Six years later on a cruise up the Inside Passage from Vancouver, British Columbia to Glacier Bay in Alaska, we visited the Juneau Icefield and Mendenhall Glacier, another landmark and what seemed to be a permanent fixture of the West Coast landscape.
Having seen current pictures of both ice fields and glaciers, the changes since our visits back then have been astonishing. Both glaciers have retreated over the past four decades. They were mostly white back then. Now they have a layer of gray and brown dust covering their surfaces and look nothing like what we saw.
Alpine glacier thinning is happening across the planet. From 1980 to 2018, the cumulative thinning equals a vertical loss of 24 metres (nearly 80 feet) per glacier. It, therefore, is no surprise to see articles being published on this subject and two in particular referring to the glaciers we visited so many years ago.
They were incredible sights. The Athabasca stretched almost to the edge of Alberta’s Icefields Parkway, a roadway that skirts the Rocky Mountains for 232 kilometres (almost 144 miles) with breathtaking scenery every few miles. I remember we stopped often to witness rushing torrents of water tumbling down mountainsides or view spectacular valleys with mountain peak backdrops. The glacier itself was a startling white with hints of blue in the cracks at its face. Today it is covered in a layer of dirty snow and has retreated far from the roadway.
The Mendenhall didn’t make the same kind of impression on us because to see it we had to get off our ship and take a bus to a viewing area far from the front of the glacier. It was beautiful to see but far more spectacular was Glacier Bay where our ship wandered while we came face-to-face with calving glaciers tumbling icebergs into the Pacific Ocean.
The articles I have been reading about glaciers in retreat related to global warming have looked at the icefield plateaus of the Himalayas, the glaciers of the European Alps, the disappearing ice on Mount Kilimanjaro in Africa and the ice sheets of Antarctica and Greenland.
A 2017-published Cambridge University study looked at changes to the Columbia Icefield from 1919 to 2009. It noted that the field feeds 25 glaciers of which the Athabasca is the one most visible and most often visited.
Results from land-based and satellite measurements show “substantial recession and mass loss” for all 25 glaciers. The losses have not been consistent across the entire period with some decades showing acceleration and some not.
Overall, however, the trend is downward.
This week I read a Newcastle University-led team article published in Nature Communications looking at the rate of ice loss from the Juneau Icefield. The period of study goes back to the first sightings of the Mendenhall Glacier, one of more than a thousand that the Icefield feeds. Juneau measurements date back to 1770. This study accumulated 250 years of data ending in 2020 and concluded that the Icefield had lost a quarter of its mass.
The Juneau is a plateau icefield. In the 250 years, 63 of the glaciers it feeds have melted away. Since 2005, the melting on the field has accelerated the loss by 10%. Ice volume losses are expected to be steady until 2040 and accelerate after that as more land under the melting ice gets exposed accelerating the albedo effect.
The term “albedo effect” refers to the nature of how light interacts with reflective and white surfaces. A glacier or icefield with fresh snow and ice reflects light. A photon of light when it reaches the ice surface bounces off and is reflected into space.
A darker surface such as that which happens when glacial ice melts and exposes exposed underlying rock absorbs the energy from photons converting it to heat.
Icy, light surfaces stay cold because of the albedo effect. Exposed dark surfaces warm up because of the albedo effect. Both create feedback loops. The ice tends to cause more ice while the warming accelerates more warming.
One thing is certain. Atmospheric warming combined with more exposed dark surfaces will cause alpine glaciers like the Athabasca and Mendenhall to keep melting. Dr. Bethan Davies, Senior Lecturer, at Newcastle University and the Juneau study lead believes that alpine glaciers are being pushed beyond the “tipping point into irreversible recession.” She believes that “current glacier projections may be too small and underestimate glacier melt in the future.”
How much will alpine glaciers contribute to the rise in sea levels? As more water from melting alpine glaciers eventually gets to the ocean it will make its contribution. It should be noted, however, that as glaciers melt, the land underneath them experiences a phenomenon called isostatic rebound. When the weight of the ice is removed from the land beneath, it rises.
