Arctic to lose all summer ice by 2100

Typedef

http://www.newscientist.com/hottopics/climate/climate.jsp?id=ns99993138

The Arctic Ocean will be completely devoid of summer ice before the 21st century has ended, a NASA study predicts.

The new work shows that the permanent ice cap over the ocean - the cover that survives through the warm summer months - is disappearing far faster than previously thought.

Between 1978 and 2000, 1.2 million square kilometres of apparently permanent ice melted away. That is an area five times the size of Britain and represents a loss of nine per cent per decade.

"At this rate, permanent ice will have disappeared before the end of this century," says NASA ice physicist Josefino Comiso.

If this prediction is correct then the consequences of such a cataclysmic release of extra water into the environment would be hugely apparent for all.

I can't imagine what would happen if so much extra water would be present in oceans, but, one thing is for sure, flooding would be more commonplace then it ever was before.

This is an impending problem that effects most people living 'now' within our lifetimes, if the prediction is correct.

Yes, people can prattle off statistics about how some random (and singular to my knowledge) criteria has found sea levels to have dropped over (n) years in 'one' region of the planet. What this sort of evidence does in my opinion, is, cast a blinkered blind eye to phonema such as El-Nino and La-Nina, the fact that Ice caps are melting (and the water is not simply disappearing).
What is likely and indeed evidenced by fact that the wettest years on record have in fact been in recent years is that in a warmer world, evaporation and hence precipitation is where the water is going.

Global Warming May Lower Sea Levels



Last week we reported on Fred Singer’s Cooler Heads briefing to congressional staff and media where he argued that on decadal time scales there is an inverse relationship between global temperatures and sea levels, due to sea surface evaporation that transports moisture to the polar ice caps.

http://www.globalwarming.org/sciup/sci10-27-99.html

I find it worrying in the extreme that people can simply pretend that global warming has somehow been fixed by the banning of leaded petrol and eradication of CFCs.

Victor

It's not a sea-levels / flooding issue, the displacement occupied by the free ice in the Arctic is more or less the same as the displacement of the equivalant mass of water. It is an issue for on-land ice and especially for Antarctic and Greenland ice and for water expansion elsewhere. It is also a major ecological issue.

Keeks

I don't think it will be as dramatic as that. I can't see the hole lot of the artic ice disappearing. I think it a little bit of an overreaction.

Granted that the ice packs are receding and the overall ice thinknes is receding. But how do we that this isn't natural? We have onlt data going bak 100-150 years.

From what i know from history this seems quite natural. From the 9th through the 13th centuries founded colonies in Iceland and Greenland, a region that may have been more green than historians have claimed. It was also during this period that Scandinavian seafarers discovered ‘‘Vinland’’—somewhere along the East Coast of North America. At the time it was believed that the temperature in this region was 1-2 degrees higher than now. Agriculture was possible in Greenland then but not now. But a subsequent cooling of climate (Known as the Mini Ice Age) cut off the colonies in Greenland from Europe as Ice Bergs drifted futhur south in Greenland from Europe, and they eventually died off.

bonkey

Not trying to play down the discussion, but am I the only one who gets really annoyed to see so-called science magazines printing tripe like this :

Between 1978 and 2000, 1.2 million square kilometres of apparently permanent ice melted away. That is an area five times the size of Britain and represents a loss of nine per cent per decade.

Last time I checked, Ice had volume, not area. Without the thickness of the ice, or (more simply) the total volume melted, as opposed to the total area this volume covered, this is sensationalist pseudo-information rather than anything terribly relevant.

I would also question Comiso's statement of the melt being "irreversible". Surely if his reasoning held true, then there could never have been multiple ice-ages, as once the ice had reached its "irreversible" melting point at the end of one age, then it would never have come back again.

I would imagine that he means "irreversible in our lifetime", or "irreversible by human intervention", or something else.

I find it worrying in the extreme that people can simply pretend that global warming has somehow been fixed by the banning of leaded petrol and eradication of CFCs.

