She Who Bicycles With Fishes

Discussion in 'Road Cycling' started by Claire Petersky, Nov 19, 2003.

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  1. Tom Keats

    Tom Keats Guest

    In article <[email protected]>, "David L. Johnson"
    <[email protected]> writes:

    > I do believe that global warming is a real thing.

    So does NOAA: http://www.ncdc.noaa.gov/oa/climate/globalwarming.html#Q3

    > I think that the oceans rising 80 meters is way out of range. Consider this: How much would the
    > oceans rise if all the ice in the Arctic were to melt?

    I dunno, but here's what the above site has to say:

    "sea level rising? Global mean sea level has been rising at an average rate of 1 to 2 mm/year over
    the past 100 years, which is significantly larger than the rate averaged over the last several
    thousand years. Projected increase from 1990-2100 is anywhere from 0.09-0.88 meters, depending on
    which greenhouse gas scenario is used and many physical uncertainties in contributions to sea-level
    rise from a variety of frozen and unfrozen water sources."

    cheers, Tom

    --
    -- Powered by FreeBSD Above address is just a spam midden. I'm really at: tkeats [curlicue] vcn
    [point] bc [point] ca
     


  2. On Sat, 22 Nov 2003 04:46:10 +0000, cheg wrote:

    > Theoretically, the water could rise 80 meters from where it is today. That would turn my city,
    > Seattle, into an island group.

    I guess we'll find out. Did this theory predict when we would get this 80 meters? Not to mention
    where from. BTW, if it would turn Seattle into an island group, most of the world's population
    would not have a whole lot of sympathy, since many of the world's major cities are at lower
    elevations than that. Hmm. Including Philadelphia. Yes, you, that is a major city, or at least we
    like to think so.

    I do believe that global warming is a real thing. I think that the oceans rising 80 meters is way
    out of range. Consider this: How much would the oceans rise if all the ice in the Arctic were to
    melt? The answer is 0, since that mass is already supported by the water underneath. The only
    "extra" water that could raise the ocean levels is land-based ice, chiefly in Antarctica, and even
    much of the Antarctic ice is floating.

    --

    David L. Johnson

    __o | What is objectionable, and what is dangerous about extremists is _`\(,_ | not that they are
    extreme, but that they are intolerant. (_)/ (_) | --Robert F. Kennedy
     
  3. Cheg

    Cheg Guest

    "David L. Johnson" <[email protected]> wrote in message
    news:[email protected]...
    > On Sat, 22 Nov 2003 04:46:10 +0000, cheg wrote:
    >
    > > Theoretically, the water could rise 80 meters from where it is
    today. That
    > > would turn my city, Seattle, into an island group.
    >
    > I guess we'll find out. Did this theory predict when we would get
    this 80
    > meters? Not to mention where from. BTW, if it would turn Seattle
    into an
    > island group, most of the world's population would not have a whole
    lot of
    > sympathy, since many of the world's major cities are at lower
    elevations
    > than that. Hmm. Including Philadelphia. Yes, you, that is a
    major city,
    > or at least we like to think so.
    >
    > I do believe that global warming is a real thing. I think that the
    oceans
    > rising 80 meters is way out of range. Consider this: How much
    would the
    > oceans rise if all the ice in the Arctic were to melt? The answer
    is 0,
    > since that mass is already supported by the water underneath. The
    only
    > "extra" water that could raise the ocean levels is land-based ice,
    chiefly
    > in Antarctica, and even much of the Antarctic ice is floating.
    >
    > --
    > David L. Johnson
    >
    >

    http://pubs.usgs.gov/fs/fs2-00/ "Most of the current global land ice mass is located in the
    Antarctic and Greenland ice sheets (table 1). Complete melting of these ice sheets could lead to a
    sea-level rise of about 80 meters, whereas melting of all other glaciers could lead to a sea-level
    rise of only one-half meter. "

    The referenced table shows the volume of water frozen in Antarctica and elsewhere. That's what I
    mean by theoretically.

