Friends of Science, Calgary 16th May 2011
Human-induced global warming: Why I am sceptical
Ian Plimer
Earth and Environmental Sciences, The University of Adelaide Emeritus Professor of Earth Sciences, The University of Melbourne Constant cyclical climate change
Known Cycles Variable tectonic, PDO 143 million year galactic 100,000 years orbital 41,000 years orbital 23,000 years orbital 1,500 years solar 210 years solar 87 years solar 22 years solar 18.7 years lunar 11 years solar Climate change over time Is the speed and degree of modern climate change unprecedented?
6 4 ° C) 2 0 Today -2 -4 -6
Temperature ( Temperature -8 -10 -12 400 300 200 100 0 Time – Thousands of Years Before Present Sea levels
ª SL always changing (Neoproterozoic glaciation ±1500 m, Quaternary glaciation ±130 m)
ª 116,000-128,000 years bp SL +7m
ª 6,000 years bp SL in Indian/Pacific Oceans +2m
ª Atolls rise as SL rises
ª Many reasons for SL change Holocene Balding Bay, Great Barrier highstand Reef coast oyster beds Holocene highstand coral microatolls
Microatolls on dead reef flat Orpheus Island, central GBR Great Barrier Reef margin
Summary of Holocene local relative sea- level indicators Holocene glacio-isostatic rebound
Uplift rate 4-20 m/ky
Raised (+30 m) gravel beach ridges Bannenjar’ga, Porsanger Fjord, Norway (“Tapes Transgression”, 6,000-7,000 ybp) Regional isostasy & local relative sea-level since 6 ka
Clark, J.A. & Lingle, C.S. 1979 Predicted relative sea-level changes (18,000 Years B.P. to present) caused by late-glacial retreat of the Antarctic ice sheet. Quaternary Research 11, 279-298.
Cooling with increasing CO2 Temperature
Location, location, location….. Urban heat island effect
23.5 Tucson U of Arizona (32.2N, 111.0W) F) ° 22.0
20.0 Annual Mean Temperature ( Temperature
18.5 1880 1900 1920 1940 1960 1980 2000 2020 What is really measured?
0.8
0.7
0.6 ° C) ( 0.5
0.4 1996
- 0.3
0.2 1940 0.1
0 Temperature Trend per Decade Trend Temperature -0.1 10,000 100,000 1,000,000 10,000,000 Population of Country Reliability of surface measurements
The 28 years of high quality satellite data 1.0
° C) Global 0.5 0 -0.5 1.0 Northern Hemisphere 0.5 0 -0.5 1.0 Southern Hemisphere 0.5 0 Temperature Variation ( Variation Temperature -0.5 1980 1985 1990 1995 2000 2005 The Southern Hemisphere is the same temperature it was 28 years ago, The Northern Hemisphere has warmed slightly Models for atmospheric temperature
10 10 NASA/NSIPP GFDL
50 50
100 100
200 200 300 300 500 500 700 700 950 950 60°S 30°S EQ 30°N 60°N 60°S 30°S EQ 30°N 60°N
-7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 10 10 SNU NASA/GEOS5
50 50
100 100
200 200 300 300 500 500 700 700 950 950 60°S 30°S EQ 30°N 60°N 60°S 30°S EQ 30°N 60°N
Zonally-averaged distributions of predicted temperature change in °K at CO2 doubling (2xCO2-control), as a function of latitude and pressure level, for four general-circulation models (Lee et al., 2007) Radiosonde measurements
No “greenhouse warming” signature is observed in reality hPa Km 25 24
50 20
100 16
200 12 300 8 500 700 4 1000 75°N 45°N 30°N 15°N EQ 15°S 30°S 45°S 75°S
Source: HadAT2 radiosonde observations, from CCSP (2006), p116, fig. 5.7E
Smoothing of ice core CO2 data - why pre-industrial choice of 280ppm?
