Slashdot Mirror
Abrupt Climatic Change Coming Soon?
rRaAnNiI writes "Just read an extremely interesting article about the possibility of having a 'little ice age' quite soon - within a decade.
The frightening thing is that it makes a lot of sense to me. Does anyone know how to build an igloo?"
Abrubt climate changes aren't new. In 1816, there was no summer. Volcanic side effects from the year before blotted out enough light to cause a winterry year.
But this is slashdot. I suppose we could cuddle up with the stuffed penguins instead.
Does anyone know how to build an igloo?
I'm still living in my igloo, is Y2K over yet?
The government has a defect: it's potentially democratic. Corporations have no defect: they're pure tyrannies. -Chomsky
Yeah, at the staff meeting on Thursday. They say we're looking at fire, brimstone, and a 60% chance of efficiency experts. Didn't you get that memo?
I saw something on the discovery channel the other night that mentioned the same thing, it was called ocean mysteries or something similar...
Showed how if the planet got just a wee bit warmer, it would frell with the ocean's thermal regulation system and frell it up for a while...
And yes, just a drop of a few degrees will really frell things up! Look at the florida citrus farmers - they are teetering on the edge now. they can't exactly move further south when they want - even a slight freeze, and their fruit is worthless...
if rivers freeze at the wrong time, it could interfere with salmon spanning and the like, causing small cascades in the food web. Oh nature as whole will handle it, though we will suffer during the adaptation...
After all, even one degree is the difference between freezing and melting point, no?
won't put us into what we think of as an 'ice age'
Are you aware of what an ice age is? An ice age is characterized by summers that aren't hot enough to melt back the advancing ice sheets that developed over the winter. 1C - 2C changes in temp can affect this to some degree. The thing with long ice ages is that they are measured in geographic time, so even a few feet advancement a year can leave much of North America under ice in several tens of thousands of years.
The global economy is a great thing until you feel it locally.
Read the damned article. The ice age may be caused by global warming via changes in ocean salinity.
The climate is a chaotic nonlinear system. The results of twiddling its parameters may be counterintuitive or unpredictable. There never seems to be any shortage of armchair climatologists who can't comprehend this fact.
... that it is us causing this?
Almost everyone knows that the Earth's climate shifts over time, sometimes dramatically. What is still unclear (despite best efforts of people to firmly convince you one way or the other) is how much impact human activity has on the climate. Volcanic emissions dwarf global emissions due to human activities, for some gases and chemicals. The past has seen dramatic climate changes without humans having anything to do with it
The question is not if we are bringing about an ice age or a warmer period (depending which scare of the day is going around). The question is if we are accelerating the change and by how much. If we bring an ice age about 100 years sooner than it would have occurred naturally, it hardly matters in the long run (but this generation might think otherwise). I believe in cutting back emissions and energy usage, cleaner factories and recycling and all that. But I am tired of the "we are killing the Earth" line.
If construction was anything like programming, an incorrectly fitted lock would bring down the entire building...
You need a long saw / chainsaw and it helps to have an ice auger.
Drill a hole in the ice (at least 8" deep) with your auger - this is your starting point.
Use your long saw (they have speciality ice saws for this used by ice fishermen) to cut away from the hole. Make your cuts parallel from each other. Cut longways before crossways. Make your blocks about 8 inches cubed.
Once you have your first row cut, remove the ice with special tongs made for the purpose. Do not try to remove these by hand as you'll throw out your back and likely end up in your now open hole in the ice.
Work parallel from your hole towards shore, do not work towards the center of the water, and the ice can thin dramatically and quickly (especially over rivers with strong currents).
As a good safety guide, have someone else with you and a large ladder nearby if available.
Once you have enough ice blocks, you will want to choose a place to put them. As heavy as the ice blocks are, it may be tempting to build the igloo right next to where you removed them. This is a bad idea as the finished igloo will be quite heavy and could easily crash through the ice. Be careful to build this over stable flat terrain.
Arrange your first row of largest ice blocks in a circle. It doesn't need to big. The smaller it is inside, the better it will preserve warmth. Once you have the first row done, pack the crevices with snow. Put snow on top of the first row as a sort of mortar. Remember to put a hole for getting in and out!