    Seattle we would be much better off than most of the world since we have hills every where. I live
    at about 81 meters. 80 meters of seawater would submerge Washington, Baltimore, Philadelphia,
    Houston, New York, Boston, New Orleans, all of Florida, and the central California basin. Elsewhere,
    it would submerge London, all of Holland, nearly all of Denmark, Lisbon, Venice, Alexandria, Cairo,
    Bagdad, Karachi, all of Bangladesh, Madras, Calcutta, Bangkok, Singapore, Manila, Hanoi, Shanghai,
    Bejing, among other major population centers. Even moderate changes in sealevel will cause enormous
    dislocation of people.

    BTW: the sea level was 120 meters lower than now 21000 years ago. Could go either way...
     
  4. Zoot Katz

    Zoot Katz Guest

    Sat, 22 Nov 2003 08:07:31 GMT, <[email protected]_s51>, "cheg"
    <[email protected]> wrote:

    >
    >BTW: the sea level was 120 meters lower than now 21000 years ago. Could go either way...

    But Seattle was buried under a mile of ice.
    --
    zk
     
  5. Tomp

    Tomp Guest

    So what becomes of the bike, after completing this event of "Extreme Commuting"? Do you use a beater
    bike that just suffers in silence, until one day it disintegrates to a pile of rust. Or is there
    some regiment of service performed at the end of the day's commute?

    cheg wrote:

    > Nice day for going north from Seattle to south Everett, too. Steady snow all the way out, a foot
    > of water over the road on Maple under the Mukilteo Speedway , and the 20 minute hail storm on the
    > way home was a nice touch. I must have looked like a camel driver in a sandstorm with my wool
    > scarf wrapped around my face. Who needs adventure travel when you have eXtreme Commuting.
    >
    > Still, it was a lot more fun than driving up I-5 would have been, and probably safer today.

    --

    Tp

    -------- __o ----- -\<. ------ __o --- ( ) / ( ) ---- -\<. ----------------- ( ) / ( )
    ---------------------------------------------

    Freedom is not free; Free men are not equal; Equal men are not free.
     
  6. Cheg

    Cheg Guest

    "TomP" <[email protected]> wrote in message news:[email protected]...
    > So what becomes of the bike, after completing this event of "Extreme Commuting"? Do you
    > use a beater bike that just suffers in silence, until one day it disintegrates to a pile
    > of rust. Or is
    there
    > some regiment of service performed at the end of the day's commute?
    >

    Weekly cleaning and lube. Fortunately they don't salt the roads here.
     
  7. On Sat, 22 Nov 2003 08:07:31 +0000, cheg wrote:

    > http://pubs.usgs.gov/fs/fs2-00/ "Most of the current global land ice mass is located in the
    > Antarctic and Greenland ice sheets (table 1). Complete melting of these ice sheets could lead to a
    > sea-level rise of about 80 meters, whereas melting of all other glaciers could lead to a sea-level
    > rise of only one-half meter. "
    >
    > The referenced table shows the volume of water frozen in Antarctica and elsewhere. That's what I
    > mean by theoretically.
    >

    Something I found: http://www-nsidc.colorado.edu/sotc/sea_level.html

    Over the past 100 years sea level has risen by 1.0 to 2.5 millimeters per year, thus the
    contribution from melting of smaller glaciers would be approximately 10 to 30 percent of the total.
    However, climate models based on the current rate of increase in greenhouse gases indicate that sea
    level will rise at a rate of about two to five times the current rate over the next 100 years as a
    result of the combined effect of ocean thermal expansion and increased glacier melt

    OK, at 5 times the current rate of sea level increase, say 10mm/year, in 100 years the sea would
    rise exactly 1 meter. This is presuming that the rate of increase of greenhouse gas emmissions would
    continue to increase at the current rate. It's worth noting that we don't have the petroleum to
    accomplish that feat, either.

