While does our earth have a 21% Oxygen Atmosphere, when our neighboring planets, Mars, and Venus, have mostly Carbon Dioxide? Could our earth have a runaway greenhouse effect like Venus? Is there life on the billions of exo-planets?

1. PLANETARY VACUUMS, ATOMOSPHERES, & LIFE
Paul H. Carr
www.MirrorOfNature.org

2. VACUUM ON THE MOON 3 X 10-15 BAR
No greenhouse gas atmosphere
• Diurnal Variations:
Day 123 C (396 Kelvin)
Night -233 C (40 Kelvin)
ON EARTH
• Greenhouse gasses, blanketing the earth, give much
smaller variations.
• On cloudless nights, non-condensing and increasing
CO2 (100 year life) and other greenhouse gases keep us
warmer than on the moon.

3. Increasing CO2 gas density: 1. raises temperature of earth’s surface.
2. reduces temperature of the stratosphere.
3

4. -Outgoing spectral radiance at the top of Earth's atmosphere showing the absorption at specific
frequencies and the principle absorber CO2 at 16 microns.
-The red curve shows the flux from a classic "blackbody" at
294°K (≈31°C≈69.5°F). Schmidt, G.A., 2010 J. Geophys. Res.,115, D20106, doi:10.1029/2010JD014287.
4

5. Vacuum of
1 Bar 3 x 10-15
10-14 0.0192
Gravity helps hold planet’s atmosphere.
Venus had a CO2 runaway greenhouse effect.

6. PLANETARY TEMPERATURES, VACUUMS, & ATMOSPHERES.
Science, 330, 356-359, 15 October 2010
Parameter Mars Earth Venus Mercury
Temp. (K) 223 Day 300 Day 730 Day 700 Day
213 Night 280 Night 730 Night 100 Night
Pressure (bar) 0.01 1 92 10-14
Ultraviolet observations of VENUS’ cloud cover----
Venus surface temp hotter than Mercury’s 700 K.
ATMOSPHERES
Venus: 96% CO2, 3% Nitrogen.
Earth: 21% Oxygen, 78% Nitrogen, 0.04% CO2
Mars: 95% CO2, 3% Nitrogen

7. Why does our earth have 21 % oxygen, 0.04% CO2?
-Neighboring Venus & Mars are mostly CO2

8. Figure from “Cosmic Dawn” by Eric Chaisson
Photosynthesis of blue-green algae converted CO2 to Oxygen
Carbon Dioxide, CO2
Prokaryote Cells Eukaryote Cells
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9. • Cambrian Explosion of multicellular life made possible
by increasing oxygen levels.
- CO2 was converted to O2 by photosynthesis.
- Enabling animals that get energy by oxidizing sugars.

10. Might our earth undergo a runaway
greenhouse effect similar to Venus?
Fossil fuel burning is increasing CO2 concentrations.
Temperature increases correlate with CO2.

11. CORRELTAION BETWEEN TEMPAND CO2 INCREASE
From the Greenhous Effect. 11

12. At present rate
of 2.5 ppm
rise per year,
humans are
increasing
CO2 at a rate
300 times
faster than
the recovery
from the ice
age 18,000 -
10,000 years
ago.
CO2 CONCENTRATIONS, HIGHEST (33%) IN 800,000 YRS,
COULD REACH ~1000 PPM BY 21OO.
Ice
Age
12

13. • Our present level of 400 ppm could reach ~ 1000 ppm by 2100.
• Arctic became ice-free 8 M years ago when CO2 = 300 to 450 ppm.
• Antarctic melted ~ 40 M years ago, CO2 ~ 700 ppm
-Earth was ice-free, sea levels 100s meters (~300 ft) higher.
Dinosaur Extinction 65M Yr. BP Figure from Dr. James Hansen, NASA GISS
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THERMAL MAXIMUM

14. Photograph by Ira Block When the Ocean Went Dark
National Geographic October 2011, vol 220. no 4. pg. 90
http://ngm.nationalgeographic.com/2011/10/hothouse-earth/kunzig-text
Paleoceanographer James Zachos holds a replica of a sediment core that shows an abrupt
change in the Atlantic Ocean 51 -55 million years ago, at the onset of the Paleocene-
Eocene Thermal Maximum (PETM). White plankton shells vanished from the seafloor
mud, shifting its color from white to red. As planet-warming CO2 and CH4 clathrates
surged into the atmosphere, Zachos says, it also seeped into the seas, acidifying the
water and dissolving the shells.

15. PROPOSED DEBATE ON
LIFE on the EXO-PLANETS
Between
Cosmologist, CARL SAGAN (1934 – 1996)
Believed many kinds of intelligent life could form, but that the lack
of evidence suggests that intelligent beings destroy themselves
rather quickly.
And
Evolutionary biologist, ERNST MAYR (1904 - 2005, Bedford, MA)
Single cell life in the universe is very likely,
but intelligent life very rare.

16. PLANETARY VACUUMS, ATOMOSPHERES, & LIFE
CONCLUSIONS:
• We must stop CO2 fossil fuel emissions by:
-Conservation, efficiency increases,
carbon emission surcharge.
- Energy from solar, wind, nuclear.
• The 21% oxygen that enables our life was
made possible by the emergence of plant
photosynthesis.