1812-2004 Northern Hemisphere, Chemical Measurement
from 1958 Mauna Loa CO2 5 year average Ice core Antarctica 450
400
(ppmv) 350 2 CO 300
270 1810 1850 1900 1950 1970 Year Doubling CO2 at 388ppm has no effect
The warming effect of atmospheric carbon dioxide
1.6 1.4
° C) 1.2 1.0 0.8 0.6 0.4 Temperature ( Temperature 0.2 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 Atmospheric carbon dioxide in ppm Water: Main greenhouse gas & driver of CO2
100% 0.001% Man made Natural 80%
60%
40%
20% 0.117% 0.066% 0.047% 0.047% 0% Water CO2 Methane N2O Misc Vapour Gases Greenland ice sheet 5.4cm/yr increase*
Greenland ice sheet change in cm/yr d180 Site15 GISP2, Boltzman Strobel 1994 10per. Mov. Avg (d180 Site15 GISP2, Boltzman Strobel 1994) 80°N -30° -32° -34° -36° -38 75°N ° 20°W -40° -42° 80°W 1940 1945 1950 1955 1960 1965 1960 1975 1980 1985 Year 70°N
30°W -29.5 -30 65°N -30.5 -31 -31.5 -32 60°N 40 W -32.5 70°W 60°W 50°W ° 1000 800 600 400 200 100 Time – Years Before Present 30 20 15 10 5 0 -5 -10 -15 -20 -30 *Derived from 11 years of ERS-1/ERS-2 satellite altimeter data, 1992-2003 Is global warming melting the ice caps and reducing sea ice? NO!
1.0 Antarctic Sea Ice Trends 0.5 …. going up! 0
-0.5 0° 30°W 30°E -1.0 Antarctic 60°W 60°E Source: National Snow and Ice data Centre Peninsula -1.5 1978 1990 2000 2006 Year
Antarctic Land Ice Trends 90°W …. going up over most Amundsen of the continent! Sea 120°W Kamb 120°E Ice Stream 150°W Source: Vaughn, D.G., 2005. Science, 3008, 1877-1878. 2000 Km 180° 150°E 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) Atmospheric evolution
Evolution from reduced CO2-rich (>5%) to oxygenated. CO2 and volcanism
USGS
If each of the 1511 active land-volcanoes on Earth emits
5,000 t C-equivalent of CO2 each dayKyle et al. (2008) http://erebus.nmt.edu/geochemistry.php?page=Gas%20Chemistry => 7,5 Mt/day CO2/CO average
If 4X more CO2 is emitted from submarine volcanoes (30.0 Mt) 8,800 => 37,5 Mt total
This is approximately double the amount of CO2 derived from human burning of fossil fuels (<20 Mt/day).
Slide after Tom Segalstad, Oslo CO2 and volcanism A mantle melt may have up to 8 wt.%
CO2 at ~125 km depth. Surface lava can only hold 0.01-0.001 wt.% CO2 dissolved. CO The difference is degassed to the atmosphere. 2 www.volcanodiscovery.com
Oldoinyo Lengai, active carbonatite volcano, East Africa, North Tanzania
A strong correlation exists between emissions of CO2 at times of extensive volcanism and deposition of limestones during the last ~600 million years (Mikhail Budyko).
