Showing posts with label Little Ice Age. Show all posts
Showing posts with label Little Ice Age. Show all posts

Tuesday, July 7, 2009

Sea Ice July 2009

The areal extent of the sea ice was around a half million square kilometers larger this year than it was over the past four years. However that has abruptly changed and it is almost as low now as 2007. Most interesting this year is that Davis Strait is wide open already and it is also way ahead on the Eastern side by Russia.

http://www.socc.ca/cms/en/socc/seaIce/currentSeaIce.aspx

What appears different this year to this observer is that the polar ice seems more intact for the moment. That means to me that the Northwest Passage may stay sealed. No bets yet.

The period of maximum attack on the ice has begun and it will be interesting to see just how much it opens up.

Do recall that it was reported much thinner than expected earlier this spring, so these pictures may be misleading.

I will say however, that it is very vulnerable to wind activity.

I notice that I can sail deep along the north coast of Greenland for the first time and that Lancaster is already wide open until you hit the end of Ellesmere.

The attached report is important because it discounts the extent of sea ice decline during the medieval warm period. That may be because of proxy failure rather than reality. However, the strong warming in the early part of the twentieth century kicked of an ongoing cycle of ice retreat with modest recoveries. Therefore the net loss over each cycle is positive for one century.

Up to this point, I was only comfortable that that held true for the past three decades or so. Our present decade is only slightly cooler than the past decade, but it is apparent that the trend line on ice loss is still positive.

We are set up right now, should weather cooperate, for another sharp decline in ice thickness this year, at a time in which there is much less to work with. Again the remarkable and unexpected thinness this spring is remarked.

I hate to say this, but we are on track for open water around the pole in 2012. Nothing has reversed the established trend, and this item has established that the condition has persisted over a whole century and losses now are quite visible and reflect expectations of final breakup.

The Least Sea Ice In 800 Years

http://www.terradaily.com/reports/The_Least_Sea_Ice_In_800_Years_999.html

by Staff Writers
Copenhagen, Denmark (SPX) Jul 03, 2009

New research, which reconstructs the extent of ice in the sea between Greenland and Svalbard from the 13th century to the present indicates that there has never been so little sea ice as there is now. The research results from the Niels Bohr Institute, among others, are published in the scientific journal, Climate Dynamics.

There are of course neither
satellite images nor instrumental records of the climate all the way back to the 13th century, but nature has its own 'archive' of the climate in both ice cores and the annual growth rings of trees and we humans have made records of a great many things over the years - such as observations in the log books of ships and in harbour records. Piece all of the information together and you get a picture of how much sea ice there has been throughout time.

Modern research and historic records

"We have combined information about the
climate found in ice cores from an ice cap on Svalbard and from the annual growth rings of trees in Finland and this gave us a curve of the past climate" explains Aslak Grinsted, geophysicist with the Centre for Ice and Climate at the Niels Bohr Institute at the University of Copenhagen.

In order to determine how much sea ice there has been, the researchers needed to turn to data from the logbooks of ships, which whalers and fisherman kept of their expeditions to the boundary of the sea ice. The ship logbooks are very precise and go all the way back to the 16th century.

They relate at which geographical position the ice was found. Another source of information about the ice are records from harbours in Iceland, where the severity of the winters have been recorded since the end of the 18th century.

By combining the curve of the climate with the actual historical records of the distribution of the ice, researchers have been able to reconstruct the extent of the sea ice all the way back to the 13th century. Even though the 13th century was a warm period, the calculations show that there has never been so little sea ice as in the 20th century.

In the middle of the 17th century there was also a sharp decline in sea ice, but it lastet only a very brief period. The greatest cover of sea ice was in a period around 1700-1800, which is also called the 'Little Ice Age'.

"There was a sharp change in the ice cover at the start of the 20th century," explains Aslak Grinsted. He explains, that the ice shrank by 300.000 km2 in the space of ten years from 1910-1920. So you can see that there have been sudden changes throughout time, but here during the last few years we have had some record years with very little ice extent.

"We see that the sea ice is shrinking to a level which has not been seen in more than 800 years", concludes Aslak Grinsted.

Thursday, January 8, 2009

Arctic Volcanic Multiplier

Piecing together the effect of volcanic activity on the global climate, I recently recognized an oversight. It is that there must be an order of magnitude difference between the impact of an equatorial blast and an Alaskan blast. More importantly, while an equatorial blast has good prospects of affecting the whole globe, an Alaskan blast is going to be limited to the northern portion of the northern hemisphere. This rather obviously coincides with the details of the little ice age.

That also explains the savage impact on climate of the 1159bc Hekla blast that suppressed temperatures for a full generation throughout Northern Europe. It only had to be a much too normal one to three cubic mile event that kept cooking at a smaller scale for a few years to do its job as advertised.

This also makes explaining the Little Ice Age much simpler. Instead of two or three close together, we now need a major volcano that keeps cooking over fifty or more years in the Alaska Russian volcanic arc. Ash and aerosols need to feed into the Arctic weather gyre where escape is difficult and protracted over time. This will induce sharply lower temperatures that then impact Europe.

There is a very good chance that it is a single specific volcano. I say that because there is erratic evidence of a several century long cycle that could easily coincide with the active phase of one volcano. The good news is that we have three or four centuries of good weather before it is heard from again. The bad news is that there are plenty of other volcanoes thinking about it.

Mt Pinatubo in the Philippines impacted our climate for perhaps three years and reduced temperatures by a significant amount. Had it been in Alaska, its effect could well have been multiplied by an order of magnitude and have surely ravaged Europe.

