Jennifer Marohasy

a forum for the discussion of issues concerning the natural environment

Climate & Climate Change

Not Enough CO2 in Fossil Fuels to Make Oceans Acidic: A Note from Professor Plimer

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In response to a question concerning the likelihood of our oceans becoming acidic from global warming Ian Plimer, University of Adelaide, has replied:

THE oceans have remained alkaline during the Phanerozoic (last 540 million years) except for a very brief and poorly understood  time 55 million years ago.

Rainwater (pH 5.6) reacts with the most common minerals on Earth (feldspars) to produce clays, this is an acid consuming reaction, alkali and alkaline earths are leached into the oceans (which is why we have saline oceans), silica is redeposited as cements in sediments, the reaction consumes acid and is accelerated by temperature (see below).

In the oceans, there is a buffering reaction between the sea floor basalts and sea water (see below). Sea water has a local and regional variation in pH  (pH 7.8 to 8.3). It should be noted that pH is a log scale and that if we are to create acid oceans, then there is not enough CO2 in fossil fuels to create oceanic acidity because most of the planet’s CO2 is locked up in rocks. 

When we run out of rocks on Earth or plate tectonics ceases, then we will have acid oceans.

In the Precambrian, it is these reactions that rapidly responded to huge changes in climate (-40 deg C to +50 deg C), large sea level changes (+ 600m to -640m) and rapid climate shifts over a few thousand years from ‘snowball’ or ‘slushball’ Earth to very hot conditions  (e.g. Neoproterozoic cap carbonates that formed in water at ~50 deg C lie directly on glacial rocks). During these times, there were rapid changes in oceanic pH and CO2 was removed from the oceans as carbonate. It is from this time onwards (750 Ma) that life started to extract huge amounts of CO2 from the oceans, life has expanded and diversified and this process continues (which is why we have low CO2 today.

The history of CO2 and temperature shows that there is no correlation.

Ask your local warmer:

1. Why was CO2 15 times higher than now in the Ordovician-Silurian glaciation?

2. Why were both methane and CO2 higher than now in the Permian glaciation?

3. Why was CO2 5 times higher than now in the Cretaceous-Jurassic glaciation? 

The process of removing CO2 from the atmosphere via the oceans has led to carbonate deposition (i.e. CO2 sequestration).

The atmosphere once had at least 25 times the current CO2 content, we are living at a time when CO2 is the lowest it has been for billions of years, we continue to remove CO2 via carbonate sedimentation from the oceans and the oceans continue to be buffered by water-rock reactions (as shown by Walker et al. 1981). 

The literature on this subject is large yet the warmers chose to ignore this literature. 

These feldspar and silicate buffering reactions are well understood, there is a huge amount of thermodynamic data on these reactions and they just happened to be omitted from argument by the warmers.

When ocean pH changes, the carbon species responds and in more acid oceans CO2 as a dissolved gas becomes more abundant.

