Huge Freshwater Bulge In Arctic Ocean 382
New submitter turkeyfish writes "UK scientists are reporting today in the journal Nature Geoscience that a huge bulge of freshwater is forming in the Western Arctic Ocean caused by a large gyre of freshwater. The gyre appears to indicate that the ice is becoming thin enough over the Arctic Ocean that the wind is beginning to affect the motion of water under the ice. A sudden release of this water or its emergence to the surface will greatly accelerate the melting of the remaining polar oceanic ice and likely alter oceanic circulation in the North Atlantic."
Re:How "An Inconvenient Truth" can it get (Score:5, Informative)
Melting sea ice won't lead to a significant increase in ocean levels, it's the land ice you have to worry about.
Thermohaline (Score:5, Informative)
Read more about the thermo-haline cycle on Wikipedia - http://en.wikipedia.org/wiki/Thermohaline_circulation [wikipedia.org].
Re:How "An Inconvenient Truth" can it get (Score:3, Informative)
Except that the fraction of the ice that is floating above the water is the volume it shrinks when it melts.
There's a second order effect due to higher density of the salt water, so there will be small net sea level rise,
and will also cause reduced atmospheric pressure due to less volume occupied which could bulge the surface,
but these effects won't flood your coast anytime soon.
Re:How "An Inconvenient Truth" can it get (Score:4, Informative)
I think its about 100 metres, which means half the current land masses would be underwater. As I understand it, this would be likely to take a thousand years to play out.
Re:Yeah, but. (Score:5, Informative)
Re:How "An Inconvenient Truth" can it get (Score:3, Informative)
It won't affect glaciers on land. I don't see where you get that. The glaciers on land are melting too by the way. The glaciers on land melting will cause the sea levels to rise (Antarctica etc.).
The currents will never stand still however they will become a lot less active causing, as you said, the tropics to overheat and the north pole to freeze over. Yes, eventually nature will balance itself but this process will take a really, really long time while generations of people will either bake or freeze (depending on where they live) and the process will be violent.
Finally, it's indeed the CO2 from SUV's and coal plants that causes glaciers to melt but as the glaciers melt they also release the CO2 stored in/under them. Water acted as a sink to CO2 before the last ice age after which it froze and got captured in the ice. It's basically a positive feedback cycle which will only accelerate the process faster.
Climate change is real, global warming is real and the cause for this is real. This has been established by practically all scientists in the field. Denying it is as futile and idiotic as the few that still refute the theory of evolution based on their personal religious or political ideas.
Re:Don't panic. (Score:5, Informative)
http://science.howstuffworks.com/environmental/earth/geophysics/question473.htm [howstuffworks.com]
The main ice covered landmass is Antarctica at the South Pole, with about 90 percent of the world's ice (and 70 percent of its fresh water). Antarctica is covered with ice an average of 2,133 meters (7,000 feet) thick. If all of the Antarctic ice melted, sea levels around the world would rise about 61 meters (200 feet). But the average temperature in Antarctica is -37ÂC, so the ice there is in no danger of melting. In fact in most parts of the continent it never gets above freezing.
At the other end of the world, the North Pole, the ice is not nearly as thick as at the South Pole. The ice floats on the Arctic Ocean. If it melted sea levels would not be affecteÂd.
There is a significant amount of ice covering Greenland, which would add another 7 meters (20 feet) to the oceans if it melted. Because Greenland is closer to the equator than Antarctica, the temperatures there are higher, so the ice is more likely to melt.
The numbers here are likely to be more accurate:
http://www.ipcc.ch/publications_and_data/ar4/wg2/en/spmsspm-c-15-magnitudes-of.html [www.ipcc.ch]
The complete melting of the Greenland ice sheet and the West Antarctic ice sheet would lead to a contribution to sea-level rise of up to 7 m and about 5 m, respectively [Working Group I Fourth Assessment 6.4, 10.7; Working Group II Fourth Assessment 19.3].
