Is global warming mostly man-made?

[mkirkpatrick]

Prehaps it is 50/50/ half natural,and half manmade,either way we are heading for diaster.




regards michael.

[AntonioLao]

Is global warming mostly man-made?

Certainly not. It's mostly nature-made. However, in various localities around the world, especially, the industrial districts, there are local hot spots that are mostly man-made. A good example is my kitchen during hot food preparation.

[G_burnett]

No has been my cast of ponder.

Over the history of the Earth there have been as Leskey reports many such the near eradication of all life on Earth due to the high presence of CO2. The reasons for this have been from outer space as our MF has failed to protect us and our own Earth core release of three major eruption, points still noticeable.
Kind regards, g.

[G_burnett]

Prehaps it is 50/50/ half natural,and half manmade,either way we are heading for diaster.




regards michael.

Di`as´ter
n.1.(Biol.) A double star; - applied to the nucleus of a cell, when, during cell division, the loops of the nuclear network separate into two groups, preparatory to the formation of two daughter nuclei.

Yes, I fully agree Michael that we are heading for a loop. (sage wants his own body and not a sock) kind regards g

[Mohan.C]

oh, I thought Michael had misspelled disaster,
thanks g...

[everymansmedium]

Hello:
I have been looking at the possibility of the effects of mankind resulting in many global effects. The worst of this is relative to the use of fossil fuels, reduction of forest land, and the introduction of toxic substances. To this we may soon add introduction of unnatural biological structures causing an imbalance to the natural planetary biological structure.

I have also noticed that sunshine is the major contributor of all the energy that is found on this planet. With the minor exceptions of fissionable material and geothermal energy. All burnable substance is the result of photosynthesis. This combining of all carbon into a material that is then buried in the ground is the common way to remove all of the carbon from the environment. When the concentration of carbon is high in the atmosphere the tendency is toward global warming. This warming causes a larger mass of land to be available for the growth of vegetation. The extra carbon also aids directly to the growth of vegetation. This extra vegetation gets buried in the ground until the atmosphere again clears the extra carbon. In this way a balance is formed that regulates the amount of carbon that is in the atmosphere that in turn regulates the global thermal condition. This burying of carbon has been on going for millions of years. It is on occasion upset by volcanic action resulting in an ice age. This action is all normal to our planet.

Along comes man and digs up tons and tons of this carbon that has been buried for millions of years and spews it into the air all in less than 100 years. Don’t you believe for even one minute that this action will not have it’s effects on our planet. The dance we have had is not for free. It is now time to pay the piper. There is no such thing as a free lunch. We have a planet that is very forgiving and will in time return to its normal patterns. The reason for this is because of the amount of water on our planet. The major store of ICE is in the southern hemisphere. The ice in the north may melt without excessive incident. We will loose the polar bear we will add this creature to our list of “killed off by mankind” creatures.
However when the ice in the southern hemisphere begins to melt and the WAIS shelf breaks up and the global water level rises by 50 feet over night. Then the effect of mankind’s global warming will be erased. Then we will be required to survive the resulting ice age that follows the breakup of the WAIS.

This sounds like the worst thing that could ever happen. It is not. The worst thing would be if there was no WAIS to turn around the global warming to become an ice age from which we can survive and from which the globe will eventually recover. If it was to continue to the warming trend there would be no recovery. WE would end up like our neighbor nearer the sun. Did you ever wonder how all this water got to be on this planet? As far as I know the natural region of a solar system to collect this type of material is in the very outer shell of the solar system. At this point of our solar system there are great numbers of ice asteroids. I would be willing to bet that the greatest amount of water in our solar system is in the outer shell of our solar system. If I am correct then it might be considered as planetary engineering 101 to stop at this point when entering a star system to collect the water necessary to make a planet livable. Simply aim some of the asteroids to fall in an orbit around the planet you like, then aim an equal amount to orbit the same planet from the opposite direction. The result will be to crash the ice above the planet so the ice falls and melts and turns to rain on the planet. It might even rain for 40 days and 40 nights.