No offence Type, but there is still no clear evidence as to how much of this temperature raise is actually caused by human effects on the environment. You can pick and choose your reports to suit your argument, but the simple truth is that there is no general consensus within the scientific community as to the degree of influence man has actually had. What is virutally unanimous is that it is caused by a combination of natural and man-made factors. There the differences come in is on what extent each one figures into the equation.

(also, wasnt lead removed from petrol because of its environmental poisoning...not because of global warming)

I agree that we should cut down on emissions etc. But I have that stance regardless of whether or not the emissions contribute to global warming or any other direct or indirect pollution.

I find it worrying that people believe global warming can be "fixed". It makes the automatic assumption that none of it is natural, and that there is something wrong with it. This is as dangerous an assumption - in my opinion - as the assumption that nothing needs to be done.

Consider this : if science came out with incontrovertible proof tomorrow that global warming was a natural phenomenon, and mankind's impact on things was negligible (say it brought the schedule forward by a couple of centuries, but that the schedule was inevitable), what should we do? Should we then turn all of our scientific prowess to counteract nature to maintain a preferable living habitat for ourselves, or should we accept that this is the way that nature wants to go, and we should just go with it?

jc

Victor

Originally posted by bonkey
Between 1978 and 2000, 1.2 million square kilometres of apparently permanent ice melted away. That is an area five times the size of Britain and represents a loss of nine per cent per decade.

Yes this does seem to have fallen foul of the journalist not knowing how to present statistics. However if the ice cap has substantially reduced in area, it can also expect to have thinned (not that free Arctic ice is a that think).

Originally posted by bonkey
I would also question Comiso's statement of the melt being "irreversible".

I suspect what they mean is that once all the ice melts, it would need a substantial drop in temperature to create a "sustainable" mass of ice again. Experiment: put one ice cube in a glass of cold water (in a cold room) every hour for ten hours, put ten ice cubes once in another glass of cold water next to it. Which will have (or more likely to have) more ice after ten hours?

Originally posted by bonkey
I find it worrying that people believe global warming can be "fixed".

Perhaps it can't, but that doesn't mean we shouldn't (a) try (b) moderate out contribution to the problem.

Originally posted by bonkey
Consider this : if science came out with incontrovertible proof tomorrow that global warming was a natural phenomenon, and mankind's impact on things was negligible (say it brought the schedule forward by a couple of centuries, but that the schedule was inevitable), what should we do? Should we then turn all of our scientific prowess to counteract nature

I suspect you are playing devils advocate here, but I would say we would need to do two things (a) moderate nature, just as we do anytime we build a house, a road, a dam (or even put on a warm coat) (b) work towards relocating communities away from danger areas, everywhere from Sandymount to Bangladesh.

bonkey

Originally posted by Victor
I suspect what they mean is ...

I'd tend to agree, but again, it seems to be a journalist not knowing how to put forward a simplified statement accurately. If this were an article in the Irish Times, but a regular journo with an interest in the occasionaly sciency bit, I could understand.

Coming from anything which purports to be a scientific magazine is just plain annoying. If I wanted inaccurate and potentially misleading soundbites, I'd read a tabloid.

Perhaps it can't, but that doesn't mean we shouldn't (a) try (b) moderate out contribution to the problem.

Agreed...but not quite my point. If we've done all we can realistically do, and it turns out to be not enough, where do we go? Look to pro-actively affect the environment to stave off changes we dont want, or accept that this is happening and learn to cope?

I suspect you are playing devils advocate here,

Absolutely. I'm just interested in seeing where people think the line should be drawn in terms of what is and is not acceptable interference with nature.

jc

Keeks

Originally posted by Victor
but that doesn't mean we shouldn't (a) try (b) moderate out contribution to the problem.

But first we must try and find out what exactally is causing the problem.

As bonkey stated you can pick and choose reports to suit your argument. But not only that you can pick and choose data to suit your argument

With referenece to global warming the temperature has increased by 0.4 - 0.8 celcius over the past 150 years. This is fact and data is taken from measurements.