Isostatic rebound is still occurring in North America, 10,000 years after the last Ice Age ended. A good example is areas from the Ohio River Valley to the Great Lakes and St. Lawrence River Valley continue to rise. As this land rises it is causing Tidewater Virginia, Maryland and the Chesapeake Bay region to tilt downward. That’s why sea level rise is faster along the Chesapeake shoreline than other areas along the Atlantic Ocean’s Eastern Seaboard.
As alpine glacier ice melts, the bigger impact will not be on sea levels. It will be on the river systems that flow from the water stored in the icefields that feed them. Rivers originating from the Rocky Mountains like the Columbia, Fraser, Bow, North and South Saskatchewan will see water volumes impacted by disappearing alpine glaciers.
Melting polar ice sheets and sea ice and the thermal expansion of the ocean will likely be far greater contributors to future sea levels.
]]>Last August a paper appeared in the Journal Nature entitled, “Sufficient conditions for rapid range expansion of a boreal conifer.” It is one of a number of documents describing a changing pattern of tree growth and range across the Arctic landscape in Alaska, Siberia, Canada, and Scandinavia. The more trees establish themselves in high-latitude environments, the faster warming is coming as a low albedo effect takes hold.
The paper described what was happening to the North American White Spruce population in Alaska’s tundra conditions. White Spruce require temperatures of 10 Celsius (50 Fahrenheit) or greater for seeds to germinate. And White Spruce don’t start producing seeds until they are 30 years of age. So seeing an expanding population of White Spruce in areas where none have been observed in human recorded history is rather compelling evidence that the Arctic climate conditions are undergoing significant change. The rate of the northward march is about 4 kilometres (2.5 miles) per decade. The advance corresponds with both rising land temperatures and disappearing sea ice.
The data for the study comes from a field survey done in 2019 where previously unknown White Spruce forests appeared to be well established in the Noatak River basin of Alaska. The Noatak drains into the Chukchi Sea which is seeing the fastest rate of sea ice decline within the Arctic Ocean. The forest included trees of all sizes with a well-established treeline extending 42 kilometres (more than 26 miles). They appeared to have propagated from a population of trees first established at the beginning of the 20th century. These parent trees remained confined to a small area during the first half of the century. But in recent decades, that is, since the mid-20th century has expanded their range. Initially, the rate was 1.4 kilometres (0.8 miles) per decade. But now the rate is accelerating. Juvenile trees seeded from their parent population are now over 35 years old and seeding areas even further into the tundra.
Previously I referred to the albedo effect. What is it? High and low albedo describes changes in the way the Earth absorbs or reflects sunlight. Whether high or low, albedo effects create feedback loops. Earth’s average albedo is 0.3, meaning 30% of sunlight gets reflected back into space while 70% contributes to the planet’s warming. A high albedo occurs when light from the Sun gets reflected by the Earth’s surface. Snow and ice cover have a 0.8 albedo effect. That is, they reflect 80% of the sunlight back into space and absorb only 20% of its energy. Low albedo happens when the Earth’s surface is darkened by vegetation, or water surfaces become ice-free. Low albedo contributes to the heating of the air above these surfaces. Forests have a 0.15 albedo. They reflect 15% of the sunlight and absorb 85%. So the presence of a growing forest of conifers such as the White Spruce in this study acts to accelerate Arctic warming providing the feedback loop the Alaskan Arctic is experiencing that I referred to earlier.
Take into consideration the fecundity of these trees. A typical White Spruce spreads its seeds up to 60 metres (almost 200 feet). But with the feedback loop creating increased warmth the dispersal range has grown to as much as 800 metres (almost a half mile). The scientists who wrote the paper in Nature note that the trees they observed appear to be healthy and growing in Arctic conditions which have warmed by as much as 2.3 Celsius (4.14 Fahrenheit) degrees over the last one hundred years.
In addition, the scientists note that winter precipitation has been increasing and soil conditions are changing with increasing microbial activity leading to greater nutrient availability and a longer growing season. Hence we are seeing trees interspersed with normal tundra vegetation that are as tall and healthy as the one seen in the picture at the top of this posting.