It is up to all of us to decide where the science ends and the science fiction begins.

John EMM.

[timeparticle]

Climatologists can predict what part of a cooling trend or warming we are in through Ice Age Cycle studies....

The Marvelous Speed of Deglaciation


The fresh water, moving south from the melting glacier, carries some saltwater with it, which must then replaced by saltwater from the south. This process could have carried warmer water from the south to the north during the Boelling-Alleroed.

The Potential Energy of Ice

The fact that ice age cycles have a "sawtooth" shape, featuring slow buildup and rapid decay, begs the question: Why should deglaciation be so fast? From a standpoint of physics, we should perhaps expect the reverse: to make ice requires getting rid of energy but it takes lots of energy to melt ice. Hence wasting energy into space would seem to be more easily done than bringing energy to the ice and making it do work.

What we must not forget is that the ice itself has lots of potential energy stored within it. If we can get an ice sheet to start moving, internal friction will heat it from the inside, it will waste into the sea, and its water carried to warmer regions. From this point of view, deglaciation can be fast because the ice is inherently unstable, especially after it has had time to depress the earth’s crust upon which it sits. At elevations below sea level, ice can erode the bedrock very deeply. This crustal depression happens each time the ice builds up, but the erosion is cumulative over the entire period of the northern ice ages, beginning about 3 million years ago. Once there is a deeply carved portion of the Earth, like Hudson Bay and Baltic Sea, there is then a potential heating system right within the center of the ice sheets, which can be activated when seawater is admitted. The same is true all around the margins, for example in the spectacular fjords of western Norway and Alaska.

If this idea about instability is correct, then once deglaciation starts we should see faster and faster decay of ice sheets, and, on the whole, this is true. The largest number of fast deglaciations is found within the last quarter of the entire "Pleistocene," the period of northern ice ages. Also, it seems, the more ice there is, the faster the deglaciations.

We might also expect another feature if this concept of unstable ice is correct: those glaciers which have their base below sea level should be extremely unstable. And there should be other glaciers that are not so unstable, whose bases are firmly grounded on solid bedrock. If that is so, we should see a two-step deglaciation: first the unstable ice is destroyed and then, later, the stable one. The detailed record of the last deglaciation suggests that this is indeed so. The best record for what happened is seen in the Greenland ice itself. According to the data, around 14,500 years ago there was extremely rapid warming, with conditions changing from fully glacial to fully interglacial conditions in one person's (or one mammoth's) life time. Unstable glaciers responded by collapsing at a furious pace. Within a thousand years or so, sea level rose by 100 to 200 feet! Within one century there would have been people witnessing the flooding of vast areas of low-lying coastal plains.


Graph of mean sea surface temperature versus relative abundance of N. pachy and a microphotograph of N. pachy (sin.). Note how the abundance of this foraminfer increases with colder waters. [From: NOAA]
The Boelling-Alleroed
The period of warmth associated with the first step of deglaciation lasted about 1500 years; it is called the "Boelling-Alleroed," after places in Denmark where the layers of sediment were first described that established this warm period. The warmest conditions are concentrated at the beginning of this period, the reason for which not clear. Perhaps it had to do with the import of heat from the south by a process associated with the filling of the northern seas with meltwater. The meltwater would have moved south on the top layer of the ocean (since its lack of salt makes it light). This meltwater would have entrained saltwater in this movement through mixing. The saltwater is then replaced by influx of ocean waters from the south. This well-known process is known as "estuarine circulation" and is commonplace wherever rivers enter the sea. The subsurface flow from the south could have brought heat to the north. Another possible mechanism for early warming is ocean circulation changes. The ocean is intimately involved in what is going on during deglaciation, and this is seen in the abundance of a cold-water planktonic foraminifer Neogloboquadrina pachyderma (sin.) (The "sin." refers the chambers in the protist that make a leftward spiral when looking at the earliest chamber and drawing a line to the later ones.). In glacial conditions, the ocean off Greenland is rich in this cold-water species, but in warmer conditions, this species rapidly disappears. In fact, this plankton indicates whether the place where the sea floor core was north of the polar front or south of it.