What you don't see from that statement is that the warming took part in during two periods. From 1910-45 and 1979-present. Around 1970 the big envionmental worry was global cooling not gloal warming.

Also you're not told either is that solar brightness has increased by 0.4% during the last 200 years which is blieved to cause a 0.4 celcuis increase in temperature.

Also you're not told what effect cloud cover has on temperature. It has both a cooling and warming effect depending on the clouds height from the ground.

There are more and more. History is full of events that were caused by climate change. Why should it now be that climate change is suddenly casued anthropogenically?

Typedef

Proposition.

Millions of years of carbon stored in fossil fules, beneath what used to be sea beds, are burned, thus releasing carbon dioxide, carbon monoxide and a lexicon of ancillary yet, important green house gasses.

Ice caps are seen to be melting quite significantly, due to a warmer global climate.

So, due to human activity, millions of years woth of pent up carbon and other gasses (which warm the atmosphere) are being released in ever greater amounts and at ever greater rates.

Furthermore, trees and other naturally occuring forms of carbon catalysers are continuously being reduced again, due to human industrial activity, so, the ability of the environment to process greenhouse gasses is being constantly degraded.

Thus it is illogical in the exteme to suggest that the burning of fossil fuels and the millions of years worth of carbon contained in such substances being released into the atmosphere (as known green house agents) is not warming the planet and that such warming is in no way connected to the melting of Arctic Ice.

Yes the planet goes through cycles of heat and cold, that is a matter of historical fact, however what is not a matter of history, is so much gas which contributes to the warming of the planet being present in such massive and increasing amounts, with a lessening means of catalysing that gas.

If the planet is going though a natural warm period, I'd like to see evidence aside from human caused damage to the envrionment that is causing the warming. A different orbit of the planet, perhaps. Currently some quarters expect reasonable people to swallow the theory that all the extra green house gases being relased by man, and the reduction of the planet's ability to catalyse such gasses, is in no way connected to global warming, a fundamentally illogical proposition, in actuality, or, at least, in my opinion.

Here is some interesting reading on the possible causes of Ice ages and climate change in general.
http://abob.libs.uga.edu/bobk/ccc/ce120799.html

To understand the cause of
interglacials we must look to catastrophic events. The impact of a
comet-sized object into a major ocean appears essential to the ending
of an ice-age. An object of mass 1016g would have sufficient energy to
throw up some 1020g of water into the stratosphere, immediately
creating a powerful greenhouse effect as the water spread around the
world to give some 10 g of precipitable water per cm2. Such a
greenhouse effect lasting for some months, and at a lesser level for
several years, would produce a sufficient warming of the surface waters
of the ocean to jerk the Earth almost discontinuously out of a long
drawn-out ice-age into the beginning of an interglacial.

The 18O/16O analysis of Greenland ice cores shows that an immense
melting of glacier ice began about 13,000 years ago and was essentially
completed within a millenium. But this information is slow-moving in
time, although it possesses the great merit of being of world-wide
significance. On a more restricted geographical scale, fossil insect
records show that the summer temperature in Britain rose by 10oC or
more in as little as 50 years, an essentially decisive indication of a
catastrophic event as its cause. The fossil insect record also shows
that a second catastrophic event of a similar nature occurred 10,000
years ago, again with a major temperature rise in only a few decades

If a large meteor ended the last ice age, then what, if not man's industiral activity is 'causing' global warming. Unless you can acutally evidence how (as in give a good reason other then, "the planet goes though cycles 'apparently' that we don't understand") the current appreciable state of global warming, then I'm afraid it seems quite unreasonable to accept arguments such as.
"Yes the earth is warming, for some unknown reason, but, it's definately, 'nothing' to do with the massive amounts of green house gasses relased by man".
Err, sorry, try again, that sort of argument, for me, at least, just doesn't cut it.

bonkey

Originally posted by Typedef
Yes the planet goes through cycles of heat and cold, that is a matter of historical fact, however what is not a matter of history, is so much gas which contributes to the warming of the planet being present in such massive and increasing amounts, with a lessening means of catalysing that gas.

