Video acquired from Space Rip [All Rights Reserved]

Greenland's Ice Sheet Is Melting

Analyzing the issue that has recently been popularized by National Geographic's Before The Flood 

By: David McDonald

 

Since the emergence of the Industrial revolution in the late 19th century, humanity's impact on the planet in just over 150 years has been nothing short of catastrophic, but you knew that already.

It’s not easy to constantly assess our living habits given the fast-paced lives we are almost forced to lead. Regular distractions creep in leaving us either too busy, or capitulated towards the daunting beast we call climate change, because changing our lifestyles to accommodate a vastly overwhelming issue such as this, seems almost inconsequential when assessing the larger picture.

That’s why film’s like Leonardo Dicaprio and National Geographic’s Before The Flood are imperative to maintaining the health of our planet - not because they reveal unfamiliar information to us (well, maybe to some who don’t pay much attention to the health of our planet) but because they reinforce established knowledge and re-engage us into considering our living habits and the far-reaching consequences they have on our planet, even if just for a brief moment.

I consider myself reasonably educated on environmental news, which is why I was a bit surprised that I had 'learned' a few things from this film that I had not already known at all, or not in as extensive detail as portrayed by Dicaprio and company. However, with big-budget films like these, you can expect some sort of 'shock value' to keep the viewer enticed.

Among the various topics covered in the film, the one that stuck with me the most was the issue of Greenland’s melting ice sheet.

Greenland’s Melting Ice Sheet: What’s Really Happening?

The Greenland Ice Sheet is the second largest ice body in the world, after the Antarctic ice sheet. The ice sheet is almost 2,400 kilometres (1,500 mi) long in a north-south direction, and its greatest width is 1,100 kilometres (680 mi) at a latitude of 77°N, near its northern margin.

 

The mean altitude of the ice is 2,135 metres (7,005 ft). The thickness is generally more than 2 km (1.2 mi) and over 3 km (1.9 mi) at its thickest point. It is not the only ice mass of Greenland – isolated glaciers and small ice caps cover between 76,000 and 100,000 square kilometres (29,000 and 39,000 sq mi) around the periphery. If the entire 2,850,000 cubic kilometres (684,000 cu mi) of ice were to melt, it would lead to a global sea level rise of 7.2 m (24 ft).

Greenland ice sheet

The Greenland ice sheet (Jonathan Bamber / University of Bristol / NASA’s Goddard Space Flight Center Scientific Visualization Studio).

However, for that to happen, we would need to burn through all of our natural gas resources within the next century or two, which is impossible.

“Computer simulations of complex deglacial melting and surging processes are still too primitive to be very reliable, but even the extreme projections require many centuries to do the deed. Most scenarios stretch the thaw over several millennia, depending on how warm it gets; some take as much as 20,000 years.” - Curt Stager

The concern with Greenland’s melting ice sheet doesn’t lie with the entire mass melting, but rather, the more realistic, irreversible effects that we will see in the next century from our harmful living habits. A criticism I have with certain news coverages of this phenomenon is that they are misleading. Take Leonardo DiCaprio's Before The Flood for example; in the film, Leo and company depicted the extent of ice loss in Greenland by using a measuring tape. He told us that the length of the measuring tape, which was about 10 metres, signified the loss of ice in the Greenland ice sheet.

This demonstration earned my attention but simultaneously skewed my perception of the severity of Greenland's ice sheet depletion; that demonstration led me to believe that Greenland was losing more ice than it actually is. But as I said before, a proportion of these environmental movies and news feel they need to incorporate some level of shock value in order to entice the viewer, I mean, it worked on me at the time.

However, after a bit of research, I found that the situation in Greenland isn't quite as dire as mainstream media outlets will lead you to believe.

The Real Numbers

A new study based on GPS measurements of the Earth's crust suggests the Greenland ice sheet is melting about seven per cent faster than previously believed and may contribute more to future sea level rise than predicted.

The research found that Greenland did not lose about 2,500 gigatons of ice from 2003-2013 as scientists previously believed, but closer to 2,700 gigatons — a difference Bevis calculates at 7.6 percent.

More recent findings show a continuation of the Greenland Ice Sheet dilemma.