Yet another source: http://nsidc.org/cryosphere/sotc/sea_level.html [nsidc.org]
Antarctica and Greenland, the world's largest ice sheets, make up the vast majority of the Earth's ice. If these ice sheets melted entirely, sea level would rise by more than 70 meters.
Your move. Let's see what asshole you pulled this "not more than a foot" number from.
Re:How "An Inconvenient Truth" can it get (Score:5, Informative)
The fact that there was someone there to look at the formation of the plume means that it is not entirely unexpected, as in "someone got their project funded, and thus made a reasonable case for it".
Of course this would be found/discussed in fairly technical papers. If you trust journalists to do science reporting right, I have a bridge on the Moon to sell.
http://www.sciencedirect.com/science/article/pii/0924796395000062 [sciencedirect.com] for example dates from 16 years ago.
http://onlinelibrary.wiley.com/doi/10.1034/j.1600-0889.2001.530504.x/abstract [wiley.com] is from 11
years ago and directly related. Hint: sciencedirect or google scholar are a better way to get scientific information/papers than plain google.
Re:doh. (Score:4, Informative)
Maybe. Or maybe there'll be another mass extinction event. Who knows, right? Pretty serious people, whose job it is to study climate, are pretty worried. Maybe you should be, too. Odds are, they know better.
This is in fact not an argument from authority, it is more akin to realising that you can either trust some scientist who has devoted his life to the question, or you can trust the oil industry. It would be better if you could become a climatologist, but specialisation in society means we must trust other people to do the research for us. When someone tells me something which is thermodynamically reasonable, is backed by evidence, is supported by a well established Theory, I tend to believe them.
And so should you.
Re:How "An Inconvenient Truth" can it get (Score:4, Informative)
Except Gore never lied about inventing the internet. Some weenies on the other side just took his words and twisted them so it sounds like he did. From the Wikipedia article on Al Gore and information technology: [wikipedia.org]
Of Gore's involvement in the then-developing Internet while in Congress, Internet pioneers Vint Cerf and Bob Kahn have also noted that,
As far back as the 1970s Congressman Gore promoted the idea of high-speed telecommunications as an engine for both economic growth and the improvement of our educational system. He was the first elected official to grasp the potential of computer communications to have a broader impact than just improving the conduct of science and scholarship [...] the Internet, as we know it today, was not deployed until 1983. When the Internet was still in the early stages of its deployment, Congressman Gore provided intellectual leadership by helping create the vision of the potential benefits of high speed computing and communication. As an example, he sponsored hearings on how advanced technologies might be put to use in areas like coordinating the response of government agencies to natural disasters and other crises.
Re:How "An Inconvenient Truth" can it get (Score:5, Informative)
Predictions are rarely that specific. They're not going to tell you that's there's a fresh water "plume" as TFA so indicates. What predictions do is give you trends, and the effect of these trends on the overall system. The predicted effects are also not specific, but instead the prediction of more trends.
Reality is a little different. There's a lot of noise in the system. The variances of what happens and is expected to happen can be extreme. But the average--the predicted trend--will remain barring unaccounted for variables that may make things much worse or much better. This plume may be a part of the trend. Or it may be one such deviation from the system. Or it could be an unaccounted for variable that's about to accelerate the glacial melt timeline significantly.
Only time will tell whether the initial predictions still hold after this. And if the data doesn't support it, it will be revised. But I can't imagine that 20+ years worth of data supporting the predicted trend will be outright reversed by one event. To even fancy such a notion so would be wishful thinking indeed. More likely, things will either get a little better, or a little worse.
Of course, there actually is a point of no return that we are quickly approaching, and even if things go better than expected for us and the predictions are on the high side, we'll still end up there if we don't change our lifestyles. There's a huge amount of methane stored in the Siberian tundra. Methane is a much worse greenhouse gas than CO2. It's a missile compared to the bullet that the trapped CO2 in glacial ice would be. As the tundra begins to defrost, methane gets released into the atmosphere. When the climate reaches the point where the permafrost is no longer permanent, no amount of CO2 emissions cuts will be able to prevent the sudden release of greenhouse gas into the environment. And at that point, everyone might as well start staking their turf on high ground.
