Something else to worry about: road salt and climate change

Scientists examine link between surface-water salinity, climate change

Syracuse University Ph.D. candidate Kristina Gutchess authors paper on impact of road salts on Tioughnioga River watershed

The interplay between surface-water salinity and climate change in Central New York is the subject of a recent paper by researchers in Syracuse University’s College of Arts and Sciences.


The paper draws on the group’s study of the impact of de-icing salt from Interstate 81 and other surrounding roads and highways on the Tioughnioga River watershed. Gutchess says their findings make her “cautiously optimistic” about the watershed’s future surface-water chloride concentrations.

“The long-term application of road salts has led to a rise in the river’s salinity level,” says Gutchess, who studies processes affecting the quality of surface water and groundwater. “While various models have been used to assess potential future impacts of continued de-icing practices, they have not incorporated different climate scenarios, which are projected to impact hydrogeology in the 21st century.”

Gutchess’ team combined various computational approaches with rigorous fieldwork and laboratory analysis to simulate surface-water chloride concentrations in the Tioughnioga–a large, deep, 34-mile tributary of the Chenango River, flowing through Cortland and Broome counties.

Central to their experiment was INCA (short for “INtegrated CAtchment”), a semi-distributed catchment-modeling platform that assesses environmental-change issues. Gutchess calibrated the model for a historical, or baseline, period (1961-90), and used the results to make projections for three 30-year intervals: 2010-39, 2040-69 and 2070-99.

Based on the model’s projections, the salinity of the Tioughnioga’s east and west branches will start decreasing in 20-30 years. “A gradual warming trend between 2040 and 2099 will lead to reductions in snowfall and associated salt applications, causing [the river’s] salinity to drop. By 2100, surface-water chloride concentrations should be below 1960s values,” Gutchess says.

This is potentially big news for a part of the country that has experienced rising surface-water chloride concentrations since the 1950s, when road salting began.

Salt, or sodium chloride, is the most commonly used de-icing chemical in the country, spread at a rate of more than 10 million tons a year.

In New York State, a typical wintertime event requires 90-450 pounds of salt per lane-mile. Vehicle traffic picks up about 10 percent of the residue; the rest enters adjacent water catchments in the form of runoff, jeopardizing terrestrial ecosystems and drinking water resources.

Gutchess’ hydrogeological study is one of only a few combining long-term climate variability and salinity management. The INCA model framework enabled her team to assess stream response under 16 different future scenarios, taking into account climate, land use and snow management.

“INCA originally was developed to assess sources of nitrogen in catchments in a single-stem main river,” Jin says. “Here, we modified the model to incorporate a new multi-branched structure, enabling us to simulate daily estimates of in-stream concentrations of chloride. We also allowed for differences in salting practices between rural and urban areas.”

According to INCA, road salt accounts for more than 87 percent of Tioughnioga’s salinity. Current de-icing practices, combined with increased urbanization, will likely add to its salinity, but only for a while, thanks in part to the changing climate.

According to Lu, the study suggests that climatic impacts are not always negative in a specific region: “It is important to understand the nuances of climate change at various time and geographic scales. Ultimately, this project will help us manage our resources more effectively, as we adapt to future changes.”

With a wink and a nod, he adds, “At the same time, we should not make blanket statements about climate change. No one is exempt from its effects, pro or con.”

Gutchess is a member of EMPOWER, a water-energy graduate-training program at Syracuse that is sponsored by the National Science Foundation and directed by Lautz. Additional support for Gutchess’ research comes from the University’s new Campus as a Laboratory for Sustainability program. Upon graduation in May, she will begin postdoctoral research at Yale.

Kristina Gutchess, a Ph.D. candidate in Earth Sciences, is the lead author of the article in the prestigious journal Environmental Science and Technology (ACS Publications). Her co-authors at Syracuse include Laura Lautz, the Jesse Page Heroy Professor and chair of Earth sciences, and Christa Kelleher, assistant professor of Earth sciences.

Another co-author is Gutchess’ Ph.D. supervisor, Associate Professor Zunli Lu.

