What Do We Think About Climate Change

Discussion in 'All Things Boats & Boating' started by Pericles, Feb 19, 2008.

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  1. Boston

    Boston Previous Member

    those graphs show an unprecedented rise in c13 co2 kids
    of a significantly higher magnitude than was previously thought

    pretty scary stuff
    maybe we should try and cut the level of emissions
    just a thought

    cheers
    B
     
  2. Tcubed
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    Tcubed Boat Designer

    Boston you have it backwards.

    <<<<he Suess effect is dilution of the atmospheric concentrations of heavy isotopes of carbon (13C and 14C) by the admixture of large amounts of fossil-fuel derived CO2, which is depleted in 13CO2 and does not contain any 14CO2.[1] It is named for the Austrian chemist Hans Suess,[2] who noted the influence of this effect on the accuracy of radiocarbon dating. More recently, the Suess effect has been used in studies of climate change. The term originally referred only to dilution of atmospheric 14CO2. The concept was later extended to dilution of 13CO2 and to other reservoirs of carbon such as the oceans and soils.[3]
    >>>>>>
    http://en.wikipedia.org/wiki/Suess_effect

    This is what we're talking about and it has been clearly shown that burning fossil fuels has contributed significantly to atmospheric carbon levels.
     
  3. Boston

    Boston Previous Member

    I think you must have completely misunderstood me

    Im saying that the graphs clearly show a significant rise in co2 that can be directly atributed to the burning of fossil fuels
    ie
    13 co2

    and that that isotope of co2 has a significantly longer life span in the atmosphere

    what did I get backwards
    B
     
  4. Tcubed
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    Tcubed Boat Designer

    When you burn fossil fuels you are returning ancient plant biomass to the atmosphere. Since plants prefer C12 they have less C13 in them than what is found in the pre industrial atmosphere . That is how one can actually measure the contribution from fossil fuel burning. So there is now much more C12 than before thus proportionately less C13.

    This lifetime business of carbon i do not understand. And i notice Jimbo has not yet responded on this point. C12 and C13 are stable. That means they never become anything else. Only C14 is unstable with a half life of 5700 yrs approx.

    It never disappears it just moves from one place to another.
     
  5. mark775

    mark775 Guest

    You know, I don't pretend to be an expert on global warming though I've actually had more 200+ level courses in this vein than Big Al - that is exactly one. So, I'll throw this out to the experts on global warming that happen to be hovering on BoatDesign.net; Mars was Earthlike at one time, Mars' atmosphere is 95% carbon dioxide, and Mars is a refrigerator. I'm really not being a smart-***, here - how can that be? It should be a no-brainer to explain as all of the models that extrapolate a half degree temperature variation in the last 100 years into the "end of life on Earth as we know it" by 2012 should fit nicely there. Thanks - Mark
     
  6. BillyDoc
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    BillyDoc Senior Member

    That's a good question Mark, so I did a Google search to find the answer. The issue basically boils down to the fact that Mars is quite a bit further from the sun than earth is, so the solar flux density is proportionately lower.

    Fortunately, when I Googled I stumbled on this explanation as part of a test question here: http://www.atmos.washington.edu/~robwood/teaching/301/quizzes/Quiz_Week_3_solutions.pdf

    2 (a) The orbit of Mars around the sun is more eccentric than that of the earth. At its closest Mars is 200 million kilometers from the sun, and at its furthest it is 250 million kilometers from the sun. Given that the solar constant at the earth distance is 1368 W m^2 and the earth-sun distance is 150 million kilometers, estimate the solar constant (i.e. the solar flux density) impinging upon Mars at its two extreme distances from the sun. [3]

    What do these numbers tell you about the likely variations in the mean temperature of the surface of Mars during its passage around the sun? [1]

    (a) Use the inverse square law so that the solar flux density F at a distance d2 from the sun is related to that at some other distance d1 by F(d2)/F(d1) = (d1/d2)2

    Thus if d1 (=150 x 10^9 m) is the earth-sun distance, then F(d1) = 1368 W m^2

    For d2 = 200 x 10^9 m, F(d2) = 770 W m^2
    For d2 = 250 x 10^9 m, F(d2) = 490 W m^2

    (b) If the planet is in thermal equilibrium then the emission temperature will change considerably during the orbit. Given that Mars has little atmosphere, we would expect significant fluctuations in the mean planet surface temperature during the orbit. This is indeed what is observed.