We need to identify an aerosol rich volcano able to charge up the Arctic atmospheric gyre easily and perhaps monitor it if that is not already happening. The known suspects have not been that significant but that only means that the main event is apparently dormant.

This comfortably explains the episodes of radical cooling that have typically occurred in the Northern Hemisphere and cannot be explained as Global in origin or by the more benign Pacific Decadal Oscillation. A three or four degree drop caused by a volcano explains ice on the Rhine, or even the Nile. Fortunately these events are not particularly long lasting most of the time and recovery is pretty predictable. A farmer will have one year of crop failure to deal with before he adjusts to the tougher conditions with more robust crops and we learn to like oatmeal.

By the output been trapped in a small area of the globe, the volcano’s effect on climate is hugely magnified. It fortunately still disperses fairly quickly. The only reason that this is as yet not fully understood is that we have not had the chance to watch it unfold as we watched Mt St. Helens and Mt Pinatubo unfold. We are sure to get the chance.

And yes, let us warm up the earth with reforesting the Sahara. The climate was much better back in the Bronze Age.

Monday, December 22, 2008

Post 1492 Reforestration

Without a doubt, an explanation for the Little Ice Age is a priority item on my personal to do list. Here we are introduced to a factor that I certainly have overlooked and may turn out to be valid. We do not know the real extend of pre Columbian agriculture except to recently recognize that slash and burn was not part of the program.
The early explorers in North America found woodlands and small tracts but that was a century after Columbus and several centuries after a previous economic high. A die off could have progressed generation by generation penalizing organized high density populations whose remnants merged with less organized groups.

The few reports we have out of the Amazon is saying the same thing. The real question is what size of population was necessary to create the warmer original regime as per this theory. Viewed in reverse, it quickly becomes much less convincing and sounds more like an argument in favor of today’s global warming theory.

In the event, strong reforestation was taking place, as is happening today in the East.

I am inclined to think that expanding forests will absorb more of the incoming solar energy and thereby add to the Earth’s total heat.

In any case, this is a factor that is quite real whose effect may be measurable and needs to be accounted for. The problem is that we have a very poor understanding of the impact.

We know that the Bronze Age saw the stripping of the Sahara coinciding with the end of the two millennia climate optimum that was warmer than the present. This is explained easily by understanding that the Earth lost the ability of the Sahara to absorb and hold heat. Since then we have had a well frozen Arctic and a cooler regime in Europe with some warm pauses.

That is why I am a little hesitant to assign an extended little ice age to this cause, but the carbon ratios and the decline in atmospheric CO2 certainly points at a contemporaneous shift in biomass size independent of the weather.

New World Post-pandemic Reforestation Helped Start Little Ice Age, Say Scientists

ScienceDaily (Dec. 19, 2008) — The power of viruses is well documented in human history. Swarms of little viral Davids have repeatedly laid low the great Goliaths of human civilization, most famously in the devastating pandemics that swept the New World during European conquest and settlement.

In recent years, there has been growing evidence for the hypothesis that the effect of the pandemics in the Americas wasn't confined to killing indigenous peoples. Global climate appears to have been altered as well.

Stanford University researchers have conducted a comprehensive analysis of data detailing the amount of charcoal contained in soils and lake sediments at the sites of both pre-Columbian population centers in the Americas and in sparsely populated surrounding regions. They concluded that reforestation of agricultural lands—abandoned as the population collapsed—pulled so much carbon out of the atmosphere that it helped trigger a period of global cooling, at its most intense from approximately 1500 to 1750, known as the Little Ice Age.

"We estimate that the amount of carbon sequestered in the growing forests was about 10 to 50 percent of the total carbon that would have needed to come out of the atmosphere and oceans at that time to account for the observed changes in carbon dioxide concentrations," said Richard Nevle, visiting scholar in the Department of Geological and Environmental Sciences at Stanford. Nevle and Dennis Bird, professor in geological and environmental sciences, presented their study at the annual meeting of the American Geophysical Union on Dec. 17, 2008.

Nevle and Bird synthesized published data from charcoal records from 15 sediment cores extracted from lakes, soil samples from 17 population centers and 18 sites from the surrounding areas in Central and South America. They examined samples dating back 5,000 years.

What they found was a record of slowly increasing charcoal deposits, indicating increasing burning of forestland to convert it to cropland, as agricultural practices spread among the human population—until around 500 years ago: At that point, there was a precipitous drop in the amount of charcoal in the samples, coinciding with the precipitous drop in the human population in the Americas.

To verify their results, they checked their fire histories based on the charcoal data against records of carbon dioxide concentrations and carbon isotope ratios that were available.

"We looked at ice cores and tropical sponge records, which give us reliable proxies for the carbon isotope composition of atmospheric carbon dioxide. And it jumped out at us right away," Nevle said. "We saw a conspicuous increase in the isotope ratio of heavy carbon to light carbon. That gave us a sense that maybe we were looking at the right thing, because that is exactly what you would expect from reforestation."

During photosynthesis, plants prefer carbon dioxide containing the lighter isotope of carbon. Thus a massive reforestation event would not only decrease the amount of carbon dioxide in the atmosphere, but would also leave carbon dioxide in the atmosphere that was enriched in the heavy carbon isotope.

Other theories have been proposed to account for the cooling at the time of the Little Ice Age, as well as the anomalies in the concentration and carbon isotope ratios of atmospheric carbon dioxide associated with that period.