One of the research scientists describes the spread of White Spruce as not moving but rather leaping north. Roman Dial, of Alaska Pacific University, in a recent article appearing in Wired notes, “These new colonists, you’d think that they’re beyond the tree line, they should just be struggling. But they’re actually growing really rapidly. They’re happy as pigs in poop—they’re just going gangbusters out there in the Arctic tundra and alpine tundra. They’re way ahead. They’re even doing better than the shrubs.”
]]>Scientists have noted in several peer-reviewed studies that the Jet Stream in the northern hemisphere is not acting in a normal way. That’s why the last few years have witnessed sudden polar vortices that descend over parts of North America, Europe, and Central Asia, bringing abnormally cold weather for longer than normal periods of time.
It is a meandering Jet Stream that is seen as the cause. And now it is bringing Sahara Desert dust to the North Pole by pulling dust from North African cyclonic events and transporting the stuff in large amounts to the extreme north. The researchers note an increasing frequency in the phenomenon over the last few decades believing that change brought about by rising global temperatures is the primary cause.
The dust forms an aerosol that serves to dampen the normal radiative effect of Arctic ice. The Arctic is seeing more clouds as a result, which rain down grit in the form of carbon and mineral dust which is then deposited on the sea and land ice contributing to accelerated melt. The study states that “coarse size aerosol particles such as dust act like greenhouse gases by absorbing and emitting longwave radiation…..The longwave radiation plays a particularly important role in the energy balance in the Arctic because of prolonged polar nights with little or no sunlight.” The end result, radiative heating of ice surfaces with near-surface temperatures increasing.
The average lifetime of an aerosol particle from the Sahara can vary from days to weeks. Maximum concentrations occur during a period known as the Arctic haze season (late winter and early spring). The aerosols then accumulate as they rain out or fall to the surface where their physical, chemical and thermodynamic properties destabilize the ice surfaces.
The research shows that 60% of the Arctic dust appearing in the spring comes from the Sahara with a lesser contribution from the Taklamakan, Gobi, and other deserts. The mineral and carbon dust contributes to 24% of the absorption mass in the spring and summer contributing to thermodynamic changes in the ice.
This appears to be the first comprehensive study linking Saharan mineral and carbon dust to the Arctic albedo effect responsible for the shrinking of inland glaciers, ice shelves, and sea ice.
The authors of the study used observations from instrumentation on board the Meteosat geostationary satellite to compile the data, as well as data from the European Centre for Medium-range Weather Forecasts. From these sources, they were able to create a computer model that validated the distribution of Saharan dust from North Africa to the Arctic.
Our increasing understanding of the role the Jet Stream plays is significant as data we collect show an increased meandering “in a waveform pattern that allows the extensions of low pressure lobes and cold fronts much further to the south. …. These low pressure lobes can become stationary for a few days and block the normal circulation of the atmosphere.” It is this phenomenon that generates the dust storms in the Sahara and facilitates the transfer of aerosols to the far north.
We now know that here on Earth atmospheric dust can travel a very long way from its source. The phenomenon is not unique to our planet. In the past year, Mars has seen what started as a local dust storm grow into a global one that is only now, many months later, beginning to subside. The rover, Opportunity, may have been a victim of the aerosol storm that blanketed Mars. And recently images and data from the Cassini spacecraft show that a similar phenomenon is native to the Saturnian moon Titan.
While less dramatic than Mars or Titan here on Earth, and less obviously visible, we are witnessing a similar phenomenon on our planet and the movement of the dust poleward and westward is impacting the thermodynamics and albedo of the ice of Greenland, the Canadian Arctic archipelago, and the Arctic Ocean.
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One solution was to remove carbon from emission sources. That meant putting expensive carbon-capturing technology in place in manufacturing facilities and power plants. Another solution was to try and draw carbon out of the ambient air continuously in the same way plants do it using artificial photosynthesis and complex filtering systems. Taking stuff out of the atmosphere seemed like a good way to draw down on the carbon our industrial society was producing.
But then there were those who didn’t want to add complexity to industrial plants and power generation. Rather they wanted to leave industry as is and attempt to manipulate the atmosphere by adding even more chemistry to it in the form of aerosol spraying to cool the Earth in the same way volcanic eruptions do. Others thought that seeding to create more clouds would serve the same purpose. And then there were the even more ambitious who wanted to put satellites in Earth orbit with large reflecting mirrors to bounce sunlight away from the Earth’s atmosphere and thus lowering its temperature.
