[nocar]

Having lived most of my 64 winters in Stockholm Sweden, I would say we currently have an entirely normal winter, but more on the warm side than the cold. In the first week of 2009 we hade a cold snap which created great skating on the lakes, but already we are back up to melting temps. That is warm for the middle of January, actually several degrees Celsius above the mean. Although varying temps is entirely normal too.

nocar

[dohboi]

An ice age is pretty damn unlikely with atmospheric concentrations of CO2 around 400ppm and the Arctic icecap about to collapse. Remember that this is already far higher than any time during the last million or so years, during which there were many ice ages and warming periods.

The only mechanisms that might be strong enough to do anything like this that I can think of are the ones I mentioned--dimming and especially shut down of thermohaline circulation. But any of these would likely be temporary, given the feedback loops that are already being set in motion.

As was mentioned on another thread, the main trigger for previous alternations between ice ages and warming periods was the Milankovitch cycle. As I understand it, this represented a rather week forcing that triggers feedback loops one direction or the other. Since, as I said, we are already into feedback loop mode, I doubt that Milankovitch is going to play much of a roll any time soon.

My general impression is that most folks in the discussion so far are not interested in considering such messy and complex details. Please prove me wrong.

By the way, V, as far as I have heard from climatologists, the sudden deep freeze from cyclone-like spirals bringing stratospheric cold air down to ground level is the least probable climate shift depicted in the film. (And of course a mega tsunami is not the way anyone I have heard of envisions sea levels to rise. But these do make for good cinema, if only the acting and plot were a bit better.)

[Heineken]

I've lived in Maryland, the District, and Virginia for the past forty years. During that period I've noticed an unmistakable, pronounced warming trend, year-round. And I've always been a close weather watcher.

My earlier years here were full of snow---big snows, one and two feet. The ponds froze over and I ice-skated and played hockey on them. Now it virtually never snows, and when it does it's an inch or two or a dusting. Ponds get at most a skin of ice.

The summers are far hotter and we have terrible droughts.

I can't speak for where you live, but that's the way it is where I live.

This region is a good indicator of climate change because it tends to sit on the rain/snow line. Or used to.

[FrankRichards]

So, what do you guys think? I know the Ice Age scare went around in the 70's too, before people got on the global warming bandwagon. Now cold winters in 07, 08, and likely 09 have folks talking ice age again.

Huh? The winter of 06-08 was record setting warm. o7-08 was cooler than that, but still warm. This year so far is 1990s normal, not cold to anyone who's lived here a while.

[Byron100]

I grew up in the Piedmont region of North Carolina, and I can remember some big snows (1 foot +) back in the 70's and 80's which doesn't seem to happen nearly as often these days. Don't remember droughts being nearly as bad back then either - now, we seem to have them 4 years out of 5.

Bring on the new Ice Age, I'll gladly take that over this nasty global warming any day...hehe. Of course, it might give me pause in regards to my plans to relocate up to central New York in the near future.

At least the long-running north Georgia drought is on hold, for now.

[dissident]

The Day After Tomorrow was a comedy spoof on science. Really now, super cool air descending into the troposphere and flash freezing everything in sight. Hollywood is world famous for its mangling of science. Some details that might clear up this particular piece of nonsense:

The atmospheric density falls off exponentially with height. So bringing air from stratospheric altitudes involves quite a bit of compression and hence temperature increase. For the rapid descent shown in the movie we can safely assume nearly adiabatic conditions. Then you can use the potential temperature distribution to assess how much temperature an air parcel would have at the surface given its current location in the stratosphere: T_p = T(p_surf/p)**(2/7). if air was brought from 40 km down to the surface in a matter of hours, it would have a temperature of 2000 K.

Temperatures inside the Antarctic Polar vortex reach below 180 K during winter. There is no indication of any mass flux associated with these temperatures. All of the downward mass flux in the polar vortex is driven by dynamics: gravity wave drag and Rossby wave drag. The air in the middle atmosphere is heated through the absorption of UV by ozone which thermalizes this energy through molecular collisions. CO2 is the primary cooling agent in the middle atmosphere as it is a strong infrared emitter (goes together with being a good absorber).