Variations in the amount of sunlight striking the Earth, caused by a drop in sunspot activity, could also be a factor in cooling down the globe, as could a flurry of volcanic activity in the late 16th century.

But the timing of these events doesn't fit with the observed onset of the carbon dioxide drop. These events don't begin until at least a century after carbon dioxide in the atmosphere began to decline and the ratio of heavy to light carbon isotopes in atmospheric carbon dioxide begins to increase.

Nevle and Bird don't attribute all of the cooling during the Little Ice Age to reforestation in the Americas.
"There are other causes at play," Nevle said. "But reforestation is certainly a first-order contributor."

Friday, November 7, 2008

Sunspot Cycle 24 Kicks In

This just in from the NASA feed and it is important. We have been waiting for the next solar sunspot cycle to stick its head up for a long time and it just did. The long delay will still give sunspot fans plenty to play with for a while yet , but at least we are no longer speculating on why they are not to be found.

The problem we have with sunspot theory is that the era of the Little Ice Age is coincident with an apparent lack of sunspots. And the problem with that is that the observation of sunspots was then in its infancy and we are not sure just how accurate they in fact were. Out of that and a few hints from the Dalton minimum we have woven a skein of theory.

The fact remains that the forty year cycle does coincide with an observed forty year hurricane cycle and a forty year shift of heat into the Northern Hemisphere which has just been turned off a few months past and not with the eleven year cycles of the sunspots. The apparent driver that is big enough to shift heat back and forth is the Pacific Decadal Oscillation and it also just shut down.

The heat masses are large enough to qualify for the observed impact in the Arctic.

The short term evidence is now pointing to a full return of colder winters in the Northern Hemisphere. That means that I need to buy proper winter foot ware for the first time in twenty five years in Vancouver.

What this is doing, particularly if it all stands up over the next couple of years, is establishing a forty year cycle that peaks with the conditions experienced in 2007 and then switches back to cool for forty years or so.

Simply put we have a natural cycle that we can isolate from our long term data that appears to a simple atmospheric response not unlike El Nino and unlinked to sunspots and cosmic rays and CO2 speculation.

Its range is about one degree and does not explain the unusual events such as the Little Ice Age and the Medieval Maximum.

As I have posted earlier, the Little Ice Age fits the profile of a Alaskan Volcano that spewed huge amounts of gas and ash into the Arctic during an era that did not give us access to the right locales. I would guess that we had a string of volcanoes letting loose over a twenty year span which is completely believable for that locale. We are actually in a quiet era and it is still going bang every couple of years.

So what about the Medieval Maximum or for that matter the Roman Maximum? Both lasted for hundreds of years. My surmise is that this cool period is actually going to sit at or above the average for the past forty years. I still think that the long term trend is toward those higher temperatures and will only be interrupted by those volcanoes in Alaska.

The Sun Shows Signs of Life

10.07.2008

http://science.nasa.gov/headlines/y2008/07nov_signsoflife.htm?list1109684


Nov. 7, 2008: After two-plus years of few sunspots, even fewer solar flares, and a generally eerie calm, the sun is finally showing signs of life.

"I think solar minimum is behind us," says sunspot forecaster David Hathaway of the NASA Marshall Space Flight Center.

His statement is prompted by an October flurry of sunspots. "Last month we counted five sunspot groups," he says. That may not sound like much, but in a year with record-low numbers of sunspots and long stretches of utter spotlessness, five is significant. "This represents a real increase in solar activity."

Above: New-cycle sunspot group 1007 emerges on Halloween and marches across the face of the sun over a four-day period in early November 2008. Credit: the Solar and Heliospheric Observatory (SOHO).

Even more significant is the fact that four of the five sunspot groups belonged to Solar Cycle 24, the long-awaited next installment of the sun's 11-year solar cycle. "October was the first time we've seen sunspots from new Solar Cycle 24 outnumbering spots from old Solar Cycle 23. It's a good sign that the new cycle is taking off."

Old Solar Cycle 23 peaked in 2000 and has since decayed to low levels. Meanwhile, new Solar Cycle 24 has struggled to get started. 2008 is a year of overlap with both cycles weakly active at the same time. From January to September, the sun produced a total of 22 sunspot groups; 82% of them belonged to old Cycle 23. October added five more; but this time 80% belonged to Cycle 24. The tables have turned.

At first glance, old- and new-cycle sunspots look the same, but they are not. To tell the difference, solar physicists check two things: a sunspot's heliographic latitude and its magnetic polarity. (1) New-cycle sunspots always appear at high latitude, while old-cycle spots cluster around the sun's equator. (2) The magnetic polarity of new-cycle spots is reversed compared to old-cycle spots. Four of October's five sunspot groups satisfied these two criteria for membership in Solar Cycle 24.

The biggest of the new-cycle spots emerged at the end of the month on Halloween. Numbered 1007, or "double-oh seven" for short, the sunspot had two dark cores each wider than Earth connected by active magnetic filaments thousands of kilometers long. Amateur astronomer Alan Friedman took this picture from his backyard observatory in Buffalo, New York:

On Nov. 3rd and again on Nov. 4th, double-oh seven unleashed a series of B-class solar flares. Although B-flares are considered minor, the explosions made themselves felt on Earth. X-rays bathed the dayside of our planet and sent waves of ionization rippling through the atmosphere over Europe. Hams monitoring VLF radio beacons noticed strange "fades" and "surges" caused by the sudden ionospheric disturbances.

Hathaway tamps down the excitement: "We're still years away from solar maximum and, in the meantime, the sun is going to have some more quiet stretches." Even with its flurry of sunspots, the October sun was mostly blank, with zero sunspots on 20 of the month's 31 days.

