Greg Retallack - The Once and Future Global Cooling: Lessons from Prehistory From Biodiversity for a Livable Climate conference: "Restoring Ecosystems to Reverse Global Warming" Saturday November 22nd, 2014 www.bio4climate.org

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Eocene-Oligocene paleosols Badlands National Park, South Dakota

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Crumb structure (mollic epipedon) in tall grassland
paleosol (Mollisol) Dayville, OR: late Miocene (7 Ma)

3. Smell the grass
Grassland soil (Mollisol) Lake Nakuru National Park, Kenya
cis-3-hexenal
carbon gray, hydrogen white,
oxygen red

4. QUATERNARY RECORD
1: PALEOSOLS
Quaternary Palouse Loess,
eastern Washington
Paleosols near Kahlotus, WA, data from Busacca (1998)
Paleosols near Dayton, WA

5. QUATERNARY 2: SOIL TYPES
Palouse Loess near Clyde,
Washington, alternation of
interglacial deep-calcic
grassland and glacial
shallow-calcic sagebrush
Mt St Helens ash S
23.7 ka
36.1 ka
40.1 ka
46.2 ka
Mt St Helens ash C
thermoluminescence dates from Busacca (1998)
Also in paleosols,
are fossil mam-mals
(Rensberger
& Barnosky, 1993),
& phytoliths
(Blinnikov et al
Earthworm fabric in 46 ka Nix grassland paleosol
Taenidium (cicada) burrow
in 40 ka Tlal sagebrush paleosol
2002)

6. QUATERNARY 3: ECOSYSTEM SHIFTS
Modern dry grassland
near Benge, Washington
Modern sagebrush
near Denio, Nevada

7. CENOZOIC 1: PALEOSOLS IN DEEP TIME
Longview Ranch, Oregon, with green Oligocene paleosols in hill

8. CENOZOIC 2:JOHN DAY FM OLIGOCENE
Well dated (Ar/Ar, paleomagnetic) fossiliferous sequence

9. CENOZOIC 3: SHRUB/GRASS TRACES
Taenidium
cicada burrow
of sagebrush
Edaphichnium
earthworm chimney
of grassland
Pallichnus
dung beetle nests
of grassland

10. CENOZOIC 4: VEGETATION FROM SOIL
Blocky structure
red forested
paleosol (Alfisol),
Painted Hills, OR:
Oligocene (31 Ma)
Crumb structure
(mollic epipedon)
in tall grassland
paleosol (Mollisol)
Dayville, OR:
late Miocene (7 Ma)
Crumb structure (mollic epipedon)
in short grassland paleosol (Mollisol)
Kimberly, OR: mid-Miocene (19 Ma)
Merychippus seversus Dayville,
OR: mid-Miocene (16 Ma)

11. CENOZOIC 5:
VEGETATION
PALEOSOLS
-bunch then sod
grasslands at warm-wet
times
-dry times expanded
sagebrush (not
grassland)
PHYTOLITHS
-36-0 Ma abundant
grassland phytoliths
(Strömberg, 2002, 2004)
PEDOGENIC δ13Ccarb
-40 Ma of 20-40% C4
(Fox and Koch, 2003)

12. CENOZOIC 6: CLIMATE FROM SOIL
Red forested non-calcareous paleosols
(Alfisols) pass upwards into brown
calcareous grassland paleosols
(Andisols) by mid-Oligocene (30Ma)
Painted Hills, Oregon
Paleoprecipitation estimated
from paleosol Bt (blue)
or Bk (red) follows decline
in atmospheric CO2

13. CLIMATE 1: TRANSIENT SPIKES
Chesapeake impact structure
35 Ma (from Voytek, 2005)
35 Ma (Priabonian) and 16 Ma (Langhian)
transient spikes of warm-wet CO2
due to impacts and flood basalts
Columbia River Basalts,
Oregon, Washington (17-15
Ma) (Camp and Ross 2004)
Steinheim Crater, Germany 15 ma (3.8 km) by E. Stabenow
Ethiopian flood basalts 35 Ma
(from Wood and Guth 2010)