Royer, D. L., Berner, R. A. and Park, J. 2007: Climate sensitivity constrained by CO2 concentrations over the past 420 million years. Nature 446: 530-532.
Bice, K. L., Huber, B. T. and Norris, R. D. 2003: Extreme polar warmth during the Cretaceous greenhouse? Paradox of Turonian ∂18O record at Deep Sea Drilling Project Site 511. Palaeoceanography 18:1-11.
Veizer, J., Godderis, Y. and Francois, L. M. 2000: Evidence for decoupling of atmospheric CO2 and global climate during the Phanerozoic eon. Nature 408: 698-701.
Donnadieu, Y., Pierehumbert, R., Jacob, R. and Fluteau, F. 2006: Cretaceous climate decoupled from CO2 evolution. Earth and Planetary Science Letters 248: 426-437.
Hay, W. W., Wold, C. N., Soeding, E. and Floegel, S. 2001: Evolution of sediment fluxes and ocean salinity. In: Geologic modeling and simulation: sedimentary systems (Eds Merriam, D. F. and Davis, J. C.), Kluwer, 163-167.
Knauth, L. P. 2005: Temperature and salinity history of the Precambrian ocean: implications for the course of microbial evolution. Palaeogeography, Palaeoclimatology, Palaeoecology 219: 53-69.
Rogers, J. J. W. 1996: A history of the continents in the past three billion years. Journal of Geology 104: 91-107.
Velbel, M. A. 1993: Temperature dependence of silicate weathering in nature: How strong a negative feedback on long-term accumulation of atmospheric CO2 and global greenhouse warming? Geology 21:1059-1061
Kump, L. R., Brantley, S. L. and Arthur, M. A. 2000: Chemical weathering, atmospheric CO2 and climate. Annual Review of Earth and Planetary Sciences 28: 611-667.
Gaillardet, J., Dupré, B., Louvat, P. and Allègre, C. J. 1999:  Global silicate weathering and CO2 consumption rates deduced from the chemistry of large rivers. Chemical Geology 159: 3-30.
Berner, R. A., Lasagna, A. C. and Garrels, R. M. 1983: The carbonate-silicate geochemical cycle and its effect on atmospheric carbon dioxide over the past 100 million years. American Journal of Science 283: 641-683.
Raymo, M. E. and Ruddiman, W. F. 1992: Tectonic forcing of late Cenozoic climate. Nature 359: 117-122.
Walker, J. C. B., Hays, P. B. and Kasting, J. F. 1981: A negative feedback mechanism for the long term stabilization of the Earth’s surface temperature. Journal of Geophysical Research 86: 9776-9782.
Berner, R. A. 1980: Global CO2 degassing and the carbon cycle: comment on ‘Cretaceous ocean crust at DSDP sites 417 and 418: carbon uptake from weathering vs loss by magmatic activity.” Geochimica et Cosmochimica Acta 54: 2889.
Schwartzman, D. W. and Volk, T. 1989: Biotic enhancement of weathering and the habitability of Earth. Nature 311: 45-47.
Berner, R. A. 1980: Global CO2 degassing and the carbon cycle: comment on ‘Cretaceous ocean crust at DSDP sites 417 and 418: carbon uptake from weathering vs loss by magmatic activity.” Geochimica et Cosmochimica Acta 54: 2889.
                                                                         CO2 + H2O = H2CO3
                                                                                H2CO3 = H+ + HCO3-
                  2Ca2+ + 2HCO3- + KAl2AlSi3O10(OH)2 + 4H2O = 3Al3+ + K+ + 6SiO2 + 12H2O
                                                      2KAlSi3O8 + 2H+ + H2O = Al2Si2O5(OH)4 + 2K+ + 4SiO2
                                                    2NaAlSi3O8 + 2H+ + H2O = Al2Si2O5(OH)4 + 2K+ + 4SiO2
                                                    CaAl2Si2O8 + 2H+ + H2O = Al2Si2O5(OH)4 + Ca2+
                               KAl2AlSi3O10(OH)2 + 3Si(OH)4 + 10H+ = 3Al3+ + K+ + 6SiO2 + 12H2O
                                                                     CO2 + CaSiO3 = CaCO3 + SiO2
                                                                     CO2 + FeSiO3 = FeCO3 + SiO2
                                                                     CO2 + MgSiO3 = MgCO3 + SiO2

In the oceans, CO2 exists as dissolved gas (1%), HCO3- (93%) and CO32- (8%)

Skeptics to Gather in New York Again

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A highlight of my year so far is the climate change conference in New York in March.    It was a gathering of more than 500 skeptics, including many scientists, to discuss global warming. 

I was enthralled by a presentation from Stan Goldenberg from NOAA which included photographs taken inside the eye of hurricanes from flights within NOAA’s Hurricane Hunters – WP-3D Turbo Prop Aircraft.

Now there are plans to hold a second conference on March 8-10, 2009, once again in New York City.

According to the press release:

The 2009 International Conference on Climate Change will serve as a platform for scientists and policy analysts from around the world who question the theory of man-made climate change. This year’s theme, ‘Global Warming Crisis: Cancelled’, calls attention to new research findings that contradict the conclusions of the latest Intergovernmental Panel on Climate Change (IPCC) report.

Hosting the conference for the second consecutive year will be The Heartland Institute, a 24-year-old national nonpartisan think tank based in Chicago. “All of the event’s expenses are being covered by individual and foundation donors to Heartland,” said Dan Miller, executive vice president of the institute. “No corporate dollars earmarked for the event were solicited or accepted.”

“Last March we proved that the skeptics in the debate over global warming constitute the center or mainstream of the scientific community, while the alarmists are on the fringe,” said Heartland President Joseph Bast. “In the past six months, the science has grown even more convincing that global warming is not a crisis. Opinion polls and political events, including the defeat of ‘cap-and-trade’ legislation in the U.S. Senate, also suggest this ‘crisis’ is over. It has been cancelled by sound science and common sense.”

For more information on next year’s conference visit: http://www.heartland.org/events/NewYork09/newyork09.html 

For more information on last year’s conference visit: http://www.heartland.org/NewYork08/proceedings.html

You can read my perspective on Day 1 of the conference last year here: https://jennifermarohasy.com.dev.internet-thinking.com.au/blog/archives/002809.html and Day 2 here: https://jennifermarohasy.com.dev.internet-thinking.com.au/blog/archives/002813.html  and Day 3 here: https://jennifermarohasy.com.dev.internet-thinking.com.au/blog/2008/03/climate-change-conference-new-york-%e2%80%93-day-3-in-review/

Campaigning for National Parks is Against Australian’s Bush Ethos: Part 1, Buying Back Tooralee

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THERE has been much written about Australia’s national character emerging from a bush ethos: the idea that a specifically Australian outlook emerged first amongst workers in the Australian outback.  Banjo Paterson, perhaps more than any other writer, created and defined this cultural heritage.  His story about the shearer and his sheep (the jumbuck) remains our most popular national song, ‘Waltzing Matilda’.  I grew up on ‘The Man from Snowy River’; a poem about a courageous young horseman who out-rides wild brumbies in the High Country.  

