The Two-Mile Time Machine (What if global warming sparked a new Ice Age?) some amazing stuff.....

The Two-Mile Time Machine
Ice Cores, Abrupt Climate Change and Our Future, by Richard B. Alley
reviewed by ED HUNT

What if, instead of a slow linear increase in global temperatures, our climate changed so quickly, it was as if someone had flipped a switch?

What if I told you that predictions of a gradual global warming over the coming decades are really conservative, best case scenarios for human civilization -- that in truth we might not have the luxury of taking years to address greenhouse gas emissions or to adapt to changes in global temperatures.

In fact, we now know that climate throughout the Earth's history is incredibly variable -- big changes come suddenly.

As Pennsylvania State University geophysicist Richard Alley explains in his book The Two-Mile Time Machine Earth's climate is in a relatively boring period right now. Climate wise, these last millennia have been the best of times for human kind. But that could all change, very, very quickly.

Conditions have been just right for us to develop agriculture, civilization and even industrial globalization. We've known for some time now that the climate of the Earth used to be different, but it is only recently that we've come to understand the history of our planet in a way that gives us a glimpse of our future.

"Interpretation of ice cores, and of many other climate records has recently revolutionized our view of Earth," Alley writes. "We once believed that the climate is well-behaved -- a little change in the brightness of the sun or the positions of the continents, or the composition of the air causes a little change in the climate. The ice cores tell a more complicated story."

"Sometimes, a small "push" has caused the climate to change a little, but other times, a small push has knocked the Earth's climate system into a different mode of operation, bringing new weather patterns to much of the Earth in only a few years or decades. To scientists accustomed to changes over geological time, it is almost as if someone had flipped a switch to change the climate. Sometimes the climate jumped back and forth a few times before settling into one pattern, almost as if the person flipping the switch were an impish three-year-old. The climate jumps have been much larger, quicker and more widespread than those that chased the Greenland Vikings and the Oklahoma farmers from their homes -- or those experienced by any other agricultural or industrial humans. Were such changes to occur today, the consequences could be severe."

The Time Machine referred to in the title of Alley's book -- and the source of much of this disturbing insight about our past climate -- are ice core samples removed from glaciers in Greenland and Antarctica. All glaciers are made up of annual snowfalls that don't melt off in the summer. However, the best glaciers for recording past climate may lie in Greenland -- where the cores are drilled two miles down -- and thousands of years into our past.

"In Central Greenland, snow falls frequently throughout the year. The sun never sets in the summer and never rises in the winter. Winter's snow is buried without experiencing sunshine, but summer snow is "cooked" by the intense summer sun. This solar heating changes the snow, making visible layers."

So like the rings measuring a tree's growth, the annual layers of a Greenland glacier can be examined to tell us much about the ancient climate.

Two-Mile Time Machine is more than a fascinating scientific revelation, however, it is also a excellent bit of science writing. It is easy to see why Alley has won awards for his teaching as well as his research. Alley packs information into your brain almost effortlessly. The voice -- occasionally slipping from the explanatory to the experiential -- can be evocative, like when he describes the site of the ice pits dug during the 1990s to view the layers of ancient ice in Greenland.

"I have stood in such snow pits with dozens of people -- drillers, journalists and others -- and so far, every visitor has been impressed. The snow is blue, something like the blue seen by deep-sea divers, an indescribable, almost achingly beautiful blue. Water, whether liquid or ice, absorbs red light a bit more than blue. Let the light penetrate tens of feet into the ocean and the red is filtered out, so only the blue reaches your eyes. In snow, a ray of light passes through a tiny crystal, is bent, goes through another, bounces off another and so staggers its way to the viewer, going much farther than the straight line distance to the eye. On the way, the red is lost and the result is a beautiful blue."

Just how much scientists can divine from these ice cores in astonishing. Tiny pockets of air locked into the layers of the ice reveal the gaseous mixture of the ancient atmosphere. They can tell how much methane and CO2 built up before the climate flipped. The thickness and composition of the ice gives clues to weather and temperature. They can even see evidence of human activity -- the burning of leaded gasoline during the middle part of the 20th century for example.