But the history of it showd that this "so much gas" that you speak of is a relatively tiny increment of the overall natural global emission. 1-2 percent, if memory serves correct, is all that we have added to the total greenhouse effect through industrialised emission.

You can insist that it is a significant amount all you like Type, but the simple fact ios that the scientific community lacks virtually all sense of agreement when it comes to deciding how significant these emissions have been in terms of global warming. It may be nothing more than 1 degree over 1000 years, or it could be orders of magnitude higher. At the low end of the scale, its effects are below those of many natural climactic-influencing phenomena that we are already aware of. At the high end of the scale, yes, it is disastrous.

The point is, however, that we simply do not know where we are on the scale, and no impassioned plea based on vastly simplified figures is going to change that.

"Yes the earth is warming, for some unknown reason, but, it's definately, 'nothing' to do with the massive amounts of green house gasses relased by man".
Err, sorry, try again, that sort of argument, for me, at least, just doesn't cut it.

I agree. It cuts it about as much as the "its all due to man, man. We are the cause of it all, and if we don't realise it and stop what we're going, then the world will be one giant desert in a couple of generations as global warming gets out of hand".

The truth lies in the middle. Somewhere. And when the top experts in the field cannot agree where that somewhere is, I think that the best any of us can do is listen to what all of them are saying, rather than cherry-picking the arguments which suit a pre-chosen position.

jc

Keeks

As you say bonkey, the scientific community is plit on how much we have contributed to global warming. The IPCC has 40 different senarios and predicts that by 2100 the temperature will increase by 1.5-4.5 deg C. It arrrives at this scale by usung computer models. But when the data for the past 50 or so years in feed into the same computer models it predicts that the temperature for now is 2-3 degs above what it actually is.

I think too the the scientific community is trying to dictate what decisions the governments and policymakers do. This is delt with nicely in THe Skepticla Envionmentalist

When the three IPCC Summary for Policymakers were approved, they were also rewritten by government-appointed scientists. From the previous IPCC report, it was well known that the most important statement would be about the human culpability in global warming: "the balance of evidence suggests that there is a discernible human influence on global climate". Consequently, here was considerable discussion over the formulation in the new report. In April 2000, the text was supposed to read, "There has been a discernible human influence on global climate. In the October 2000 draft, it was stated, "it is likely that increasing concentrations of anthropogenic greenhouse gases have contributed substantially to the observed warming over the last 50 years." Yet, in the official summary, the language was further toughened up to say that "most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations." When asked about the scientific background for this change by New Scientist, the spokesman for the UN Environment Program, Tim Higham, responded very honestly: "There was no new evidence, but the scientists wanted to present a clear and strong message to policymakers".

Likewise, when discussing the costs and benefits of global warming, the October 2000 draft stated (in accordance with the background documents and as cited earlier here), that "in many developed countries, net economic gains are projected for global mean temperature increases up to roughly 2 deg C. Mixed or neutral net effects are projected in developed countries for temperature increases in the approximate range of 2 to 3 deg C, and net losses for larger temperature increases." Such a statement of net benefits from moderate global warming would naturally have been much quoted. However, the statement in the final Summary was changed to: "an increase in global mean temperature of up to a few degrees C would produce a mixture of economic gains and losses in developed countries, with economic losses for larger temperature increases."

Typedef

Originally posted by bonkey

The truth lies in the middle. Somewhere. And when the top experts in the field cannot agree where that somewhere is, I think that the best any of us can do is listen to what all of them are saying, rather than cherry-picking the arguments which suit a pre-chosen position.

jc

Which, with all due respect, seems like a quite conveinent deflection of the proposition I have posed.