    I still question the data of 80 meters total. The Greenland ice sheet, even if very thick, is very,
    very small in area compared to the oceans of the world. Same for Antarctica, plus the fact that a
    good part of that (Ross Ice Shelf) is over water, so melting would not contribute to sea level rise.
    I haven't seen the estimates that go into that number.

    --

    David L. Johnson

    __o | When you are up to your ass in alligators, it's hard to remember _`\(,_ | that your initial
    objective was to drain the swamp. -- LBJ (_)/ (_) |
     
  8. Cheg

    Cheg Guest

    "Zoot Katz" <[email protected]> wrote in message news:[email protected]...
    > Sat, 22 Nov 2003 08:07:31 GMT, <[email protected]_s51>, "cheg"
    > <[email protected]> wrote:
    >
    > >
    > >BTW: the sea level was 120 meters lower than now 21000 years ago. Could go either way...
    >
    > But Seattle was buried under a mile of ice.
    > --
    > zk

    Yeah, that's why we have the hills. If you look at a shaded terrain map it looks like claw marks
    from Bellingham to Olympia.
     
  9. Cheg

    Cheg Guest

    > I still question the data of 80 meters total. The Greenland ice
    sheet,
    > even if very thick, is very, very small in area compared to the
    oceans of
    > the world.
    Yes the Greenland ice sheet makes a small contribution, as stated in the referenced table. 90% of
    the ice in the world is in Antarctica.

    > Same for Antarctica, plus the fact that a good part of that (Ross Ice Shelf) is over water, so
    > melting would not contribute to
    sea
    > level rise. I haven't seen the estimates that go into that number.
    >
    > --
    >

    That's wrong. For one thing the Ross Ice shelf is less than 5% of the surface area of Antarctica.
    The average thickness of the remaining
    12.5 million sq.km. is over 2000 meters, for a volume of 25 million cubic km. The surface area of
    the oceans is about 300 million sq.km, so the total rise from melting all the ice in Antarctica
    would be about 80 meters.
     
  10. On Sat, 22 Nov 2003 17:43:01 +0000, cheg wrote:

    > That's wrong. For one thing the Ross Ice shelf is less than 5% of the surface area of Antarctica.
    > The average thickness of the remaining 12.5 million sq.km. is over 2000 meters, for a volume of 25
    > million cubic km. The surface area of the oceans is about 300 million sq.km, so the total rise
    > from melting all the ice in Antarctica would be about 80 meters.

    Still questioning. It would seem that the average thickness of the ice is more than the average
    altitude of the continent. Again I don't have good enough data on this, but this site
    http://astro.uchicago.edu/cara/outreach/coldfacts.htm claims that the ice gets as thick as 4776
    meters, much more than the peak altitude of the continent. So a fair fraction of this ice is already
    below sea level.

    --

    David L. Johnson

    __o | Accept risk. Accept responsibility. Put a lawyer out of _`\(,_ | business. (_)/ (_) |
     
  11. Cheg

    Cheg Guest

    "David L. Johnson" <[email protected]> wrote in message
    news:[email protected]...
    > On Sat, 22 Nov 2003 17:43:01 +0000, cheg wrote:
    >
    > > That's wrong. For one thing the Ross Ice shelf is less than 5% of
    the
    > > surface area of Antarctica. The average thickness of the
    remaining 12.5
    > > million sq.km. is over 2000 meters, for a volume of 25 million
    cubic km.
    > > The surface area of the oceans is about 300 million sq.km, so the
    total
    > > rise from melting all the ice in Antarctica would be about 80
    meters.
    >
    > Still questioning. It would seem that the average thickness of the
    ice is
    > more than the average altitude of the continent. Again I don't
    have good
    > enough data on this, but this site http://astro.uchicago.edu/cara/outreach/coldfacts.htm
    > claims that
    the ice
    > gets as thick as 4776 meters, much more than the peak altitude of
    the
    > continent. So a fair fraction of this ice is already below sea
    level.
    >
    > --
    >
    The peak altitude is actually about 4900 meters, and the average elevation of the continent as
    a whole is 2300 meters. The land mass would eventually come up a long way due to isostaic
    rebound once the
    2.5E16 tons of ice came off, occupying whatever volume is now occupied by submerged ice.