A satellite study, published last week in the journal Geophysical Research Letters, suggests that the Greenland ice sheet lost a whopping 1 trillion tonnes of ice between the years 2011 and 2014 alone. And a big portion of it came from just five glaciers, about which scientists now have more cause to worry than ever, or do they?

I found these numbers in an article from The Independent - a credible news source that is guilty of the same thing as National Geographics Before The Flood: Misrepresenting real life phenomenon to gain more exposure to their work.

Greenland's Melting Ice Sheet

 

Graphic from the AN AGU Journal depicting the areas of ice loss in Greenland. The most affected areas are highlighted in red.

The numbers in this study are certainly eye-catching; researchers found that Greenland lost on average, about 269 billion tonnes per year from January 2011 through December 2014. The numbers are indeed large, but in the grand scheme of things, not detrimental, as this study would lead you to believe.

 

Realistic Comparison

See, what these two cases have in common is that they fail to comment on Greenland's situation in the winter, instead, only detailing ice loss in warm months, as if we didn't already know ice melted in warmer temperatures.

Greenland’s ice sheet kicked off 2017 gaining about eight gigatons of snow and ice, which is well above what’s usually added to the ice sheet Jan. 1 for the last 24 years, according to Danish meteorologists.

In fact, Greenland’s ice sheet has been gaining ice and snow at a rate not seen in years based on Danish Meteorological Institute (DMI) data. DMI reports the Greenland ice sheet’s “mass surface budget” has been growing significantly since October.

Greenland’s “surface mass budget” for winter 2016-2017 is already more than two standard deviations higher than the northern ice sheet’s mean snow and ice accumulation over the last 24 years. DMI data shows the ice sheet added 8 gigatons of ice and snow Jan. 1, well above the standard deviation for that day.

Greenland Ice Melting

Greenland Ice Sheet Growth slightly higher than previous year averages.

Greenland’s booming snow and ice gains come after the U.S. National Snow and Ice Data Center (NSIDC) found the northern ice sheet had an “above average” melt season.

NSIDC found “near-average to below-average coastal snowfall levels that exposed bare ice earlier in the melting season, combined with warm and sunny conditions at lower elevations, led to high overall ice loss from runoff.”

Greenland “had a high early-season melt area, the pace slowed in mid-July relative to the warmest years,” NSIDC reported. Early 2016 saw an incredibly strong El Nino warming event.

Greenland’s extraordinary ice sheet gains also come as Arctic sea ice levels stand more than two standard deviations below normal. Arctic sea ice coverage shrank in November, setting a record low, due to “unusually high air temperatures, winds from the south, and a warm ocean.”

DMI notes Greenland’s ice sheet “snows more than it melts,” but adds that “calving of icebergs also adds to the total mass budget of the ice sheet.”

“Satellite observations over the last decade show that the ice sheet is not in balance,” according to DMI. “The calving loss is greater than the gain from surface mass balance, and Greenland is losing mass at about 200 Gt/yr” A loss that is not as catastrophic as some news will lead you to believe.

Global Warming Or Glacial Calving?

Suppose Greenland actually is losing 200GT of ice per year from glacial calving and subsurface melt. Glacial calving is caused by ice flow and increases when the ice gets thicker and flows faster — not by melting.

Perhaps Greenland is losing ice from melting below the surface, maybe where it contacts the bedrock. That melting can’t be from heat coming from the top down through the ice, or the surface would be melting first.

The point is that any atmospheric induced melting will show up at the surface first. Ice lose that does not show up as a surface ice loss is not from global warming. Non-atmosphereic melting and ice loss may very well be taking place, but if it is, it is NOT caused by CO2 and a warming planet.

Greenland ice melting

Three processes determine whether the ice sheet grows or diminishes. Accumulation of snow on top increases mass. In time, the snow is transformed to ice that flows down through the ice sheet and out towards the margins. Melt in the lower regions of the ice sheet and iceberg calving from glaciers reduces the mass. If mass loss exceeds mass gain the ice sheet will shrink. Graphics Diego Winterborg.

As for the 200GT of ice loss — it sounds huge, but it isn’t. The Greenland ice sheet has close to 3,000,000 GT of ice. If it melted, sea level would rise just about 24 feet. At 200 GT per year you are looking at 15,000 years for it to all melt. That works out to less than 2/100th of an inch per year of sea level rise.