But it's a start. Stay tuned for solar activity.

Thursday, August 14, 2008

Ice Collapse is Terminal for 2012

Unexpectedly, the arctic sea ice is now racing ahead to catch up to last years melt. It makes sense. Last years old ice was greatly weakened and only replaced by the new winter ice now been eliminated. A satellite view of the arctic shows mostly well broken up ice floes that are certainly at the ambient sea temperature right now and are been attacked by the solar energy collected by the sea. They are all in a melt environment with dropping support from adjacent ice.

It is important to understand that the overall ice mass is continuing to drop season by season and the last report stated that we have lost fifty percent in the last five years. That was after we lost sixty percent between 1959 and 2000. (we have only the two data points and the loss likely took place in the late eighties and the nineties.)

So at the current melt rate now even less impeded and accelerated by expanded open water, it will all be gone in five years at the most. Again for those keeping score, that means 2012. It now appears even possible that we will be even a bit earlier.

At least everyone is watching this year. Last year at this time they were all keeping their heads in the sand. The main point is that this is the terminal collapse of the perennial Arctic sea ice sheet that we are now watching. The only question I had two and three years ago been as to when the collapse would kick off. It kicked off last year and continues in full swing today and can only end with an ice free summer sailing season by 2012.

The cold needed to reverse this situation is actually beyond what has been experienced in the Arctic for decades.
This also makes me revisit the subject of the little Ice Age and the Bronze Age. It is now very apparent to me that the natural state of the Northern Hemisphere is warm. This now clearly means no summer time sea ice left in the Arctic. In fact, with a restored Sahara, we can expect it to be warmer still and very resistant to volcanic cooling.

It is clear that a major agent of cooling brought the temperature down two full degrees at the beginning of the Little Ice age and held it there long enough to produce a very thick ice sheet in the Arctic. This likely took place over a full century.

We have two options. The first is the Maunder Minimum of which I am a bit skeptical and unconvinced. The second is a very active eruption sequence associated with the Aleutians and Kamchatka Peninsula. For that we need eruption and ash volume histories of all these volcanoes. We also need to differentiate those that are rich in volatiles.

Recall that the impact on temperature is magnified in the Arctic. A Mount Pinatuba in the Arctic could be expected to impact several degrees as compared to the degree or so experienced on the equator.

So we really need only an increase in normal volcanism to achieve the temperature changes and preferably in the form of a major eruption followed by several others over a number of years. This is an apt description of the region's behavior.

Arctic Sea Ice Decline Accelerates, Amundsen’s Northwest Passage Opens

12 August 2008

Just several weeks ago it seemed as though the loss of Arctic sea ice would not be as extreme as last year’s, which shattered previous records. (
Earlier post.) However, the rate of sea ice loss has accelerated during the past ten days, triggered by a series of strong storms that broke up thin ice in the Beaufort and Chukchi Seas and brought warm southerly winds into the region, according to the National Snow and Ice Data Center (NSIDC).

Amundsen’s historic Northwest Passage is once again opening up; the wider and deeper route through Parry Channel is currently still clogged with ice. This route opened in mid-August last year; it may still open up before the end of this year’s melt season, according to NSIDC.

Arctic sea ice extent on 10 August was 6.54 million square kilometers (2.52 million square miles), according to NSIDC data, a decline of 1 million square kilometers (390,000 square miles) since the beginning of the month. Extent is now within 780,000 square kilometers (300,000 square miles) of last year’s value on the same date and is 1.50 million square kilometers (580,000 square miles) below the 1979 to 2000 average.

Ice extent has begun to decline sharply. The decline rate surged to -113,000 square kilometers per day on August 7 and as of August 10 was -103,000 square kilometers per day. This compares to the long-term average decline of -76,000 square kilometers per day for this time of year. Normally, the peak decline rate is in early July.

Many of the areas now seeing a rapid retreat saw an early melt onset (see July 2, 2008); this helped set the stage for rapid retreat (July 17 and April 7). However, the more fundamental issue is that these regions started the melt season covered with thin first-year ice, which is especially vulnerable to melting out completely. Thin ice is also vulnerable to breakup by winds; the last ten days have seen a windy, stormy pattern that has accelerated the ice loss.

—NSIDC

Wednesday, May 14, 2008

Holocene Climate Shift

As my readers know, I have given a lot of thought to the historical temperature record of the post Pleistocene Nonconformity era we call the Holocene. This era began with the mopping up of the vestiges of the preceding million year Ice Age that began with the closure of the Panama Isthmus. The almost total removal of the Polar ice cap produced a northern temperate climate regime that has typically varied about a half degree per century at most. We are rarely been forced to abandon huge tracts of farm land. The Holocene has been the true cradle of human emergence from its barbaric past.

This makes the understanding of temperature anomalies in the record very important. They push us to understand the more general nature of our climate engine. The recent era has seen a rough half degree increase in the northern Hemisphere over the past century. We have every reason to think that this is actually true. The fact that this is a continuing rebound from the chilling event of the little Ice age does enough to explain the shift. Other causes are so far an unnecessary conjecture.

There is exactly one major anomaly in the record that needs to be addressed. Why did the Bronze Age temperature regime abruptly end? We have been living in a post Bronze Age climate regime that is clearly a couple of degrees colder in the Northern Hemisphere that was true during the two thousand year Bronze Age.