Alley's ice core time travelers corroborate their findings with other indicators -- samples of sediments from the bottoms of undisturbed ancient lakes for example. The result has been startling even to the scientists conducting the research. Armed with a year by year history of our climate over the past 110,000 years, many of our assumptions about the climate of the earth wind up shattered.

Alley and his team made headlines recently by revealing that the last ice age ended very abruptly -- within a year or two. Yet that finding only hints how variable the climate of our planet really is.

We tend to think of climate changes as happening on almost a geological time scale -- too drawn out for humankind to notice. Global warming of perhaps only one degree average change over 100 years has been so slow, that some still refuse to believe it is occurring.

It turns out, the reason we have this perception is that over the last 11,000 years our climate has been very stable. The machinery of global ocean and air currents, biology and geology have been acting like an efficient thermostat, regulating the temperature of the planet to keep things optimized for humans to develop agriculture -- and civilization.

Yet in the mind of the planet, this short 11,000 year period is the exception, not the rule. Prior to the stability that set in, climate varied into Ice Ages and warming periods. In fact we've actually been in a long warming period for thousands of years now.

However, prior to 11,000 years ago, climate patterns swung like a pendulum between warm and cold periods. On the edge of these shifts, the change could be sudden and abrupt. An ice age could move down upon the land in as little as a year or two -- and disappear just as quickly.

Try to wrap your mind around what such a variability would mean today. As Alley notes in his opening chapter, imagine "if you went to bed in slushy Chicago, but woke up with Atlanta's mild weather. Or worse, what if your weather jumped back and forth between that of Chicago and Atlanta?"

"Large, rapid and widespread climate changes were common on Earth for most of the time for which we have good records, but were absent during the few critical millennia when humans developed agriculture and industry. While our ancestors were spearing woolly mammoths and painting cave walls, the climate was wobbling wildly. A few centuries of warm, wet, calm climate alternated with a few centuries of cold, dry windy weather. The climate jumped between cold and warm not over centuries but in as little as a single year. Often conditions "flickered" back and forth between cold and warm for a few decades before settling down."

"The jumps have occurred in Earth's wildly complex, linked, feedback-dominated climate system in which atmosphere, oceans, ice and land surface and living things interact with each other and with the solar system to drive weather forecasters and climate scientists to distraction," according to Alley.

Using the crystallized timeline of Greenland ice cores as a back drop, Alley explains that the climate of the Earth is controlled by a number of "dials and switches" that can be turned and flipped by various actors. These dials and switches control the energy the Earth receives from space and the heat transfer system that moves warm air from the equator to the northern and southern parts of the globe.

One important such switch is the North Atlantic conveyor -- an ocean current system that allows people in England "to grow roses as far north as Canadians find polar bears." The conveyor of ocean currents actually circulates around the globe through the Pacific and Atlantic oceans. In the North Atlantic it brings warm water from the tropics very far North -- thus allowing Northern Europe to grow crops.

As the conveyor warms the coasts of England and Ireland, however, the water loses some heat. It becomes colder -- and through evaporation -- saltier. This now cold, salty water is dense and it sinks deep into the depths of the ocean before it can freeze, thus turning the wheel at the end of the conveyor belt and sending a deeper flow of cold water back south.

What happens if the conveyor belt shuts down? Well, it gets a lot harder to grow roses -- and "groceries" -- in Europe that's for sure. Indeed, "polar bears might just replace roses in the north of Great Britain," Alley explains.

How do you shut down the global conveyor belt? The best place to disrupt the belt is by "sticking a fork" into where the dense salty water falls -- the North Atlantic. If you make the water less salty -- it becomes less dense and therefore, cannot get cold enough to sink. If it doesn't sink, the conveyor belt slows or stops. No more warm water from the equator distributed into the Northern climes. No more roses or groceries in Northern Europe.

For those concerned about global warming, this is where things get seriously scary. Add a little more fresh water to the north Atlantic -- say in the form of melting ice, rainfall or river runoff -- and computer models show that this is enough to jam the conveyor -- slowing it or stopping it.

Ice cores, tree rings and sediments indicate that the balance of conditions keeping the conveyor going is delicate. In the past the conveyor has been slowed and stopped, and when this happens, the climate in the North suddenly gets very cold very quickly.

So if global warming puts enough freshwater into the North Atlantic a switch could be flipped and we may suddenly find ourselves in an Ice Age -- possibly struggling through a period of variability as the climate staggers back and forth along the way.

