that are measured by the satellite altimeters. In locations where the amount of new snowfall accumulating on an ice sheet is not equal to the ice flow downward and outward to the ocean, the surface height changes and the ice-sheet mass grows or shrinks.

Snow covering Antarctic peninsula.

Keeping Things in Perspective

Such reports often include scary graphs like this one and the reader is usually provided no frame of reference or context to interpret the image. First, the chart is showing cumulative loss of mass arising from an average rate of 100 Gt lost per year since 2002. Many years had gains, including 2002, and the cumulative loss went below zero only in 2006.  Also, various methods of measuring and analyzing give different results, as indicated by the earlier section.

Most important is understanding the fluxes in proportion to the Antarctic Ice Sheet.  Let’s do the math.  Above it was stated Antarctica contains ~30 million cubic kilometers of ice volume.  One km3 of water is 1 billion cubic meters and weighs 1 billion tonnes, or 1 gigatonne.  So Antarctica has about 30,000,000 gigatonnes of ice.  Since ice is slightly less dense than water, the total should be adjusted by 0.92 for an estimate of 27.6 M Gts of ice comprising the Antarctic Ice Sheet.

So in the recent decade, an average year went from 27,600,100 Gt to 27,600,000, according to one analysis.  Other studies range from losing 200 Gt/yr to gaining 100 Gt/yr.

Even if Antarctica lost 200 Gt/yr. for the next 1000 years, it would only approach 1% of the ice sheet.

If like Al Gore you are concerned about sea level rise, that calculation starts with the ocean area estimated to be 3.618 x 10^8 km2 (361,800,000 km2). To raise that area 1 mm requires 3.618×10^2 km3 or 361.8 km3 water (1 km3 water=1 Gt.) So 200 Gt./yr is about 0.55mm/yr or 6 mm a decade, or 6 cm/century.

By all means let’s pay attention to things changing in our world, but let’s also notice the scale of the reality and not make mountains out of molehills.

Let’s also respect the scientists who study glaciers and their subtle movements over time (“glacial pace”).  Below is an amazing video showing the challenges and the beauty of working on Greenland Glacier.

From Ice Alive: Uncovering the secrets of Earth’s Ice

For more on the Joys of Playing Climate Whack-A-Mole 

Impaired Climate Vision

We are entering the season where governments, especially the US are reviewing and finalizing Climate Assessments.  Whenever citizens or decision makers are presented with an assessment and recommendations, it is important to take the stance of a “reasonable person.”  That means one applies critical intelligence by asking if assertions are well-founded and logical.

In starting to read the draft Climate Assessment reports, it strikes me that the difference between alarmists and others is not so much in the data or facts, but in the perspective through which one sees and interprets the information.  From experience the last few years, I suggest that readers of these reports need to be alert for two errors that crop up often.  The general impairments are stated below followed by some examples for illustration.

  1. CO2 Alarm is Myopic: Claiming CO2 causes dangerous global warming is too simplistic. CO2 is but one factor among many other forces and processes interacting to make weather and climate.

Myopia is a failure of perception by focusing on one near thing to the exclusion of the other realities present, thus missing the big picture. For example: “Not seeing the forest for the trees.” AKA “tunnel vision.”

2. CO2 Alarm is Lopsided: CO2 forcing is too small to have the overblown effect claimed for it. Other factors are orders of magnitude larger than the potential of CO2 to influence the climate system.

Lop-sided refers to a failure in judging values, whereby someone lacking in sense of proportion, places great weight on a factor which actually has a minor influence compared to other forces. For example: “Making a mountain out of a mole hill.”

Correcting for Myopia and/or Lop-sidedness

Example of Greenland Ice Sheet

It was recently suggested to me that we should all be concerned about the Greenland ice sheet melting resulting in dangerous rising sea levels.  The evidence presented came from US climate.gov in the form of this chart.

