Download What is CO2 - friend or foe?

What is CO2 – friend or foe?
Tom V. Segalstad
Head of the Geological Museum,
Natural History Museum,
University of Oslo
http://folk.uio.no/tomvs
Atmosphere gases
The Earth's atmosphere contains on wet basis
~73.5 % nitrogen, ~22.5 % oxygen, ~2.7 % water,
and ~1.25 % argon per weight.
Among the trace gases
are: CO2, neon, helium,
methane, and others.
The content of CO2 is ca.
0.05 weight-%, compared
with ca.
2.7 weight-% water.
What is CO2?
Carbon dioxide CO2 is an colorless,
odorless, non-toxic gas.
CO2 occurs as a linear O=C=O
molecule, where two oxygen atoms
stick strongly together with one
carbon atom with double bonds.
Hence CO2 is not very reactive.
An analogy is how strongly two
men (oxygens), each with their two
arms, would like to stick to a
beautiful woman (carbon).
Some daily life uses of CO2
• Fire extinguishers (replacement of oxygen)
• Baking soda (expansion of non-toxic gas)
• Soda ”pop” drinks, beer, champagne (effervescense;
added or from fermentation)
• Neutralizing agent for acid lakes (limestone)
• Life jackets (gas expansion)
• Cooling agent
• Product of our breathing!
CH2O
+ O2
CO2 + H2O
carbohydrate + oxygen
CO2 + water
Plant photosynthesis consume CO2
Plants make carbohydrate by combining
atmospheric CO2 with water, powered by light:
photosynthesis
CO2 + H2O + energy
CO2 + water + energy
CH2O
+ O2
carbohydrate + oxygen
breathing,
decay
Increasing CO2, water and energy will make the
chemical reaction go from left to right, making the
plants produce more carbohydrates.
We need for living carbohydrates made by plants.
Hence CO2 is: THE GAS OF LIFE !
Consequence of photosynthesis
The photosynthesis / breathing+decay reaction
CO2 + H2O + energy
CH2O + O2
shows us that all CO2 accumulated by the plant, will
be released again to the atmosphere when the plant
material rot or is burned.
Then tree planting
will only temporarily
remove CO2 from the
atmosphere, unless
the trees are
somehow buried to
prevent them from
decay or being
burned.
IPCC TAR 2001:
CO2 in air (upper graph)
and surface temperatures
(lower graph) were
constant for some 900
years, but have risen
considerably the last 100
years. IPCC’s scenarios
involve drastic rises in both
air CO2 concentration and
surface temperatures.
These assertions have
been strongly opposed by
CO2 measurement critics
and historical temperature
facts: warm + cold missing.
Medieval warm period missing
called the ”Climate Optimum”
The ”Little Ice Age”
missing
Geological temp. evolution
Figure from Bryant (1997)
A geologist’s view of the evolution of the surface temperature
of the Earth, based on geological data. We see the Pleistocene
ice ages (middle right), the Medieval warm period (= the
”Climate optimum”), the Little Ice Age, and future projections!
Energy relations
Some of the trace
gasses in air can absorb
heat, making the Earth
habitable (~14°C vs.
minus 18°C) by the
“Greenhouse Effect”,
146 W/m² of cloud-free
air, dominated by water
vapor. Anthropogenic
CO2 is less than ½
W/m², judged from C
isotopes (more later).
Clouds are the real
thermostat, with far
more temperature
regulating power than
CO2.
Other energy relations
All ice on Earth has a mass of 3.3 x 1022 g. Its latent heat of
fusion is 9.3 x 1024 J. The Earth’s ocean has a mass of 1.4 x
1024 g. Assertions say that ”all ice on Earth will melt in a short
time from anthropogenic CO2”. If melting energy hypothetically
had been taken from the ocean, all its water would cool 2°C.
Heat-absorbing part of the air has a mass of only 1.4 x 1022 g.
Heating all of the atmosphere
2°C would require energy of
1.2 x 1022 J. This amount of
energy is not enough to first
heat the air over the poles to
the melting point of ice (0°C)
and next to overcome the
latent heat of fusion for all ice
on Earth. Thus ice and ocean
participace as “thermostats”.
