How Fast Can Ice Melt? Understanding New Sea Level Estimates

April 11, 2016

Decided to put together a video intro to the advancing science of ice sheet dynamics, which has been in the news recently.

New paper by Deconto et al has added more realistic simulations of “cliff failure” to models of Antarctic ice loss, and come up with more rapid sea level scenarios.

Above, Jason Box’s very valuable discussion about accelerators of Greenland ice melt, which is an analogue for what we could see, starting on the Antarctic Peninsula, in the south.

Here, James Hansen clearly summarizes the findings of his most recent, widely publicized paper.


Leading up to these, a large body of research had made this clear – Sea level was much higher in recent epochs when greenhouse gases were at current levels.
How fast do those sea levels respond to a changing atmosphere?

And finally, John Cook and I were left with jaws on the floor after the stunning interview with Eric Rignot in 2014.

Compare the sense of urgency above, with the calmer demeanor of just 2 years before.


11 Responses to “How Fast Can Ice Melt? Understanding New Sea Level Estimates”

  1. Tom Bates Says:

    There is a tiny fly in the study and in the comments by the people you quote. Antarctica is gaining land ice not losing it as is Greenland.

    • ubrew12 Says:

      East Antarctica has been gaining mass since the end of the last glacial period, 10,000 yrs ago (more precipitation). But along the rim, esp. West Antarctica and the Peninsula, it looks like the ice drove off a cliff since around 1995. So, overall, Antarctica is now losing mass, according to GRACE:

      Note the exponential shape of that curve.

    • Sorry, you are wrong, Greenland surface ice is increasing.

    • redskylite Says:

      Maybe some world travel might help change your viewpoint Thomas.
      . . . . . . . .

      “I see [climate denial] as a sign of poor education, and maybe a bit too much influence from some of the more religious groups or the right wing,” said one Swedish IT developer. “And most of all, I think it’s something sad, actually, for all of us, that we can’t agree that climate change is happening to our planet.”
      . . . . . . . . .

      One Stockholm resident, Frederick, was incredulous there are people who deny climate change is happening. “People are denying that climate change is happening? … Are you sure?” he asked, adding some advice for his American counterparts: “I think maybe they should open their eyes then, because I think it’s a fact. I don’t know anything about it, but I do know it’s happening.” The U.S. might want to take some notes.

  2. dumboldguy Says:

    Got a source for this misinformation, Tom? No? You made it up? Thought so.

    Once again, the MasterBates-er gets his facts wrong. Land ice is in net decline on every continent.

  3. ubrew12 Says:

    Regarding Ice in Antarctica, when has the News ever been good? Like, in the last 50 years. Does anybody else detect a pattern to Scientific estimates from that region? I ask because we may be in a ‘fool me once, fool me twice’ situation here. As a practical matter, for policy purposes, should we be doubling whatever the latest estimate is for sea level rise by 2100? I personally think so.

  4. redskylite Says:

    The Arctic was ice free a mere 10 million years ago and the atmospheric CO2 concentration at that time wasn’t far apart from today’s readings.

    The Antarctic is a completely different environment, a lot more land mass in the Oceanic Southern Hemisphere, the Southern Hemisphere has never been a mirror of the North, it usually lags behind a couple of centuries or so, but catches up in the end.

    I don’t enjoy pointing out the reasons to be worried, but don’t let us continue to sail on ignorantly and carelessly into our not too distant future. We are taking all of humanity down with a lot of our cousins too.

    So Tom stop reading the shit that only glorifies flawed science and get up to speed with reality.

    • redskylite Says:

      Reminder – Atmospheric CO2 density is rising and how . .

      “Carbon dioxide levels are increasing faster than they have in hundreds of thousands of years,” Tans said. “It’s explosive compared to natural processes.”

      . . . . . . . . . . . . . . . .

      The last time the Earth experienced such a sustained CO2 increase was between 17,000 and 11,000 years ago, when CO2 levels increased by 80 ppm. Today’s rate of increase is 200 times faster.

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