Since it ended, we have a constant cycle of failed recoveries, punctuated by sharp reversals that create so called little ice ages. Somehow these reversals lower the temperature a degree or so and we then spend decades if not a century or two recovering. The chilling mechanism is not yet well understood but after watching the macroclimatic behavior of this past year, I would place my bets on the wind circulation system as more than capable of transporting enough heat around to mess up the system. It is just that it is unusual.

This is clearly not enough to explain the climate regime of the Bronze Age. We simply had more heat in the Northern Hemisphere for two thousand years.

I will make the following conjecture. During the Bronze Age, the Sahara Desert was created by mankind. The creation of the Sahara, released a huge amount of solar energy back into space. There was nothing on the ground capable of absorbing all that energy and turning it into atmospheric heat and plant material unable to escape easily to space. That is why the desert becomes so cold at night and so frightfully hot in the daytime. This meant that the Northern Hemisphere has had measurably less available heat for the past four thousand years or so.

An immediate corollary of this conjecture is that the full restoration of the Sahara and all Asian deserts generally will warm and moderate the climate of the Northern Hemisphere and hugely expand the agricultural potential of Eurasia.

This agricultural terrain was systematically destroyed be the advent of goats during the Bronze Age throughout this region. It is their nature to eat a plant to destruction and must be carefully controlled, an option never available in primitive agriculture.
I had previously speculated that perhaps the little Ice Age temperature declines were driven by volume changes in the ocean current systems. This may still have merit but I am much less inclined to support that conjecture now that the strength of the atmospheric circulatory system is much more apparent in northern latitudes.

Also we have had an apparent shift in the volume of the Gulf Stream without any visible effect on its climatic effect over the past fifty years. This means that the principal current is dragging a surface layer of warm water containing most of the heat into the Arctic and affecting climate that way while the varying driver current is doing its thing primarily out of harms way a little deeper.

I think that we have laid the last brick in fully understanding the modest climate variation experienced during the Holocene era. That is good news, because if we cannot reasonably understand our climatic baseline and run experiments against it, we end up talking rubbish.

That is what predictions of a new ice age are and even to a large degree anthropogenic warming when you understand that right now all variation is well within the anticipated variation from the well established baseline.

None of this excuses us from the proper use of good practice to sequester waste CO2. After all, I am predicting that the reforestation of the Eurasian Desert and much of the remaining Northern Hemisphere will raise the temperature of the Northern Hemisphere significantly and powerfully enhance agriculture. In other words, proper sequestration of CO2 will actually warm the planet, but that is a good thing.

Thursday, November 29, 2007

John Carlisle in 1998 on Global Warming


I think it is very appropriate to reprint this article by John Carlisle put out in 1998. I do not know how accurate the temperature ranges quoted are and they seem to reflect the European experience. Yesterday's post shows us why northern regions are far more prone to temperature shifts in general. It also suggests that at any global set point, that a lot of variability is possible in the northern Hemisphere.

I wish to make one point though. My perusal of the various reports on historic temperatures has shown me that these numbers were cobbled together using various proxies and at the time and place represented at best a best guess. They have not necessarily been overly reviewed and even when reappraised, the former information, usually in chart form, lingers for a long time.

Once a position is accepted for any length of time, it is natural for critical analysis to fade and for that position to be given more credence than even the authors intended. In the game of climate analysis we have an uncommon amount of speculation been accepted too easily as fact. After all, I have the same problem. I need true proxies for global temperatures at any point in time and I have no choice but to accept the reported consensus. It is a little maddening to see this consensus shifting around.

The best most recent example is the infamous 'hockey stick' which is still been trotted out and will be with us so long as anyone watches Al Gore's documentary.

Thus while a six degree swing may be the experience in much of the Northern Hemisphere, the rest of the globe experienced a more modest half degree swing between the two hemispheres.

Today we are in the middle of a northern warming upswing that is lifting Europe to at least a couple more degrees of warmth before it is over. It appears to be very explainable as a rebound from the very real Little Ice Age which principally impacted Northern Europe. At least they complained the most.


Global Warming: Enjoy it While You Can
by John Carlisle

Policymakers have been arguing for nearly a decade over what to do about global warming. Noticeably missing from this debate has been any mention of the fact that natural fluctuations in the Earth's temperature, not Man, is the likely explanation for any recent warming.

Proponents of the global warming theory repeatedly cite a 1.5° F temperature increase over the last 150 years as evidence that man-made CO2 is dangerously heating up the planet and will cause huge flooding, severe storms, disease and a mass exodus of environmental refugees. Based on this, the Clinton Administration and its environmental allies want Congress to ratify a treaty that will hike consumer prices 40 percent and cost the American economy $3.3 trillion over 20 years. But the apocalyptic predictions on which they justify these drastic steps are totally unsubstantiated and ignore some fundamental truths about the Earth's climatic behavior.

The fact is, the planet's temperature is constantly rising and falling. To put the current warming trend in perspective, it's important to understand the Earth's geological behavior.

Over the last 700,000 years, the climate has operated on a relatively predictable schedule of 100,000-year glaciation cycles. Each glaciation cycle is typically characterized by 90,000 years of cooling, an ice age, followed by an abrupt warming period, called an interglacial, which lasts 10,000-12,000 years. The last ice age reached its coolest point 18,000 to 20,000 years ago when the average temperature was 9-12.6° F cooler than present. Earth is currently in a warm interglacial called the Holocene that began 10,700 years ago.