14. CLIMATE 2: HIMALAYAN COOLING?
PRO. Mountain uplift promotes weathering and albedo
(Ruddiman and Raymo 1988)
CON. Physical not chemical weathering, metamorphic CO2

15. CLIMATE 3: ANTARCTIC CURRENT?
PRO.
Thermal isolation
ices Antarctica,
consumes H2O,
raises albedo
(Kennett 1978)
CON.
Warms mid-latitudes,
minor reductions of
atmospheric H2O,
CO2 and albedo

16. CLIMATE 4: GRASSLAND EXPANSION?
Grasslands not due to drying, expanding into wetter regions
-from 35-0 Ma expanded from 0-25% of land
Mollic and near-mollic paleosol records from 3 continents (Retallack 2001)

17. COEVOLUTION 1: GRASSES-GRAZERS
BIOLOGICAL
MECHANISM
-adaptation to
others not to
environment
-grasses best
withstand
grazers
-grazers best
cope with
phytoliths
and growth
of grasses
from Retallack 2007

18. COEVOLUTION 2: PACK HUNT & HERDS
Paratomarctus euthos
middle Miocene, Valentine
Formation, Gordon Quarry, Nebraska
Hesperocyon
gregarius 32 Ma
Mesocyon sp. 27 Ma
Tomarctus
euthos 16 Ma
Canis meso-melas
(living)
5 cm
from Radinsky 1969
Prorean
gyrus
-prorean gyrus found in pack
hunting wolves and dogs, not foxes
-prorean gyrus appears in boro-phagine
dogs of Nebraska 19 Ma

19. COEVOLUTION 4: DUNG AND SOD
Agate Springs, NE: Miocene (19Ma)
by Jay Matternes
bear dog den
(Daphaenodon)
Mollisol paleosol
Silica husk
of grass
(Panicum
elegans)
cursorial, hypsodont, tridactyl
(Parahippus tyleri) Dung cake of ruminant
- pack hunting
- running escape
- prey herding
- hypsodont grazing
- siliceous grasses
- dung cakes
- weedless sod
- mollic soil

20. COOLING 1: CARBON STORAGE
- organic C like net primary productivity increases with precipitation
-grasslands rule strategic zone (300-1200 mm mean annual precip.)
African grasslands
Mean annual precipitation (mm) Soil organic carbon (kg/m2)
Australia from Wynn et al. 2005, Africa from Zinke et al 1984
y = 1.7492Ln(x) - 8.4142
R2 = 0.7439
12
10
8
6
4
2
0
Australian woodlands
0 500 1000 1500 2000 2500 3000 3500 4000

21. COOLING 2: TRANSPIRATION
- grasslands
have moist
soil, dry air
-woodlands
have drier
soil (20-30%),
moist air
-water vapor
is a green-house
gas,
although easily
rained out
Nairobi National Park, Kenya Kakamega Forest, Kenya

22. COOLING 3: ALBEDO
- grasslands light (albedo 15-19 %), covered by snow (albedo 40-85%)
-woodlands dark (albedo 8-13%) hard to cover with snow

23. CARBON FARMING 1: MOTIVATION
- global warming due to CO2 could
be offset by C storage in farm soils
-tests already underway in Australia,
baseline soil C assay, then carbon
credit payment for gains

24. CARBON FARMING 2: TECHNIQUES
1. CELL GRAZING
Pen cattle with electric
for each days grazing:
grazing takes out weeds
leaving sod grasses.
2. PASTURE CROPPING
Drill seed and raise
crop through sod:
prevents soil oxidation
by plowing.
3. CONTOUR
COPPICING
Plant trees at inflexion
point in slopes: prevents
Electric fence and cell grazing, Horsham, Victoria gully erosion.

25. CONCLUSIONS
There’s some good news beneath
the horizon,
Next to swamps, grassland soils
have more carbon,
Since these are the soils that we
already use
We can manage soil carbon and
curb soil abuse,
It was just coevolution, a process by
which we got sod.
By grazing so hard on grassy sward,
The Ice Age no longer seems odd.
Still we have coevolution, a way
that we can go forth
And use the soil against big oil
To try to cool the Earth.
Grassland soil (Mollisol), Dionysiou, central Greece.