Melting Ice Caps May Not Shut Down Ocean Current (phys.org) 43
Most simulations of our climate's future may be overly sensitive to Arctic ice melt as a cause of abrupt changes in ocean circulation, according to new research led by scientists at the University of Wisconsin-Madison. Phys.Org reports: Climate scientists count the Atlantic Meridional Overturning Circulation (or AMOC) among the biggest tipping points on the way to a planetary climate disaster. The Atlantic Ocean current acts like a conveyor belt carrying warm tropical surface water north and cooler, heavier deeper water south. [...] In a study published [...] in the journal Nature Climate Change, He and Oregon State University paleoclimatologist Peter Clark describe a new model simulation that matches the warmth of the last 10,000 years. And they did it by doing away with the trigger most scientists believe stalls or shuts down the AMOC.
Warming temperatures on Earth's surface cause sea ice in the Arctic Ocean and the Greenland Ice Sheet to melt, releasing fresh water into the ocean. Scientists widely believed that the freshwater influx disrupts the density differences in the North Atlantic that make the AMOC's north-bound water sink and turn back south. "The problem," says He, "is with the geological climate data." Though the climate record shows an abundance of freshwater that came from the final melting of the ice sheets over North America and Europe, the AMOC barely changed. So, He removed the assumption of a freshwater deluge from his model.
"Without the freshwater coming in making the AMOC slow down in the model, we get a simulation with much better, lasting agreement with the temperature data from the climate record," He says. "The important result is that the AMOC appears to be less sensitive to freshwater forcing than has long been thought, according to both the data and model." [...] The widespread consequences of a drastic weakening of the AMOC include rapid sea-level rise on the eastern coast of North America, cooling over Europe that could disrupt agriculture, a parched Amazon rainforest and disruption of Asian monsoons. The new modeling study anticipates a much smaller reduction in AMOC strength, but that doesn't rule out abrupt change.
Warming temperatures on Earth's surface cause sea ice in the Arctic Ocean and the Greenland Ice Sheet to melt, releasing fresh water into the ocean. Scientists widely believed that the freshwater influx disrupts the density differences in the North Atlantic that make the AMOC's north-bound water sink and turn back south. "The problem," says He, "is with the geological climate data." Though the climate record shows an abundance of freshwater that came from the final melting of the ice sheets over North America and Europe, the AMOC barely changed. So, He removed the assumption of a freshwater deluge from his model.
"Without the freshwater coming in making the AMOC slow down in the model, we get a simulation with much better, lasting agreement with the temperature data from the climate record," He says. "The important result is that the AMOC appears to be less sensitive to freshwater forcing than has long been thought, according to both the data and model." [...] The widespread consequences of a drastic weakening of the AMOC include rapid sea-level rise on the eastern coast of North America, cooling over Europe that could disrupt agriculture, a parched Amazon rainforest and disruption of Asian monsoons. The new modeling study anticipates a much smaller reduction in AMOC strength, but that doesn't rule out abrupt change.
So that's nice (Score:1, Flamebait)
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But hey,. Sure, if we're wrong it's the end of all life on earth. That's a risk worth taking off it means I don't have to look at windmills or upgrade the grid.
If the Greenland ice sheet melts then ocean currents won't be high on the list of priorities.
Re:So that's nice (Score:4, Insightful)
Right, let's keep going down the path of only wind and solar because it produces more CO2 than nuclear fission, kills more people per MWh than nuclear fission, and takes more valuable resources like land, labor, raw materials, and fresh water.
What is the problem with nuclear fission? The waste? Um, no. https://www.youtube.com/watch?... [youtube.com]
People have been trained for decades to fear nuclear power. Now we are seeing people trained for decades to fear global warming. Tell me, which is worse? I ask because at some point we will have to choose one, the other, or freezing in the dark.
I believe people will choose nuclear power.
Wind, solar, and everything else is optional, nuclear power is required. Solar power is just plain shit for power on the grid, we have many better options. Wind power is cheap and simple, so is hydro and geothermal, so long as there is favorable geography and climate. We will still seek a varied supply of energy to keep everyone honest on pricing but nuclear power is necessary or there will be an energy shortage.
