Skip to comments.A LOOK AT THE ENVIRONMENTAL CHANGES AND "GLOBAL WARMING"
Posted on 05/13/2002 5:55:28 PM PDT by Excuse_My_Bellicosity
In the story "Is This Warm Winter a Sure Sign of Global Warming?" we looked at a number of factors that cause changes in global mean temperatures on both the short and long term. We showed that although most of the attention in recent years has been on the greenhouse gases as the primary driver of the global temperature trends, it may still be a relative "bit player" in the climate ride we, like it or not, all find ourselves on.
When I give a talk or write on the subject of climate change, I frequently get the response "How do you explain the environmental impacts that are reported by the IPCC and other scientists that show the global ice is disappearing from the Polar Regions and from the world's mountains. Isn't that proof of accelerated global warming?"
Before I respond to this, let me say that I have always considered myself a friend of the environment. Many years ago when working on a grant to study "air quality," I did a radio show on Science and the Environment. When I was a Professor of Meteorology, I taught about the greenhouse effect among the factors affecting climate in my Weather and Climate courses. It was only when researching the current status of greenhouse warming and climate change for Intellicast.com that I began to find inconsistencies in what the data said, and what was being presented to us by the global warming activists.
My interest is finding the truth and presenting the facts, not in promoting controversy. Like everyone else, I get a delivery of oil every month and I can assure you I get no special discounts.
I do not advocate a careless disregard for the environment in our policy or actions. I welcome reasonable steps to clean up our world in order to make it a better place for our children and their children.
Here are some of the environmental changes "in the news" and some of the likely causes.
REPORTED DEMISE OF THE POLAR ICE CAPS
In the report "Are the Icecaps Really Melting", we discussed this issue. Greenhouse theory has it that the polar regions should be "leading the way" on global warming as carbon dioxide is most effective at trapping the earth's heat at polar temperatures.
The facts show this is not happening. First, lets look at the Southern Hemisphere. Most (98%) of Antarctica has actually grown colder over the last 20 years during which time the ice extent has actually increased.
The Antarctic warming reports in recent years have been based on observations on the Antarctic Peninsula, which juts out into the ocean and not on reports from any stations in the vast interior. In a recent BBC story, scientists confirmed the cooling on the continent and presented evidence that the cooling trend has persisted for decades. The reports showed summer temperatures were especially cool, which was having the greatest economic impact on the environment. We also showed in the story on the recent Antarctic Ice Sheet Breakup how this summer was especially cold on Antarctica.
We also showed how the ice extent has not decreased, but actually increased in recent decades.
As we showed in the story the Antarctic Ice Sheet Breakup, the changes in ice extent seems to be tied to the Pacific Decadal Oscillation (PDO), which changed modes in the late 1970s and again in the middle 1990s. During the last negative so-called "cool phase" of the PDO, which lasted from 1947 to 1977, the Antarctic ice sheet extent diminished (and there may have been some slight warming - see Vostok temperature graph). During the PDO positive "warm phase" from 1977 to 1997, the ice extent increased (and temperatures cooled).
In the Northern Hemisphere, the Polar Regions too have undergone changes in ice thickness and extent. The blame of course is placed on global warming, but the facts suggest this too is just another cyclical change relating to a large-scale ocean circulation change this time both in the Pacific and in the Atlantic.
The data for Fairbanks and the surface temperature correlation map for the northern Polar Regions showed some warming during the positive PDO phase (1977 to 1997). However, the change in ice thicknesses widely reported in the media as due to global warming, is more likely due to ocean circulation changes. Though the Pacific, through the PDO, may cause temperatures to oscillate here slightly on a decadal scale, it appears the Atlantic circulation may be the driver for the changes in the ice.
The North Atlantic Oscillation is a major driver for winter temperatures in the United States and Europe.
During the positive phase of the NAO, stronger than normal southwesterly winds blow across the Atlantic. These winds blow mild air into Western Europe. They also push warmer water north. This water pushes under the arctic ice and can melt it from the bottom.