Dryas octopetala, after which the “Younger Dryas” was named.
The Younger Dryas
After the initial warm spell, between 14,500 and 13,100 years ago, there was a drop of temperature toward colder conditions that briefly reversed, but then remained long-lasting after 12,800 years ago. In fact, this drop near 12,800 years ago was precipitous and resulted in extremely harsh conditions. After much balmy weather in the British Isles and northwest Europe, permafrost was re-forming in the lowlands of Holland and northern Germany, and an icy wind blew (again) from the east. Chances are this was a major time of stress for mammoths, other great mammals, and people: the “Great Ice Giant” in Scandinavia was winning the fight. The sea level rise stopped entirely, and a great wall of moraines was built by the remaining Scandinavian ice cover during the time that followed, reaching from southern Norway through southern Sweden into southern Finland. This period of cold, the last attempt of the ice age to hold on, is called the "Younger Dryas," with the term "Dryas" being the name for the genus of an arctic flower growing on fields close to glaciers, found on top of the "Alleroed" layers of sediment in Denmark.The Younger Dryas ended as abruptly as it began. All through this grim period, the sun had stood as high as ever in the summer, and was larger than average, as Earth was now closest to its star when the days were longest. The additional summer heat was soaked up by the glaciers and perhaps by the oceans, until a threshold was reached. As before, when jumping into the Boelling-Alleroed from glacial conditions, the climate now jumped into the second step of deglaciation and again, the change in one person's (or one mammoth's) life time was truly extraordinary. The polar front in the North Atlantic rapidly receded to its present position, and all of Europe and much of the rest of the northern hemisphere benefited from this, as the Iceland Low took over to move heat from south to north.

Warming improved conditions for the growth of plants and any mammals that had made it through the grim climatic fluctuations of the Younger Dryas were now ready to expand. Alas, there may not have been many left to take advantage of this boon. The few animals that were present apparently were rapidly decimated by skilled hunters using increasingly sophisticated weapons and methods. This was a time for the expansion of people and reduction of everything else. It was the first great mass extinction of the last million years, and it started the domination of humankind over everything else on the planet. Sea level rose quickly, very rapidly at first and then slowing as the easy-to-melt ice was gone. Again, vast areas of low-lying coastal plains were flooded. River mouths drowned and estuaries such as Chesapeake Bay were created. Shorelines expanded and hunting and fishing were good.

Forests all over the planet expanded greatly, taking carbon dioxide out of the atmosphere. However, other processes kept pumping carbon dioxide into the atmosphere from the ocean because as sea level reached its maximum it began to flood great regions of carbonate shelves, and shell-making organisms responded vigorously. They extracted calcium carbonate from seawater to make their skeletons — corals and coralline algae, mollusks and foraminifers — and, in doing so, they changed the chemistry of the seawater, which could now hold less carbon dioxide in solution than before and gave it off to the atmosphere. Hence, corals helped transfer carbon from the sea into the forests. The speed of deglaciation helped in the transfer since things went too fast for the ocean to mix deeply while the change in chemistry was taking place. This prevented the effect of degalciation from being neutralized by reactions at depth, such as carbonate dissolution on the deep sea floor.


- excerpts from Climate Change- University of California, San Diego

[timeparticle]

Dated core correlating oxygen isotopes and earth’s magnetic reversals. This correlation allows dating of each isotope stage. (Modified from: Shackleton and Opdyke, 1973)
Shackleton’s Time Series & Fourier Analysis
Concerning our theme for this section, mammoth extinction and ice ages, it is clear that the concept of ice age terminations is of the utmost importance. It suggests that the abrupt climate change occurs during destruction of ice sheets, rather than during buildup (as originally hypothesized by Agassiz). Thus, if climate was important in governing population sizes of the Pleistocene megafauna (as seems reasonable) then the times of rapid ice decay were perhaps the most stressful and dangerous for survival.