Solar energy input
NOAA’s measurements of the solar constant show that the
Sun produced a forcing of 0.24 W/m² during the past sunspot
cycle, while assertions said that greenhouse gases caused
0.25 W/m². Coffey et al. write: ”Global change models must
discern between variations caused by anthropogenic and
natural occurrences to provide a sound scientific basis for
policy making on global change issues”.
www.ngdc.noaa.gov/stp/SOLAR/solarda3.html
Carbon reservoirs on Earth
The carbon in the
Earth’s lithosphere
and atmosphere
has come from
degassing of CO2
from the Earth’s
mantle. The
amount of CO2 in
air is minute
compared to the
other reservoirs.
Without sediments,
the partial pressure
of air CO2 alone
would be 40-60
atmospheres.
Figure from
O’Nions (1984)
INORGANIC CARBON CYCLE
This review is important; IPCC’s ocean is clean distilled water.
CO2 enters the atmosphere from many sources to the left.
Atmospheric CO2 dissolves, hydrolyses and protolyses in the
ocean. CO2 may combine with calcium and precipitate as
CaCO3 in limestone, sedimented on the sea floor together with
shells from organisms. This is analogous to breathing CO2 into
a test tube with Ca(OH)2; CaCO3 almost instantly precipitates.
CO2 equilibria air – ocean – CaCO3
CO2 (g) ↔ CO2 (aq)
CO2 (aq) + H2O ↔ H2CO3 (aq)
dissolution
hydrolysis
H2CO3 (aq) ↔ H+ + HCO3- (aq)
1st protolysis
HCO3- (aq) ↔ H+ + CO32- (aq)
2nd protolysis
Ca2+ (aq) + CO32- (aq) ↔ CaCO3 (s)
precipitation
CO2 (g) + H2O + Ca2+ (aq) ↔ CaCO3 (s) + 2 H+ net reaction
Note that increase in CO2 (g) will force the reaction to the right.
Equilibria are governed by the Law of Mass Action + Henry’s Law:
The partial pressure of CO2 (g) in air is proportional to the
concentration of CO2 (aq) dissolved in water.
The proportionality constant is Henry’s Law Constant, KH;
strongly dependent on temperature, less on pressure and salinity.
Henry’s Law in daily use
Henry’s Law Constant is an
equilibrium partition coefficient for
CO2 (g) in air vs. CO2 (aq) in water:
at 25°C KH ≈ 1 : 50
At lower temperature more gas
dissolves in the water.
We have all experienced this –
cold soda or beer or champagne
can contain more CO2; thus has
more effervescense than hot drinks.
The brewery sais that they add 3
liters of CO2 to 1 liter of water in the
soda. But where did all the CO2 go?
Henry’s Law in daily use
”atmosphere”
”ocean”
Henry’s Law Constant directs that
CO2 (g) in air vs. CO2 (aq) in water
at 25°C is distributed ≈ 1 : 50
This means that there will be about
50 times more CO2 dissolved in
water than contained in the free air
above.
The soda bottle is a good analogue
to nature: there is about 50 times
more CO2 in the ocean than in the
Earth’s atmosphere.
Ocean water has 120mg HCO3- per
liter; as much CO2 as in 180 liter of air.
The speed of Henry’s Law
”atmosphere”
”ocean”
IPCC claims that the CO2 equilibration
between air and water will take 50 - 200
years as ”a rough indication”
(IPCC 1990; Table 1.1).
Furthermore that most of the CO2
added to air will accumulate in the air,
and very little be dissolved in water:
Table from Segalstad (1998); after Rohde (1992).
Experiments show this not to be the
case. Do we all wait for 50 – 200 years
for our soda or beer from the brewery?
CO2 equilibria air - water
IPCC tells us what will happen when the air CO2 has doubled.
Is this possible by burning all available fossil carbon?
O
AIR
WATER
Imagine you hold up a Roman beam balance at the red
circle, illustrating the action of the Henry’s Law balance.
To double the air CO2 – how much CO2 must be added?
+ 1 kg
AIR
+ 50 kg
= 51 kg total
WATER
CO2 equilibria air - water
Let us enter actual data for the masses of CO2 in the
atmosphere and the ocean; as carbon equivalents (GT C).
