NASA: New Video of Ice Losses, Sea Level Rise

August 28, 2015

Nasa has some new videos out tracking vanishing ice caps and rising seas. I’ll let them spell it out.

NASA:

Sea level rise is a natural consequence of the warming of our planet.

We know this from basic physics. When water heats up, it expands. So when the ocean warms, sea level rises. When ice is exposed to heat, it melts. And when ice on land melts and water runs into the ocean, sea level rises.

For thousands of years, sea level has remained relatively stable and human communities have settled along the planet’s coastlines. But now Earth’s seas are rising. Globally, sea level has risen about eight inches since the beginning of the 20th century and more than two inches in the last 20 years alone.

All signs suggest that this rise is accelerating.

While NASA and other agencies continue to monitor the warming of the ocean and changes to the planet’s land masses, the biggest concern is what will happen to the ancient ice sheets covering Greenland and Antarctica, which continue to send out alerts that a warming planet is affecting their stability.

“We’ve seen from the paleoclimate record that sea level rise of as much as 10 feet in a century or two is possible, if the ice sheets fall apart rapidly,” said Tom Wagner, the cryosphere program scientist at NASA Headquarters in Washington. “We’re seeing evidence that the ice sheets are waking up, but we need to understand them better before we can say we’re in a new era of rapid ice loss.”

Finding the Level

NASA has been recording the height of the ocean surface from space since 1992. That year, NASA and the French space agency, CNES, launched the first of a series of spaceborne altimeters that have been making continuous measurements ever since. The first instrument, Topex/Poseidon, and its successors, Jason-1 and -2, have recorded about 2.9 inches (7.4 centimeters) of rise in sea level averaged over the globe.

In the 21st century, two new sensing systems have proven to be invaluable complements to the satellite altimetry record. In 2002, NASA and the German space agency launched the Gravity Recovery and Climate Experiment (GRACE) twin satellites. These measure the movement of mass, and hence gravity, around Earth every 30 days. Earth’s land masses move very little in a month, but its water masses move through melting, evaporation, precipitation and other processes. GRACE records these movements of water around the globe. The other new system is the multinational Argo array, a network of more than 3,000 floating ocean sensors spread across the entire open ocean.

“To study sea level rise, the Jason series, GRACE, and Argo are the big three,” said oceanographer Josh Willis of NASA’s Jet Propulsion Laboratory, Pasadena, California, the project scientist for the upcoming Jason-3 altimetry mission.

Observations from the Jason series have revolutionized scientists’ understanding of contemporary sea level rise and its causes. We know that today’s sea level rise is about one-third the result of the warming of existing ocean water, with the remainder coming from melting land ice.

And it has shown precisely that the sea, of course, is not actually level. It varies as much as six feet (two meters) from place to place. And it is not rising evenly, like a bathtub filling with water. Currently, regional differences in sea level rise are dominated by the effects of ocean currents and natural cycles such as the Pacific Ocean’s El Niño phenomenon and Pacific Decadal Oscillation. As the ice sheets continue to melt, scientists predict their meltwater will overtake natural causes as the most significant source of regional variations and the most significant contributor to overall sea level rise.

Or as Willis put it: “You ain’t seen nothing yet.”

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17 Responses to “NASA: New Video of Ice Losses, Sea Level Rise”

  1. fletch92131 Says:

    How would you explain this webpage, http://bit.ly/1NET05S

    • dumboldguy Says:

      Easy. That BS webpage is about SEA ice EXTENT, not ice SHEET melting and SEA LEVEL rise, which is the topic of this post. Your “cut and paste” of some denier horseshit that is not related to the topic at hand at all shows just how ignorant you are of the science.

      Did you even watch the three video clips? Do you have ANY idea what they mean?

      • greenman3610 Says:

        There’s nothing “conservative” about lying and distortion, Fletch. I just got a mailer from the Heartland Institute that relied heavily on exactly this slight of hand, to deceive low information, Fox News types.
        Don’t be that guy..

        • Andy Lee Robinson Says:

          Peter, I’ll produce ice cube video for 2015 in the first week of October, please use liberally…

          Deniers hate it!

          • dumboldguy Says:

            Deniers hate it, indeed. And I love it. Almost as much as the “death spiral” graphic, which compresses a 16 or 18 foot graph into a small space. Perhaps not as appealing to the general public as the ice cube, but it contains more data for these with more science and math background. Both are truly scary, especially in what they show happening over the last decade.

            Would you care to venture a guess as to what year the cube disappears and becomes a puddle?

          • Gingerbaker Says:

            I find this graphic to be the most eloquent of all the graphs out there, especially for the lay audience (me) – seriously, great work!

            I would love to see the same or a similar thing done with Greenland and Antarctic volume as well, even though the Antarctic loss will be barely discernible, it will be honest.

            Perhaps you might also do, for the Antarctic, or perhaps for all three, another dynamic graph showing the accelerating ice loss per year without showing total ice volume to scale? Maybe the volume-static comparator could be something like Mount Everest or Lake Superior or The Congress Building?