But few Australians now have anything much to do with the bush.  They mostly live in cities, don’t know how to ride a horse and go to the beach for their holidays.  They just singing about sheep at sporting events and read poems about mighty rivers and like the idea of saving the outback.  And so it seems every new Australia government makes saving the Murray River part of their platform. 

The previous Howard government was going to save the Murray from salinity – and achieved this through the construction of salt interception schemes and catchment wide drainage plans all administered by the Murray Darling Basin Commission.     

The new Rudd Government wants to save the Murray from climate change.   This is a much more ambitious undertaking than saving the Murray from salt.  

As part of this campaign the new government has new legislation, The Water Amendment Bill 2008, and it is currently being debated in federal parliament with its second reading beginning last week.   A centre piece of the new legislation is the creation of a ‘The Murray Darling Basin Authority’.   This new institution is claimed to be needed because the existing Murray Darling Basin Commission doesn’t have enough control over the states, but in reality the new organisation, like the old, will still be subject to state politics.  In short, nothing much will change, but it keeps the politicians in politics.   

Politician and new Climate Change Minister, Penny Wong, plans to relieve the claimed climate change problem by buying up farms; most recently through the purchase of a 91,000 hectare property called Tooralee near Burke in NSW.  Tooralee currently grows maize, cotton and beef cattle but following the federal government takeover will be converted to national park.  

Internet campaigners ‘GetUp’ helped get the Rudd-government elected, and have recently joined ‘the fray’ on Murray River issues claiming to provide an opportunity for Australians “to keep the rivers flowing” and save “Australia’s food bowl” through a few mouse-clicks.   But this new campaign is particularly deceptive as Penny Wong’s policies will actually close-down agriculture in the Murray-Darling Basin i.e. empty the food bowl!  Indeed the federal government has something like $3.6 billion to buyback farms like Tooralee.
Furthermore, as some farmers explained on ABC’s TV’s Four Corners program on Tuesday night, you can’t buy back rivers, not even with billions of dollars, because water allocations are just air space until it rains.   

But hey, modern Australia’s are now a mostly soft and gullible lot and likely to support this campaign which is essentially a campaign in support of more politics and big government and against bushies because they now know no better.   But none of this makes senses in the context of our heritage which was about being practical and a part of the bush – the floods and the droughts and the climate change.

Beyond Burke, May 2005. Photograph by Jennifer Marohasy

How Melbourne’s Climate Has Changed: A reply to Dr David Jones (Part 2)

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IT is generally believed that there has been a decline in rainfall across Australia and that as a consequence cities like Melbourne must suffer severe water restrictions.   Indeed if you live in Melbourne you must get prior written approval to fill a swimming pool, there are strict rules explaining how and when you can water your garden, and it is illegal to wash to your car with a garden hose.

In Melbourne reducing water demand and ensuring the efficient use of water is now government policy and the public is continually reminded of this imperative. 

Melbourne’s broadsheet, The Age, recently published an opinion piece entitled ‘Our hot, dry future’ by David Jones, head of climate analysis at the Bureau of Meteorology.  The piece reinforced the popular belief that there has been a long term decline in rainfall as a consequence of climate change.  Dr Jones wrote:

“We also know that over the past 11 years Melbourne’s rainfall has been about 20% below the long-term average, and that south-east Australia as a whole has now missed out on more than a year’s worth of its normal rainfall over the duration of the event. The run-off into Melbourne’s dams has been 40% below average over this drought period compared with the longer term, while regional areas have fared even worse. And the drought hasn’t ended.”  

Total rainfall for the major water-harvesting catchments feeding Melbourne is archived on a weekly basis at the Melbourne water website  as well as total dam storage levels back to September and August 1998, respectively.   My assistant at the Institute of Public Affairs, Nichole Hoskin, asked the Water Commission if we could have this information in an excel format for ease of manipulation, but a Mark Kartasumitra, explained we would have to make-do with what was at the website.   So Nichole extracted the individual weekly values for rainfall and water storage from their archives and entered these values into a spread sheet and then plotted a chart for rainfall, shown below, and also a chart for water storage. 

There has been a steady decline in the amount of water in Melbourne’s dams since 1998, but the chart of total catchment rainfall shows no such decline.   Indeed rainfall over the last decade appears to have been fairly steady. 

When Dr Jones writes that rainfall has been 20% below the long-term average I wonder what time frame he uses by way of comparison?   When Dr Jones writes that runoff has been 40% below average it is interesting to again ponder time frames and also what changes in land management in the catchment may have contributed to the reduction.  Indeed the available data suggests that dam levels have fallen significantly even though there has been reasonable rain.

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Part 1 of ‘How Melbourne’s Climate Has Changed: A reply to Dr David Jones’ was published on October 14th, 2008, and can be read here.