O
AIR
WATER
How much can the CO2 content increase in the
atmosphere by burning all available fossil fuel, 7.000 GT C,
under the condition of chemical equilibrium?
+ 137 GT
+ 6 863 GT = 7 000 GT
AIR
= 20% increase
Anthropogenic doubling is impossible
WATER
IPCC’s proof of anthropogenic
global warming
• Atmospheric CO2 increase ”closely parallels”
accumulated emissions from the burning of fossil
fuels.
• CO2 in ice cores show that air CO2 has increased
21% from 280 til 353 ppm over the last 150 years.
• Carbon isotope ratios of 13C/12C and 14C/12C have
decreased in atmospheric CO2, they ”agree
qualitatively” with expected additions of 12C from
burning of fossil fuel (enriched in 12C). This implicate
that CO2 has a long lifetime in the Earth’s
atmosphere (”rough indication 50 – 200 years”).
IPCC’s proofs rejected
In a number of publications our research group has
rejected IPCC’s 3 proofs of anthropogenic warming.
Cumulative CO2 emissions
Me!
CO2 measurements near the top of the strongly CO2-emitting
active volcano Mauna Loa in Hawaii have been taken as
representative of the world’s air CO2 level. There is a 50% error
vs. the expected CO2 level from burning fossil fuel.
This enormous error of 3 – 4 GT C annually has been
nicknamed ”The Missing Sink”, and disproves the IPCC.
Stable carbon isotopes
isotope ratios are expressed as δ (delta) values
defined as the standard-normalized difference from the
standard, expressed as δ13C in per mil (‰). The reference
standard used is PDB (Pee Dee Belemnite).
13C/12C
Proof from stable carbon isotopes
Figure from
Segalstad (1992 & 1996)
Left: reservoirs found to be in carbon isotopic equilibrium. Burning of
biospheric fossil fuel adds 12C (low δ13C) to the air. δ13C of air in 1988
show ~4% anthropogenic CO2 in air (right scale shows % mixing). Not
21% as asserted by the IPCC, which would have given air δ13C ≈ -11.
Proof from isotopic mass balance
Figure from
Segalstad (1992)
Using the radioactive decay equation for the lifetime of CO2 in air, we
can calculate the masses of remaining CO2 from different reservoirs
using isotopic mass balance; checking for match vs. air CO2 in
December 1988: mass = 748 GT C; δ13C = -7.807 (Keeling et al. 1989).
Proof from isotopic mass balance
Figure from
Segalstad (1992)
The calculations confirm that maximum 4% (14 GT C) of the air CO2
has anthropogenic origin; 96% is indistinguishable from non-fossil-fuel
(natural marine and juvenile) sources. Air CO2 lifetime is ~5 years.
~134 GT C (18%) of air CO2 is exchanged each year, far more than the
~6 GT C annually released from fossil fuel burning.
Proof from isotopic mass balance
Figure from
Segalstad (1992)
We also see why the IPCC’s ”rough indication” lifetime 50-200 years
for atmospheric CO2 gives an atmosphere which is too light; only 50%
of the atmospheric CO2 mass. This explains why the wrong IPCC
model creates the artificial 50% error, nicknamed ”The Missing Sink”.
Conclusions
• CO2 is the ”gas of life”, essential for life of organisms (photosynthesis).
• CO2 is an integral part of an enormous natural cycle between the Earth’s
interior – atmosphere – organisms – ocean – limestone.
• The atmospheric CO2 is a small, short-lived, temporary stock of CO2.
• The 50 times larger marine reservoir of CO2 is governing the atmospheric
CO2 reservoir, not vice versa.
• Carbon isotopes show that maximum 4% of air CO2 has anthropogenic
origin; the rest is ”natural” CO2 from the ocean and the Earth’s interior.
~1/5 is exchanged each year, more than 20 times more than
anthropogenic CO2.
• Atmospheric CO2 absorbs minimal heat compared to the total
”greenhouse effect”; hence CO2 cannot affect the climate much.
• Heat stored in the ocean, and the thermostat action from clouds,
dominate the weather and climate on Earth.
• Earlier warm periods were called ”climate optimums”.
• Increase in air CO2 might be beneficial, not catastrophic, considering
increasing plant growth and ability to feed more people on Earth.
… spectacular facts are hard to beat …