I know that O3 loss and CO2 increase are mixed up in the public mind thanks to bad media coverage of both issues. But we are not going to lose all of the O3 in the stratosphere, especially if we still have O2 available. The CFC chlorine problem has been dealt with. In any case, the upper atmospheric layers would not go to absolute zero even if all of the O3 magically disappeared. There is still some H2O and CO2 which would still be absorber gases, giving a colder middle atmosphere but with temperatures well above 100 K. So the silly Day After Tomorrow scenario would involve air over 1000 K hitting the surface. So it would never happen since various dynamical adjustment procesess (eg convection) would kick in to disrupt the descent.

[Revi]

It sure feels like good old fashioned winter around here. We had a lot of snow last winter, and this winter is shaping up to be similar. The snow is perfect for skiing. Lots of really hard styrofoam consistency fell early, and now it's all powder on top.

Yesterday was one of those perfect blue sky days. I snowshoed to the top of our woodlot and saw Mt. Washington, the Longfellow Range and Sugarloaf. Easily 100 mile visibility. The temp was around 22 degrees with no wind at all.

Winter can be really nice from here on in.

February brings more of those bluebird days around here.

[Heineken]

Byron, we're well hydrated too, finally. It's nice to see water flowing over my dam.

But I read La Nina is still not done with us.

[Tanada]

So, what do you guys think? I know the Ice Age scare went around in the 70's too, before people got on the global warming bandwagon. Now cold winters in 07, 08, and likely 09 have folks talking ice age again.

I'm reminded of Colleen McCullough's pretty good novel _A creed for the Third Millenium_, a story set in a post 2000's America struggling with the descent of a new ice age.

For those more knowledgeable than myself, perhaps you can answer a question for me. If the Holocene period is ending and we are indeed returning to Ice Age, what would be the progression timewise? How long for the norhern US to be uninabitably cold and such? And how long for ice sheets to form and grow?

The proxiamat cause of glaciation is lack of warmth in the summer, not extra cold in the winter. It doesn't matter if it gets down to -40 degrees every day of the winter, if you have any period of about 90 days where temperatures are above freezing the snow that falls in that extreme cold period will all melt. Look at the Tundra region bordering the Arctic Ocean, it gets colder than I want to live in every year, but every spring all the snow melts to form lakes and bogs. The first sign of a new glaciation will be when the Tundra regions quits melting completly in the summer. Even an inch of snow left over each year will build and build and build until it makes a glacial ice sheet after a few hundred years.

However even back in 1816 when volcanic ash and sulfates caused the 'year without a summer' and it is recorded that snow fell in June in many places in the USA and Europe, the snow all still melted before winter set in with the real cold weather. The crops were ruined and most people were hungry at least part of the time but none of the summer snowfall stayed throughout the season, at least in the inhabited parts of the USA and Canada. That was also during the Little Ice Age which lasted into the 1850's by most estimates, so if we couldn't get snow to stick in 1816 when the whole globe was colder I don't think we will be seeing it stick all summer any time soon.

[frankthetank]

This is your future... Check out what it will be like soon to walk out your front door...in Houston, TX

http://www.youtube.com/watch?v=qz2SeEzxMuE

Couple of early Jan maps...
Jan 1-8 AvgTemp Departures
Map (large)

This map will look a lot different by next weekend.


Edit: Converted [img] to [url].-FL



I don't see an ice age quite yet. If a volcano erupts, all bets are off.

[PrestonSturges]

Waah! There was ice in my freezer the morning!

I'm going to run out and buy a malumute. I hear there's a new big box outlet called Malumute Warehouse out on the interstate.

[StormBringer]

Growing up in Mo. we get a bit of everything here from bitter cold in winter to extreme heat in summer. But I remember as a child snow measured above the foot mark, and I haven't seen that in a long time. Admittedly the temps are colder than average but the snow fall is much less. ANY IDEAS? WHY THE COLD YET NO SNOW?

[Lore]

Growing up in Mo. we get a bit of everything here from bitter cold in winter to extreme heat in summer. But I remember as a child snow measured above the foot mark, and I haven't seen that in a long time. Admittedly the temps are colder than average but the snow fall is much less. ANY IDEAS? WHY THE COLD YET NO SNOW?