In the fictional account of our human experiment in geoengineering, tinkering with the atmosphere led to unintended consequences. Much of western North America suffered from extensive and prolonged droughts leading to a new Dust Bowl in the American Midwest. Africa and Australia became even drier. And India and South Asia saw the annual monsoon come to an end. The Amazon rainforest, the single most important biome of our planet was disrupted leading to massive deforestation. Famine followed drought. Nations collapsed.
The story is a work of fiction yet there are disturbing parallels in the current path humanity is taking to address the growth of carbon in our atmosphere problem. No longer fiction, since 2013 the United States and a number of other governments are seriously investigating geoengineering solutions to climate change.
In January of 2017, the American government’s strategic plan on the climate acknowledged that rapid changes were happening to the global climate and suggested a number of actions. Among these were experiments to reflect sunlight and produce atmospheric cooling, described as albedo modification by the experts who contributed to the report.
Not familiar with the reference to albedo, it refers to the ability of an object to reflect sunlight. For instance, ice and snow have a high albedo effect. Forests and the ocean have a low albedo effect. Painting rooftops white increases their albedo effect. Leaving them dark does not.
As early as 2015 the U.S. Department of Energy, NASA, NOAA and the National Academy of Sciences were all into studying ways to reflect sunlight to cool the Earth. Thought of as a last-ditch effort to save the planet, it appears that last ditch is moving up to becoming more like the first ditch.
There is geoengineering and then there is GEOENGINEERING. Painting rooftops white to cool city environments and reduce the heat island effect is the lowercase version of the field. Seeding the stratosphere with an army of jets spewing out aerosols is geoengineering in upper case. We have no idea of the unintended consequences of such acts. Nor do we understand what will happen if we use satellites to reflect sunlight away from the Earth.
Here is a future scenario that has horrific consequences. We continue to raise the carbon atmosphere load to 500 or more parts per million. To compensate we put a series of satellites in orbit that act like giant sunshades. Something happens to one or more of the satellites and suddenly we have no cooling shield. What would be the consequences? Sudden temperature spikes? More extreme weather than what we have previously experienced? Devastation to crops?
The kind of geoengineering that can work takes stuff out of the air and puts it away permanently either by burying it or turning it into growing things or into materials we can use.
For Canada, we are fortunate to be on the leading edge of sequestering carbon with interesting technologies already in place. Our problem as a nation is our lack of salesmanship in getting the world to understand what we are creating here. Whether we are talking about Boundary Dam and the sequestration of carbon from a coal-burning thermal power plant in Saskatchewan, to the Shell Quest project in the Alberta oil sands, sequestering carbon from bitumen production processes, or Carbon Engineering‘s technology that harvests carbon dioxide directly from the air, or CO2 Solutions with an enzymatic process to extract carbon at industrial plants, Canada has the net-negative emission goods to sell to the world. And although these technologies are expensive right now because the initial price includes the costs of engineering as well as all the research and development, the designers already have indicated they can streamline processes and production, and scale can further reduce the cost to make these technologies attractive to every country that is a signatory to the Paris Climate Agreement.
With the window closing on keeping atmospheric warming at no more than 2.0 Celsius (3.6 Fahrenheit), and better yet, no more than 1.5 (2.7 Fahrenheit), there should be a sense of urgency to make these made-in-Canada geoengineering solutions available. The tens of thousands of jobs that can be created from these negative emission technologies cannot be dismissed by business or government.
As for geoengineering that adds more complexity to our atmosphere through seeding, or that shields our atmosphere from the sun, I have serious concerns should these projects get green-lighted by any country. I state this because, in the media in the last few weeks, there have been commentaries written suggesting that developing nations should collectively invest in sunshade geoengineering projects because they will be most impacted by climate change. This, in my opinion, could be potentially disastrous for the planet.
Why?
Because theoretically it is believed this will work in similar fashion to what happened in 1991 with Mount Pinatubo (see image below).
