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Does it matter if the Greenland sheet and glaciers melt?

If global warming does that, it will also result in increasing ice cover on the Antarctic (which we are already seeing), and even the IPCC concedes that these two effects would cancel each other out.

What's the problem, exactly?

If global warming was sufficient to melt the Greenland sheet, the increase in temperatures would not be enough to melt the one in Antarctica, because the southern temperatures are much lower. In fact, warming would increase atmospheric moisture in the south but since the temperatures are lower this would only reselt in increased snowfall, and hence an expansion in the Antarctic ice mass. Part of the southern ice sheet is currently breaking up due to changes in ocean currents, but most of it is actually increasing and the net effect is an increase.

On the thermohaline circulation, it's true that a shutdown in the North Atlantic Conveyor would reduce temperatures on sea and land in western Europe, but the effect of this would be be increased ice formation which in turn would increase the salinity of the sea. It might even restart the THC.

As for doubling CO2 levels, it is extremely dubious that CO2 is sufficient to have much overall effect on global temperatures. During the period of massive glaciation some 480 million years ago, atmospheric CO2 levels were TEN TIMES present levels, but the planet was wrapped in ice. Certainly on the basis of physics, doubling CO2 levels has a minimal effect on temperature due to the logarithmic effect of added CO2. Where's the connection?

Ed, the temperature increase would have to be very much larger than even the IPCC forecasts to have an adverse effect on Antarctic ice coverage. It would have to be much larger than CO2 could possibly provide - recall the 10 times CO2 levels with a global freeze, too - and the effect of methane would have to be larger than expected.

So how does the anthropogenic global warming assumption address global freeze combined with 10 times greater CO2 levels?

Could it possibly be that CO2 is simply not as big a factor as some people think? Could it be that, after all, the solar cycle is really the key to it? Aren't anthropogenic warming advocates simply...wrong?

Ed, it's in the IPCC report you keep citing, so I don't see how you're saying it's unsubstantiated. You say you've read the whole report, so I assume you've seen the bit where they say that it's entirely possible that ice loss in the north could be cancelled by ice gain in the south, the reason being the large difference in mean temperatures.

Is it not rather that the real "inconvenient truth" may be that the global warming crowd are just plain wrong and you find it hard or impossible to counter the case?

Does not the global freeze with 10 times CO2 levels more or less utterly demolish the anthropogenic warming thesis? Isn't that just a bit embarrassing and impossible to answer?

Try looking here:

href="https://www.grida.no/climate/ipcc_tar/wg1/418.htm

Money quote is:

"In summary, the static sensitivity values suggest a larger role for Antarctica than for Greenland for an identical local temperature increase, meaning that the polar ice sheets combined would produce a sea level lowering, but the spread of the individual estimates includes the possibility that both ice sheets may also balance one another for doubled atmospheric CO2 conditions"

It doesn't matter that there is increased ice retreat in the western Antarctic, given that the rest of it is increasing. Western ice retreat is actually due to a shift in ocean current patterns in the area, not rising temperature.

Also, the reason you don't see the decadal variations in ice extent in the south corresponding to rising temperatures is that the higher temperature is still too low to cause significant melting. The higher temperature instead result in increased precipitation, which at the low temperatures means snow, which in turn means more ice.

Now, I'd really like the response to my question about global freezes with CO2 levels 10 times higher than at present. How do you explain this, if CO2 is so deadly?

Ed,

The report clearly shows the huge range of uncertainty and, frankly, speculation that drives the "findings" which aren't often particularly well supported by what we see in reality, and which certainly are absolutely not borne out by the record of geologic history. It's basically a guess.

Within that guess is the possibility that the north and south caps will cancel each other out. How long that may last is also a guess, and one can have little to no confidence in speculative guesses about what may happen over a period of a century to a complex system we don't understand terribly well, particularly when the whole guess is based around some political (rather than scientific) assumptions about man's impact, and particularly when it contradicts the geologic and historic records and follows very closely trends in other systems which we cannot control.