Man, is releasing mega tons of green house gases and the climate of the planet is warming, so, unless you or anybody else can pose a realistic alternative to the reasons for measurable climate change, I think it is highly illogical and perhaps even blinkered to deny in perpetuity that mega tons of green house gas released by man, isn't the actual cause of climate change, on the basis that some, unknown, unpronounced phonema is.

I won't lecture you on the logic.

bonkey

Originally posted by Typedef
Which, with all due respect, seems like a quite conveinent deflection of the proposition I have posed.

No - its a criticism of the fact that your proposition appears to be based on choosing the articles you want to believe, presenting them, and then arguing that these facts present a "logical" conclusion.

Of course they do - thats why you chose the facts/reports you did. If you chose the ones which counter your argument, your conclusion wouldnt be so obviously logical.

All I am doing is pointing out that those other reports exist, and that there are other points of view - and that the top scientists in the world cannot agree that your logical position is the correct one.

Now, if you call that "handy deflection", fair enough.

so, unless you or anybody else can pose a realistic alternative to the reasons for measurable climate change, I think it is highly illogical and perhaps even blinkered to deny in perpetuity that mega tons of green house gas released by man, isn't the actual cause of climate change, on the basis that some, unknown, unpronounced phonema is.

Type - no offence - but what are you on about?

You begin by agreeing that the scientific community is split on how much we have influenced it. I have taken the stance that we do not know how much we have influenced it, and yet here again you are making some case about the illogicality of assuming we havent modified it at all. When have I ever made or supported that position? When has anyone here made or supported that position? What we are saying is that while man and his gasses has had some influence on the environment, it is far from clear what the influence has been, and it is far from clear that there arent other effects also in operation - potentially more significant ones at that.

Up until relatively recently, there was no rational explanation for global warming. Now, you would argue that because we have found what we believe to be one of many possible significant factors in global warming, this must be the one which is significant. After all, the others are all some "unknown phenomena" and this one is identified, so it must be the cause.

I notice that you also continuously refer to these unknown phenomena, despite the fact that many of them are not - in fact - unknown at all. What is lacking in all of them is a direct quantification of how significant a factor they are. Strangely enough - this is exactly the same factor which is missing from the cause you wish to use (greenhouse emissions) in your "logical conclusion", but you're conveniently ignoring that. You're happy to assume that there must be a connection because you want there to be one, but - for example - the 4.5% increase in solar output matching up to the temperature "burst increases" (which are strangely almost exactly the size such a solar output increase should lead to) is classified as some unknown phenomenon which is clearly illogical and not worth considering.

50+ years ago, your logic would have led us to the inescapable conclusion that the tar in roads was a driving force behind the mass of ill health effects which happened almost in synch with the massive increase of modern roads. After all, that was the logical conclusion based on the known facts, the synchronicity of the road-building and the ill-health, and everything else that was known. Any other explanation required an "unknown phenomenon", and as you point out - thats just plain illogical and blinkered.

Once we had identified that tar could be the cause, even though it coulnt really fit the data correctly, and anything else would involve some "unknown phenomenon", your logic would dictate that looking for other causes was blinkered and illogical.

Funnily enough, it was the emissions from the vehicles on the roads causing the problem.

You mention a model which cannot account for today's temperatures. You neglect to mention that no model has been built which can take any accepted figures for greenhouse gases and produce results which match the current reality either. Does this mean that by your own reasoning we shouldnt accept that greenhouse gases are the problem either?

At the end of the day, Type, no-one is arguing that emissions should not be reduced. At least, no-one posting here is.

All I am saying is that there is a right and a wrong argument for why they should be reduced. The "undeniability" of these emissions being the key factor in global warming is - as far as I am concerned - the wrong argument, because it is far from a cut-and-dried issue, and it is far too easy to present alternate scientific points of view that guarantee your conclusion is, at best, shaky. Presenting a shaky conclusion as the definitively and undeniably correct one is a sure way to get dismissed as little more than a crackpot or conspiract theorist, which is exctly how the major industrials try to deflect the arguments in the first place.