The question of dating was greatly advanced by using magnetic stratigraphy to date a deep-sea core from the western tropical Pacific, a technique first established in 1964. Magnetic stratigraphy allows a geologist to date a rock or sediment by looking at the magnetic signal imprinted into it by virtue of the fact that Earth’s magnetic field periodically reverses. This discovery was put to good use in dating a large suite of cores from the Lamont's core library, and soon after, James Hays, a paleoceanographer at Lamont, had the splendid idea to tie oxygen-isotope fluctuations to magnetic reversal stratigraphy. He sent samples from a core that had been dated using the new paleomagnetic method off for isotopic analysis by Nick Shackleton (later Sir Nicholas) in Cambridge, England.

The result could not have been more significant. The first distinct magnetic reversal of the core, called the "Brunhes-Matuyama" reversal, was found to occur just before Isotope Stage 19, the 19th warm peak (counting the present peak as Number 1). The reversal had been dated (on land) as about 700,000 years before present. It was now possible to assign ages to each isotope stage, by interpolation. Stage 5e came out near 123,500 years. Bingo! A time scale was now available for the entire period for which Milankovitch had made his calculations.

The dated signals now became "time series," analogous to an oceanographer’s tidal records. Such time series are routinely subjected by engineers and physicists to "spectral analysis," a technique invented by the eminent French mathematician Jean Baptiste Joseph Fourier (1768-1830). Fourier showed how any time series can be represented as a sum of sinusoidal fluctuations (the Sines, Cosines and Tangents of trigonometry). When analyzing a series by the Fourier method, it emerges that some cycles stand out. Thus, “Fourier analysis” allows the identification of those cycles that are most important in a given time series.

When Fourier analysis was applied to deep-sea records in 1975, it emerged that the oxygen-isotope series contained strong cycles with periods near 100,000 years, 41,000 years, and 23,000 years. These are precisely the periods expected if Earth's orbital elements (eccentricity, obliquity, and precession) govern ice-age climates, as proposed by Milankovitch Theory. Thus, there could be no more doubt that orbital elements had to be considered as important drivers of climate on long time scales.

-excerpts from Climate Change- U.C. San Diego

[timeparticle]

Climate in the Spotlight


There has been much discussion in the media and in the political realm about the evidence for climate change in connection with the greenhouse effect and the expected global warming that goes with it. In fact, no other environmental issue has garnered more attention in our nation’s capitol than climate change and the associated debate over global warming. This issue has been the topic of countless hearings over the past several years, most of which have been essentially economic in focus, although some have dealt directly with climate change science.

The list of calamities that come with continued global warming is by now known to everyone: sea level rise, hot spells in summer, drought, floods, hurricanes, and perhaps even blizzards, among others. Each time there are unusually bad weather conditions the question arises whether perhaps global warming is to blame. Perhaps it is indeed at fault. Or perhaps there was an equal abundance of bad weather before global warming set in. Or perhaps the weather would have gotten worse without global warming. Or perhaps the weather is in fact no worse than it has been in the past, and we just notice things more now since we have more people, better instruments, and better communication. Another possibility is that perhaps global warming does not exist, and it is an illusion.

Full media attention to the issue first arose in the summer of 1988, which brought the worst drought in decades to the US. For many this was proof that the man-made greenhouse effect had finally brought the expected global warming. In fact, during the 1980’s one temperature record after another was broken. And then the same happened again in the 1990’s. Has global warming arrived?