Given all that, the most one can say is that the caps *might* both melt, or one *might* cancel the other, or one *might* overcompensate for melting in the other. It's still speculation. And it's political speculation, because it focuses on things man can change at the expense of what clearly seems to be the true cause which man cannot influence.

Now, how about the 10 times greater CO2 coupled with a global freeze? Any answers?

I don't know about you, Ed, but I cannot get particularly excited by a potential 10mm increase in sea level coupled with a possible 2 degree temperature rise over the space of a century, and I certainly cannot see this as adequate justification for condemning billions to enduring poverty.

Can you?

Yes, I'm ok with 5m - I live about 100m above sea level. But it isn't going to happen, and even if it did it's going to take decades, more likely centuries. We can cope.

The thing is that all these environmental scares over the past decades, even going back as far as Malthus in the early 19th century, have been shown to be bunk. Why would this be any different? The evidence contradicts the politics. It's not even called global warming any more, just in case the environmentalists are caught out when it doesn't get particularly warmer. Now it's climate change, but the climate ALWAYS changes, which is somewhat unfair since the environmentalist can point to virtually anything as say "we told you so" when in reality they are just guessing.

Poetry isn't a good enough justification, either, by the way.

It's not at all discredited. The plain fact is CO2 simply does not have all that much warming effect.

It's swamped by solar output. Care to explain why global temperatures do not track CO2 levels but do track solar output levels? Why should this be?

CO2 levels in the Ordovician fluctuated between 4,500 and 4,000ppm. Even if you take the "low" point at the boundary between the Ordovician and the Silurian, it's still 3,000ppm. It's WELL above current levels. It didn't fall to levels like todays until well into the Carboniferous.

In geologic time there have been several big freezes and ovens. Not one of them tracks CO2 content. In more recent times, all of the global temperature variations track closely variations in solar output and not one of them tracks CO2 levels.

What I'd like to know is why this should be the case, considering the anthropogenic warming thesis blames it all on energy and carbon. This is plainly not true, so why the discrepancy?

Ed,

Nothing to do with Philistinism. Actually, I enjoy poetry, just as I enjoy baroque music, a nice glass of wine and Russian literature. My point is that aesthetic sensibility is not a good enough justification for severely disrupting human civilisation and giving mankind increased poverty, rationing, squalor and disease.

Anthropogenic global warming is most certainly *not* fact. It is pretty much fact that we are in the midst of a warming, but it is no more than supposition that man's behaviour has anything to do with it - my own view is as stated before that the link between industrialisation and warming is one of coincidence and not causation. I have yet to see any credible evidence that this is not the case. As has been pointed out repeateadly by me here and by many others elsewhere, warming and cooling trends on Earth seem unrelated to variation in atmospheric composition - indeed, it seems quite often that increased CO2 level *follows* rather than causes increases in temperature. Temperature variation does seem to follow remarkably closely variations in solar output, which no amount of sanctimony about lifestyle can possibly influence. Perhaps that's why it's ignored. If someone would be good enough to post a plausible explanation of why in the past it has been warmer with lower CO2 levels and colder (often much colder) with higher (often much higher) CO2 levels, then we might get somewhere. Ignoring the question doesn't make it go away.

Also, there is no frantic scramble for alternatives to fossil fuel as general use energy stores or sources. Nuclear power is established, far safer and cleaner than most environmentalists concede (indeed, far more so than most of the general public think and frankly a lot cleaner and safer than fossil) and has the capability to provide large quantities of energy for a considerable time. Hydrogen is a handy storage system for portable power, and again this technology is well enough known and shown to be workable. In some cases, wind, wave, solar or some combination of them is practical for fairly small scale generation in certain circumstances - again, known and workable although not feasible on the large scale.

The only reason for mad scramble and panic would be because environmental activists poison the body politic against progress, and if it causes problems in the future it will be because of and not in spite of environmentalist alarmism and pseudoscience.