Instant Iceage?

[Knuckledragger]

I'm watching the movie the day after tomorrow and wondered if this was possible over let's say a year? I'm guessing the reality is over thousands of years with the temperature dropping lower and lower and ice creeping slowly across the landscape but is there any instances where a sudden ice age would be possible as in if an asteroid smashed into us, knocked us off our orbit into deep space or if a giant asteroid smashed into the sun and extinguished it?

[jim360]

Not the way it's portrayed in the Day after tomorrow, certainly. If an aeteriod smashes into us, very possibly things can change drastically. It would be less about knocking us off orbit, and more about the massive amount of dust and rubbish blown up into the atmosphere that might blot out the Sun, or disrupt weather patterns, etc.

If an asteroid impact were powerful enough to knock us off orbit, I don't think there would be anyone left to worry about an Ice Age anyway...

[Clanad]

Actually, something of that nature did happen... almost instantaneously... so to speak.

The year 1816 was known as the Year without a summer ( alternately known as the Year of Pverty). A qutoe from one historical document says "...The Year Without a Summer, a peculiar 19th century disaster, played out during 1816 when weather in Europe and North America took a bizarre turn that resulted in widespread crop failures and even famine.

The weather in 1816 was bizarre. Spring came but then everything seemed to turn backward, as cold temperatures returned. The sky seemed permanently overcast. The lack of sunlight became so severe that farmers lost their crops and food shortages were reported in Ireland, France, England, and the United States.

In Virginia, Thomas Jefferson, retired from the presidency and farming at Monticello, sustained crop failures that sent him further into debt.

It would be more than a century before anyone understood the reason for the bizarre weather disaster: the eruption of an enormous volcano on a remote island in the Indian Ocean a year earlier had thrown enormous amounts of volcanic ash into the upper atmosphere.

The dust from Mount Tambora, which had erupted in early April 1815, had shrouded the globe. And with sunlight blocked, 1816 did not have a normal summer..."

Crops failed over most of the northern hemisphere. The phenomena could be extrapolated on a wider, more severe scale if sevral of the known volcanos were to erupt in unison or over an extended period of time...

[Mosaic]

It's worth remembering that we're completely dependent on the whims of the great earth machine. Clanad rightly points out that even in recent recorded history there have been relatively minor temperature changes that have had catastrophic results for human societies.
Also bear in mind that growing and losing ice caps is one the periodic things that happens over great periods of geological time.
A large asteroid strike has caused mass extinction on earth at least once in the distant geological past.
You're correct to assume that most of the time these changes happen very slowly on the human scale.
If the sun were extinguished......always a possibility, but a very remote one, and not one to occupy your thoughts with.
Lots of links to useful geological facts and sites from here: https://sites.google.com/site/geology3408/home

[LazyGun]

It would be impossible for any asteroid to knock earth out of its orbit. it would require something with an equivalent mass to the earth, travelling at some speed, to effect that kind of change, and were that to happen, there would be no one left alive on earth to appreciate any changes in the climate.

Nor could a giant asteroid smash into the sun and extinguish it. The Sun is staggeringly, massively large.

You could fit approximately 1.3 million earths inside the Sun. No asteroid is going to quench that :)

If we had a large enough asteroid strike on the earth or an exchange of nuclear weapons between countries on earth for instance, there has been speculation about a nuclear winter, with the dust and ejecta filling the atmosphere and blocking the suns rays - that scenario offers a prospect of a kind of rapid onset iceage I suppose...

[bibblebub]

we'd only have a few months warning if a rogue planet was headed this way

[LazyGun]

No expert bibble, but I think we would probably spot a wandering astronomical body the size of a planet fairly early on, especially one close enough to the earth that it was on a collision course....

Its the large asteroids and meteorites that are more of a problem to spot..

[modeller]

An Ice Age takes 100.000 years to reach its maximum but only 3,000 years to return to normal temps and sea levels. However the uplift/rebound of land masses continues for millennia.

[jomifl]

Having looked the film up on Wiki, I realised that I have seen it. I thought it was very silly at the time as the physical phenomena were ridiculously exaggerated and inconsistant in relation to one another. Temperatures low enough to cool the building interiors as quickly as they were depicted would probably have required air temperatures lower than absolute zero and at the very least below the boiling point of the atmosphere. A confection of daft ideas cobbled together with misunderstood science....entertaining though with the usual suspension of disbelief.