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let's keep going down the path of only wind and solar because it produces more CO2 than nuclear fission
Current nuclear technology is comparable to wind or solar from a CO2 emissions standpoint. The problem with nuclear is that it's unattractive to investors. A wind farm is very attractive, it can start paying for itself in under a year. That's why Texas has become a national leader in wind power; private enterprise is driving that, not state policy.
If you want to go down a nuclear "path", the only way to do that is the way France did it: with government money. France managed a crash program of nuclear co
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Fukushima.
Chernobyl.
Tokaimura.
Stop me when you hear a nuclear disaster you like. I've got more.
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Three Mile Island.
Fukushima.
Chernobyl.
Tokaimura.
Stop me when you hear a nuclear disaster you like. I've got more.
I agree, and at one time I supported that position. But in spite of the rare scraps of good news like the one in TFS, I've become convinced that the effects of AGW are going to get really ugly really fast, and that nuclear power is the only way our civilization stands a chance of surviving given our refusal to lead simpler, less vain, less wasteful lives.
I don't like it, but I think ramping up nuclear power quickly, in combination with pulling a rabbit our of the hat and coming up with a viable means of rem
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Three Mile Island.
Fukushima.
Chernobyl.
Tokaimura.
Stop me when you hear a nuclear disaster you like. I've got more.
Banqiao Dam 26k Immediate Dead 145k Dead 11M homeless
Machchhu Dam 1.8k to 25k Killed
Oroville Dam 180k Evacuated
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People have been trained for decades to fear nuclear power. Now we are seeing people trained for decades to fear global warming.
Widespread fear of nuclear power is one of the reasons I don't fear global warming.
It is obviously not an emergency.
SHUT UP! (Score:2)
Don't let the facts of reality smack you where the God Lord split you, on the way out.
I thought that thermal turnover was powered by ice (Score:2)
Ice has high albedo. If the ice retreats far enough, is the fresh water even necessary to disrupt the conveyor?
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Damn, someone escaped the Fox asylum.
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is the fresh water even necessary to disrupt the conveyor?
We don't know. Because there was nobody around making salinity and ocean temperature measurements the last time the AMOC (Atlantic Meridional Overturning Circulation) shut down. If it actually did. Science in the 14th century wasn't that great. We do know about the Little Ice Age that resulted from what has been theorized as an increase in fresh water from arctic ice melting. But only what we can see in old Dutch paintings.
The climate scientists are fiddling with model parameters to make their analysis fit
Climate change denier now? (Score:1)
What really no way! (Score:1, Troll)
Geeze another one of the doom predictions turns out to be BS.
Who would have guessed, it would follow the pattern of literally every other dire climate prediction.
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Unless this prediction is wrong.
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So, the prediction that the conveyor would shut down and northern Europe would get colder is a doom prediction, but this new prediction, that the conveyor won't shut down as readily, so northern Europe will get too hot like the rest of the world is not a doom prediction?
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So, the prediction that the conveyor would shut down and northern Europe would get colder is a doom prediction, but this new prediction, that the conveyor won't shut down as readily, so northern Europe will get too hot like the rest of the world is not a doom prediction?
Doom is a necessary component of all predictions!
*facepalm* (Score:2)
And they did it by doing away with the trigger (fresh water from ice cap melt) most scientists believe stalls or shuts down the AMOC.
And if we remove CO2 from the climate change calculations then there isn't any heating. Unless he has data suggesting that the ice caps aren't made of fresh water then this is a baffling level of stupid.
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And they did it by doing away with the trigger (fresh water from ice cap melt) most scientists believe stalls or shuts down the AMOC.
And if we remove CO2 from the climate change calculations then there isn't any heating. Unless he has data suggesting that the ice caps aren't made of fresh water then this is a baffling level of stupid.
He has the same "data" that all the other climate predictions have -- modeling.
The answer to your question can be found by understanding the "it" that "they did" in the sentence you quoted.
We do not know what will happen with the climate. Climate is not have a deterministic macro-Newtonian system where all the inputs can be reduced to simple free-body diagrams with clear cause-effect relationships and outputs can then be calculated with precise universal equations.