Re:How "An Inconvenient Truth" can it get (Score:5, Informative)
If all of the ice on Greenland and Antarctica (and other lesser ice caps) were to melt it would cause a bit over 200 feet [usatoday.com] (~65 meters) of sea level rise. However, it would take thousands of years for all of that ice to melt The ice on Antarctica averages ~7,000 feet in depth and it's up to ~12,000 feet in places so it won't melt that fast at any temperature that still supports humans living on the Earth. Current estimates for sea level rise by 2100 are in the 3-6 foot range. 20 feet above the current level isn't inconceivable in 2200.
Regarding what it would take to melt all of it, a paper out recently said that the big ice sheets started to form when CO2 levels dropped below 700 ppmv maybe 30 million years ago. We are currently at ~390 ppmv, up from 280 ppmv in 1830 and ~320 in 1960. At the current rate we would hit 700 ppmv in less than 200 years.
IPCC3 says 68m (Score:5, Informative)
(Undoing moderation to post this)
IPCC 3 WGI Chap 11 [grida.no] Table 11.3 estimates a 61m sea-level rise if all of Antarctica melts, and 7m from Greenland. This could take 1500 years, though other factors like lubrication might speed this.
It's also worth noting that sea levels have already risen 120m since the last glacial maximum.
Re:Level is not the danger (Score:3, Informative)
Of course there is. It's readily available for those who look. Start here [joannenova.com.au] and then spend some time over at wattsupwiththat.com. More scientific evidence than you can shake a hockey stick at.
Most of it shows that most of the globe was warmer about 700 years ago, and it was pretty damn awesome. More arable land everywhere (warmer AND wetter climate) generally milder weather patterns, and an extended growing season allowed civilization to flourish. Good times.
Unfortunately, it's looking like we are actually heading into an extended cooling period until roughly 2068 or thereabouts. In a way, I almost wish that AGW was true. I'd have more hope for our future. If things progress the way that the evidence shows, pack a parka. You'll need it.
Re:doh. (Score:4, Informative)
Re:Don't panic. (Score:3, Informative)
think of how much heat is generated from voltage down stepping
also, without electricity mass de-urbanization would occur due to lack of refrigeration (people would be forced to move near to where produce is grown) so atmospheric inversion would gradually dissipate, along with reduction of introduction of new vehicles and precision equipment
life expectancy would probably increase due to reduction in stress from lifestyle simplification, healthier diets (more basic vegetables and unprocessed foods) and increased exercise due to reduction in availability of petroleum products for vehicles
world dominance would gradually shift from modern centers of civilization to the third world due to their reduced dependence on electricity
there would be wide scale civil unrest in large centers of population dependent on electricity, and starvation, murder and suicide would be rampant until a sustainable population density is reached
the world would become a much bigger place again
Re:doh. (Score:4, Informative)
Well, my "microclimate", meaning the southern half of the United States, just spent a summer with temperatures several degrees warmer than usual and we got no more freakish weather than usual. The winter before that was a few degrees colder than normal, and still no hurricanes over land. So, in a single year, I've seen periods warmer than usual and cooler than usual with no freakish behavior. I think we'll be OK with a 1.6 degree increase over the next 100 years.
Actually, no. There was a lot of freakish behaviour, I don't know how you are able to ignore it*. More than half of the continental United States was affected by either drought or flood last year, a record level of both. In particular, Texas had the worst drought since they started keeping temperature records. On the flooding side, I saw an article indicating that Atlanta had an estimated 500 year high flood, if a one in 500 years event isn't unusual, I'm not sure what qualified for you. Maybe your community escaped the freakish weather, but there was plenty to go around.
It's not just the U.S. either, for the first time in it's history, most of Canada had a green Christmas. Australia had record setting flooding. In fact there was so much rain and flooding this past year that the evaporation that fuelled the flooding actually lowered the sea level slightly.
* Although my guess would be a combination of Fox News, confirmation bias, and ignorance.