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A Bizarre Albedo Anecdote

  1. Jan 26, 2006 #1
    Suppose I was to publish this study.

    Andre et al, 2006, Earth Albedo variations dwarf greenhouse effect EOS, Vol. 87, No. 4, 24 January 2006

    We compute Earth albedo (reflectivity) in the period 1984-2004, using cloud data and coverage, confirmed by measuring reflectivity of the shadow side of the moon. We observe a remarkable decrease in reflectivity in the period 1984- 1997 followed by a gradual increase after that. Correlation of the data with global temperatures (GISStemp Hansen et al) reveals a statistical relevance of R2=0.575 apparently confirming the obvious relationship between reflectivity and temperatures.

    The associated variation of energy flux in the Stefan Boltzman law with 10% albedo change, results in a black body temperature change of 2,7 K. However, since the actual temperature variation is a mere 0.6K we must conclude that Earth generates a robust negative feedback that effectively reduces the effects of large albedo changes. This result dwarfs the greenhouse gas forcing theory that considers only flux changes of an order of magnitude less.

    Is this true? No, unfortunately I did not write that study, however if you look at the data, the logic seems nevertheless to be very true, justifying to write it anyway.


    But with exactly the same albedo data, we see this study instead:

    E. Pallé, P R. Goode, P. Montañés rodriguez, SE. Koonin (2006) Can Earth’s Albedo and Surface Temperatures Increase Together? EOS, Vol. 87, No. 4, 24 January 2006

    this incredibly bizarre narration
    based on a completely wrong -not confirmed- assumption about the recent temperatures (still rising - NOT!). The contrary as can be seen at the GISS temp graph.
    Last edited: Jan 26, 2006
  2. jcsd
  3. Jan 29, 2006 #2
    Okay in common language this means that the study shows that clouds have a much stronger cooling effect than a warming effect. More clouds, more reflection, less sunlight on the ground, lower temperature. Less clouds, more sun, warmer.

    Instead of all kind of scary assumptions about self sustained global warming - perhaps almost out of control - is out of the question. This is what the graphs show. Consequently, if less cloud cover is the bigger reason of causing global warming, why would CO2.

    But the effect could have been much stronger, considering the back of the envelope calculations of black body temperature. Hence there is a mechanism that moderates the effect.

    Conclusion, This is the strongest evidence ever that CO2 has little if any influence on climate and moreover that the climate is generally stable.
  4. Jan 29, 2006 #3
    Tell that to Venus!

    If it weren't for global warming, we'd be in the middle of an ice age right now, based on the fact that Earth's perihelion now occurs during the northern summer.
  5. Jan 29, 2006 #4
    But why not Mars? with much more absolute CO2 content in it's atmosphere than Earth but with hardly any greenhouse effect

    Anyway about Venus, Let's predict for Venus that it the Venus Express, arriving in April will confirm again the never really solved mystery of the 15% radiation imbalance reported here:

    Then we could explain that right away with another article, which abstract would read:

    Incidentely, there is a very old thread about that here somewhere.

    Now about those Milankovitch cycles. The number of believers is declining fast. Richard Muller can explain why.


    Figure 1 should say it all. It's that weird 100,000 years cycle that kicked in 850,000 years ago that spoils it. Before that in the 41,000 years cycle world it would have been a neat solution.

    Check Spencer Weart:


    But we're working on that. The Ice ages are not what they used to be.
    Last edited: Jan 29, 2006
  6. Jan 29, 2006 #5
    Are you sure about the total amount of Martian CO2? According to the Handbook of Chemistry and Physics, Mars' atmosphere is 95% CO2, but the total pressure is only .007 bars, whereas on Earth it's only 0.03%. So on Earth there's .03 bars worth of CO2, whereas Mars only has .00665 bars worth of CO2. The Handbook doesn't list the total masses though.

    That is weird about Venus radiating energy still. Do you think if a large moon collided with Venus, that would heat it up? Also forming in the inner solar system, it might have a higher concentration of heavy radioactive elements than Earth.

    Regarding global warming, I was thinking of a March 2005 article by William Ruddiman in Scientific American that argued that humans have been adding CO2 to the atmosphere for 10,000 years now due to deforestation and agriculture, and that this has prevented the onset of a new ice age.
  7. Jan 29, 2006 #6
    ABout Mars, have been rambling a bit with the numbers here.


    Actually due to the lower gravity = force = pressure, it's even much more for Mars.

    The story for Venus is much more complicated. Not collisions, but inner core and mantly gyroscopic precession properties, fighting each other in special circumstances, like chaotic resonance when precession and obliquity cycles are in resonance.

    It's a long story.
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