Instead, we refine our predictions by looki
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We do not know what will happen with the climate.
With absolute, precision, no. We do, however, know that the climate will get hotter and therefore melt the "ice caps" which will release their water into the ocean. This is the basis for the AMOC.
This team built a set of guesses, and chose to remove one of the guesses commonly included in many established models.
Why do you think ice melting is a guess? Seriously, it's getting warmer which makes ice melt. This isn't a guess, this is a fact.
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We do not know what will happen with the climate.
With absolute, precision, no. We do, however, know that the climate will get hotter and therefore melt the "ice caps" which will release their water into the ocean. This is the basis for the AMOC.
This team built a set of guesses, and chose to remove one of the guesses commonly included in many established models.
Why do you think ice melting is a guess? Seriously, it's getting warmer which makes ice melt. This isn't a guess, this is a fact.
Again, I would suggest you take time to read the linked article or the original journal article to actually understand what the "it' is.
"ice melts when it gets warmer" isn't the "it" under discussion.
The original article is published in an academic journal specifically devoted to Climate Change. This isn't some random fringe agenda-dude trying to hand-wave away the existence of CC on a cherry-picked technicality. This is a team of scientists working within Climate Change research to build more accurate mode
We will stil need more nuclear fission power. (Score:2, Insightful)
I'd hate to see everyone use this as an excuse to stop looking for energy that is safe, abundant, low cost, and low in CO2 emissions. They can't. That's because our economy requires nuclear fission power to keep running. So we will lower our CO2 emissions whether anyone likes it or not.
We will see more nuclear power because we are running out of alternatives.
You know what a physician calls "alternative medicine" that works? They call it "medicine". What's the deal with "alternative energy"? If it work
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Who funded this "study"? (Score:3, Interesting)
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There is something suspicious about this new "study", with it's models that conveniently show the exact opposite of hundreds of previous models.
And conveniently fits the historic data better than hundreds of previous models that don't? Must be a conspiracy.
Modern Day Martin Luther (Score:2, Interesting)
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Hope this guy likes being a heretic. This won't go over well with all the climate change acolytes.
Only if his model doesn't hold up.
If good proper science suggests that AGW isn't as big a concern as we think it is then that's awesome.
But someone claiming an emergency isn't an emergency based on BS reasoning is decidedly not awesome.
The vast majority of "climate change is overblown!" stories fall squarely into the latter category.
At a glance this sounds like a legit research group, and if their work holds up that's good news. Unfortunately, it's probably not "the planet will be fine" news, but any reduct
It's a common refrain (Score:4, Interesting)
Oversensitive Models: An Exploration of Late 20th Century Climate Science and How It Impacts Our World Today
Nothing to worry about either way. (Score:2)
Either the polar ocean currents will be affected by the melting of the polar ice cap, or they won't. Either way, the ice cap is going to melt (or maybe not), and what follows will follow regardless of our efforts to alter the outcome.
Either we've long passed the point of no return with greenhouse gasses, or we haven't. It doesn't matter, because climate change is here. We can argue about the meaning of finding
The science ... (Score:3)
If they are going to keep putting things in, taking them out and putting them in again to see what happens, they are approaching the futility of my love life.
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Who do you trust? "Nobody" is a reasonable answer - but if you trust nobody, why should anybody trust you?
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The science is nowhere near done. [...]
If they are going to keep putting things in, taking them out and putting them in again to see what happens, they are approaching the futility of my love life.
And no one has ever claimed the science was anywhere near "done". In fact climatologists go at great length to emphasize the complexities. Given the shear number of variables, it's one of, if not the, most complex areas that humanity is trying to decode.
But we don't need to know 100% of the variables to make working models. We don't have a complete understanding of fluid dynamics, but we know that putting a flame under water will make it boil. We don't have a complete understanding of aerodynamics, but we h
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but we know that putting a flame under water will make it boil
And that's about the extend of climate science from the sound of it. If they keep going maybe they'll win the science fair prize.
Ho hum. (Score:3)
Infinitely complex models have infinitely many assumptions that might be wrong., and at least a finite number will be. Ho hum.