Justus For All

The reaction Lomborg gets always amazes me. Many environmentalists seem aghast at the idea of questioning the belief that the sky is falling. The concern is if we’re not all scared to freaking death, we won’t take steps to fix the problems that do exist. What they don’t understand is if they try to scare us to death when that reaction isn’t warranted, they run the risk of blowing their credibility and not having the attention they deserve when it really matters.

You know, boy crying wolf and all that.

Gib, I can agree at least in part. Certainly the likes of “The Day After Tomorrow” runs against all science that I know.

But, in the meantime, there are other things to consider. The best prognostications in the meteorological science world down here include;

A 50/50 chance of the collapse of the Ross Ice Shelf within the next 10 years. That alone would add the water contained at present in an area of ice the size of Europe.

The impact on sea levels might be fairly small. What would impact most is the effect of the energy being taken out of global weather systems as it melts - it will get colder…

Looking just at this little hunk of dirt in the middle of the South Pacific, the prognostications include the possibility of tropical diseases (Red River Fever mosquitos have already been found here) in the Far North, the Canterbury Plains (one of the best agriculture climate areas in the world) becoming a rain-shadow desert…

Ice that is floating on the ocean, such as the Ross Ice shelf, have no effect on sea level. Simple science will realize this, as the water has the same weight whether frozen or not, and therefore displaces the same amount of other liquid water, whether it is frozen or not.

I would be surprised if the melting takes all that much energy out of the global climate system, indeed albedo reduction gives a worry that it might increase global climatic energy. Of course if the Ross Sea melting did cool the planet, then of course that would help mitigate global warming.

I also think that worry over tropical diseases is probably unfounded. Certainly even if there is an increase there, it would likely be either mitigated or eclipsed by a lowering of deaths related to cold.

As for localized whether pattern changes that would be detrimental to agriculture, I am skeptical that we have any realistic capability of predicting that. Even then, it is reasonable to guess that while some areas might get worse, other areas might get better. I don’t think their is any reason to assume that current global temperatures are at the optimum for the most agriculture in the most places. If for example, the Canterbury Plains started to suck, but the Sahara became a garden spot, that would be a win globally, although quite arguably a loss for New Zealand.

You can’t conclude that something will be catastrophic by only looking at the negatives and ignoring the positives.

Dave, your knowledge of basic science continues to astound…

Oh, and try this as well…. Remember that it takes 100 cal to take 1 gm of water from 0* to 100*. It takes 78 cal to convert 1 gm ice at 0* to water at 0* - almost as much as it takes to boil the same gram. That heat has to come from somewhere!

If the average temperature of the Canterbury Plains were to increase by 1* C, How much do you think that the Sahara might decrease

Yes, freshwater is denser then seawater. The effect of sea level change from floating ice is so neglible that it can be discounted however. Unlike the demonstration you link to, the oceans are not a super concentrated saline solution.

Of course the heat is coming from somewhere, it is coming from the sun and a greater percentage of that heat is remaining in the earth’s climate due to high amounts of greenhouse gas. Once again, although I haven’t done the math I suspect that the phase change heat required to change the ross shelf to water is negligle in the global system, also most of that energy is already in the ross ice shelf, which is WHY we think it might melt in the next 10 years. The energy doesn’t all go into it on the day it melts, that is exactly the point of the explanation you linked to.

What does the heat to the Canterbury plains compared to the Sahara have to do with anything? If a change in climate patterns results in those plains being in a rain shadow that will make them less productive because they are drier, not because they are hotter.

The last part of my previous comment got lost but it is of little matter.

Remember this - from my first comment?

“The impact on sea levels might be fairly small. What would impact most is the effect of the energy being taken out of global weather systems as it melts - it will get colder… ”

So I fail to see why you are getting on your high horse.

I believe that the predictive models that NZ met’s are playing around with these days include the possibility of regional cooling and warming. While it is not part of global warming, the El Nino patterns of the west and central Pacific are an excellent case in point. So, if you were to consider the Greenland Ice Cap as another instance, what might be the impact of that melting over a twenty year period. Not in terms of sea levels, but in the average temperatures of north-east Canada and the Gulf Stream?

So, if the Ross Ice Shelf were to melt the initial impact would be regional cooling in the Sub-Antartic south of NZ. That would impact upon weather patterns for NZ, then South America as the cold, less saline water moves west. If at the same time temperatures over South East Asia and Australia were higher than average, it seems reasonable that there would be major weather instabilities in the areas between…

Where did I suggest that the Ross Shelf would melt in a day? Can’t see that anywhere. It is pure science that every gram of that ice will absorb 78 cal from somewhere as it melts.

Remember “Larsen B”? The final remnants have ended up as a tourist extravaganza off Dunedin over the past few weeks. It has taken seven years for them to get here. I am not blaming that event for the absolutely stink weather we have had since mid October.

I was trying to rationalise the Sahara-Canterbury connection. You raised it. Perhaps with your great wisdom you could explain it?

Oh, and whilst you are about it, perhaps you could take a look at fresh water being more dense than salt water? Given the same temperature of water and ice, of course!