Yes, I do, and I don't mean to sound trite here, but what you're experiencing is "weather". Being aware of climate change doesn't automatically cancel winter weather even though its effects may make weather more chaotic then normal in nature.

The decadal trend is still on track for the anticipated 0.2ºC/decade increase in temperatures. It's no suprise that a fractional increase such as this would mean it still gets fairly cold when it should. However, as current observation would tell us, the bigger picture suggests that the planet is very sensitive to even these minor increases in temperature.

[bratticus]

Earth on the Brink of an Ice Age

Prada.ru
January 11, 2009

The earth is now on the brink of entering another Ice Age, according to a large and compelling body of evidence from within the field of climate science. Many sources of data which provide our knowledge base of long-term climate change indicate that the warm, twelve thousand year-long Holocene period will rather soon be coming to an end, and then the earth will return to Ice Age conditions for the next 100,000 years.

...

The [global warming] theory is based on data that is drawn from a ridiculously narrow span of time and it demonstrates a wanton disregard for the ‘big picture’ of long-term climate change. The data from paleoclimatology, including ice cores, sea sediments, geology, paleobotany and zoology, indicate that we are on the verge of entering another Ice Age, and the data also shows that severe and lasting climate change can occur within only a few years. While concern over the dubious threat of Anthropogenic Global Warming continues to distract the attention of people throughout the world, the very real threat of the approaching and inevitable Ice Age, which will render large parts of the Northern Hemisphere uninhabitable, is being foolishly ignored.

[Fredrik]

How about Sweden? Any difference there?

Answer: Yes much colder then the last 3years. but winter isnt over untill late march-mid april. But sure as hell feels like we are in for 2 cold months. Last year we barely saw snow in stockholm.

Here in Finland this winter and the two previous have been warmer than usual, aside from a few and short cold spikes. By contrast, summers 2007 and 2008 have been cooler and wetter than average.

I read somewhere that there is a cycle in the North Atlantic circulation system that is now in the cold phase, which should end around 2015. If that's true, with all the carbon dioxide and methane emitted into the atmosphere by then, the warming for Scandinavia might be very abrupt.

[Bas]

Is a new Ice Age upon us?

it's called winter, happens almost every year

[Tanada]

I found an excellent video lecture which gives a great review of Milankovitch cycle theory and explains why it is very unlikely we will enter a new ice age for at least 50,000 years and if we burn all the conventional Petroleum, Natural Gas and Coal our next glaciation is delayed 400,000 years. Oh yes, you need Realplayer to watch it if you don't already have it.

Climate lecture

[dinopello]

I remember reading a fiction book called ICE! back in the early 80's that probably came out of the 70's Ice Age talk. It was a good read. Basically, the climate system went unstable and following one of the hottest summers, the Glaciers/Ice Caps started growing and reached a tipping point in a month or so and the city (Buffalo ?) was pummeled by glaciers. The story lines were all about adaptation. The domestic dogs quickly formed packs and fed off the weak, the wife of the main character adapted to eskimo ways, but the main character - a scientist couldn't adapt, was left behind and was killed by the Glacier.

[GoghGoner]

sixstrings or any other cooling believer,

Care to make a wager on whether the annual mean temperature anomaly based on NASA b/w 2009-2015 exceeds one of the top 4 years? I haven't figured out the probablity but the odds are greatly in your favor if we are in the cooling trend that you contend.

$150/ 6 month locked in an account administered by a neutral third party. If at any point, the other person doesn't pay the ante then the money goes to the other person. The bet continues until the temperature data comes back for the year 2015 if neither party drops out. So the winning purse will have a min value of $150 and a max value of $2250. Initial deposit immediate and then on 6/30 and 12/31 of each year.

Based on GISS, the anomaly must exceed 0.56

1995 .38 .29
1996 .30 .38
1997 .40 .39
1998 .57 .38
1999 .33 .42
2000 .33 .45
2001 .48 .45
2002 .56 .48
2003 .55 .54
2004 .48 .55
2005 .62 .55
2006 .55 .53
2007 .57 *
2008 .44 *


GISS Data

[vision-master]

Our solar system is heating up.

Peak Sun is 2012 time frame.

The ice age was caused by a very large impact from outer space.

No ice age here.......