Add one layer at a time, adding in a small opening for crawling in and out of. The opening needs to in the form of an arch, and no taller or wider than about 1 1/2 feet at most. Just barely big enough to crawl through is good.
As you build up, you can start to discover that you are bring the ice blocks towards the middle. This is the tricky part to get right. Have one person on the outside, and one in. The snow that you have been using a mortar can help or hinder here, depending on where you got it. Try to find stick snow
Cap the igloo. For your first igloo, this can be pretty tricky. If you have built it tightly, it will lean in on itself and support itself. The top piece needs to be a pressure fit piece. For this, you'll want to start with a bigger piece and cut it down to size.
You can also build an igloo out of snow, the process is much the same, but not all snow can be used for this.
Finally, pack all the crevices with snow. This will help preserve warmth and keep the wind out. All things considered these things are actually pretty comfortable for winter camping.
Remember, your just building a big Roman arch, get help, and you'll be fine. It helps to bring ice fishing gear to go ice fishing when your done:)
So now we have two ways to prove that CO2 is affecting the climate of the Earth:
The Earth's climate is getting warmer.
The Earth's climate is getting cooler.
Whichever we see, we know it was the fault of CO2, right?
If only Compaq hadn't EOL'd the Vax, we might have easily laughed off a puny 10 degree drop in avg winter temperatures. Is it any wonder southern California is a desert? You youngin's might not be aware of it, but 50 years ago it was a tropical paradise. About that time, California universities and colleges started ordering various DEC computers, and the damage was soon irreversible.
I kid you not, last year NASA published an article claiming that from the years 1976-1984, that side of the planet actually heated the sun, not the other way around.
Our only chance, is to pull as many MicroVaxen as we can out of retirement/storage, and strategically place them throughout the North Atlantic. If we start soon, maybe we can end this ice age before it even begins!
But if you ask me, I think global warming is the trend.
Hey Sherlock, how about you take your foot out of your mouth and read the article? The issue is that global warming *is* melting the polar ice caps, which in turn could cause a local cooling effect in northern Europe -- to the point of ice age.
That global warming doesn't make it hotter everywhere is old news, too. The BBC wrote about about this exact scenario (temps up --> ice melts --> atlantic currents change --> temps down...) years ago. It plays out with a rapid & general failure of agriculture across the British isles and western Scandanavia, due to massive increases in snowcover.
(There is some debate about how the Gulf Stream moving south from the British Isles to Iberia would affect the weather in Spain, and Portugal. One camp thinks it would bring traditionally British rains; another argues the local heating effect of the Gulf Stream would rapidly create more arid/desert conditions. Either change devastates local agricultures however, destroying traditional grape & olive industries of the region.)
Note that from 1965-1990 (a period of a general mild warming trend globally, depending on whose graphs you look at), the North Atlantic went through a period of exceptional salinity, especially on the eastern seaboard. The article makes no attempt to comment on this.
What it raises alarms based on are the last 10 years of data, in which the North Atlantic appears to be abnormally fresh. Unfortnately, we have no centuries-long data series for seawater salinity at depth, so what the article really means is "fresher than we've seen in the last 40 years," not "fresh is a manner that is historically significant."
But we've been dumping carbon in the atmosphere all century long. If human activity is to blame for the recent freshness, how can we explain the previous salinity when the human activity in question has more or less continued unchecked throughout the whole time period?
Personally, I think the truth is scarier than any environmental alarmism can paint. Articles like this would have you believe that
The climate is a delicate balance that can change suddenly.
Human activity can cause such changes.
Such a change appears imminent.
Therefore we should stop certain human activities to avoid the disaster.
All fine and good, but the truth is more like
The climate is a delicate balance that can change suddenly.
Human activity can cause such changes.
So can a whole lot of other stuff.
Supercomputers and all, we still have minimal understanding of how the climate actually works.
It's possible that major climatic change could happen within the decade as a result of human activity.
But ceasing that activity might not make a difference.
In fact, for all we know, ceasing that activity might at this point cause a climatic change that otherwise would have been avoided.
Chaotic dynamics can make you want to go run to mommy sometimes.
Now may be such a time.
While the difference of 5 to 10 degrees may not sound like much given the range of temperatures that we experience in Europe or North America just in a single day much less throughout the year, an average drop of 5 to 10 degrees is very significant and would create agricultural havok.