Slide after Tom Segalstad, Oslo Terrestrial felsic explosive volcanicity
ª Pathetic: Mt St Helens (1 km3) ª Weather changing: (Krakatoa 1883, Tambora 1815, Thira 1470 BC)
ª Gases: H2O, CO2, CH4, HCl, HF, SO2, H2S (e.g. White Island [NZ] 1150-4120 tpd CO2, 320-1200 tpd SO2) Terrestrial felsic volcanicity
Structurally-controlled volcanicity, gas vents and epithermal systems (Andes,Chile) Subglacial terrestrial volcanicity
Antarctica (felsic), Iceland (mafic) Submarine basaltic volcanicity Submarine basaltic volcanism Acid oceans: When the planet runs out of rocks, the oceans become acid
2+ - 3+ + 2Ca + 2HCO3 + KAl2AlSi3O10(OH)2 + 4H2O = 3Al + K + 6SiO2 + 12H2O + 2KAlSi3O8 + 2H + H2O = Al2Si2O5(OH)4 + 2K+ + 4SiO2 + + 2NaAlSi3O8 + 2H + H2O = Al2Si2O5(OH)4 + 2K + 4SiO2 + 2+ CaAl2Si2O8 + 2H + H2O = Al2Si2O5(OH)4 + Ca + 3+ + KAl2AlSi3O10(OH)2 + 3Si(OH)4 + 10H = 3Al + K + 6SiO2 + 12H2O
CO2 + CaSiO3 = CaCO3 + SiO2
CO2 + FeSiO3 = FeCO3 + SiO2
CO2 + MgSiO3 = MgCO3 + SiO2
In the oceans, - 2- CO2 exists as dissolved gas (1%), HCO3 (93%) and CO3 (8%) Ocean pH is 7.9 to 8.2 Rainwater pH is 5.6 Submarine basaltic volcanicity
Extension, continental fragmentation, basalts and degassing Terrestrial felsic explosive volcanicity
Gas-driven explosions Terrestrial felsic explosive volcanicity
CO2-driven explosions (Tahkt-e-Sulieman, Iran) Terrestrial felsic explosive supervolcanoes
ª Toba: 74,000 bp (2,900 km3)
ª Yellowstone: 2.1, 1.3, 0.64 Ma (1,000-5,000 km3)
ª Taupo: Many recent (5,000-10,000 km3) Terrestrial basalt supervolcanoes
ª 106 km3 lava in <1 Ma
ª Huge H2S and SO2 emissions, temporary surficial ocean acidity and life loss
ª Roza Flow, Columbia River Basalt
>1000 km3 lava
>10,000 Mt SO2 aerosols Terrestrial basalt supervolcanoes
ª Large provinces, sites of juvenile CO2 degassing Submarine basaltic supervolcanoes
ª Not monitored, earthquake swarms and El Niño
ª Particle and 3He plumes
ª No aerosols
ª CO2 (gas) and CO2(liq) dissolves (cool high pressure bottom water) Submarine basaltic volcanicity ª Lava, hot springs, gas vents
ª 64,000 km mid ocean ridges (10,000 km3 water for cooling per annum; buffers seawater)
ª Seamounts (>3,477,403* million > 0.1 km high), off axis volcanoes (cf 800 terrestrial felsic volcanoes)
ª Slow spreading (Gakkel Ridge basalts; >13.5% CO2; explosive [1999])
ª No monitoring; gas measurements from 20 basaltic volcanoes, total emissions calculated at 0.08% of annual human emissions
ª Upwelling thousands of years later
*Hiller & Watts (2007) Terrestrial CO2-rich springs, sinters, vents Terrestrial CO2-rich springs, sinters, vents
6 13 Milos (Greece): CO2 exhalations (2.5 x 10 tpa, δ C = -1.0 to +1.0) Terrestrial warm springs and travertine Submarine basaltic volcanoes
Vent CO2 (gas and liquid) exhalation Hydrothermal fluids Hot spring precipitates
Epithermal carbonate replacement and laminated crack- seal carbonate veins (Acupan, Philippines) Continental evaporites? Degassing
MOLTEN ROCKS (liquid, solid, gas): Degassing of molten rocks (2-15% gases in solution) Carbonate lava
MOLTEN ROCKS (liquid, solid, gas): Carbonatites Basalt CO2 degassing MOLTEN ROCKS (liquid, solid, gas): Extension settings such as rifts (basalts, twice temperature of
felsic melts, higher gas solubility, main gas CO2), mainly unseen) Volcanicity, CO2 and carbonate precipitation Warm CO2-bearing earthquake fluids
EARTHQUAKES
Warm water and gas CO2, CH4, He etc emissions) CO2-bearing springs
MOUNTAIN BUILDING: Thermal springs (bicarbonate), gas
vents (CO2) Decarbonation from mountain building MOUNTAIN BUILDING: Dewatering, degassing,
precipitation of carbonate, CO2- and bicarbonate- bearing springs Atmospheric CO2 residence time
The effective lifetime for CO2 in the atmosphere can be determined using radioactive, radiogenic and stable isotopes.
Estimates made using many different methods show effective lifetimes for atmospheric CO2 of only c. 5 - 7 years.
