[Humerox]

OK...here we go.

The "simple" argument that carbon dioxide levels in the atmosphere - and there is no doubt that CO2 levels have been rising because of humans but as to whether this is greater than even a single major volcanic event is questionable - because warming relies on assumptions that may be quite false.

More CO2 and it is possible you get more refraction at the equator (warming), but also more cloud (warming in the short term - seriously cooling in the longer term), a change in the albedo readings at all latitudes (warming or cooling depending on your theory). And this does not even take into account changes in so many other factors. The trouble is the study of climate with respect to these factors is all very new.

The best weather programs can get the weather right about 80% of the time in temperate climates now four days out. That is a major advance over the last 50 years but try for seven days and the same programs are about as good as throwing darts at a board listing "hot", "cold", "rain", "clear".

Personally, I think the earth is currently warming, man-made or not, which is actually a good thing considering a cooling event in contrast. Which is what we worried about in the 70's... and I'll get to that in a minute.

Had the earth not changed to an interglacial period when it did, civilization would not have happened. That it lasted 11,000 years meant that man could actually develop civilization to a point that even a glaciation is probably not going to put us back in the stone age. If cooling had occurred when the mini ice age occurred about three hundred years ago, man would have gone right back to the stone age. That is pretty amazing.

Warming? Another few degrees and the earth will be able to support far more agriculture than it presently does. Rainfall patterns would change dramatically so that the arid parts of Australia would become breadbaskets, as would more of Canada, parts of Africa, China and Russia. The downside is unlike the nice predictions of a few calorimeters of sea level rise, a real global warming will cause a very sudden shrinking or elimination of ice caps and major sea level rises, killing a great many of the world's population.

But far worse for mankind would be a glaciation. The last model that I saw indicated the loss of around 90% of the world's population in 3 years and getting up to only a 2% survival 5 years out (this assumes a three year changeover or flip between interglacial periods and glaciations - a theory that does have significant evidence in support of it even if the prevailing teachings state that the change takes in the order of thousands of years).

Which would you rather have? Problems because of warming that mean dislocation and movement of large amounts of the population but little loss of life due to starvation, etc, or a change something akin to the movie The Day After Tomorrow (I don't agree with the theories in that movie but I do agree with just how catastrophic a cooling event would be).

I can only follow some of the studies and have not seen any detail of the latest study that suggests rapid loss of arctic ice coverage. I'll say that even the broad brush stuff that I have read, does not give me much faith in the validity of the predictions. If the ice coverage were really to melt as predicted, then it would ALL melt.

The difference in the albedo readings of Greenland's ice coverage and Greenland without ice in the same places, is staggering. It goes from about 95% to about 35%. Thus the area warms rapidly as the ground warms up and the air close to the ground follows suit, and this warming then causes the ice fringes to melt, resulting in an accelerating process. The best estimate of the last thaw across North America was that at its peak when the retreating snow/ice coverage managed to reach around 50 kms per day.

Yet the assumption of this study seems to be that the arctic warming will do no more than melt a percentage of the ice coverage. That just does not accord with historic evidence of both northern hemisphere retreat and return of ice in the last several cycles.

Climate is so complicated that even working out what should be happening to a single glacier has proved to be nigh on impossible. Much of the glaciers in the world are historic remnants. Except that glaciers create their own mini climates, most should have melted thousands of years ago. Most have been retreating, sometimes rapidly and sometimes slowly, ever since the warming 11,000 years ago. Maybe - because this interglacial period is somewhat longer than has been the norm - we have finally reached the point where glaciers no longer are able to exist.

Actually, I remember a theory of some time back that glacial retreat could actually be the cause of climate warming, when it reached a certain, unknown, critical point.

I do not believe that any scientific evidence has been established yet that the world is warming other than because it has been in an interglacial period for a long time, or even if the longer trend is for continuing warming.

I remember some years ago a major study was published concerning ocean temperatures. It was very detailed and the figures did seem to show the air temperatures just above the world's oceans had risen over the last 50 years. But there was a major flaw. The statistics were taken from ships records. The temperatures recorded had no controlled environment or a fixed methodology. Indeed, as ships became much larger, the distance between the ocean surface and where the temperatures were measured increased dramatically. Now the study authors had suggested a formula to take this into account (although this was not in the major findings of the report) but the formula seemed to be no more than a guess. Since the variables are immense, no simple formula can account for enough of them to return an accurate comparison.