Rounding out the group are Li Jin G’08, associate professor of geology at SUNY Cortland; José L. J. Ledesma, a postdoctoral researcher of aquatic sciences and assessment at the Swedish University of Agricultural Sciences; and Jill Crossman, assistant professor of Earth and environmental sciences at the University of Windsor (Ontario).



85 thoughts on “Something else to worry about: road salt and climate change

  1. “At the same time, we should not make blanket statements about climate change. No one is exempt from its effects, pro or con.”

    Well, that is true. Whatever one is meant to do about it.

    But as for the rest of this article? Hmm…

    I can’t find anything that is said with enough certitude to accept or challenge.

    • We are familiar with the term, “fake news”, but I wonder whether we should adopt another term, “non-news”, for other situations. Non-news has a lot of words and pictures, and somehow manages to say or show nothing. I once took an advanced, grad-student-level philosophy class that had a similar impact on my perceptions.

      • FFS, you would WANT increased planetary temps then no need (less need) for salt. Silly rabbit, more ‘warmth’ = less freezing and therefore less salt ergo less of that corrosive chemical out there rusting our cars, polluting our rivers, etc – what am I missing?

      • Your “non news” comment reminds me of Mark Twain’s, “A Connecticut Yankee in King Arthur’s Court”

        The protagonist encourages a local, Clarence, to publish a court circular. One story in the paper goes,
        “Monday: the King rode around the park today.
        Tuesday: ditto
        Wednesday: ditto
        Thursday: ditto
        Friday: ditto

        Then the protagonist says..”..The best way to manage—in fact, the only sensible way—is to disguise repetitiousness of fact under variety of form: skin your fact each time and lay on a new cuticle of words. It deceives the eye; you think it is a new fact; it gives you the idea that the court is carrying on like everything; this excites you, and you drain the whole column, with a good appetite, and perhaps never notice that it’s a barrel of soup made out of a single bean. Clarence’s way was good, it was simple, it was dignified, it was direct and business-like; all I say is, it was not the best way:”

      • No, no no Pyeatte, you don’t understand. The climate angle is the most important part. It gets them the money.

      • Actually, the road salt (ionic content) does change the soil structure. Maple trees are particularly sensitive to these changes. Others not so much. I did a literature review on this issue back in the early 70’s for a DOT location planning assessment. Even then it was a well known problem in certain areas.

      • The climate is the independent factor in this. Less snow and ice means less salt usage. Of course, the normal year-to-year variability dwarfs climate change, so this means quite little in a given year, but if there is substantial warming, the soil and waterways would actually lower in salinity.

    • My bad.
      Please help me to pronounce the waterway’s name – Tioughnioga.
      I guess that ante-dates European immigration, so I fear I need help.



  2. I don’t see anything here which indicates (or proves) that road salt CAUSES or exacerbates climate change – either way, colder or warmer. I would be really surprised if they had NOT come to the conclusion they did – that if there is decreasing snow (and cold) then less salt will be used and the salinity – if measurable – in the river ‘model’ will be reduced. duh!!
    Whomever spent their money on funding the grant used to fund this paper has WAY too much to spend.

    • I work in water treatment. We do notice an increase in non-carbonate hardness in winter. (I suspect the increased use of CaCl rather than NaCl.)
      But, uh, is the paper claiming that using road salt to deice roads is making things warmer or colder?
      Do we need a “War on Salt” to save the planet?

      • By my parsing, the “claim” is that future (expected) warming will decrease the use of salt, allowing the catchments to dilute the salinity back to baseline levels.

  3. “While various models have been used to assess potential future impacts of continued de-icing practices, they have not incorporated different climate scenarios, which are projected to impact hydrogeology in the 21st century.”

    And thus, a research grant granted.

  4. Hey, if more New Yorkers in that region would just drive SUVs, they could use less salt on the roads… and get the same salt effect right away. ;-)

    • If this weather continues, we’ll have more of it.
      Government grant to further this statement please.

    • You have to learn how to say that in a minimum of 10,000 words, plus graphics, and have it extensively peer reviewed in order to quality. They do not hand out PhD’s for nothing.