Carbon Dioxide (CO2) Increase
Although it is only a trace gas having concentrations much less than 1% in our atmosphere, carbon dioxide’s tremendous increase from the combustion of fossil fuels since the mid-1800’s has had scientists worried about its potential to exacerbate what is called the greenhouse effect. The greenhouse effect is a phenomenon whereby atmospheric gases with special physical properties (like carbon dioxide, methane and even water vapor) help trap heat received from the sun, making our planet warmer than it would be otherwise. To its credit, the greenhouse effect has been around long before humans began to burn fossil fuels, and it is a “natural” phenomenon in that makes life habitable for all living things. The problem lies in the possibility that human activities over the past 150 years may result in an increase of this greenhouse effect that could, in turn, cause large-scale changes in the climate system. It is this potential for human-induced change in the greenhouse effect that we refer to as global warming. Since carbon dioxide has the highest concentration of all the greenhouse gases and is the most likely to cause us problems in the very near future, it is the greenhouse gas that has received the most attention in the debate over global warming. However, as we shall learn in later chapters, increased emission of other gases, especially methane, also pose a strong threat to the stability of Earth’s climate.


A graph of Dr. Keeling’s now famous curve of increasing CO2 concentration. The measurements are made at a station on top of Mauna Loa in Hawaii. Note carefully the magnitude of the increase from 1958 until present. We’ll discuss the seasonal variations (the squiggles) in Chapter 4. To link to the scientific article by Dr. Keeling and Dr. Whorf go to : Carbon Dioxide Information Analysis Center
The rise of carbon dioxide gas in our atmosphere has been measured continuously since 1958 and follows an oscillating line known as the "Keeling Curve," named after Dr. Charles David Keeling, professor at Scripps Institution of Oceanography. A renowned expert on the way carbon cycles itself on our planet, Keeling was the first to measure carbon dioxide in the atmosphere. He demonstrated its annual fluctuations (the little squiggles in the curve) and was the first to report that global atmospheric concentrations of carbon dioxide were rising. The concentration of carbon dioxide is given in units of parts per million by volume, also abbreviated ppmv. (For the more scientifically inclined: ppmv is the same as what chemists call the “mixing ratio” of a mixed gas, in this case the ratio of carbon dioxide molecules with all other air molecules, because equal volumes of gas at equal pressure hold equal numbers of molecules) Before the industrial era, circa 1800, atmospheric CO2 concentration was between 275 and 280 ppmv for several thousand of years (that is, between 275 and 280 molecules of CO2 for every one million molecules in the air); this we know from the composition of ancient air trapped in polar ice. Carbon dioxide has risen continuously since then, and the average value when Dr. Keeling ted his measurements in 1958 was near 315 ppmv. By the year 2000 it has risen to about 367 ppmv (that is 367 molecules of CO2 for every one million molecules in the air). Thus, it is higher than pre-industrial values by one third of the pre-industrial era. (You can check the math on your calculator.)

Global Temperature Increase
While this increase in carbon dioxide has occurred, temperatures in the northern hemisphere have risen by between 1°F and 2°F (almost 1°C) since A.D. 1850, as recorded by measurements. The record only goes back 150 years because direct measurements before 1850 are hard to find. The ten warmest years on record have occurred since 1983, seven of them since 1990. Global temperature in 1998 was the hottest in the historical record. This amount of overall increase in temperature is approximately equal to the amount of increase that is predicted by raising the abundance of carbon dioxide by one third of pre-industrial values – exactly what has happened in the last 150 years.

-excerpts from Climate Change- U.C. San Diego

Clearly, it's man's contribution for this sudden climate change.... 100%.

[G_burnett]

.....it is indeed a problem to note all the reasons as the solar system itself in linear spin moves through space never to return to the exact space ever again and as such we are hard pressed to note the little discrepancies in cause to such the constant new view in the all.

We can only say the (setofvaritables,then) approximate (the set of variables now) to an approximate percent for a prediction.

It is not an exact science. ...being thus our lack as human be the fact we are doomed to act only after the effect is felt and to such degree, ...ouch it burns.

let us all hope it is just the finger.

good articles.

Kind regards g.