As Alley writes, "...climate may be like a drunk -- when left alone; it sits, when forced to move, it staggers."

For all of human history, the Earth's climate has been somewhat stable, sitting, but as greenhouse gasses collect in the atmosphere and the Earth's global temperature rises, we may be closing the bar, forcing the drunk to get up and move along in his unpredictable, sudden and lurching way.

What if, instead of a slow linear increase in global temperatures, our climate changed so quickly, it was as if someone had flipped a switch?

I'd tell you that your hot air has hit a cold brick wall.

Actually, there is plenty of evidence that we are living in a relatively stable and pleasant period. However, the idea that our own efforts will produce an abrupt change is typical of the doomsayers which we have come to know and love.

imagine "if you went to bed in slushy Chicago, but woke up with Atlanta's mild weather. Or worse, what if your weather jumped back and forth between that of Chicago and Atlanta?"

Translation: After decades of studying the climate, these people STILL don't know what they're talking about. Ship these turkies off to Kyoto and make them stand in the corner until they make up their minds.

I'm reading a novel right now, "Fallen Angels" (Larry Niven, Jerry Pournelle, and somebody else), that partly deals with some of these same issues. It's about an ice age starting. The great thing is that it's the enviro-whackos who are the targets! Also it's a very amusing book for science fiction fans, but it's right on about most of the problems we have being not the results of anything we do. Some of the suggestions in the book for dealing with the ice age including burning more fuel to try to start 'global warming', but the Greens won't let them do it.

It's a great counter to the whole global warming scare, anyway, and a pretty decent story. This article just made me think about it.

Thanks for posting this!

Translation from the enviral green liar who wrote this.

Our big lie about Global Warming is about to be proven wrong with hard scientific data. So we have to quickly change our lies to say that a short and intense Global Warming is now causing a new ice age. We will go back to the warnings of the new ice age of a few years ago before we went to Global Warming Hysteria to weaken America.

Regardless of the cycles of change we will continue to blame capitalism and America for whatever short term cycle of weather we are in. Send money to Club Sierra, and other Watermelon Enviralist organizations. We need your money to harass GW and to weaken the American economy!

Now support the Kyoto Agreement/non Treaty to prevent Global Freezing due to the evil Americans and GW!

The somewhat unnerving variability of climate recorded in Greenland is real.

The bogus attempt to link this fact to "global warming" politics looks like a stab at ensuring continued funding and political leverage for the lefties if temperatures start to cool instead of warming. Since temperatures are just about always rising or falling to some degree, this is a pretty safe gig. A more appropriate response would be massive defunding of politially-driven, Soviet-style science...

The somewhat unnerving variability of climate recorded in Greenland is real.

I've read such as this before. And I find the likelihood of rapid climate change quite plausible once the "switch" is flipped.

But as for what these switches actually are, and what causes them to flip, who can say.

I CALLED THIS ONE THE OTHER DAY!!!!!!!!

There was another thread about the possibility the earth was COOLING and I said "I blame global warming for this" !!! LOL I am becoming as precient as my hero Rush, thank you thank you thank you

and somebody else

Michael Flynn

I found what looks like the whole book online: "Fallen Angels"

I'll give it a shot, sounds good.

Yeah, that's the whole thing. Baen's being really cool about epublishing, offering some books online free. Then again Baen tends to have the best (read:semi-conservative) sci-fi these days.

By the way the book isn't nearly as funny if you don't know anything about science fiction fandom. I laughed so hard at the inclusion of the "Yngvi is a louse" joke...

Saw a science special that went into the Ocean/N.Atlantic/Humbolt current. After it sinks it works its way back to the west Pacific deep ocean areas prior to rising again. Water rising now, went sub-ocianic in the N. Atlantic at the time of Christ.

There is so much misinformation and half-truth put forth in this one sentence, it's difficult to even know where to begin to address it all.

What if ignoramuses pushing global warming were shown not to have a clue about the extreme global climate variations in history and the total impossibility of explaining global "warming" in pre-industrialist times past?

For all of human history, the Earth's climate has been somewhat stable,

Most hilarious, ignorant, stupid, uninformed, moronic, idiotic statement of the century...

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