Crop plants are very sensitive to climative changes and have particular temperature/rainfall ranges in which they thrive. Make the local weather a little too hot, a little too cold, a little too wet or a little too dry and suddenly your fruit trees fail to produce, your vegetables wilt and your grains fail to pests, if they growq at all. Minor changes in the average temperature greatly effects the success of fungus and insects in damaging crops, allowing them to spread into new regions.
To put this into better perspective, during the peak of the last ice age, 18,000 to 20,000 years ago, the average temperature in was about 9 to 12F cooler than today. Even an average change half of that would create dramatic changes in natural plant distribution.
During the so called Little Ice Age from 1650-1850, a 3F temperature drop caused serious crop failure in Europe, leading to famine and disease. And that is just a 3F degree average drop.
Animals are also effected my temperature changes. Here on the Pacific NW coast, salmon require stream temperatures to be within a very delicate range in order to spawn. This is why cutting down trees (which shade the streams) causes a decline in salmon runs. That's just one of many examples.
Humans are much more adaptable to climate change than most other plants and animals. But with 6 billion+ mouths to feed, its not quite clear how we'd adapt to a climatic problem of this kind of scale.
As for the ocean conveyor belt, it naturally seems to have some tiny warming and cooling cycles which in turn effect rainfall and storm formation in many parts of the world. For a nice overview, go here: Climate Rides on Ocean Conveyor Belt. Over the past century+ a 20-year cycle of minor warming and cooling has been found in the conveyor belt, and supposedly the conveyor belt should be in a strong cycle right now, based of previous trends. But is it?
If global warming (natural cycles or man-made) causes too much melting of the Greenland glaciers, all of that extra fresh water poses quite a risk to the ocean conveyor belt.
Perhaps what we should be saying about the steady warming that has happened over the past 150 years is "enjoy it while it lasts."
I spent all of those years as Anonymous Coward and all I got was this lousy number (204976).
I remember watching videos on how to build igloos in elementary school. They're pretty easy, actually!
1. Make sure the snow is really hard on top, and at least 4' deep. Make sure you're wearing your snow-shoes or you'll fall through!
2. Use a long, thin, "snow-cutting" saw to cut the snow into curved-rectangular blocks.
3. Starting at the base, line the outside of the igloo with the blocks, being sure to leave room for a doorway. You'd be surprised how many hosers forget this!
4. After each layer, have a beer. This only works if you drink Canadian beer. That's MOLSON Canadian, not that "Canadian budweiser" crap. You can rest your beer on the ice blocks to keep it cold.
5. As you get to the top and can no longer reach high enough to put any more blocks up, just give up. Who needs an entire igloo anyway? That can be your "breathing hole".
6. It'll still be freezing, because this is Canada, after all. Build a fire inside your igloo.
7. If your hole isn't big enough, some of the ice on top will melt. This is normal. If your entire igloo melts, it's too warm for igloos right now. Wait until igloo season.
8. Since there's no power outlet, you won't be able to watch Hockey Night in Canada in your igloo. Go back to your house and watch it there.
This is what I can remember from grade 3, so don't quote me on anything.
I am working on a master's degree in Oceanography...and I have studied the subject a little bit.
n ode8.ht ml (American Geophysical Union)/ sem-abs95/ASc hiller.html (Aussie coupled ocean-atmosphere-ice model)
The global thermohaline circulation, better known as the great oceanic conveyor belt, transports warm, salty water from the equitorial pacific ocean to the far North Atlantic via the Agulhas Current (south Africa), North Brazil Current, and the Gulf Stream. In the southern hemisphere, water temperature at the surface is essentially 0 C at 60 S latitude. In the north pacific, the same is true at 60 N latitude. In the north Atlantic, at 60 N latitude, the water temperature west of Greenland is 0, and the water temperature east of Greenland is +10. This warm water is the reason that Norwegian fjords are ice free in winter, despite the fact that they are located far north of the arctic circle. It is also why Labrador, Canada and Iceland have wildly different climates, despite their being near the same latitude.