Although precise temperature readings over the entire period of geologic history are not available, enough is known to establish climatic trends. During the Holocene, there have been about seven major warming and cooling trends, some lasting as long as 3000 years, others as short as 650. Most interesting of all, however, is that the temperature variation in many of these periods averaged as much as 1.8° F, .3° F more than the temperature increase of the last 150 years. Furthermore, of the six major temperature variations occurring prior to the current era, three produced temperatures warmer than the present average temperature of 59° F while three produced cooler temperatures.

For example, when the Holocene began as the Earth was coming out of the last Ice Age around 8700 B.C., the average global temperature was about 6° F cooler than it is today. By 7500 B.C., the climate had warmed to 60° F, 1° F warmer than the current average temperature. However, the temperature fell again by nearly 2° F over the next 1,000 years, settling at an average of 1° F cooler than the current climate.

Between 6500 and 3500 B.C., the temperature increased from 58° F to 62° F. This is the warmest the Earth has been during the Holocene, which is why scientists refer to the period as the Holocene Maximum. Since the temperature of the Holocene Maximum is close to what global warming models project for the Earth by 2100, how Mankind faired during the era is instructive. The most striking fact is that it was during this period that the Agricultural Revolution began in the Middle East, laying the foundation for civilization. Yet, Greenhouse theory proponents claim the planet will experience severe environmental distress if the climate is that warm again.

Since the Holocene Maximum, the planet has continued to experience temperature fluctuations. In 900 A.D. the planet's temperature roughly approximated today's temperature. Then, between 900 and 1100 the climate dramatically warmed. Known as the Medieval Warm Period, the temperature rose by more than 1° F to an average of 60° or 61° F, as much as 2° F warmer than today. Again, the temperature during this period is similar to Greenhouse predictions for 2100, a prospect global warming theory proponents insist should be viewed with alarm. But judging by how Europe prospered during this era, there is little to be alarmed about. The warming that occurred between 1000 and 1350 caused the ice in the North Atlantic to retreat and permitted Norsemen to colonize Iceland and Greenland. Back then, Greenland was actually green. Europe emerged from the Dark Ages in a period that was characterized by bountiful harvests and great economic prosperity. So mild was the climate that wine grapes were grown in England and Nova Scotia.

The major climate change that followed the Medieval Warm Period is especially critical as it bears directly on how to assess our current warming period. Between 1200 and 1450, the temperature plunged to 58° F. After briefly warming, the climate continued to dramatically get colder after 1500. By 1650, the temperature hit a low of 57° F. This is regarded as the coldest point in the 10,000-year Holocene geological epoch. That is why the era between 1650 and 1850 is known as the Little Ice Age. It was during this time that mountain glaciers advanced in Switzerland and Scandinavia, forcing the abandonment of farms and villages. Rivers in London, St. Petersburg and Moscow froze over so thoroughly that people held winter fairs on the ice. There were serious crop failures, famines and disease due to the cooler climate. In America, New England had no summer in 1816. It wasn't until 1860 that the temperature sufficiently warmed to cause the glaciers to retreat.

The significance of the Little Ice Age cannot be overestimated. The 1.5° F temperature increase over the last 150 years, so often cited as evidence of man-made warming, most likely represents a return to normal temperatures following a 400-year period of unusually cold weather. Even the United Nation's Intergovernmental Panel on Climate Change (IPCC), the chief proponent of the Kyoto Protocol global warming treaty signed in December 1997, concludes that: "The Little Ice Age came to an end only in the nineteenth century. Thus, some of the global warming since 1850 could be a recovery from the Little Ice Age rather than a direct result of human activities."

Leading climate scientist Dr. Hugh Ellsaesser of the Lawrence Livermore National Laboratory says we may be in for an additional 1.8° F of warming over the next few centuries, regardless of Man's activities. The result would be warmer nighttime and winter temperatures, fewer frosts and longer growing seasons. Since CO2 stimulates plant growth and lessens the need for water, we could also expect more bountiful harvests over the next couple of centuries. This is certainly not bad news to the developing nations of the world struggling to feed their populations.

Thus, far from being a self-induced disaster, global warming is the result of natural changes in the Earth's climate that promises to yield humanity positive benefits. In the geological scheme of things, the warming is not even that dramatic compared to the more pronounced warming trends that occurred during the Agricultural Revolution and the early Middle Ages. Moreover, there is strong evidence that this long-needed warming is moderating. All things considered, global warming should be viewed for what it is: A gift from the often fickle force of Nature. Enjoy it while you can.

John Carlisle is director of the Environmental Policy Task Force, a project of The National Center for Public Policy Research. Comments may be sent to him at JCarlisle@nationalcenter.org.


Tuesday, October 9, 2007

Long Arctic Indian Summer

For the moment, I want my readers to totally put all you have been brought to believe about the human impact on global warming completely out of your mind and travel with me on a thought experiment. Let us imagine that humanity is missing. What does the data tell us then?

500 years ago, we had a climate down shift called the Little Ice Age that ended the long lasting Medieval Warm P9eriod that had held sway for over two hundred years. Since then, the climate of the Northern Hemisphere has very slowly warmed back to the previous climate regime. My analysis of the impact of a modest positive warming influence has shown us that this can explain all the current evidence, and that we are about to have a full return to a warmer Northern climate.

The planet Earth has two natural heat sinks at the poles that operate over a yearly cycle due to the tilt of the poles. We like to ignore the Antarctic, but it is the dominant cooling engine, simply because it has a small continent able to collect an ice cap and a huge uninterrupted circumpolar ocean current that shields it from warm water intrusions. This is one mean cooling machine.