Like the PDO, the NAO undergoes decadal scale changes. During the 1950s and 1960s, the NAO was primarily negative, while in the 1980s and early 1990s, it was primarily positive.
When it turned positive, the arctic ice thinned (1980 to 1995).
The NAO may have switched back into a negative mode in the middle 1990s. This might be expected to cause the ice to thicken again. Indeed the Sea Ice Extent chart above seems to show this thickening.
GREENLAND ICE CAP
The Greenland ice cap is huge. It contains 1/8th of the total global ice-mass. The total ice-mass on earth is 30 million cubic km; Antarctica has 27 million cubic km; and Greenland 2.5 million cubic km.
Greenland ice was reported by NASA to be thinning in places over the last few decades. However, temperatures have not been warming. In fact, it was unusually cold there in the 1980s and 1990s. This is consistent with a negative phase of the NAO, which is characterized by a deep cold low over the North Atlantic.
The NAO controls the temperature in this region and it has a major effect on precipitation. The correlation map of precipitation with the NAO (courtesy NOAA CDC) shows indeed a negative correlation with the NAO in much of the southern half of the continent. Thus, when the NAO is negative, there is more precipitation than normal and when it is positive, less. This may have contributed to the decrease in ice cover in some parts of the icecap.
So again, the evidence suggest there are changes going on here, but they do NOT suggest that warming due to greenhouse gases are driving them.
A rapid demise of the glaciers over Greenland from any cause would not be a good thing. The first concern would be rising sea levels, which could flood coastal cities. But ironically the biggest problem could be that it could actually trigger another ice age. A NASA Goddard study showed how such a melting would introduce fresh water into the North Atlantic and slow or even shutdown the large-scale ocean circulation there. This would cool down Europe and North America and possibly eventually evolve into an ice age.
MID-LATITUDE AND TROPICAL GLACIERS
There have been reports in recent years about an accelerated shrinking of glaciers in middle latitudes and the high mountains in the Tropics. Presently, about 10% of the earth's surface is covered by ice sheets and glaciers. During the last ice age, 32% of the earth was covered. Most of the ice is tied up in the icecaps (Antarctica, Arctic and Greenland) and the rest is found in the world's largest mountain ranges in mid and even tropical latitudes. Many of the world's glaciers have been retreating since the ice age at varying rates. The rate of retreat varies with changes in temperatures AND precipitation.
In the story "Pacific Northwest Glacier Retreat, Is It Global Warming?" we showed how the accelerated retreat of the glaciers in the 1980s and early 1990s was related to the PDO cycles. Here too temperature changes do not reflect a major warming. The temperatures in the mountains have been relatively steady in the last 75 years.
There has been a big difference in precipitation associated with the PDO though. It was wetter in many years during the PDO cool phase (which favors La Ninas) in the 1950s and 1960s, and drier during the PDO warm phase (which favors El Ninos) in 1980s and early 1990s.
With the return to the cool phase, one might expect the precipitation to again increase (and any retreat to slow). Indeed, recall the record snow year a few years ago and despite the dry year last year, a return of wetter conditions again this year. The Nisqually Glacier on Washington's Mt. Rainier is growing thicker at the rate of more than 18 feet per year. With all of the added weight, scientists expect the glacier to begin advancing within this decade (Washington Geology, p. 24, Sep 2000).
In the story Europe Providing Another Example of Climate Change, we addressed the concerns about desertification in Europe blamed on global warming. Glaciers in Europe (Alps and Pyrenees) are also said to be in an accelerated decline and again global warming is the reason given. However, both observed changes could be blamed on the NAO cycles. The positive phase of the NAO, which predominated from the late 1970s to the mid 1990s, is a very dry pattern for much of Europe (and Africa).