The undeniability of their pollutive effect in general, and the strong probability of their being at least a non-trivial contributor to global warming is a better reason, and one which is much harder to dismiss. It may lack the emotive impact that grabs headlines, but it is still a more true representation of what we know, rather than what we choose to believe.

I won't lecture you on the logic.

Thats quite alright. I had a formal education in it.

jc

Keeks

Originally posted by Typedef
Man, is releasing mega tons of green house gases and the climate of the planet is warming, so, unless you or anybody else can pose a realistic alternative to the reasons for measurable climate change, I think it is highly illogical and perhaps even blinkered to deny in perpetuity that mega tons of green house gas released by man, isn't the actual cause of climate change, on the basis that some, unknown, unpronounced phonema is.

I won't lecture you on the logic.

I know we were on about cheery-picking data b4 to suit arguments but this is a little passage taken from the IPCC report on climate change. It also goes someway to explaining what this topic stated out with.

Recent surveys of the Arctic Ocean (Quadfasel et al., 1993;
Carmack et al., 1995; Jones et al., 1996) have revealed a subsurface Atlantic-derived warm water layer that is up to 1°C
warmer and whose temperature maximum is up to 100 dbar
shallower than observed from ice camps from the 1950s to the
1980s, as well as from ice-breaker data in the late 1980s and early 1990s. Warming is greatest in the Eurasian Basin.

Now from elswhere within the IPCC report it states that the world has warmed on average 0.6 deg C (land surface temp) over the past 100 years or so. Yet the above passage states that Water from the Atlantic is 1°C in the last 50 years. Now if I remember from physics class that water takes longer to heat than land.

So how would the masses of greenhouse gases effect the temp of the water in the Atlantic?

If the greenhouse gases are at fault for this increase in the water temp, then why hasn't the land temp increase by much more?

Also with a temperature increase like that it is no wonder the ice is melting. I haven't gone far enough into the report to find out the answer, but as soon as I do I will come back here.

At the end of the day, Type, no-one is arguing that emissions should not be reduced. At least, no-one posting here is

I might take up that argument......someday. It might be interesting to see where our priorites lie

Victor

Originally posted by Keeks
Now if I remember from physics class that water takes longer to heat than land. So how would the masses of greenhouse gases effect the temp of the water in the Atlantic?

Land also cools quicker, by using data from 50 years agoa nd 100 years ago, you are falling foul of the selective data issue.

Keeks

Originally posted by Victor
Land also cools quicker, by using data from 50 years agoa nd 100 years ago, you are falling foul of the selective data issue.

Not really becasue the increase in global temperature is mainly caused by warming winters and not an overall temperature change during all the season

Typedef

Not trying to be provocative, however with two (or is it three) rebuttals of human caused greenhouse gas as the main cause of climate change, I have counted 'so far' one, alternate explanation for global warming.

Increased solar activity. Both are undoubtedly factors in global warming. While greenhouse gas emissions are in the power of humans to reduce, increased solar activity is not. In any case solar flare activity is a cyclic phonema.
http://hesperia.gsfc.nasa.gov/sftheory/flare.htm

To my knowledge global warming has been happening appreciably for quite some time longer then eleven years and in the abscence of a different orbit for earth, a signifcant impact event (to cause global warming)[1], increased volcanic activity or long-term increased solar activity (not meaning cyclic solar flares), I personally think that the exponential increase in green house gases over the last fifty years or so, must be, logically the only tangable reason for global warming.

Without doubt, there are a number of factors which contribute to global warming and there is no one accepted paradigm as to the why, the earth is warming, but, for me, the only new factor introduced over the last one hundred years or so, seems to be human created greenhouse gas and is therefore, to my mind the principal rational exponent of global warming. That is not a cherry picked causality to support my argument, simply what I regard to be good disjunctive logic.

If the greenhouse gases are at fault for this increase in the water temp, then why hasn't the land temp increase by much more?