    So, to get back to your question, the difference between a solar flux density of from 490 W m^2 to 770 W m^2 on Mars and 1368 W m^2 on earth, plus the much lower atmosphere density on Mars accounts for at least most of the difference. Another factor for which I didn't bother to look for data would be different thermal circulation processes between the two planets.

    Hope that answers your question.

    BillyDoc
     
  7. alex folen
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    alex folen Flynpig

    Tuced you are on the right TRACK. (i THINk)...pardon me drunk state.,
     
  8. alex folen
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    alex folen Flynpig

    Yes Mars was earthlike acording to the "really" latest data. Can provide.The earh is not gona end in 2012, I'll bet my boat, i think. FYI ,as you already know (Oh here goes it, i't's possible!). Heck thats 4 years? I'm only 31! Yikes!
     
  9. alex folen
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    alex folen Flynpig

    inescapable. Really a perfect word here for me, yet i'd slide 'almost" inescapahble in there....just because.
     
  10. Boston

    Boston Previous Member

    seems like I hit right on the nail head
    based on what the above says
    but I see your point in this next
    still the answer is clear
    co2 emitted from fossil fuels can be tracked and its rising dramatically
    and Jim's graphs show it clearly



     
  11. Tcubed
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    Tcubed Boat Designer

    Always good to have people cross check my statements.

    <<<<CO2 produced from burning fossil fuels or burning forests has quite a different isotopic composition from CO2 in the atmosphere. This is because plants have a preference for the lighter isotopes (12C vs. 13C); thus they have lower 13C/12C ratios. Since fossil fuels are ultimately derived from ancient plants, plants and fossil fuels all have roughly the same 13C/12C ratio – about 2% lower than that of the atmosphere. As CO2 from these materials is released into, and mixes with, the atmosphere, the average 13C/12C ratio of the atmosphere decreases.>>>>>

    AND


    <<<<Sequences of annual tree rings going back thousands of years have now been analyzed for their 13C/12C ratios. Because the age of each ring is precisely known** we can make a graph of the atmospheric 13C/12C ratio vs. time. What is found is at no time in the last 10,000 years are the 13C/12C ratios in the atmosphere as low as they are today. Furthermore, the 13C/12C ratios begin to decline dramatically just as the CO2 starts to increase — around 1850 AD. This is exactly what we expect if the increased CO2 is in fact due to fossil fuel burning. Furthermore, we can trace the absorption of CO2 into the ocean by measuring the 13C/12C ratio of surface ocean waters. While the data are not as complete as the tree ring data (we have only been making these measurements for a few decades) we observe what is expected: the surface ocean 13C/12C is decreasing. Measurements of 13C/12C on corals and sponges — whose carbonate shells reflect the ocean chemistry just as tree rings record the atmospheric chemistry — show that this decline began about the same time as in the atmosphere; that is, when human CO2 production began to accelerate in earnest.***>>>

    12 C is now higher than anytime in the last 10000 years. And it started changing just in time for the beginning of fossil fuel burning.

    Humans have no effect on the atmosphere? Keep your heads firmly wedged into the sand me lads.
     
  12. Tcubed
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    Tcubed Boat Designer

    MARS;

    <
    Mars lost its magnetosphere 4 billion years ago, so the solar wind interacts directly with the Martian ionosphere, keeping the atmosphere thinner than it would otherwise be by stripping away atoms from the outer layer. Both Mars Global Surveyor and Mars Express have detected these ionised atmospheric particles trailing off into space behind Mars.[49][50] The atmosphere of Mars is now relatively thin. Atmospheric pressure on the surface varies from around 30 Pa (0.03 kPa) on Olympus Mons to over 1,155 Pa (1.155 kPa) in the depths of Hellas Planitia, with a mean surface level pressure of 600 Pa (0.6 kPa). Mars's mean surface pressure equals the pressure found 35 km above the Earth's surface. This is less than 1% of the surface pressure on Earth (101.3 kPa). The scale height of the atmosphere, about 11 km, is higher than Earth's (6 km) due to the lower gravity. Mars' gravity is only about 38% of the surface gravity on Earth.
    The atmosphere on Mars consists of 95% carbon dioxide, 3% nitrogen, 1.6% argon, and contains traces of oxygen and water.[4] The atmosphere is quite dusty, containing particulates about 1.5 µm in diameter which give the Martian sky a tawny color when seen from the surface.[51]>