The same thing seems to happen with land temperatures but in a much more biased way. Most people with an interest in climate change or even recent historic weather for an area, are aware that, the trend has been for the last 80 years for land temperatures in the northern hemisphere to increase in cities and decrease in smaller communities. It would seem that temperatures for major cities are used in most studies with a formula attempting to negate the heat sink effect of massive injections of concrete into the hearts of those cities, and the major increase in application of heat absorbing and retaining materials in the surrounding areas of the city.

I have yet to see any scientific study that shows a way to actually determine just how much a change this has caused. In order to do that, you need the temperatures to remain stable somewhere, so that the change in the city structure can be seen as the reason for any average temperature change. The trouble is there is no such thing as a stable temperature. Even in the most stable of periods in the earth's cycle of warming and cooling, there a fluctuations, year to year, and for several years at a time.

The suggestion should be to only use land temperatures where the temperatures have accurately been recorded at exactly the same location for the study period, in a town with a population of no greater than 5,000, at least 80 kms from any city, where the recording area has not had any major change to its environs such as even a three story building being built within several hundred meters of it, or a car park being paved over, or even major trees being changed. One very big problem is that temperature recording equipment is periodically changed and in small towns, no one goes to the trouble of making sure that the new piece of equipment matches the old or a deferential is calculated and clearly inserted into the records.

Even with all these problems, there are enough small towns that fit the criteria for studies to be done. They just do not seem to be done for any climate warming studies.

You do not have to go back very long in time to find most earth sciences did not agree with plate tectonics as the major shaping force of our earth and its climate. Yet even though the scientists were in the vast majority, they were wrong. So I do not believe that because anyone can suggest that there are 25,000 scientists who accept global warming and a small number who do not, that this suggests anything other than once a theory gains favor it stays in favor, even in the face of damming counter evidence.

A study of glacial retreat proves nothing but glaciers melt in interglacial periods - eventually. It might be that they are melting because the earth is warming but a study on the retreat does not prove that or even suggest it.

The fact that northern hemisphere winters have actually been worse in the past few years also does not suggest that global warming is not occurring. The climate has not become more violent or unpredictable. While records have been broken with the number of Atlantic hurricanes recently, records are always broken,and overall, the frequency or severity of hurricanes or any other major climate event does not seemed to have taken a dive for the worse. The cause more damage because more people live in the areas and because of stupidity - such as building bridges and levies not capable of withstanding the force that a hurricane will one day exert.

A 1979 study matched the years 1974-1979 to the years that preceded the last switch to a glaciation, from the evidence then available. This was a time when there was real concern about cooling. The then Soviets had managed to have five major wheat harvest fiascos because of temperature drops, areas in Canada had much greater ice flows than a decade before, snow fell and stayed on the ground much further south in Europe, parts of the Soviet Union and North America than for the previous decade. Many animal species seemed to be responding to triggers that had not been recorded by civilized man, some winter coats were not changing in certain species back to summer coats, some herd and pack behaviors had been observed to have changed to what some specialists suggested was the behavior required during a glaciation. But 1980 proved to turn it all around. There were several factors for this but all were events that were "special", thus seeming to alter the balance enough to stop what might have been a slide towards cooling.

Personally, I was very glad it happened. I didn't want half of the Soviet Union to starve. That might have started WWIII.

Global warming? It's possible. Has the scientific community proved it yet? Not in my view. Is it going to wreck the world? Much less than a cooling cycle.

As to the world's climate, the only real assumption that one can make with total accuracy is that the world's climate is not a static thing and the earth will get warmer and cooler several times in the next 100,000 years. A cooling event is likely to kill off much of the world's population (which might be a good thing if you are a member of PETA or believe that the world cannot keep on supporting us humans without it eventually being destroyed by pollution, the using up of fossil fuels, loss of habitat and the earth's lungs in the form of forests, etc).