On the NOAA page where it appears, they explain:

The ups and downs in the graph track the accumulation of snow in the cold season and the melting of the ice sheet in the warm season. The Arctic Report Card: Update for 2016 reported that between April 2015 and April 2016, Greenland lost approximately 191 gigatonnes of ice, roughly the same amount that was lost between April 2014 and April 2015. Though the April 2015–April 2016 mass loss was lower than the average April-to-April decline over the entire observation period, it continued the long-term melt trend: approximately 269 gigatonnes per year from 2002 to 2016.

Now that NOAA graph needs to be understood in context.  That means looking at the data in the largest relevant scope (test for myopia) and checking that conclusions are in proportion (not lop-sided) compared to the base reality.

First, it turns out that the years since 2002 are not representative.  From DMI (Danish Meteorological Institute Aerial photos from Greenland topple climate models

Between 1985 and 1992, Greenland experienced a large loss of ice mass because of dynamic ice-mass loss. But the glaciers stabilised and there was no dynamic ice-mass loss for more than ten years.

This loss started again in 2004 and has continued until today.

“We can see that the dynamic ice-mass loss is not accelerating constantly, as we had believed,” says Shfaqat Abbas Khan, a senior researcher at DTU Space – the National Space Institute.

“It is only periodically that the ice disappears as rapidly as is happening today. We expect that the reduction in Greenland’s ice mass due to the dynamic ice-mass loss will ease over the next couple of years and will reach zero again.”

And sure enough Greenland is making a surplus of ice this year

But the call for concern is also lop-sided in the context of the actual massiveness of Greenland’s ice sheet which has persisted for millennia. (That’s why they go there for ice cores.)

Doing the numbers: Greenland area 2.1 10^6 km2 80% ice cover, 1500 m thick in average- That is 2.5 Million Gton. Simplified to 1 km3 = 1 Gton

200 Gton is 0.008 % of that mass.

Annual snowfall: From the Lost Squadron, we know at that particular spot, the ice increase since 1942 – 1990 was 1.5 m/year ( Planes were found 75 m below surface)
Assume that yearly precipitation is 100 mm / year over the entire surface.
That is 168000 Gton. Yes, Greenland is Big!

Inflow = 168,000Gton. Outflow is 168,200 Gton.

So if that 200 Gton rate continued, an assumption not warranted by observations above, that ice loss would result in a 1% loss of Greenland ice in 800 years.

Seen in the proper perspective, there is no reason for panic.

Example: Movement of Ecological Life Zones

I have been referred to studies in places like Arizona finding that certain species are moving to higher altitudes because of warming to their native habitat.  The research seems solid and I do not doubt either that climate zones shift over time or that plant and animal life adapt.  But how serious is the problem?  The US Southwest has warmed in recent decades, while the US Southeast has cooled.  What is the global story on changing climate zones?

188767-004-6bde1150

Köppen climate zones as they appear in the 21st Century.

Fortunately we have a well-established framework classifying climate zones based upon temperature and precipitation patterns.  And researchers have addressed this question in this paper: Using the Köppen classification to quantify climate variation and change: An example for 1901–2010  By Deliang Chen and Hans Weiteng Chen Department of Earth Sciences, University of Gothenburg, Sweden

Hans Chen has built an excellent interactive website (here): The purpose of this website is to share information about the Köppen climate classification, and provide data and high-resolution figures from the paper Chen and Chen, 2013: Using the Köppen classification to quantify climate variation and change: An example for 1901–2010 (pdf). A synopsis is at my post Data vs. Models #4: Climates Changing.

Briefly, for this discussion, Chen and Chen presented tables and charts showing that most places have had at least one entire year with temperatures and/or precipitation atypical for that climate. It is much more unusual for abnormal weather to persist for ten years running. At 30-years and more the zones are quite stable, such that is there is little movement at the boundaries with neighboring zones.  Over time, there is variety in zonal changes, albeit within a small range of overall variation.