      • Asp,
        Generally – “They do not hand out PhD’s for nothing” – is correct.
        However the University of Zimbabwe may be shortly withdrawing one issued to one Grace Mugabe, which may not have fully completed the usual review, peer review, etc. Or so the BBC reveals.

        Plainly the BBC is being genderist, racist, sexist, ageist (etc.) in suggesting that Ms Mugabe needed ‘years’ to complete her PhD.


        Mods – this, plainly, is not /Sarc.
        How can it be when there is a deprived person being denied the fruit of her husband’s state terrorism?
        Is that right?
        I struggle to keep up with what is PC this week. Sorry.

      • “They do not hand out PhD’s for nothing.”

        Given the quality of many so called PhD’s, I have to challenge that statement.

  5. As a local I can say that river is adjacent to the interstate in that area for miles. It is in the lake-effect area and, trust me, they are not stingy with the use of salt to keep the road clear. No question there is a relationship between snow and salt in the water in my mind but trying to pick up a climate change caused difference in the snowfall amount, duration and intensity that all affect how much salt will be used seems to be pretty ambitious.

  6. I’m expecting these people to next announce shoveling snow off your walkway, driveway and roof cause climate change.

  7. Warmer = more evaporation = more water vapor = more precipitation = more snow. Really cold areas – Antarctica, for example = low humidity = less snow. Less ice cover in the Arctic = increased humidity in northerly winds = Canada covered in ice caps over a mile thick. More atmospheric moisture = more snow = simple. Send grant.

    • Yes, I was going to say something similar. Their assumptions are plausible but not guaranteed to be correct. In some locations on the planet, slightly warmer could mean more snow, not less.
      I’ve read that some areas near the great lakes get more snow before the lake gets largely frozen-over.

  8. I do hope this salt is not finding its way into an ocean!!!
    If so, we will have sea water saltation adding to the disaster of ocean acidification!!!
    Oh Glory Be!!!
    The fish might be better off getting the next Tesla Uber to Mars!!!
    And “Goodbye corals”!!!
    Heaven to Betsy!!!
    The world might even run out of exclamation marks!!!!

    • No!!!!!
      A potential disaster worse than a degree or so warmer on winter nights!!!!!!
      Horror of horrors!!!!!!!!

      toorightmate must be awarded an immediate Nobble for identifying an existential threat to punctuation!!!!!!!


  9. “A gradual warming trend between 2040 and 2099 will lead to reductions in snowfall and associated salt applications, causing [the river’s] salinity to drop. By 2100, surface-water chloride concentrations should be below 1960s values,” Gutchess says.

    Good grief! Are we now engaged in astrological predictions about future climate? Their guess about future climate and in particular snow forecasts for their exact region is way out on a limb. First they just accept that global warming is inevitable, but then extrapolate that to mean warming in their watershed where they plan to use less salt. This is an example of unacceptable science and whom ever writes this stuff should never be granted a PHD on a research method such as this, and whom ever reviews this for publication in a science publication should be fired. No wonder climate science had fallen off the rails, and now with so many tens of thousands of new wanna be climate scientists in the works, we are probably in for many years of this nonsense with all these graduating kids out to make a name for themselves in climate science.

    At worst, road salt is a seasonal problem, and many cities already treat road runoff effluent for oil, pollutants and salt in their storm drainage control. Or other cities plow, load and haul their snow which may have salt in it to a dedicated melting spot where it is absorbed into unfettile ground. No where near the gross amount of salt applied to roadways actually makes it to streams and rivers and if it does, it is flowing to an ocean that is very salty already. In my many years of observing this, the worst I have seen is dead trees close to a road side, caused by salt runoff. If the trees are that close to roads or highways, then there is other problems with these trees falling on roads, people or power lines. Not to mention the countless lives that were saved by using road salt. Perhaps there are better alternatives such as certain crushed volcanic rock for less environmental harm, but this solution wasn’t even thought of for this report.