    VENUS;


    <Venus has an extremely dense atmosphere, which consists mainly of carbon dioxide and a small amount of nitrogen. The atmospheric mass is 93 times that of Earth's atmosphere while the pressure at the planet's surface is about 92 times that at Earth's surface—a pressure equivalent to that at a depth of nearly 1 kilometer under Earth's oceans. The density at the surface is 65 kg/m³ (6.5% that of water). The enormously CO2-rich atmosphere, along with thick clouds of sulfur dioxide, generates the strongest greenhouse effect in the solar system, creating surface temperatures of over 460 °C (860 °F).[22] This makes Venus's surface hotter than Mercury's which has a minimum surface temperature of -220 °C and maximum surface temperature of 420 °C, even though Venus is nearly twice Mercury's distance from the Sun and receives only 25% of Mercury's solar irradiance. Because of the lack of any moisture on Venus, there is almost no relative humidity (no more than 1%) on the surface, creating a heat index of 450 °C to 480 °C.>




    Atmospheric composition of Mars; <95% carbon dioxide, 3% nitrogen,
    Atmospheric composition of Venus; <[FONT=Arial, Helvetica, sans-serif]96% carbon dioxide
    3% nitrogen>
    [/FONT]

    Both have no life and atmosphere almost identical constitution. Coincidence??????


    There is a greenhouse effect on mars but since the atmosphere i very thin it is not all that pronounced. If it did not have this diminished greenhouse effect it would be even colder owing to its distance from the sun. On venus it is very pronounced due to the thickness , 460 deg C hot enough to melt lead.
     
  13. Boston

    Boston Previous Member

    mine as well
    looks like I had the concept down but the ratio proving it assbackwards
    whatever the identifying characteristic its clear that co2's source can be identified
    and has been shown to be rapidly increasing
     
  14. Tcubed
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    Tcubed Boat Designer

    What i'm loving is that the supposed
    'skeptics' ( who have swallowed the point of view of "the humans have nothing to do with atmospheric change" with apparently no skepticism ) present evidence that actually disproves them.

    Humans have no effect on the atmosphere?
    Keep your heads firmly wedged into the sand me lads.

    I myself am beyond skeptic. I like to think everything through before buying it.
     

  15. kroberts
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    kroberts Senior Member

    Jumping in in the middle here, I'll put in my two cents worth:

    I believe that there is global warming.

    I believe that human industry is at least partly responsible.

    I believe that this is a bad thing.

    I believe that all of the above is almost entirely irrelevant.

    Now, to explain the previous line:

    The theory is that GW is caused by pollution of our environment by processes we humans put in place. I will lump them all together and call them industrial processes even though not all of them are industrial.

    One thing that nobody can dispute is that there is enough obviously man-made pollution which is man made to reach every part of the globe, even the parts we don't really use. The landfills, the nasty water, the big Texas-sized floating pile of plastic in the ocean, all of this can be proved, and can be proved to originate from industrial processes of humans.

    My position on this is that in order to slow or stop the pollution, we are looking at things which the global warming believers (GWB) want to do anyway. Cleaning up the mess is another thing I think we should start doing, but that won't necessarily improve the GW problem.

    Also keep in mind that I think that the GWB are distinctly different than the governments of the world. Governments do things for political reasons which have nothing to do with the ecological reality. Same thing with those so-called GWB who are into the political or social side of it. Putting in a bamboo floor might be green in the abstract, but it makes no difference if you drive a Hummer.

    By GWB I mean those people who believe that global warming is a scientific fact based on evidence they have seen and at least partially understand. I also mean people who believe that pollution is a very tangible problem and which needs to be addressed, which makes them fit into the larger category of pro-environment enthusiasts. I mean people who either are involved in or who support measures which genuinely address one or both of these problems. Everyone else who claims to belong in this category is a poser.
     
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