A Final Example: Rising Temperatures

A tv show in Australia illustrated how vision is impaired on this subject.  A typical graph was used to claim warming is alarming.  It came from the NASA Goddard Institute of Space Studies (GISS):

The graph shows no pause whatsoever.  This is accomplished by lowering the 1998 El Nino spike relative to 2015 El Nino. To see what is going on, here is a helpful chart from Dr. Ole Humlum at Climate4you.

It shows that indeed, GISS is showing 1998 peak lower than several years since, especially 2002, 2010 and 2016. In contrast, the satellite record is dominated by 1998, and may still be in that position once La Nina takes hold. The differences arise because satellites measure air temperature in the lower troposphere, while GISS combines records from land stations with sea surface temperatures (SSTs) to fabricate a global average anomaly, including adjusting, gridding and infilling to make the estimate of Global Mean Temperatures and compare to a 30-year average.

An insight into the adjustments is displayed below.  Dr. Humlum demonstrates that GISS is an unstable temperature record.

Dr. Humlum:

Based on the above it is not possible to conclude which of the above five databases represents the best estimate on global temperature variations. The answer to this question remains elusive. All five databases are the result of much painstaking work, and they all represent admirable attempts towards establishing an estimate of recent global temperature changes. At the same time it should however be noted, that a temperature record which keeps on changing the past hardly can qualify as being correct. (my bold)

All of these charts also suffer from lop-sidedness.  Considering the range of temperatures experienced by most Americans in a typical year, the following graph is more representative.

Why did GISS ignore the platinum standard satellite temperature dataset?  Why should the current graph be believed when it differs from previous ones, and maybe the next one?  Was not the 1C warming since 1850 a boon for civilization and the biosphere?  Should we wish for it to get cooler and start the slide into the next ice age?

Summary

There are a great many claims assembled in these Climate Assessments, all of them in support of policies like the Paris accord.  Reasonable people need to test for myopia and maintain a sense of proportion in order not to be taken in.

Glaciermania

A stream flows through the toe of Kaskawulsh Glacier in Yukon’s Kluane National Park. In 2016, this channel allowed the glacier’s meltwater to drain in a different direction than normal, resulting in the Slims River’s water being rerouted to a different river system..

The Weather Network (who do a decent job on local weather forecasting) are currently raving about Glaciers:

You know climate change is getting serious when rivers are resorting to piracy.

Canadian geomorphologist Dr. Daniel Shugar and his team headed to the Yukon last year to study changes in the flow of the Slims River, only to find out the river was gone.

The Slims, which was fed by the Kaskawulsh glacier, has become the victim of the first case of what’s known as river piracy in modern recorded history.

The team’s investigation soon turned up the culprit – the retreat of the Kaskawulsh Glacier, which has been retreating thanks to more than a century of climate warming.

What Actually Happened

Prior to May of last year, the glacier had been supplying water to two watersheds and feeding multiple rivers; the Kaskawulsh River, which drains to the Pacific Ocean via the Alsek River, and the Slims, which flowed north to the Bering Sea via Kluane Lake.

During the last days of May 2016, melt water at the base of the glacier finally managed to eat through the thinning ice sheet, opening a new canyon and sending the Slims’ share of the water into the Kaskawulsh instead.

Thanks to this abrupt change, water from the glacier that used to flow north to the Bering Sea has changed direction and flows toward the Pacific, instead, leaving the Slims basin high and (mostly) dry.

And Now, the Leap of Faith

In the published paper lead author Daniel Shugar goes on to state:
Based on satellite image analysis and a signal-to-noise ratio as a metric of glacier retreat, we conclude that this instance of river piracy was due to post-industrial climate change.

And others can’t resist piling on:

“To me, it’s kind of a metaphor for what can happen with sudden change induced by climate,” said John Clague, who holds a chair in natural hazard research at Simon Fraser University and was a co-author on the report.

