From the “not that yellow snow” department. Research into light and snow interactions provides new insights into how black carbon pollution can affect vegetation growth and impact ecosystems. As I’ve always suspected, it plays a central role in some of the melts we see on surface ice in the Arctic. This study confirms what I’ve said and written in the past about it, but takes it further and applies it to plant growth. -Anthony
Via Eurekalert:
As Canada experiences record snowfall, new research from the University of Waterloo suggests that tiny amounts of industrial pollution trapped in snow can change how sunlight reaches the ground below and significantly alter fragile environments.
The culprit is black carbon, a sooty form of pollution produced when fossil fuels burn incompletely. It can come from vehicle exhaust, industrial emissions and other combustion sources. While black carbon is already known to contribute to warming, the Waterloo research highlights another, less visible effect: how it alters the “light environment” under snow in ways that affect plant growth.
Even at the height of winter, some sunlight is transmitted through snow and reaches soil, seeds and vegetation beneath. Snow doesn’t let all light through equally. As it propagates certain wavelengths of light and absorbs others that are vital for biological processes, like seed germination, cold activation tolerance and chlorophyll production, it can affect the development of vegetation that’s just below the snow. Conversely, snow reflects light at specific wavelengths that can actually disrupt plant dormancy and stimulate stem growth, influencing how higher plants develop.
“Our research indicates that black carbon can have a significant effect on vegetation growth patterns even when there are only a few parts per billion in snow,” said Dr. Gladimir Baranoski, a professor of computer science at the University of Waterloo. “It can alter which wavelengths of light make it through snow, throwing off finely tuned natural cycles.”
The researchers used computer simulations to examine how different amounts of black carbon change the light that snow reflects into the atmosphere and transmits down to the ground. Their results show distinct changes at specific wavelengths, changes that align with “greening,” a phenomenon observed in some high-latitude and high-altitude regions where vegetation appears to be expanding or emerging earlier than expected.
In places that normally remain snow-covered well into the season, plants may begin growing sooner, or different types of vegetation may gain an advantage. The team says their findings are consistent with reports of forested areas expanding in some northern landscapes, while some low-lying plants may struggle to develop under altered conditions.
Those shifts matter because northern and alpine ecosystems are finely tuned to short growing seasons and predictable snow cover. If plants start growing earlier, or if certain species begin to outcompete others, the effects can ripple outward, influencing biodiversity, habitat and how much carbon the landscape stores or releases.
The work builds on a detailed model of how light interacts with snow, developed by Baranoski and Dr. Petri Varsa, a recent PhD graduate in computer science. Using field measurements collected by scientists worldwide, the team has built a versatile model that can be adjusted to predict changes in the light emitted by snow, a major driver of climate change.
This research reflects the University of Waterloo’s Sustainable Futures work—bringing together experts across disciplines to better understand climate-driven environmental change and develop evidence that supports resilient ecosystems and communities.
While this research focused on black carbon, the next step is to investigate brown carbon, a pollutant produced by burning organic matter, such as during forest fires.
The team’s research is discussed in two papers, “Black carbon impacts on snow and vegetation interactions affecting environmental feedback loops and climate change” and “Aggregate effects of density and black carbon content variations on the hyperspectral reflectance of snow under natural conditions,” both found in the 2025 Proceedings of SPIE: The International Society for Optical Engineering.
Gotta keep the troughs filled ….
😉
Speaking of snow.we had a few weeks of bitterly cold a 14” of snow 25 miles north of NYC. My Acurite weather station start acting up. Suddenly it was stuck on 32 degrees and 99 % humidity while the temperature was swinging form freezing to 10 degrees. The outdoor sensor was missing from the wall (we had some high winds at the beginning of the storm.) The unit was buried under 2 feet of snow. It was interesting how steady the snow held the temperature.
“Those shifts matter because northern and alpine ecosystems are finely tuned to short growing seasons and predictable snow cover.”
In our rural NY dairy farm country here in the north, there is an ingenious method of altering the finely tuned interaction of sunlight and snow cover. They apply this readily available dark substance on the surface of the snow-covered fields, I presume, to promote melting and possibly earlier planting. I think it’s called manure, but surely it’s more advanced than THAT! /sarc.
And also when wood or grass burns, in volcanic events, and many if not most activities by humans that don’t involve coal or petroleum combustion.
Who tuned those cycles, and what set of inputs did they use?
This is called “greening.” Airborne soot and CO2 are therefore net gains for the environment.
“While this research focused on black carbon, the next step is to investigate brown carbon, a pollutant produced by burning organic matter, such as during forest fires.” When did chemistry classes start teaching carbon colors, black OK, but brown, even blue? Problem with computer screen?
Uh oh …
… that they did not follow up the model indications with real-life field tests.
Sorry, bud. No more useful than climate models without field followup.
Not really on topic…When I was a student in the late 60s in St Louis living in the dorm for the medical/dental complex Peabody coal was throwing out tons of soot, so much so that the huge Peabody sign was mostly obscured.
I walked outside in the early morning in January; there was snow on the ground covered by soot. I couldn’t believe this went on for years.
“… this went on for years …”
Potato skins conveyored out of a processing plant into a ditch that carried it to a nearby river;
Effluent from paper mills sent to a river;
. . . .;
Sulfur ladened water from old well and strip mines.
In the Northeast of England in the 70s, when all the houses used coal for heating, shortly after a snowfall the snow would turn black due to the soot particles contained in it, as a result the snow melted rapidly.
“If plants start growing earlier, or if certain species begin to outcompete others, the effects can ripple outward, influencing biodiversity, habitat and ….”