That eruption was the second largest of the 20th century with columns of ash reaching 40 kilometers in altitude. Over 17 megatons of sulphur dioxide (SO2) was injected into the lower stratosphere. The SO2 formed sulfate aerosols spreading around the globe in less than three weeks. Within the year the net impact to mean atmospheric temperatures was a decline of 0.5 to 0.6 Celsius (0.9 to 1 Fahrenheit) degrees in the Northern Hemisphere. For the Southern Hemisphere where the larger presence of oceans mitigated the cooling temperature decline was less.
What do aerosols do that can alter mean atmospheric temperatures?
They inhibit sunlight from reaching the Earth’s surface.
By how much?
In the case of Mount Pinatubo scientists calculated an light inhibition factor 10 to 100 times normal levels.
Mount Pinatubo wasn’t the first volcano to give scientists pause about the relationship between volcanoes and climate. The Mount Krakatoa eruption of 1883 which pumped millions of tons of ash into the stratosphere also created volcano-induced cooling with records of the time showing exceptionally cold temperatures around the globe over the next year. Even ocean temperatures declined after Krakatoa’s eruption with lasting effect into much of the 20th century.
So let’s get back to the U.S. Senate. It seems that human influence on climate is denied when talking about greenhouse gas emissions. But human intervention through technological wizardry to mitigate atmospheric warming is accepted.
Geoengineering has been proposed as a means to mitigate and reverse climate change. It is seen as a way for us to “have our cake and eat it too.” Through geoengineering we can continue to burn fossil fuels at present rates while offsetting their impact by tinkering with the amount of solar energy reaching the Earth’s surface.
Some scientists support the idea of testing the geoengineering capacity of current technology. I’ve written about it in the past with proposals made by some to operate fleets of jet aircraft to pump aerosols into the stratosphere. And these scientists argue that without testing the hypothesis and technical feasibility we lack the data to know whether human-induced albedo modification is viable.
In 2015 the U.S. Departmetn of Energy, NASA , NOAA and the National Academy of Sciences commissioned a study “Climate Intervention: Reflecting Sunlight to Cool Earth.” What had been thought of in the past as a “last-ditch response” to climate change, was now being explored as an option worth studying. The Senate, participants in blocking Executive efforts to address climate change, suddenly has reversed course in its thinking about how humans interact with the planet by proposing a bill that would fund us geoengineering the atmosphere. The cost a mere $5.4 billion U.S. for a pilot project and who knows how much more in the future.
There is a supreme irony in all of this. We have the Environmental Protection Agency (EPA) heading up programs to convert coal-fired power plants to capture carbon emissions. We have carbon capture and sequestration (CCS) projects being funded to the tune of billions of dollars with a facility about to open in Mississippi this year. And now we have another government agency being given money to study putting human-produced pollutants into the atmosphere to mitigate global warming.
It sounds ridiculous because it is.
No till practices have more than doubled in the last two decades and appear to be on an acceleration curve across all areas of the planet. In as 2010 study, the authors reported 2009 data showing 111 million hectares (274 million acres) of no-till farmland with fastest adoption in South America where almost 70% of cultivable land uses this practice. In the United States, although farmers occasionally leave fields after harvesting, it is common practice to occasionally put these fields to the plough. Compare the 111 million hectare number to the total amount of land currently used for agricultural production, 4.92 billion hectares (1.2 trillion acres), and you can see that no till remains an uncommon global practice.
Why does no-till reduce daytime peak temperatures? It is called the albedo effect. In not ploughing, sunlight is less likely to be absorbed into the surface soils where it converts to heat, warming the air above it. In fact no-till fields are 50% more reflective during peak summer months than fields that are tilled before planting.
During the hottest summer days, which have been getting hotter, a fluctuation of one or more degrees can make a big difference during a heatwave. And not just for the crops but also for the humans and livestock.
The research so far, done by Sonia Seneviratne, a climate scientist at the Swiss Federal Institute of Technology, points to a local effect, rather than a broadly distributed one. That may be in part because testing has been done for only a small area sample. Seneviratne believes a test over a larger area of no-till farming practices would be a useful next step to determine if this should become standard practice as our atmosphere continues to warm here in the 21st century.
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