“Climate change is happening, is affecting us and it’s not just about far-off islands in the South Pacific. .  Climate change may bring new changes that we’re not even really thinking about.” said Shugar.

It’s a nice PR touch to call this “Piracy”, but they are “jumping the shark” by claiming humans did this by burning fossil fuels.

“Jumping the shark” is attempting to draw attention to or create publicity for something that is perceived as not warranting the attention, especially something that is believed to be past its peak in quality or relevance. The phrase originated with the TV series “Happy Days” when an episode had Fonzie doing a water ski jump over a shark. The stunt was intended to perk up the ratings, but it marked the show’s low point ahead of its demise.

Hyping a Glacier retreating to prove global warming/climate change looks to be a similarly desperate move. Most people sense that the dynamics of glaciers growing, shrinking and moving is much more complex than simply fingering CO2 as the culprit.

south-glacier-as-seen-during-its-1986-surge-photo-p-johnson-and-in-2005-photo-g

FIG. 3. South Glacier as seen during its 1986 surge (photo: P. Johnson) and in 2005 (photo: G. Flowers). To facilitate comparison, the black line in each photograph marks the same feature.

For context and scientific perspective we can turn to papers like this one:  Contemporary Glacier Processes and Global Change: Recent Observations from Kaskawulsh Glacier and the Donjek Range, St. Elias Mountains From the Abstract:

The scientific objectives of these projects are (1) to quantify recent area and volume changes of Kaskawulsh Glacier and place them in historical perspective, (2) to investigate the regional variability of glacier response to climate and the modulating inuence of ice dynamics, and (3) to characterize the hydromechanical controls on glacier sliding.

the-donjek-range-and-environs-geobase-r-image-8-september-2008-within-the-st-elias

FIG. 1. The Donjek Range and environs (Geobase ® image, 8 September 2008) within the St. Elias Mountains (NASA Aqua – MODIS image, 9 August 2003; North and South Glaciers are outlined, and locations of automatic weather stations operated since 2006 – 07 are marked with stars.

Excerpts (bolded text is my emphasis)

Kaskawulsh Glacier is ~70 km long from its shared accumulation area with the upper Hubbard Glacier, at an elevation of ~2500 m asl, to its terminus ~25 km southwest of the Kluane Lake Research Station, at ~820 m asl (Fig. 1). It provides the source of the Slims River, the primary water input for Kluane Lake to the northeast (which drains to the Bering Sea), and the source of the Kaskawulsh River to the southeast (which drains to the Gulf of Alaska).

One of the most iconic and best studied outlet glaciers of the St. Elias Mountains, Kaskawulsh Glacier was the focus of much glaciological research during the Icefield Ranges Research Project between the 1960s and early 1970s  and contemporary studies suggest that the glacier is temperate throughout. The current area of Kaskawulsh Glacier is ~1095 km2. Ice thicknesses range from 539 m near the topographic divide with the upper Hubbard Glacier and ~500 m at the confluence of the north and central arms at ~1750 m asl to 778 m at ~1600 m asl. The equilibrium line altitude is estimated from 2007 late summer satellite imagery as 1958 m asl, and it appears to have changed little since the 1970s.

The size of Kaskawulsh Glacier has varied considerably through time, with radiocarbon dating suggesting that it expanded by tens of kilometres into the Shakwak Valley (currently occupied by Kluane Lake) ~30 kya during the Wisconsinan Glaciation. In the historical past, Borns and Goldthwait (1966) mapped three sets of Little Ice Age moraines in the glacier forefield on the basis of distinctive variations in vegetation cover, morphology, and the ages of trees and shrubs.

Kaskawulsh Glacier was advancing by the early 1500s and reached its maximum recent position by approximately AD 1680. A recent study based on tree-ring dates suggests that the Slims River lobe reached its greatest Little Ice Age extent in the mid-1750s, whereas the Kaskawulsh River lobe reached its maximum extent around 1717. However, it appears that the glacier did not start retreating from this position until the early to middle 1800s. The recent discovery of a Geological Survey of Canada map of the glacier terminus from 1900 to 1904 indicates that the glacier was still in a forward position at that time, suggesting that most of the terminus retreat occurred in the 20th century.