Isn’t it amazing how every single possible change is portrayed in language that suggests it is bad even when it is so obviously good. ie, increased plant growth.
Couldn’t or shouldn’t they have said “If plants start growing earlier then the effects can ripple outward leading to increased growth across the whole biosphere.”. Mind you, even this would be regarded as bad in the Green world where all change, no matter how obviously good, is bad.
Only staticism is an acceptable outcome for all environmentalists. A changing environment is unacceptable and they all work against it.
Rememeber, even the entire evolution of human beings was due to an invasive species event.
The researchers used computer simulations to examine how different amounts of black carbon change the light that snow reflects into the atmosphere and transmits down to the ground.
Call back when they have results from a real experiment done in the real outdoors with real weather and clouds and sunshine.
Be sure to take your boots off before coming inside to analyze your data and write your paper.
Some soot (“carbon” from forest fires, here called brown) is known to take about 3 years to be moved from forest canopy to ground. It may be that in some years and in some places, snow melts faster than it otherwise would. At least I think I recall Susan saying that.
https://www.cwu.edu/about/directory/geological-sciences/susan-kaspari.php
“has built a versatile model that can be adjusted to predict changes in the light emitted by snow,
‘ Ah, Computer predictions? Where have i heard that before?
Adjustable computer predictions, mind you, adjustable.
“The researchers used computer simulations to examine how different amounts of black carbon change the light that snow reflects into the atmosphere and transmits down to the ground.”
Stop right there. These lazy illegitimate children could have gone off and stuck some photometers in the snow. But, no that would be hard work and they would be cold and wet. So they stayed indoors and played video games. This is not science, it is self abuse.
In the second paper n=2 I think we need a few more samples and change the “may” and “could” by actual observations
I ask this question: Since 1900, where has the many billion pounds of rubber dust and particles from car and truck tires gone? The short simple answer is any where and every where. To this should be added black dust from asphalt road surfaces and brown brake dust.
Modern BSR rubber is non-biodegradable, and contains anti-oxidants, anti-UV protectants, and anti-microbials agents. Since many major cities are located on ocean coasts, these black and brown particles will be eventually be washed into the oceans by rain. The chemicals in the rubber particles will be leached into water and are probably harmful to all the creatures in the oceans.
To study the effects of the rubber and asphalt contamination of environment, we can request a big grant like many millions of dollars from the EPA for model studies.
Probably had a better chance if submitted a month or two ago?
My goodness, they are finely using the word “carbon” in the right context.
But only if it is prefixed with “black.”
If you want to melt snow on your driveway, vacuum your carpets then sprinkle the dust on the snow. When the sky is clear the dark dust will soak up enough solar energy to at least partially melt the snow. The darker the dust, the better it melts. Pulverized fireplace ash will work too.
I remember the times of the late 70’s and early 80’s when scientists such as John Holdren were suggesting spreading soot over the North Polar Ice Caps so that we could avoid the coming ice age.
That’s quite a pic. My last flight over Greenland however was all white and a vastly larger in size.
It is funny to read that they blame “vehicles” for soot and Black Carbon (BC). By FAR the greatest source of BC is forest fires and the burning of agricultural residues in the fields where they fall post-harvest. Such fires are very inefficient in terms of combustion efficiency and the BC fraction of the smoke is much higher than that of a vehicle exhaust. The weight of burnt biomass is many billions of tons per year.
My point is that historically vast areas of forest burned each year for millennia PLUS the whole of Southern Africa (grass fires in winter). A huge experiment was conducted in Africa (Safari 2000 – see Wikipedia article) which tracked veld fire smoke from Botswana to Australia demonstrating that rainfall there was seeded by BC particles which are cloud condensation nuclei (CCN).
Virtually all raindrops on this planet have a CCN in the centre and the vast majority of those CCN formed from the incomplete combustion of biomass, and always did.
It is astonishing that a university with the pedigree of Waterloo U would have an output that deviates significantly from well established physical science knowledge.
I remind readers that at that same institution is Prof Q Lu who has an atmospherics replication laboratory. He it was who discovered the heat venting function of the ozone hole over Antarctica and its primary cause: cosmic rays.
DOI: 10.1103/PhysRevLett.102.118501
“This Letter reports reliable satellite data in the period of 1980–2007 covering two full 11-yr cosmic ray (CR) cycles, clearly showing the correlation between CRs and ozone depletion, especially the polar ozone loss (hole) over Antarctica. The results provide strong evidence of the physical mechanism that the CR driven electron-induced reaction of halogenated molecules plays the dominant role in causing the ozone hole. Moreover, this mechanism predicts one of the severest ozone losses in 2008–2009 and probably another large hole around 2019–2020, according to the 11-yr CR cycle.”
What a contrast. BC has been deposited on terrestrial snow for over 4 billion years. Long may it continue.
Well:
black on top of melting snow is well known phenomenon in citiesshouldn’t be much coal burned to heat buildings these days, furnace oil is still common in areas that have not had NG for long (such as southern Vancouver Island), both depend on maintenance of furnacesautomotive exhaust is much cleaner today because of computer control of engines, but soot from diesels in heavy trucks may still be a problemwhile there is some vegetation perhaps, like ‘winter wheat’ planted in fall, I ask how much there is. True, a famed HBC explorer was able to find berries under snow to save his workers with their vitamin C.As for forested areas expanding, that will happen as climate warms, it also happens because human production of food is more efficient so less land is used. Study authors confuse people – need Editor.
Beware however – researchers used _models_.
My wife was born and raised in Gary, Indiana, back when the steel mills were in full operation. It wasn’t until she went off to college that she first learned that the normal color of snow is white, not dark gray.