          • dumboldguy Says:

            Considering that Arctic sea ice is only a couple of dozen feet thick at most, and the Greenland and Antarctic ice sheets are many thousands of feet thick, a similar “melt” graphic wouldn’t show much. It would be like taking a couple of slices of bread off a loaf that is the length of a football field or two. The NASA graphs from the GRACE data are the best you’re going to get.

          • Gingerbaker Says:

            shoot – I was referring to Andy’s wonderful graphic

          • dumboldguy Says:

            Andy’s graphic IS great, but the “death spiral” has greater resolution and more information. Does the music turn you off, perhaps?

          • Gingerbaker Says:

            No – the music is fine. I think the graph is just not nearly as easily digested by the general public as Andy’s. Keep it simple, stupid works for me. 🙂

          • dumboldguy Says:

            Yep, you’re right about the “cube” being more digestible for most. The “death spiral” is what the mathematicians call “elegant”, and would mean far less to the public. Some who look at it are confused by the fact that the graph is overlaid on a map of the Arctic—-in actuality that’s just clever wallpaper and has no relationship to the data.

  2. redskylite Says:

    Thank god that NASA are staying true to their scientific principles, in the rocky face of politics. They have brought the issue of sea level rise to the forefront in the last few days. Everything I read suggests acceleration. No more comfortable linear or near linear graphs that delay the severity by a few centuries, out of sight, out of mind, that is the inconvenient truth.

    I am also truly glad NASA are not alone . . . . .

    this from Scripps Institute today:

    From the Field: What is Making Arctic Ice Melt Faster than Expected?

    “Historically the Arctic Ocean interior has been quiet, and the heat contained in sub-surface waters was sequestered from contact with the surface by a layer of thick ice.   However, the more the ice melts, the more turbulent the ocean is likely becoming, and this deeper heat might be getting mixed upwards, warming surface waters and accelerating the rate of ice melt.”

    https://scripps.ucsd.edu/news/field-what-making-arctic-ice-melt-faster-expected

  3. dumboldguy Says:

    Excellent videos from NASA.

    This is exactly why Cruz and the other Repugs are trying to starve NASA’s earth studying satellite programs. We are gaining knowledge from them that is an “inconvenient truth” for climate change deniers. The GRACE satellites in particular are most valuable, with what they show about water on land, in the ice sheets, and in the oceans. And the news gets ever worse.

    Of course, Cruz and Co would rather have us sending men to Mars than studying the ONLY place man will ever live.. Bread and circuses, folks, bread and circuses.

  4. Gingerbaker Says:

    Sorry – I need the new NASA graphs explained to me a bit better. I didn’t come away with a good understanding of what all the colors actually meant.

    The Josh Willis video and graphic was very good, easy to understand and good graphics. I did need to go back to understand the time period he was talking about for “recent” SLR (1993- ).

    I think most people do not realize how much SLR has already occurred since 1850 and how much acceleration we have already seen in the past 25 years. This needs to be a “talking point” for our side – repeated constantly.

    Eight inches of SLR since 1850 and ~2.5″ just in the past two decades is tangible and dramatically scary. So is the best available data on the acceleration of mm/year SLR. Although it is still early days, we should have a bar graph of that data (way less than 1mm/year in 1850 now up to 4.4mm/year as of last year(?)) splashed (pardon the pun) everywhere.

    • dumboldguy Says:

      I’ll try.

      The NASA graphs show loss of ice mass in Greenland and Antarctica from 2004 to 2014—green line.. Vertical axis is in gigatons, and both started at ~zero in ~2004.

      Greenland has lost more ice than Antarctica (~2500 Gt vs. ~1500 Gt), and that’s why the colors are darker and more widespread on the Greenland graph (remember G-land is smaller—only ~1/6 the size and about 1/6 as much ice).

      More ice is melting in Greenland over a larger area. The colors relate to the little “thermometer” bar to the right—“equivalent H2O height in CM”—-the darkest red represents ice melt equal to over 2 meters of water.

      All that took place in ten years, and if the melt rate speeds up, SLR is going to accelerate even more.

      Someone check me if I’m wrong—-wouldn’t want to lead GB astray.

  5. Gingerbaker Says:

    “the darkest red represents ice melt equal to over 2 meters of water. ”

    See – that is what I don’t understand – two meters of water measured where? In the footprint of the area defined by the color map?

    And thanks for explaining – you have a challenge, tho, with me!

    • dumboldguy Says:

      “See – that is what I don’t understand – two meters of water measured where? In the footprint of the area defined by the color map?”

      Yes, the colors actually represent the decrease in gravity caused by the loss of mass there—the deeper the color, the more ice has melted in that area and run off as water, making gravity go down. They ran the data through a computer to generate the graphics. Where the ice is white, that indicates no melting (or at least that accumulation in winter has kept pace with melting in summer).

      The GRACE satellites are so sensitive to changes in gravity that they are used to measure groundwater depletion on land as well. A drop in the mass in a locale due to a drop in the water table is as detectable as the ice loss. I think Peter has posted some GRACE images showing how groundwater is going down in CA because of the drought.


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