During the boreal spring through fall, the (relatively) warm, salty water enters the Norwegian, Greenland, and Labrador seas. When winter sets in, winter storms cause the surface waters to cool (through mixing and heat flux into the atmosphere) until the water is of constant density to depths of 1000m or more. Further winter storms cool the surface waters even further, making the surface waters more dense than the deeper waters. Under these conditions, oceanic deep convection occurs. Deep convection is a rare thing--it only occurs in 6 places worldwide. Most of those are in the northern North Atlantic (Labrador Sea, Greenland Sea, Irminger Sea, Norwegian Sea). One is in the Mediterranean (Gulf of Lyons) and one is in Antarctica (Weddell Sea).
Oceanic deep convection is a fragile thing. There are three conditions that must be met before it can occur: A closed, bounded circulation; weakly stratified or unstratified water to depth; and sudden density change (e.g. rapid cooling at the surface). If any of these conditions is absent, deep convection cannot occur. This is why global warming presents a problem to the conveyor belt--fresher water from melting glaciers, melting multi-year sea ice, and increased rain and snow sits on the surface, but even though it might be strongly cooled, the density will not change enough for this cooled water to sink to depth. If the surface mixed layer is only 50m deep, and the layer below the surface mixed layer is cooler saltier than the surface layer, then even if the surface layer is cooled to the same temperature as the next layer, *it will only sink to that same level*. That is, 50 m. Here, deep convection is not possible.
If the conveyor belt stops, then we have a thermohaline catastrophe. In thermohaline catastrophe, then certainly the climate of western Europe would change dramatically. A lot of models are being run on this. They are trying to couple the atmosphere, ocean, and sea ice, and are running simulations such that 2x, 4x, and 8x the present level of CO2 is in the atmosphere. Thermohaline catastrophe occurs in a few of them, and doesn't occur in others. In some, the conveyor belt fails for a few years, but then starts up again as the a salinity gradient develops between the tropical oceans (where evaporation is high) and the subpolar oceans.
There is one other weak link in the conveyor belt--the Agulhas current. The Agulhas winds down the east coast of South Africa before leaving the coast, heading south, and then bending back east again. Occasionally the current sheds warm, salty Indian Ocean eddies into the south Atlantic before bending back on itself. These eddies, called Agulhas rings, transport heat and salt from the tropical pacific into the Atlantic basin. A Dutch-South African experiment (MARES) tracked a few of these rings for a while. The Dutch team came to the conclusion that if the Agulhas ring-shedding breaks down, that there is a risk of thermohaline catastrophe.
Here are some websites with a bit more info:
*http://earth.agu.org/revgeophys/schmit01/
*http://kellia.nioz.nl/mare (MARES experiment)
*http://www.marine.csiro.au/seminars
----yellowcat >- ??
yellowcat ^_^ ??
This is a common misconception. Just because its hard to understand small parts of the system, does not mean that it is impossible to understand the whole system. For example, heisenbergs uncertainty principle states that you cannot know the exact position or velocity of a single subatomic particle. however, if that subatomic particle happens to be in my car, and im going down the freeway at 60 mph, and ive got my gps on, Ive got a pretty good idea not only of its position and velocity, but the position and velocity of its surrounding particles. Each particle is going to have lots of other velocities due to heat, collisions etc, but I know that at least one component is 60mph. My point is, its hard to predict what the weather is going to be like tomorrow, its relatively easy to predict what the weather trend is going to be, warming cooling, wetter, drier. Take el-nino for example. We know that when el-nino occurs, it will be a milder winter. We dont know that its going to snow on the 21st of december in buffalo, but we do know that when the winter is over, buffalo should have recieved less snow than normal.
Now go take that bad mood and your dumb joke and shove it somewhere else.
Bleh!
but are still unclear as to the cause of the southern yearly iceage
Thousands upon thousands of penguins living in the southern polar cap. They constantly inhale and exhale the cold air there. Every time they exhale, the air move a little bit north (as everyone of them is always facing north). After some months the whole polar air mass is above the southern continents and it takes another three months for the tropical heath to disperse it. At the same time the penguins are hibernating. Then the penguins wake up and start moving the air again.
An international consortium formed by Autralian, Brazilian and South African tourist industry representatives have a project to kill all penguins (bringing an ethernal summer to the region), but they are being prevented from implementing it by the Greenpeace and a bunch of Linux zealots.