    • It is some of those same dedicated melting spots that can also raise salinity levels of ground water supplies. Would be far better to truck it to barges and dump it in the ocean. A little added salt won’t affect the seas

    • Dont forget even with 100% electric cars we will still need as much road salt because all cars use same types of tires (Rubber to the road so to speak)

    • i predict vast expansion of Atmospheric or Enviromental Science faculties so much so that the other faculties will soon start complaining. Of course those expanded faculties will all have PhDs who have drank the AGW KoolAid. KoolAid being an appropriate concoction to counter the warming that is 1000% certain to arrive. In the ordinary scientific circles 100% is the most you can have but in the AGW world there are no limits even to %s.

      • Well, that would kill two birds with one stone, if the crushed volcanic rock they substitute for road salt was used on the roads. Plus it is a fertilizer, unlike salt, so would be good for land plant growth, but perhaps add to excess runoff to watersheds, lakes and ocean a bit. Plus as you say Auto, the crushed volcanic rock used for traction on the roads and melting snow would soak up CO2. Although I don’t think CO2 at current levels are of any significant negative consequence, and probably are a net positive for the planet overall. Its may take 30-40 more years to prove that, but I am confident that future history will bear this out.

  10. “A gradual warming trend between 2040 and 2099 will lead to reductions in snowfall and associated salt applications,…”

    So what’s not to like?
    – A gradual warming trend.
    – Less ice on the roads.
    – less salt to rust-out your car.

    Our grandchildren just won’t know what winter road salt is anymore….

  11. Years ago, snow would be plowed into the middle of a city’s streets.
    Then it would be loaded into trucks and dumped into a river.

    => salt, oil, brake liner, tire material, dead animals, toys and other stuff

    Life was simpler then.
    Now, find where the road snow is dumped and go have a look this spring.
    Go as it melts so you can see the black parts.

    • In the UK there’s a salt-tolerant weed which is spreading along the edges of major roads — its competitors are suppressed by the high salt levels.

      On airfield runways we used to use urea which is much less corrosive than NaCl.


      • When I was a kid we used a toothpaste that had a big promotional banner on it that said “NOW WITH UREA! “.

        Everything was great until my dad, a physician, told us what Urea actually was. He had a good chuckle over that.

  12. If, as some folks suspect, there’s a cooling trend in the coming years,
    we’ll need studies on the impact of increased use of calcium chloride
    to cut the ice at lower temperatures.

    Here in Ohio, our Department of Transportation stops using sodium
    chloride at about 17 F, and switches over to calcium chloride if the
    temperatures are going to drop further for any length of time.

    One notes from weather reports out of Great Britain and Europe this
    year they still call their plows “grit trucks”.

  13. The main impact of chloride on the river watershed should be higher corrosion rates on the steel structures over and adjacent to the river. Corrosion of ferrous metals requires the presence of iron (in the steel), oxygen (from the air), and water (from the river). It involves the oxidation of the iron at interfaces between the air and the water to form iron hydroxides (rust). The presence of chlorides accelerates this process by converting the insoluble iron hydroxides into soluble iron chlorides, allowing the rust scale to be easily removed, exposing fresh surfaces to the ravages of rust-formation. Salt from the streets will eat the steel bridges and other structures.

      • There have been a number of studies on the effects of increased salt content in streams, rivers & lakes. They uniformly report the salt resulted in higher biomass, species diversity, and productivity found. This is why the article uses insinuation and obfuscation about salting results.

        In fresh water solutes make ion-exchange easier on the inhabitants and high solute water like those found in spring creeks are the most productive waters, while low solute waters are the most unproductive.

  14. Salt on roads does have a measurable impact on the environment. Coastal plants which thrive in salty soils establish on highway shoulders. This effect is noticeable up to about three feet from the edge of the asphalt.

    • I remember this from the 1970s after some particularly harsh winters in Europe. Coastal plants on verges of roads as far as the Swiss Alps.

  15. I am a bored student seeking to become a postgraduate. I have no private income. I am pretty stupid. I can just about look up other peoples measurements on the internet and plonk them on a map,. My professor says ”just mention climate change and you will get a grant’. ‘Climate change and what?’ I ask.

