It's the final act for the Larsen B ice shelf | Hacker News Reader

It's the final act for the Larsen B ice shelf

climate.nasa.gov

43 pointsanigbrowl19 comments

"These are warning signs that the remnant is disintegrating," Khazendar said. "Although it’s fascinating scientifically to have a front-row seat to watch the ice shelf becoming unstable and breaking up, it’s bad news for our planet. This ice shelf has existed for at least 10,000 years, and soon it will be gone."

One could argue that when the glaciers retreated off the northern hemisphere and allowed thrive in the temperate zones, that was bad for the planet. :-)

The key word there is our - bad news for our planet. anthropogenic climate change is not bad for the planet, but it is potentiality very bad for humans.

Or how Carlin put it - "The planet is fine. The people are fucked."

https://www.youtube.com/watch?v=ovbF0D2wySI

How come you chose to subset "climate change" into "anthropogenic climate change"? Regardless of the origin, it seems though climate change will be bad news for humans.

Because anthropogenic climate change (in particular) is happening quickly and happening now; perhaps more quickly than a lot of us—or at least the things or places we depend on for life—will be able to adapt.

Ah, gotcha. I must have misinterpreted your tone. It seemed to me that you (unnecessarily but intentionally) introduced a politically loaded term to your (quite correct) idea.

I've been spending too much time reading about the Earth before humans, when massive changes were commonplace. Only discussing human-triggered change strikes me as massively more limited and less interesting. Apologies if I caused any confusion.

What potential implications are there for the Bay Area? Anything dire and urgent (like, SF under water)?

Not trying to downplay the magnitude of what this implies about our planet, but curious to know whether I should perhaps make sure I am high above sea level a few years from now...

You could look here: http://coast.noaa.gov/slr/ or http://geology.com/sea-level-rise/san-francisco.shtml for a less fine-grained version.

One thing to remember is that while mean sea level rises may seem quite small, one also has to factor in tidal forces, which have both daily and lunar (near monthly) cycles. Tidal flooding looks set to be a major problem in the coming years; this report only discusses cities on the east coast of the US but I'm sure it will generate its share of similar problems here: http://www.ucsusa.org/global_warming/impacts/effects-of-tida...

In case it isn't clear: the collapse of an ice shelf does not raise sea levels. A ice shelf is floating ice. If it all breaks off and becomes icebergs, then it's still floating. No sea-level change.

The worry is because ice shelves block the flow into the ocean of glaciers, which are not floating ice. If some large glaciers flow into the ocean a lot faster, then we can expect an impact on sea levels.

However -- and here is the key point that the article leaves out -- we would not expect a significant change in the rate of sea-level rise within the 5-year timeframe they are talking about for the final collapse of the Larsen B ice-shelf remnant.

I don't know what timeframe we're talking about. Maybe New York would be in serious trouble by the end of the century; or maybe not. San Francisco, being hilly, has rather less to worry about, I think.

----

Here is a nice SVG map of Antarctica from Wikipedia: https://upload.wikimedia.org/wikipedia/commons/c/c0/Antarcti...

The gray areas are ice shelves (floating ice). The white areas are ice that is on land. The Larsen Ice Shelf is on the left, along the Antarctic peninsula. The division into A, B, C portions is not indicated on this map.

If the sea level rises, does that mean the oxygen content at a previously high altitude increases?

For example, I could build a nice beachside villa in La Paz, formerly at 14,000 ft, and now live there without the aid of Bolivian marching powder and various other herbal remedies?

Various projections[1] estimates a sea level rise of up to two metres until the end of this century, so that would put La Paz at 13,994 ft. I don't think oxygen changes would be significant.

[1] http://en.wikipedia.org/wiki/Sea_level_rise#Projections

The sea level rise comes from melting ice that already existed on top of land. In fact, since the water is more dense than the ice (hence takes up less volume), the net effect on the atmosphere will be a slight compactification, as the air's average altitude decreases.

I wonder what it would take to hold those glaciers where they are compared to the coastal dikes and population moves that will be made necessary by rising sea levels.

This ice shelf has existed for at least 10,000 years, and soon it will be gone.

Pretty much a blink of the eye in the history of the planet.

Just like human civilization itself.

Precisely. On that note, allow me to offer a fun set of mental tangents.

Lambda (uppercase Λ, lowercase λ) and the Chinese character for human (人) are not visually dissimilar. Lambda is asserted to have derived from early semitic forms, which influenced Pstalter and Soghdian, each of which allegedly reached the western limits of Chinese empire and existed circa 400BCE.[1] Written Chinese has been around for about 2500 years. It also has another similar character - 入 - which in classical or ancient Chinese can mean 'to join' or 'to become a member of'. They say humans are social creatures, and social structures are built on identification. However, lambda in the programming sense means an 'anonymous' function. Unlike Indo-European languages, ancient Chinese in particular defaults to anonymity (operating on a higher level of abstraction by default - ie. less specific, more poetic, more applicable) due to an absence of enforced conjugation. OK, back to your regularly scheduled HN.

[1] http://en.wikipedia.org/wiki/Abjad

Findings like this, I think, are the most convincing arguments for retaining NASA's highly productive climate science division. There is a breadth of talent there squandered by horrible management both intra-agency and inter-agency. The fact that it's run by Congress and has little, if any autonomy is also a very sad, sad thing. I'd much rather see it spin off into its own thing that receives a set amount of funding but lets Dr. Bolden and the board have a degree of autonomy on where to spend it, much like USPS or Amtrak. Having anthropologists and attorneys decide critical science for the future just seems archaic, myopic, and horribly miscalculated.

I'm puzzled by this comment. Are you talking about GISS, the small Columbia-U. adjacent NASA institute that specializes in climate? Because there is no "climate science division" at NASA -- that activity is spread out over several centers, besides GISS, most prominently at GSFC (Maryland) and, to some extent, JPL (California). The post here, for instance, was released by JPL. Additional climate work goes on at NOAA, NCAR, etc.

I'm also puzzled by the "run by Congress"/"little autonomy" comment, which is not true.

The ice shelf did not exist just over ten thousand years ago..........

Reply on news.ycombinator.com