How Will Sea Levels Be Impacted By Greenland’s Melting Ice Sheet?

 269 billion tonnes a year is approximately 0.01% of Greenland’s ice - A rate that has reportedly raised our sea levels by 2 - 3mm over the period of 2011 - 2014.

 After a brief realization of the implications here, 2 - 3mm does not seem like it could make a sizeable difference in the grand scheme of things, but paired with melting in the much larger mass of Antarctica, the numbers become more surreal.

 By 2100, ice sheet melt would raise sea levels by 7.9 inches, enough to pose a risk to low-lying nations, according to a study published by The Cryosphere.

 By 2200, ice sheet melt would raise sea levels by 1.6 feet.

The melted water from Antarctica and Greenland, glaciers, and the thermal expansion of the ocean due to higher temperatures are expected to raise sea levels by 3.3 feet in 2100, according to the Intergovernmental Panel on Climate Change. That would be sufficient to submerge 17 percent of Bangladesh, or, displacing upwards of 30 million people in that area alone.

 However, it is important to question everything; although these statistics can seem detrimental, this is of course, not going to happen anytime soon. We will have decades to gradually move away from coastal areas like Bangladesh and New Orleans that will slowly be engulfed. So, although cities will be consumed by water, we will survive.

 But rising sea levels can’t be the only consequence of melting ice sheets, right?

 

Lingering Consequences of Melting Ice Sheets

If the Greenland Ice Sheet melts at a faster rate, (which is expected to continue to happen) it will spread a slick of fresh water on top of the heavier salt water of the North Atlantic. This change in salinity could depress the Gulf Stream and alter North Atlantic circulation patterns that control weather in Europe. Combined with a loss of Arctic sea ice, this effect could radically change global ocean circulation patterns.

 

 

 

This process will naturally disrupt the natural migration patterns of many biotic species such as sharks and whales. Furthermore, wind currents are inseparably tied to ocean circulation. Thus, when ocean circulation is disturbed, so are weather patterns. This will lead to more cold air being blown towards warmer climates near the equator, consequently, disrupting all means of life on land as well.

As the polar regions warm, the temperature difference between the equator and the poles is reduced, altering global atmospheric circulation patterns by reducing the force that drives equatorial heat energy toward the poles. Much of the world’s current pattern of rainfall would be altered as well.

Is This Cause For Concern?

In short, even small changes in ocean biology and weather systems are obviously worrisome in regards to sustaining life. Rising ocean levels will make tropical storms much more dangerous, and will displace nearly a third of our population in the coming centuries.

Furthermore, as the poles continue to lose ice, they will become warmer, as there is less ice to reflect sunlight. As the poles warm, weather patterns will fluctuate with increased conglomeration, which will in turn, cause storms to be more powerful and destructive, all while disrupting the natural migrating habits of species on land and in our oceans.

However, after briefly looking into the issue of Greenland’s melting ice sheet, the situation isn’t as drastic as you could be led to believe. Yes, Greenland’s ice is shrinking by about 200Gt/year, which may sound like a lot, but in hindsight, is only approximately 0.01% of Greenland’s overall ice.

Furthermore, claims that Greenland is losing 269 billion tonnes of ice a year don’t take into account that the mass is growing in the winter (crazy, right?!).

Nonetheless, shock value news does serve a purpose; it forces us to look at the big picture, even if for a brief moment. The numbers covered in varying news coverages of global warming can range widely depending on what type of news you are consuming, but for the most part, mainstream environmental news seems to be skewed in an attempt to scare us into leading greener lives, and maybe that isn't such a bad thing.

Regardless of misrepresented news being shoved in our faces from every angle, the numbers are still there. The massive ice sheet in Greenland will continue to melt at an increasing rate if we continue on the path we are on. Although it will take nearly 15,000 years for the entire thing to melt, we will have to live with the consequences of our disruptive living habits much sooner than that once major cities begin to sink.

This may not be a massive cause for concern yet, but if current trends continue, the future for Greenland will unequivocally, be more green.

 

Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.



Page 13 of 14


%d bloggers like this: