Does road salt increase the salinity of the oceans? Say by a millionth of a percent?
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Does road salt increase the salinity of the oceans? Say by a millionth of a percent?
SHARKS (crossed out) MONGEESE (sic) WITH FRICKIN' LASER BEAMS ATTACHED TO THEIR HEADS
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I don't know; I suspect on some absolute level it must, but it is probably immeasurably small and would have no noticable effect.
However, road salt has a huge effect on fresh water habitats.
Columbia University
SmithsonianPeople have long known that salting roads helps keep them free of ice, but what hasn’t been well understood is how the millions of tons of salt spread on U.S roads every year impact the environment. However, recent research indicates that salt is accumulating in the environment and poses an emerging threat both to ecosystems and human health.
An increasing amount of research is showing that road salt doesn’t just dissolve into thin air. Instead, as it splits into sodium and chloride ions, it gets absorbed into roadside plants, licked up by wildlife or accumulates in aquatic ecosystems—sometimes with devastating consequences. All that saltiness can help invasive or even toxic species spread, not to mention increase traffic danger due to deer and moose drawn to salt-covered roads.
“It has a really widespread number of effects on the whole food web or ecosystem,” says Rick Relyea, a professor of biological sciences at Rensselaer Polytechnic Institute.
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ensia.com
quora.comU.S. road maintenance departments have been spreading salt on streets and highways to melt snow and ice since the 1940s, but the use of salt skyrocketed over time — from 0.15 metric tons (0.16 tons) per year during the 1940s to about 18 million metric tons (19.8 million tons) per year today.
(18 * 10^6) / (36 * 10^18) = 5 * 10^-13The concentration of salt in seawater (salinity) is about 35 parts per thousand. In other words, about 35 of 1,000 (3.5%) of the weight of seawater comes from the dissolved salts; in a cubic mile of seawater the weight of the salt, as sodium chloride, would be about 120 millions tons.
A group of scientists used satellite measurements to get new estimates of the total volume of the oceans, which turned out to be 0.3 billion cubic miles.
120,000,000 x 300,000,000 =
36,000,000,000,000,000 tons of salt
give or take.
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The amount may be too low to measure accurately. It's big water.Originally Posted by Tom Mazanec
"I'm planning to live forever. So far, that's working perfectly." Steven Wright
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The Smithsonian article engages in some rather overwrought alarmism (talking about splitting up into ions like it's something dangerous, claiming salt can somehow specifically help invasive and poisonous species), but yeah, the issue isn't it eventually ending in the ocean, it's that it will take a very long time to get there and will accumulate in ecosystems that have adapted to low salt levels on the way there.
It's not like it's a completely foreign substance though. As mentioned, it attracts deer and other animals, and you can actually buy salt blocks to set out for them to lick. They do this to obtain minerals, and didn't evolve the behavior in response to road salting, they normally seek out natural deposits with large amounts of soluble salts. A road out in a rural area likely isn't going to contribute much compared to the natural contribution from eroding rocks in the surrounding land. Areas with large amounts of paved ground that all drains into the same water systems might have more of a problem.
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It is not overwrought in the least. I know that in Ohio (and elsewhere) that the use of road salt has allowed the invasive species Phragmites, which is normally found along ocean coasts, to invade fresh water wetlands and to completely take over in some areas. In the concentrations that are developing along roadways it is a foreign substance (like "the dose makes the poison", the concentration makes the pollution).
The deer might like it (though in this area, deer overpopulation is a serious problem too), but that is AT BEST a minor benefit.
Order of Kilopi
And rocker panels. Environmental impacts, corrosion, and not particularly effective. What's not to love?
Cum catapultae proscriptae erunt tum soli proscript catapultas habebunt.
Order of Kilopi
Relatives from the midwest are always surprised at the number of older cars they see here that aren’t all rusted out. People still replace cars here when they get too expensive to maintain or just to get something newer, but there are a decent number of older, good looking cars on the road. There’s no snow or ice until you get into the foothills, so road salt just isn’t used in the valley.
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The Leif Ericson Cruiser
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Probably not enough to compensate for the amount of ice melted over recent decades.
Also, the rock salt came from the ocean in the first place.
Order of Kilopi
But it's been sequestered underground for eons. Think of it like the carbon in fossil fuels, which has been sequestered and is being returned to the environment.
Cum catapultae proscriptae erunt tum soli proscript catapultas habebunt.
Order of Kilopi
Which originally came from minerals eroded from the ground.
But rock salt is mostly mined, IIRC.
"I'm planning to live forever. So far, that's working perfectly." Steven Wright
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Over long timescales the salinity of the oceans is gradually increasing, due to erosion.
Built on that trend will be shorter timescale events such as ice ages (which lock up freshwater in ice) and warm interglacials where that freshwater is returned to the oceans.
There are also events where land-locked seas are evaporated, leaving their salt behind. This is happening now at the Dead Sea. This is where our salt deposits came from, and I suspect they are not all as old as the coal deposits.
An interesting question is, what proportion of the natural erosion rate is the salt added to the roads? It's quite possible this is small compared to the natural increase in salinity over time.
Established Member
How much new water has entered the oceans from ice melt? I thought I read that most of the sea level rise was from thermal expansion of seawater?
Does the ice melt more than compensate for road salt in oceans?
SHARKS (crossed out) MONGEESE (sic) WITH FRICKIN' LASER BEAMS ATTACHED TO THEIR HEADS
Order of Kilopi
28 trillion tons of surface ice melted between 1994 and 2017. Some of that will presumably have ended up in ground water rather than the oceans.
I suspect we have only a very limited idea of how much road salt gets to the ocean. A lot of it undoubtedly ends up in soil locally, and the stuff that enters bodies of water tends to sink to the bottom. Salting is probably less common in coastal communities, too, since they tend to have fewer nights of frost than their neighbours inland.
But overall, ceteris paribus and mutatis mutandis, it would seem that the added fresh water is going to outweigh the effect of the added salt by several orders of magnitude.
Grant Hutchison
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According to NASA, thermal expansion has contributed about a third to global men sea level change over the past couple of decades.
https://sealevel.nasa.gov/understand...level/overview
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There are like a million cubic kilometers of salt under the Mediterranean. Which is about 2 billion metric tons per cubic kilometer. In the USA we use about 20 million metric tons of salt per year. So in about 50 years that would be the equivalent of one millionith of what is under the Mediterranean sea.
The moment an instant lasted forever, we were destined for the leading edge of eternity.
Order of Kilopi
The northerners of the USA have huge costs related to winter, my guess is 500 billion per year. Cars, wear and tear on homes, plowing, salting, heating, infrastructure maintenance such as roads. It is not easy, but it is never a disaster at one time so no sympathy or empathy for us.
The moment an instant lasted forever, we were destined for the leading edge of eternity.
Order of Kilopi
Yeah, the way all the sympathy goes to people who lose their lives, homes or livelihoods is pretty crass, I think.
Grant Hutchison
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Who are you talking about losing their life. Try driving on ice and snow. Or being secluded all winter due to super harsh conditions. Northerners pay for home insurance just like everyone else. We get severe summer storms, with tornadoes, downed trees, floods and all that too. It is just more spread out.
The moment an instant lasted forever, we were destined for the leading edge of eternity.
Order of Kilopi
Icy roads and power/heat failures in winter can and do claim lives.
"I'm planning to live forever. So far, that's working perfectly." Steven Wright
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They sure do. Given the job I used to do, and the places I've worked, you might guess that I've had some pretty grim experiences of these exact situations--one of which is the only episode in my entire career I've ever had a nightmare about.
So that's exactly what, among other things, I was referring to--the stuff that Copernicus didn't mention, which is the stuff that does attract people's sympathy and empathy.
Grant Hutchison
Last edited by grant hutchison; 2021-Jan-29 at 01:51 AM.
Order of Kilopi
I live in Scotland. I've lived in Northwestern Ontario. I do know what you're talking about.
Grant Hutchison
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I think the point Grant was making is different from that. I live in an earthquake-prone area, and there are things we have to do because of that, like live in (relatively expensive) reinforced concrete buildings and make sure that furniture is bolted to the walls and that bookshelves have doors with devices to prevent them from opening when an earthquake hits. And trains stop from time to time, etc. But those are just inconveniences, and it never occurred to me that I somehow deserved sympathy for that. Now yes, the tens of thousand of people who died in the earthquake on March 11, 2011 deserve sympathy, as do the drivers who died due to icy conditions, but I don't see why I deserve sympathy just for being here.
As above, so below
Order of Kilopi
Just an interesting observation, not meant to be a derail, but in Japan, for some reason I don't understand, people spray water onto the sidewalk when it has snowed... Which might be fine if the temperature rises, but if it drops...
As above, so below
Order of Kilopi
They do this on the tracks of the bullet train, to prevent the snow billowing and drifting. But then they plough out the damped-down snow overnight. Perhaps something similar is being done on the Japanese sidewalks?
When I worked in Thunder Bay, it was always a little tricky to encounter the sidewalk plough later in the winter, because the sidewalk was by that time flanked by banks of snow five feet high, and it was impossible to get out of the way without retracing your steps to the nearest road junction.
Grant Hutchison
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I didn't see that Copernicus was claiming sympathy just for living in the North.
"I'm planning to live forever. So far, that's working perfectly." Steven Wright
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Then how do you interpret that?It is not easy, but it is never a disaster at one time so no sympathy or empathy for us.
As above, so below
Order of Kilopi
Um, victims of disaster?
"I'm planning to live forever. So far, that's working perfectly." Steven Wright
Order of Kilopi
You mean you actually took that as a literal statement of fact, and not a complaint?
As above, so below
Order of Kilopi
I mean, his post clearly that "nobody has sympathy for us" (Northerners). So the reference was clearly to Northerners in general, not those who died in disasters (since Copernicus has obviously never died in a disaster).
And then Grant was just pointing that out by saying that it's natural to feel sympathy for people who die, but not people who live in snowy areas. And you didn't argue against that, but just stated the fact, that Grant knew, that people do die from snow. But that wasn't the point. The point was that Copernicus seemed to be asking for sympathy as a Northerner, not as someone who had died from a disaster.
So if it is "Um, victims of disaster," then can you explain to me why Copernicus used "us"?
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