The arctic is the complete reverse of this. We have a land ringed deep ocean for most of the ice cap forming 15 degree polar area. There is only one break in this ring and it is fed by a large bounded north equatorial ocean that must pump warm water into the Arctic. Had this been engineered deliberately, I fail to see how it could have been improved on. We may discover, once all the crustal positions are properly worked out, that this is a rarity in global history.

Remember that the ocean rose 300 feet around 12,000 years ago. Prior to that the continental shelf was shaped by ocean currents and land erosion for millions of years. This unusually stable process formed long broad and very shallow coastal plains. This could never have happened if the sea level was shifting radically back and forth.

The indications are though, that left to its own devices, that natural climate balance for the Arctic is a little warmer than what we are experiencing now. The medieval Warm Period lasted a comfortable 200 years if not a great deal longer. The Bronze Age optimum lasted for thousands of years. In between, it is fair to say that it was more often warm than cold.

In fairness, all our information is drawn from proxies that are very prone to local variation. This is particularly a factor with shifting human settlement and disturbance. The only trustworthy information comes from pollen data from the more northerly transition zones and even that will actually lag the changes by a couple of centuries. We are experiencing that today.

The fact remains that a four hundred year climate cycle may simply defy resolution. The only certainty is that the antiquity of human habitation is universal.

The question then, is not why is it not warmer, but what causes it to chill out in the first place. Left to itself, the Arctic climate will moderate with total sea ice destruction every year. A moderate Arctic will mean less extreme winters throughout the Northern Hemisphere and improved growing conditions everywhere.

The good news, is that once the North is at its natural stability point around the complete elimination of summer sea ice, it appears to stay warm for a long time. There is likely enough freezing going on to prevent any cumulative heat retention.

The bad news is that sooner or later, the party is over.

My best theory, is that a surplus of Antarctic cold water is forced into the Benguela Current, strengthening it substantially and for decades lowering the temperature of the Gulf stream sufficient to allow ice accumulation in the Arctic. We are talking of a very small switch in energy transport when compared to the total regime. We do not even know if the atmosphere is a significant factor at this point.

All we really have is plenty of misunderstood and conflicting data of which we need a lot more.

When we see the world from this perspective, the good news is that it is getting warmer. The bad news is that this will end. And what did humanity have to do with any of this?



Thursday, August 9, 2007

Cold Water on Global Warming

After alluding to the role of Antarctica yesterday, I think it is appropriate to add this article from 2001.

The climate of the northern hemisphere has experienced several major swings in climatic conditions over the past 10,000 years. The bronze age in particular appears to have been hotter that it is now as was the period before 1500 and the little ice age. The current hot spell seems to be doing no more than restoring those conditions. I also point out that these warm spells were very stable, while the sudden onset of a cold climate was abrupt. I posit that the only way it is possible to have such a shift is if the surface waters of the ocean itself was abruptly chilled by perhaps a degree.

And then the question is how? We have been blithely blaming the sun. I suspect that may well be rubbish. On the other hand we have a mechanism large enough in the southern hemisphere capable of doing this. And particularly doing this to the closed off Atlantic.

What would it take? There we do not know. Perhaps a build up of sea ice, or perhaps a decline in sea ice? That is the one thing capable of a long cycle of variation with periodic discharges into the Pacific and South Atlantic.

A discharge of cold water into the Atlantic would certainly impact on the whole of the Atlantic very quickly. It is also totally believable and I hope, unlikely to happen for a few centuries. At least enough time to get the permafrost out of the soil in Greenland and to reestablish the dairy industry there.

Here is the article:


http://www.gsfc.nasa.gov/topstory/20010917seaice.html

September 18, 2001 - (date of web publication)

El Niño, La Niña Rearrange South Pole Sea Ice

Scientists have been mystified by observations that when sea ice on one side of the South Pole recedes, it advances farther out on the other side. New findings from NASA's Office of Polar Programs suggests for the first time that this is the result of El Niños and La Niñas driving changes in the subtropical jet stream, which then alter the path of storms that move sea ice around the South Pole.

EL NINO AND LA NINA REARRANGE ICE COVER IN ANTARCTICA

Image 1


The results have important implications for understanding global climate change better because sea ice contributes to the Earth's energy balance. The presence of sea ice, which is generated around each pole when the water gets cold enough to freeze, reflects solar energy back out to space, cooling the planet. When there is less sea ice, the ocean absorbs the sun's heat and that amplifies climate warming.

By looking at the relationship between temperature changes in the ocean, atmospheric winds, storms, and sea ice, the new study pinpoints causes for retreating and advancing ice in the Atlantic and Pacific ocean basins on either side of the South Pole, called the "Antarctic dipole."

LOCATIONS OF INCREASED SEA ICE DURING EL NINO AND LA NINA YEARS

Image 2


"El Niños and La Niñas appear to be the originating agents for helping generate the sea ice dipole observed in the ocean basins around the Antarctic," said David Rind, lead author of the study and a senior climate researcher at the NASA Goddard Institute for Space Studies. The study appears in the September 17 issue of Journal of Geophysical Research.

During El Niño years, when the waters of the Eastern Pacific heat up, warm air rises. As the air rises it starts to move toward the South Pole, but the earth's rotation turns the winds eastward. The Earth's rotation is just strong enough to cause this rising air to strengthen the subtropical jet stream, a band of atmospheric wind near the equator that also blows eastward.

When the subtropical jet stream gets stronger over the Pacific basin, it diverts storms away from the Pacific side of the South Pole. Since there are fewer storms near the Pacific-Antarctic region during El Niño years, there are less winds to blow sea ice farther out into the ocean, and ice stays close to shore.