Keeks how can you seriously doubt that releasing millions of years of stored up greenhouse gases from fossil fuels (and other sources), whilst diminishing the ability of the planet to respire to terraform the gas (for want of a better acronym) is in fact the principal cause of global warming, without offering a single plausable alternative? If not the megatones of released greenhouse gas, then what? Solar flares, are cyclic and there is no increased volcanic activity to account for the change.

Now from elswhere within the IPCC report it states that the world has warmed on average 0.6 deg C (land surface temp) over the past 100 years or so.

Funnily enough you mention the last one hundred years as the span that the world has been warming significantly, funnily enough, it has been over the last one hundred years that humans have been burning fossil fuels in ever increasing amounts and releasing ever greater amounts of greenhouse gas into the atmosphere, there has been over this period, no continual factor, that anybody else has named that could reasonably cause global warming.

Sherlock Holmes
"When you eliminate the impossible, whatever you
have left, no matter how improbable, must be the truth."

Keeks

Type, you stated above that the planet goes through cycles of heat and cold. That it was a matter of historical fact.

So why are you drawing the simple conclusion, that the heat casued over the last 100 years was cuased by green house gases and not by natural cause when for thousands of years the earth has been heating and cooling itself natually. Why are the last 100 years different?

The whole climate euation is NOT a simple one. You can't just add CO2 to increase heat. It doesn't work like that. If you look at a graph of the temperature increase over the last 150 years you will see that the global temperature increase during two ditint periods. 1910-45 and 1979-present. The peorid 1945-79 the temperature cooled or a least stayed stable. Why? The grenhouse gased tdidn't just stop. If some can explain that to me. Scientists can't

You've got other factors to taken into consideration. Cloud cover, aersols (small particles), solar illuminance, El Nino, La Nina, The north atlantic oscillation, heat islands, ocean salinity etc.

there are more factors than just greenhouse gases. And plus like I stated in another thread, water vapour is the biggest greenhouse gas, contibuting 98% to the greenhouse effect.

The release of millions of years of stored up greenhouse gases from fossil fuels is not the real problem when burning them. It is the aerososl (small particles) that are the problem. These has a far greater warming effect. The burning of orgainc carbon has been shown to release aersol that have a colling effect where as black carbon (fossil fuels). But you got to remember that they were part of the carbon cycle at one stage.

I'm suggestion that greenhouse gases aren't a source of global warming. I just saying they are not the main source.

bonkey

Originally posted by Typedef
Not trying to be provocative, however with two (or is it three) rebuttals of human caused greenhouse gas as the main cause of climate change, I have counted 'so far' one, alternate explanation for global warming.

And the tar in roads is the main cause of respitary failure subsequent to the mass increase of roads in the past century? Yes? This conclusion was "logically" reached by experts applying the same degree of logical rigour that you are doing here - the "we have a possible culprit, so lets call it THE culprit and be done with all this pfaffing around" approach.

I personally think that the exponential increase in green house gases over the last fifty years or so, must be, logically the only tangable reason for global warming.

And as soon as you can explain why the experts who study this field for a living cannot reach broad concensus on this "logical" conclusion, your continued reiteration of "it is the most logical answer" may actually hold some weight. It is only the most logical answer if we assume that there are no other factors where we may not be full aware of their significance.

That is an assumption that "good" science - especially in a field as complex and not-entirely-understood as planetary dynamics - will never make.

but, for me, the only new factor introduced over the last one hundred years or so, seems to be human created greenhouse gas

Not in the slightest. Mans increased industrialisation in general has caused untold levels of change the the entire biosphere. Oceans - both the largest environment on earth, and the one we are least informed about - have had countless changes imposed on them : from straightforward pollution coming out of rivers to noise pollution from massively increased shipping traffic. We have virtually no idea of the impacts of this on the ocean....and it is beyond question that the ocean is a major contributor in terms of both CO2 emissions and CO2 scrubbing.

Now - these may be man-made problems as well, but they are not a problem connected to man's emission of greenhouse gases....which up until the post I'm replying to was the only major cause you were backing.

simply what I regard to be good disjunctive logic.