    ‘Climate change and anything that you are competent to measure. Rats in sewers! Road salt in Syracuse – anything! Everything changes, just measure it, claim its due to climate change.,, and there’s your paper!

    So I did.

    And then he said ‘Jesus, I wasn’t actually serious about road salt in Syracuse, you know’….

  16. Sodium Chloride: it does a great job of melting ice. Over about a decade or so, it also does a great job of dissolving steel cars.

    • Also bridges, marble building facades, anything steel anywhere near ground level. Western states seem to get along fine without it.

  17. “Scientists examine link between surface-water salinity, climate change

    Syracuse University Ph.D. candidate Kristina Gutchess authors paper on impact of road salts on Tioughnioga River watershed”

    This paper should have been rejected in the peer-review stage. Not once does it state that the situation is worse that we thought. This is blatant luke-warmism, and the authors should be banned from any future climate-change grants./sarc

  18. I lived in that area for 20 years. I inspected all the bridges in Cortland county. The salt deteriorates the bridges at an alarming rate. Not sure how they can state a warming climate will reduce snowfall. Even if it’s warmer its still going to be cold enough to snow. The snow in this area is primarily caused by lake effect snow. As air passes over the great lakes picks up moisture and dumps it on the other side. Syracuse averaged 120 inches per year of the white stuff. It was awefull, each day it snowed about an inch. This year for instance the great lakes froze. Hence no lake effect snow at this time period. So probably a bit warmer climate will create more snow…not less

  19. Around here, the highway departments use beet juice, among other things.

    Okay, this will solve the problem substantially.: go back to using studded snow tires and snow chains on non-studded tires. It’ll tear up the pavement, but there won’t be any of those foul chemicals in the waterways.

  20. Around here, the highway departments use beet juice, among other things.

    Okay, this will solve the problem substantially.: go back to using studded snow tires and snow chains on non-studded tires. It’ll tear up the pavement, but there won’t be any of those foul chemicals in the waterways……

  21. I’ve watched the glass ceiling in the not long ago manly art of climate science being totally shattered over only a few years. Almost all the battered old warriors of the meme are male. Judith Curry, a standout, was viciously smeared by this near redundant klatch. But wow, all the authors and the head of department have a bit of powdered glass in their hair! I’ve remarked on the takeover for some time.

    My only worry is, if pariah Jordan Peterson is correct (and I was independently of the same opinion), that boys are interested in things and girls in people, the massive influx of girls into hard sciences feeds the post normal breakdown of science. They may be attracted into climate science because they want to save the world. They care about people, they are easier to sell the precautionary principle in its extreme form. The massive influx into politics, although a people ‘subject’, also brings too strong a socialist ‘caring’ (people are helpless)factor into play instead of ‘thing’ pragmatic solutions.

    Yeah, I know about the Margaret Thatchers, Golda Meirs, Indiras and Benazirs, …hey a theory isn’t perfect.

  22. As has already been mentioned, if it keeps on getting warmer then we won’t need to salt the roads as often. There is another angle on this. In the UK we stopped salting the roads a few years ago, not because they weren’t icy but because we ran out of salt. The alarmists had told us that we Wouldn’t need it.

    • Stoney
      I have had the gritter run up my road at least four of the last five nights.
      I was out last night, but it looked as if the gritter had run last night, too.
      We have salt! [Rock salt, at least. And the chippies have salt, and vinegar!]


      • Yes, we are getting gritted now, this was a few years ago. I remember it because my car got rear ended and was written off, not due to icy roads, but in between that car going and me getting a replacement I had to commute on my motorbike on the unsalted roads and this was pretty scary.

  23. Pernaps this kind of research funding could be diverted to something a little more useful, like using acetate based de icing compounds instead of salt!
    They could also spend some money on installing water distribution in those areas where the groundwater has been ruined by road salt stockpiles! The NY state DOT has ruined that many well that it even has its own drilling rig to drill new wells! I have seen it used, the flound more salty water!

  24. Uhhh…What if we don’t have “A gradual warming trend between 2040 and 2099?” Or am I mistaken in thinking the validity of this unwarranted assumption is supposed to matter to someone or something?

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