    Unless an asteroid strikes the south pole, we won't know how much the sealevel could rise for many
    human lifetimes at least. Might as well go for a bike ride in the meantime.
     
  12. David Kerber

    David Kerber Guest

    In article <[email protected]>, [email protected] says...
    > On Sat, 22 Nov 2003 04:46:10 +0000, cheg wrote:
    >
    > > Theoretically, the water could rise 80 meters from where it is today. That would turn my city,
    > > Seattle, into an island group.
    >
    > I guess we'll find out. Did this theory predict when we would get this 80 meters? Not to mention
    > where from. BTW, if it would turn Seattle into an island group, most of the world's population
    > would not have a whole lot of sympathy, since many of the world's major cities are at lower
    > elevations than that. Hmm. Including Philadelphia. Yes, you, that is a major city, or at least we
    > like to think so.
    >
    > I do believe that global warming is a real thing. I think that the oceans rising 80 meters is way
    > out of range. Consider this: How much would the oceans rise if all the ice in the Arctic were to
    > melt? The answer is 0, since that mass is already supported by the water underneath.

    Not quite: there is a lot of water stored in land-based glaciers in the arctic zone as well. Most of
    it is in Greenland, but there are significant amounts in Scandanavia, the Canadian islands and
    Alaska as well.

    > The only "extra" water that could raise the ocean levels is land-based ice, chiefly in Antarctica,
    > and even much of the Antarctic ice is floating.

    As a percentage, very little of it is floating; only the ice shelves. Almost all of it is sitting on
    the ground, even though the ground is below sea level.

    --
    Dave Kerber Fight spam: remove the ns_ from the return address before replying!

    REAL programmers write self-modifying code.
     
  13. David Kerber

    David Kerber Guest

    In article <[email protected]_s51>, [email protected] says...

    ...

    > BTW: the sea level was 120 meters lower than now 21000 years ago. Could go either way...

    That was during the last ice age. If the ice caps melt, it's certainly not going to go that way.

    --
    Dave Kerber Fight spam: remove the ns_ from the return address before replying!

    REAL programmers write self-modifying code.
     
  14. David Kerber

    David Kerber Guest

    In article <[email protected]>, [email protected] says...
    > On Sat, 22 Nov 2003 17:43:01 +0000, cheg wrote:
    >
    > > That's wrong. For one thing the Ross Ice shelf is less than 5% of the surface area of
    > > Antarctica. The average thickness of the remaining 12.5 million sq.km. is over 2000 meters, for
    > > a volume of 25 million cubic km. The surface area of the oceans is about 300 million sq.km, so
    > > the total rise from melting all the ice in Antarctica would be about 80 meters.
    >
    > Still questioning. It would seem that the average thickness of the ice is more than the average
    > altitude of the continent. Again I don't have good enough data on this, but this site
    > http://astro.uchicago.edu/cara/outreach/coldfacts.htm claims that the ice gets as thick as 4776
    > meters, much more than the peak altitude of the continent. So a fair fraction of this ice is
    > already below sea level.

    It is, but it's not floating, and if it melts, the land altitude will rebound rather quickly once
    the extra weight is off it.

    --
    Dave Kerber Fight spam: remove the ns_ from the return address before replying!

    REAL programmers write self-modifying code.
     
  15. Mike Kruger

    Mike Kruger Guest

    "David Kerber" <[email protected]_ids.net> wrote in message
    >
    > It is, but it's not floating, and if it melts, the land altitude will rebound rather quickly once
    > the extra weight is off it.
    >
    (Wandering further off topic) How quick is quick? I heard from a not necessarily reliable source
    that Scotland is still rebounding from the last ice age, which is a while ago.