This also would apply to Mt. Kilamanjaro in east Africa. The glacier on the mountain is said to be in rapid retreat. Temperatures there however show little change. Nearby non-urban ground stations show little change and satellite data suggests no warming. The more rapid decline might be due to lower precipitation during the positive NAO decades (1980-1995).
Likewise, some groups have reported some signs that the Himalayan glaciers have also diminished. During 1998, the Dokraini Bamak Glacier in the Indian Himalayas retreated by 20 meters. Of course, 1998 was an El Nino year and El Ninos mean failure of the monsoon rains (and thus less high mountain snows). Longer term, the PDO warm phase from 1977 to 1997 would also favor less precipitation (as it favors more El Ninos), which would have led to less snow and thus increased glacial retreat. Since the PDO has changed again and we had three La Nina years, one would guess the snowfall would have increased again since 1998 (and thus the rate of retreat slowed).
LASTLY SIBERIAN TUNDRA AND FLORIDA FIRES
Two of my favorite global warming stories in recent years related to the collapse of a building in Siberia on the tundra and the three winters of Florida brush fires.
Last winter, when temperatures in Siberia set a new cold record for the Northern Hemisphere with -94ºF in the Kemerovo region, some 1800 miles east of Moscow, the story broke about the building collapse on the Siberian permafrost, blamed on global warming (I loved the timing). Of course our experience on the Alaska Pipeline showed how sensitive the tundra and permafrost is to man's activities and it should not surprise anyone that putting a building on ice might ultimately melt the ice. What surprised me the most was that this story got widespread play in the media but the new cold record for the Northern Hemisphere did not.
The other story concerned the national evening network news blaming global warming for the recent three successive years of winter and spring forest and brush fires in Florida. Of course, we know the real cause was the three-year La Nina, which caused drought in the Southeast and is very well correlated with fires that time of year.
So there is much compelling evidence that our climate and the environment in which we live has changed in recent decades. Change should not surprise us as the "only constant in nature is change." However, the facts do not suggest that greenhouse gases are entirely to blame. We are seeing that the effects of cycles in the oceans and (as we explained in Is This Record Warm Winter a Sure Sign of Global Warming?) also the sun may be the real drivers for these changes.
And, as we reported in Why Tracking Climate is Like Tracking the Stock Market, this may change shortly. The ocean circulations and the sun appear to be changing in ways that favor a turn to colder temperatures. Throw in a major volcanic eruption and who knows what we might see.
I posted the text only because I don't have the expertise to post pictures and it would probably screw up anybody who doesn't have pretty fast internet access. For people who have a reasonably fast internet connection, please take a look at the source link. The author has many color graphs and charts with data to back up the text. It is worth a look.
It is rarity to see a person in the business of meteorology write an article about global warming that is based on actual science instead of blindly accepting the word of the enviro-socialists. I'm sure there are a lot of them, too, that are afraid to speak the truth due to intimidation from the left and/or the loss of government grants that come from liberal government agencies that only fund projects that are out to "prove" that the whacko liberal enviro-socialists are right.
i am in an ongoing debate with some folks about global warming and this article provides more scientific data to support my position that humans don't measurably increase the heating of the atmosphere, no matter how important some people think they are.
The source link shows some really good charts and graphs that I didn't post because it's pretty graphics-intensive.
I would have thought that this article would have gotten more hits from Freepers, but they already know that global warming is a big fat scam and it's already been beat to death here at FR. I posted this because the author posted some really good charts and graphs that I haven't seen before. The enviro-socialists don't want you to see them either!!
If we have a cold winter, it's a sign of global warming.
If an Antartic ice shelf breaks off, it's a sign of global warming.
If the Antartic gets colder an increases it's ice buildup on the continent, it's a sign of global warming.
The flood of garbage never stops...
Greenland Ice Cap Is Melting, Raising Sea Level
Source: The Associated Press
Published: Jul 20, 2000 - 04:05 PM Author: By Paul Recer
Posted on 07/20/2000 14:37:50 PDT by Ms. AntiFeminazi
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