And bad science to boot.

Like I asked - Are respitary problems caused by the tar in roads? Your "good disjunctive logic" says that it is, and my "good science" says that there is not enough evidence to reach that conclusion. Guess which one fails this test?

Keeks how can you seriously doubt that releasing millions of years of stored up greenhouse gases from fossil fuels (and other sources), whilst diminishing the ability of the planet to respire to terraform the gas (for want of a better acronym) is in fact the principal cause of global warming, without offering a single plausable alternative?

Ahhh - so its no longer greenhouse emissions, but now its greenhouse emissions, and the removal of natural "atmosphere scrubbing" ability, and the increase in solar activity (admitted earlier in your post) which is the cause....

But greenhouse emissions are still "logically" the most significant factor, because...ummm...why exactly?

jc

Typedef

Originally posted by Keeks
Type, you stated above that the planet goes through cycles of heat and cold. That it was a matter of historical fact.

So why are you drawing the simple conclusion, that the heat casued over the last 100 years was cuased by green house gases and not by natural cause when for thousands of years the earth has been heating and cooling itself natually. Why are the last 100 years different?

It is not disputed that CO2, methane, Nitrous oxide and CFCs cause warming. Nobody has offered a single shred of evidence to suggest any other tangable reason for global warming bar, greenhouse gases.

According to the enfo pamphlet on global warming the greenhouse effect is 3-10 times greater today, then it was in the period 1860-1960 and moreover, this net increase in the greenhouse effect over the last 30 years, is directly attributed to CO2 in the main. So I'm citing government sponsored information, that is predicated up through to EU level and a government sponsored policy of Greenhouse emission reduction exponenciated through things like the Kyoto protocol.

The government pamphlet on Global warming effectively blames the rise in CO2 and methane over the last 30-40, for the what it calls (radiative forcing) aka the Green House effect.

These gases trap Infra Red radiation from the Sun and this causes warming of the climate. More Greenhouse gas and the ability to process this gas has a direct correlation to the amount of heat that gets trapped by this gas again, none of this is in dispute.

And as soon as you can explain why the experts who study this field for a living cannot reach broad concensus on this "logical" conclusion

Again jc, the Kyoto protocol and the exponenciation of forest development are predicated policies that have come about from inter-governmental level to counter act the greenhouse effect and as warming as it would be, to believe that such policy was enunciated by government's on their own, the simple fact is that said policies about Greenhouse gas reduction have arisen because scientists are in the main agreed that yes Greenhouse gases trap solar heat and this heat in turn warms the planet and I would be shocked to find any scientist (of repute or otherwise) who would suggest anything different.

now its greenhouse emissions, and the removal of natural "atmosphere scrubbing" ability, and the increase in solar activity (admitted earlier in your post) which is the cause....

I don't quite follow.
Forests reduce Greenhouse gas, Greenhouse gas retains solar heat, solar heat retained in the atmosphere is called the green house efffect. Thus decrease forests and increase Greenhouse gas at the same time and one opens a pandora's box of Greenhouse aggrivating circumstance. That seems pretty simple to me.

But greenhouse emissions are still "logically" the most significant factor, because...ummm...why exactly?

Solar flares, are simply a convienent justification for a non-Greenhouse gas stance on the causes of global warming. It is established that Greenhouse gas has increased exponentially over the last 140 years and very much so over the last 30 years. The warmest 11 years recorded years on record have been in the past 15 years (coincidentally in the period that ostensibly human caused Greenhouse gas has increased), and one can deny in perpetuity and demand an ever greater body of evidence to support the claim, that man made Greenhouse gas is the mainstay of the measued temprature increase [1] over the last 100 years, but eventually the argument sounds hollow.

In fact it sounds like argument for the sake of argument.

[1]Source : Global Warming : Briefing Sheet 23. Enfo The Environmental Information Service : Department of the Environment & Local Government.