    If it rebounds at speeds resembling geologic time, wouldn't the rebounding be substantially slowed
    because it would still have a lot of water on top of
    it (i.e. until it rebounds up to sea level, it will still have ice or water on it).

    Not that I hope to be around to see it, but the thawing out of a continent would seem to pose lots
    of interesting scientific questions.
     
  16. Cheg

    Cheg Guest

    "David Kerber" <[email protected]_ids.net> wrote in message
    news:[email protected]...
    > In article <[email protected]_s51>, [email protected] says...
    >
    > ...
    >
    > > BTW: the sea level was 120 meters lower than now 21000 years ago. Could go either way...
    >
    > That was during the last ice age. If the ice caps melt, it's
    certainly
    > not going to go that way.
    >
    > --
    > Dave Kerber Fight spam: remove the ns_ from the return address before
    replying!
    >
    > REAL programmers write self-modifying code.

    IF the caps melt. Based on the geologic record, we're overdue for another ice age. We haven't been
    around long enough to know what the natural variability of climate is. It might overwhelm our
    contribution. (Please, no global warming flame wars...)
     
  17. Buck

    Buck Guest

    "cheg" <[email protected]> wrote in message news:[email protected]_s51...

    > That's wrong. For one thing the Ross Ice shelf is less than 5% of the surface area of Antarctica.
    > The average thickness of the remaining
    > 12.5 million sq.km. is over 2000 meters, for a volume of 25 million cubic km. The surface area of
    > the oceans is about 300 million sq.km, so the total rise from melting all the ice in Antarctica
    > would be about 80 meters.

    Don't forget to calculate for the difference in volume between ice and water. Ice is about 90% as
    dense as water, so adjust your calculations downward accordingly....

    -Buck
     
  18. Cheg

    Cheg Guest

    "Buck" <s c h w i n n _ f o r _ s a l e @ h o t m a i l . c o m> wrote in message
    news:[email protected]...
    > "cheg" <[email protected]> wrote in message news:[email protected]_s51...
    >
    > > That's wrong. For one thing the Ross Ice shelf is less than 5% of
    the
    > > surface area of Antarctica. The average thickness of the
    remaining
    > > 12.5 million sq.km. is over 2000 meters, for a volume of 25
    million
    > > cubic km. The surface area of the oceans is about 300 million
    sq.km,
    > > so the total rise from melting all the ice in Antarctica would be about 80 meters.
    >
    > Don't forget to calculate for the difference in volume between ice
    and
    > water. Ice is about 90% as dense as water, so adjust your
    calculations
    > downward accordingly....
    >
    > -Buck
    >
    >
    >

    OK, but partially offset by isostatic rebound, and other icecaps.If this is calc is within 10% it's
    purely coincidental. I was just showing that 80 meters is not an unreasonable number.
     
  19. David Kerber

    David Kerber Guest

    In article <[email protected]>, [email protected] says...
    > "David Kerber" <[email protected]_ids.net> wrote in message
    > >
    > > It is, but it's not floating, and if it melts, the land altitude will rebound rather quickly
    > > once the extra weight is off it.
    > >
    > (Wandering further off topic) How quick is quick? I heard from a not necessarily reliable source
    > that Scotland is still rebounding from the last ice age, which is a while ago.

    So is a lot of northern Europe. It's a measurable amount even on a yearly basis, a few mm per year,
    and multiple meters in recorded history (since routine record-keeping began in Europe).

    > If it rebounds at speeds resembling geologic time, wouldn't the rebounding be substantially slowed
    > because it would still have a lot of water on top of
    > it (i.e. until it rebounds up to sea level, it will still have ice or water on it).

    True, but that's a lot lighter than 2000 meters of ice *above* sea level.

    >
    > Not that I hope to be around to see it, but the thawing out of a continent would seem to pose lots
    > of interesting scientific questions.

    It certainly does!

    --
    Dave Kerber Fight spam: remove the ns_ from the return address before replying!

    REAL programmers write self-modifying code.
     
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