Frequently Made Errors in Climate Science - The Greenhouse Effect - Comments

[Buzz Bloom]

I think that is miss leading. Even if the atmosphere were argon, the sky would still be blue.

Hi BillyT:

I confess that I am confused by your comment.

I don't understand why you mention argon. As I understand it, there is much much less argon in Earth's atmosphere than nitrogen. Even if, as you say, an argon atmosphere would also appear blue, am I wrong that the blue sky we see are mostly the blue photons from the sun that that been scattered by nitrogen? If so, why do we see blue photons from all directions in the sky?

I also do not understand your discussion of cubes. Are you saying that since 1/5 of the atmosphere is oxygen, that it also scatters blue photons, and 1/5 of the photons we see in the blue sky are scattered by oxygen rather than nitrogen?

Regards,
Buzz

 

[duncan61]

klimatos.I have been seeking the exact information you have provided so well.Regards Duncan

 

[stuartmacg]

While this is likely true for Greenland, it's not at all clear it's true for sea ice.

Brewster's angle (53º) is the angle where about half of light is reflected off the surface of water. This means that above 53º latitude, naively, the albedo of water is over 0.5. (It is far more complicated than that of course -- which is my point.) Since ice and snow's albedo ranges from 0.9 to 0.3, it is not clear water's albedo is lower than ice in the arctic -- even in the summer. (In the winter the albedo is irrelevant because there is effectively no incident sunlight.)

Meanwhile, the arctic area can still "see" the night sky at a 90º angle. Its emissivity remains and the area continues to emit longwave infrared radiation. The limitting factor on this is likely the ∆T⁴between the ground/sea and the night sky. Raising the temperature in the region raises the ∆T and gets that 4^th power emission bonus.

I want to make it clear I am not claiming this melting is a good thing. I'm just claiming it has been poorly studied. The arctic environment is probably the most fragile in the world. Given the large methane deposits in the tundra and oceans (clathrates) which even small temperature rises might release, there is cause for concern.

I can think of a number of things wrong with my model, the most obvious is that water (and arctic ice for that matter) is not flat. Waves will create a chop effect limiting the albedo gain due to the Brewster angle. The Brewster angle will change with the seasonal axial tilt. The atmosphere above the ice will have a large effect since waves incident at a low angle will travel through much more air. These conundrums are just off the top of my head. My point is that this is a complex subject and any positive feedback loop is at best not obvious.

But the idea that the albedo is of great concern in a region getting little sunlight seems oddly immune to logic. Global warming is a big enough problem without adherents practicing bad science and settling for confirming their bias.

I have been asking abut this for a while and not getting any answers. It does seem intuitively that if I were a 0C animal I would not get warmer by taking off my ice coat in the arctic, with -28C Greenland air temp for example.

The low angle summer sun seems unlikely to offset the sunless winter much. 0C water temp must lose heat to the (otherwise << 0C) air, and even a bit directly to space (via the few IR absorption gaps). This heated polar air should export more heat from the earth. If the net effect on the earth of removing ice is heating, I would love to know the details. It seems very far from obvious.

Variable ice, insulating in winter and exposing in summer, might have a heating effect?

 

[haruspex]

if I were a 0C animal I would not get warmer by taking off my ice coat in the arctic, with -28C Greenland air temp for example

I don't understand what point you are making. Please elaborate.
Jeff Rosenbury's argument is that the loss in albedo in going from ice to open water might not be that much. The evidence, though, (https://en.wikipedia.org/wiki/Ice–albedo_feedback#Significance) is that it is significant.

 

[stuartmacg]

Thanks for the link, though it does not directly address the balancing effect of increased heat loss from revealed sea in the cold polar regions.

I am just an uninformed chap who wanted an explanation for what seemed a counter intuitive process folk are talking about. Just curious.

The link does not mention the uncovered sea heat loss effect in describing "albido", but just talks of solar absorption and says all is considered in the models.

Winter only ice cover seems intuitively to be something moving towards a net heating effect, reducing loss in winter and sun bathing in summer - that seems to be called arctic amplification.

Having the previously covered seas heat the polar atmosphere (from <-20C say) all year round will certainly cause more heat export, and in summer get more heat import. It surprises me that the net effect would be warming.

 

[haruspex]

Thanks for the link, though it does not directly address the balancing effect of increased heat loss from revealed sea in the cold polar regions.

I am just an uninformed chap who wanted an explanation for what seemed a counter intuitive process folk are talking about. Just curious.

The link does not mention the uncovered sea heat loss effect in describing "albido", but just talks of solar absorption and says all is considered in the models.

Winter only ice cover seems intuitively to be something moving towards a net heating effect, reducing loss in winter and sun bathing in summer - that seems to be called arctic amplification.

Having the previously covered seas heat the polar atmosphere (from <-20C say) all year round will certainly cause more heat export, and in summer get more heat import. It surprises me that the net effect would be warming.

Ok, now I see your point.
Clearly it is a complex issue requiring detailed modelling, and armchair theorising is unlikely to be reliable. I put my trust in the scientists who have spent careers on it.

 

[stuartmacg]

I don't distrust at all: I would just like to hear something more than silence on the subject, from those who have done the work.

 

[haruspex]

I don't distrust at all: I would just like to hear something more than silence on the subject, from those who have done the work.

Then you will probably need to contact a research establishment.