Recent studies conducted by researchers at the University of Alaska and the University of Ottawa indicate that ice losses from Kaskawulsh Glacier have continued through the latter half of the 20th century and first decade of the 21st century, although evidence for any recent acceleration in loss rates is equivocal.

Global Context

Of the 19 glacierized regions of the world outside of the ice sheets, the region including the St. Elias Mountains made the second highest glaciological contribution to global sea level during the period 1961 – 2000. Only Arctic Canada is expected to exceed this region in sea-level contribution over the 21st century.

The St. Elias Mountains exhibit high interannual variability in ice mass change, which is due in part to the abundance of surge-type and tidewater glaciers in different stages of their respective cycles. Ice dynamics can be a confounding influence when attempting to isolate the effects of climate as an external driver of glacier change. For example, a surge-type glacier in the “quiescent” phase of its cycle may retreat even in a stationary climate. Catastrophic retreat of a tidewater glacier may be triggered by climate, but it is largely controlled by glacier and fjord geometry. Similar “flow instabilities” exist at larger scales in the form of ice streams and marine ice-sheets or outlet glaciers, the dynamics of which dominate the mass balances (and therefore sea-level contributions) of large sectors of the modern ice sheets. Our ability to project future changes on short (sub-decadal to decadal) timescales therefore hinges on our understanding of internal glacier dynamics, as well as our ability to project future climate in a given region and relate climate to glacier surface mass balance.

The ice-walled canyon at the terminus of the Kaskawulsh River in the Yukon, with recently collapsed ice blocks, that now carries the vast majority of glacier-front water down the Kaskawulsh Valley toward the Gulf of Alaska and the Pacific Ocean instead of north along the Slims River toward the Bering Sea. (Jim Best/University of Illinois)

Whether climate has fundamentally altered the surging styles of Trapridge Glacier and South Glacier from the faster, shorter, more recognizable Alaskan style to the slower and more subtle Svalbard style is an interesting question. Many small poly-thermal glaciers, whose temperate ice content is largely controlled by meltwater entrapment and refreezing in the accumulation area, are expected to become colder under negative mass balance conditions. It is therefore conceivable that thermal evolution over the course of decades can play a role in altering surge style. However, there is some evidence that both types of surges may be preceded by a prolonged—and until recently, unrecognized—period of acceleration. Thus, a “slow surge” or “partial surge” may simply represent a truncation of the ordinary surge cycle that results from a deficit of mass, rather than a fundamental change in surge character. Mass deficits have manifested themselves differently on the well-studied and temperate Variegated Glacier, where the return interval between surges adapts itself in such a way that surges are triggered at a constant cumulative balance threshold. The nature and timing of future surges of the large glaciers in the St. Elias Mountains will be instructive as we seek a more coherent understanding of the influence of climate on surging.

Summary

So it is a familiar story. A complex naturally fluctuating situation, in this case glaciers, is abused by activists to claim support for their agenda. I have a lot of respect for glaciologists; it is a deep, complex subject, and the field work is incredibly challenging. And since “glacial” describes any process where any movement is imperceptible, I can understand their excitement over something happening all of a sudden.

But I do not applaud those pandering to the global warming/climate change crowd. They seem not to realize they debase their own field of study by making exaggerated claims and by “jumping the shark.”
The lead authur, Shugar, sounds like a Michael Mann wannabe, putting out sound bites to please the naive journalists. Maybe he thinks there is a Nobel prize in it if he plays his cards right.

Meanwhile real scientists are doing the heavy lifting and showing restraint and wisdom about the limitations of their knowledge.

The Kaskawulsh River, as it exits the lower terminus of Kaskawulsh Glacier and lakes. ‘ JIM BEST