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Comment by yters | Hacker News Reader

He's not wrong. Why the down votes?

Downvotes don't mean “wrong”, they mean “not valuable contribution”. A well known fact that is tangential to the content of the article (the first paragraph of which states the reason this is important, which is not that the ice melting leads to or indicated sea level ride in the direct manner the downvoted comment dismissed) is not a valuable contribution.

It's because the discussion is derailing and completely misses the point. It's like commenting the wild fires in california with "hey, just a reminder, the burning of trees releases carbon dioxide"..

Loss of arctic sea ice has major implications, one of them is the affect on the jet stream. A discussion about that would have been much more fruitful. A brief explanation about this can be found here:

https://youtu.be/wE53Or56eNM?t=3304

Well, then just don't respond to him, or make this point that the sea ice melt is a problem for other reasons. Otherwise it looks like you are downvoting a scientific fact. To those on the skeptical side, like myself, this adds fuel to the fire.

I see you got downvoted too. So much for facts.

This is the sort of thing that makes me a "climate denier." If even basic science gets downvoted, how is the other side scientific?

Discussions about climate stories on HN have tended to get derailed by climate deniers injecting "facts" or little calculations/conjectures that seem to refute bodies of peer-reviewed science into the discussion.

And after a while this diversion of attention is irritating. Not a down voter, but I'd assume that's what's going on.

Now, about "the other side" being unscientific -- HN down vote behavior does not have much to do with the content of peer-reviewed scientific papers. So I don't agree with letting HN down voting behaviors drive your decision-making about climate science.

For climate science, a good place to start is the just-published 2017 (U.S.) National Climate Assessment, which helpfully summarizes the peer-reviewed science. See: https://science2017.globalchange.gov

It is sort of a sniff test. It is hard and time consuming for an individual to parse the validity of these studies. So people look for basic facts they know to be true, which seem to be contradicted by the global warming claims. One of these is that water displaces the same volume of water whether frozen or liquid. Thus it would appear melting sea ice would have no impact on sea levels.

He isn't right.

https://oceanservice.noaa.gov/facts/sealevelclimate.html

Stick a piece of ice in a cup of water, mark the water level before and after the melt, and tell me what happens.

Thermal expansion effect in cup of water is a little smaller than the thermal expansion effect in the oceans

Thermal expansion is a separate issue. Ice melt in and of itself does nothing to raise water level.

The commend says 'floating ice' the link you point at says 'ice on land'. The commender is 100% right but apparently the HN crowd has a lot of people that just love to downvote (which is why downvoting should be banned).

The link the op points says:

"First, as the oceans warm due to an increasing global temperature, seawater expands—taking up more space in the ocean basin and causing a rise in water level."

The ice melting is not the cause of seawater warming. Ice melt may indicate seawater warming, but the OP is correct that in itself it does not affect sea levels.

Actually, because sea ice has a different albedo than exposed sea water [0], sea ice melting is a significant cause of seawater warming (seawater warming is also, of course, a cause of sea ice melting; this is a classic positive feedback loop.)

[0] https://nsidc.org/cryosphere/seaice/processes/albedo.html

Yes, the sea water absorbing more sunlight due to lack of reflecting ice could cause it to warm significantly. But this is indirectly caused by sea ice melting, and a more speculative connection between ice melt and water levels rising. Furthermore, I'd like to see hard numbers, since most of sea ice is under water and does not reflect sunlight.

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