At the same time, the air in the tropical Atlantic basin sinks instead of rising. That sinking air weakens the subtropical jet stream over the Atlantic, guiding storms towards the South Pole. The storms, which intensify as they meet the cooler Antarctic air, then blow sea ice away from the pole farther into the Atlantic.

During La Niña years, when the Eastern and central Pacific waters cool, there is an opposite effect, where sea ice subsides on the Atlantic side, and advances on the Pacific side.

The study is important because the amount of sea ice that extends out into the ocean plays a key role in amplifying or decreasing the warming effects of the sun on our climate. Also, the study explains causes of the Antarctic sea ice dipole for the first time, and provides researchers with a greater understanding of the effects of El Niño and La Niña on sea ice.

Scientists may use these findings in global climate models to gauge past, present and future climate changes.

"Understanding how changes in the temperature in the different ocean basins will affect sea ice is an important part of the puzzle in understanding climate sensitivity," Rind said.

Wednesday, August 8, 2007

The Global Temperatrure Trend

I am reposting this post by Roger Coppock from the news groups.

July tied for 8th warmest of the 128 year NASA global land record.

Lately, fossil fools fondly repeat a lie about global warming slowing down. "Global warming ended in 1998," they say. The truth is published here every month in this section of these reports:

The month of July in the year 2007, is linearly projected to be 14.397, yet it was 14.57 above projected.

Using the line of regression, the temperature is projected. If global warming reversed, the actual measured temperatures would have to fall below the line of regression temperature, and do so for a year or more. So far this has not happened, not for even two months in a row.

Measured temperatures which are nearly always above projected temperatures mean that the temperature rise is accelerating. This is simple geometry. Each above the line measured global temperature raises the slope of the regression line when that new point joins the data. This pattern is now 5 decades old.


Please see:
http://members.cox.net/rcoppock/Slope1952-2006.jpg

Clearly therefore, the fossil fools lie, and global mean
surface temperatures continue to rise.

These globally averaged temperature data come from NASA:


http://data.giss.nasa.gov/gistemp/tabledata/GLB.Ts.txt

They represent the results of tens of millions of readings taken at thousands of stations covering all the lands of the Earth over the last 128 years. Yes, the data are corrected for the urban heat island effect.

The Mean July temperature over the last 128 years is 14.024 C.
The Variance is 0.08871.
The Standard Deviation is 0.2978.

Rxy 0.72910 Rxy^2 0.53159
TEMP = 13.644595 + (0.005877 * (YEAR-1879))
Degrees of Freedom = 126 F = 142.99616
Confidence of nonzero correlation = approximately
0.999999999999999999999 (21 nines), which is darn close to 100%!

The month of July in the year 2007, is linearly projected to be 14.397, yet it was 14.57. <- Above projected. The sum of the residuals is 21.14880

Exponential least squares fit: TEMP = 13.647507 * e^(.0004181 * (YEAR-1879))
The sum of the residuals is 21.10617

Rank of the months of July
Year Temp C Anomaly Z score
1998 14.90 0.876 2.94
2002 14.73 0.706 2.37
1990 14.66 0.636 2.14
2005 14.66 0.636 2.14
1995 14.60 0.576 1.94
1991 14.59 0.566 1.90
2006 14.59 0.566 1.90
2007 14.57 0.546 1.83 <-- 2001 14.57 0.546 1.83 2003 14.54 0.516 1.73 1981 14.51 0.486 1.63 1999 14.51 0.486 1.63 1987 14.50 0.476 1.60 MEAN 14.024 0.000 0.00 1892 13.68 -0.344 -1.15 1902 13.68 -0.344 -1.15 1889 13.66 -0.364 -1.22 1899 13.66 -0.364 -1.22 1888 13.64 -0.384 -1.29 1923 13.64 -0.384 -1.29 1912 13.59 -0.434 -1.46 1918 13.59 -0.434 -1.46 1890 13.55 -0.474 -1.59 1882 13.45 -0.574 -1.93 1884 13.44 -0.584 -1.96 1904 13.43 -0.594 -1.99 1895 13.37 -0.654 -2.19 1891 13.19 -0.834 -2.80

The most recent 176 continuous months, or 14 years and 8 months, on this GLB.Ts.txt data set are all above the 1951-1980 data set norm of 14 C.

There are 1531 months of data on this data set:
-- 744 of them are at or above the norm.
-- 787 of them are below the norm.

This run of 176 months above the norm is the result of a warming world. It is too large to occur by chance at any reasonable level of confidence. A major volcano eruption, thermonuclear war, or meteor impact could stop this warming trend for a couple of years,
otherwise expect it to continue.

What he is showing us is that the curve fits a linear up trend since 1960. The actual curve was below the line for the last several years, but this year has jumped above the trend line. Ouch!

I also have a sense that this year the land temperatures are everywhere warmer leaving absolutely no room for argument.

From a larger perspective, we are continuing to recover from the little ice age that abruptly began in the late 15th century that sent Europe reeling and also likely crashed the populations of North America. Corn is very vulnerable.

This ice age is posited as been caused by a reduction in solar activity attested by the lack of sunspot activity.

There is one other mechanism of global warming and cooling that I think we should at least contemplate. Is Antarctica capable of sending periodic ice surges into the south Atlantic, thereby abruptly dropping global surface temperatures by a degree or so?

It is clear to me that the Northern hemisphere will normally stabilize around a regime in which winter sea ice is created and destroyed annually comfortably offsetting the heat pump of the gulf stream. We are watching it happen rapidly now.

So why did we get a little ice age?