Slide after Tom Segalstad, Oslo Carbonaceous rocks
CARBONACEOUS SEDIMENTS: Natural sequestration Carbonate sediments 2,750 Ma 1820 Ma Corella Formation 1750 Ma Esperanza Formation 1640 Ma Cryogenian detritus Flinders Ranges 800-600 Ma
If [CO2] high, then dolomite CaMg(CO3)2 Great Barrier Reef, 400 Ma Napier Range Guilin 360 Ma Southern Victoria 50Ma Late Tertiary: Oxygen isotopes: ocean proxy for ocean surface temperature
Marine isotope Stages 1-11
Thousands of years
16O 18O
16O 18O Shark Bay, WA Coral reefs
Soils silicate + H2O + CO2 = hydrous silicate + carbonate Where does CO2 go to?
OCEANS: Especially polar and deep water
CO2 (g) <=> CO2 (aq)
CO2 (aq) + H2O <=> H2CO3 (aq) + - H2CO3 (aq) <=> H (aq) + HCO3 (aq) - + 2- HCO3 (aq) <=> H (aq) + CO3 (aq) 2- 2+ CO3 (aq) + Ca (aq) <=> CaCO3 (s)
Net reaction: 2+ + CO2 (g) + H2O + Ca (aq) <=> CaCO3 (s) + 2 H (aq) CONTEXT: CO2 – levels through time
280 ppm (or even 390 or 560 ppm) indicates
CO2 starvation compared with the geological past Temperature and time
Figure from Bryant (1997) Is the magnitude of late 20th C temperature change unusual?
The last 6 million years – ODP Site 677, North Atlantic Ocean
ICEHOUSE
WARM
100 C
COLD Is the speed and degree of modern climate change unprecedented (Vostok ice core; Salamatin et al. 1998; Petit et al. 2001) Temperature proxy
H2O(vap) buffer to maximum and minimum temperature 4
° C) 2 0 -2 -4 -6 280 CO 2 Temperature ( Temperature 260 -8 (ppmv) 240 220 1.5 200 1.0 0.5
Dust (ppm) 0 0 50 100 150 200 250 300 350 400 Thousands of Years Ago In ice cores, changes in DOES CO2 LEAD OR LAG TEMPERATURE CHANGE? T precede changes in CO2 by ~800-2000 yrs.
CO2 does NOT force temperature at the G/I scale
DOME C 1 mm ICE CORE ANTARCTICA
10 ka 20 ka Is the 20th Century temperature outside natural variability?
20 15 10 5 0 -5 ° C per 100 Years -10
Years BC and AD Cold snaps, rates of climate change Is the magnitude of late 20th C temperature change unusual?
The last 5,000 years – Greenland Ice Core
BC | AD
Egyptian (Menes) Little 1st Unified Ice Kingdom Age Warm Period WARM
10 C
COLD
Egyptian Old Kingdom Minoan Roman Mediaeval Late-20th C (5&6 dynasties) Warm Period Warm Period Warm Period Warm Period Warm Period
Grootes, P.M., Stuiver, M., White, J.W.C., Johnsen, S.J., Jouzel J., Comparison of oxygen isotope records from the GISP and GRIP Greenland ice cores. Nature 366, 1993, pp. 552-554.
Slide after A. Illarionov, Powerpoint presentation, December 2004. What does the history of the planet tell us?
ª Earth always changes
ª Climate change is normal
ª Climate change occurred well before humans were on Earth
ª The rate of climate change today is no different from thousands, millions or billions of years ago
ª >80% time, Earth has been warmer and wetter than at present
ª Ice is rare
ª Just because change occurs in our lifetime does not mean that we humans are driving the change The gas of life
ª CO2 gas of life, increase beneficial
ª Part of massive natural cycle (mantle-atmosphere- oceans-organisms-sediments)
ª Atmospheric CO2 short temporary stock, marine reservoir 50x larger governs atmospheric CO2
ª Heat stored in oceans and thermostat effect of clouds
ª Carbon isotopes show <4% atmospheric CO2 anthropogenic, small effect compared to total
ª To argue that human emissions of CO2 drive climate change is non-scientific political activism akin to creationism