International Association for Energy Economics
23rd Annual IAEE International Conference, Sydney 7-10 June 2000


Robert J. Foster 1, 2
Consultant, Melbourne Australia


Natural climate change ranges from global-scale Glacials/Interglacials on a 100,000-year cycle, through the 1500-year cyclicity of the North Atlantic Basin mega-region, to El Niño events of sub-decadal frequency and multi-regional impact.  Melting of continental ice has raised sea level 120 metres since the last Glacial; and, of this, the West Antarctic Ice Sheet has contributed 11 metres.  Collapse of WAIS continues today; and a rise of several metres over the next millennium is a plausible expectation.

Our Globe is warming; of that there is no doubt.  Surface warming averaged 0.4-0.8 0C over the Twentieth Century, and 0.2-0.4 0C during the past two decades (a time of soaring human-caused greenhouse gas emissions).  Is this the ‘global warming’ of the IPCC Report?  Despite IPCC’s assertions - so influential at Kyoto - there is as yet no “discernible human influence on global climate” attributable to changes in atmospheric composition resulting from GHG emissions.  While these cannot be disregarded, natural variability remains the major influence on climate.  Continuation of the Roman Empire/Dark Ages/Mediaeval Warm Period/Little Ice Age cyclicity has driven 20th C warming, particularly in that most sensitive region - the higher northern latitudes.
1.  Robert J Foster is an Adelaide University engineer by qualification, a geoscientist with the Shell Group by experience, and was latterly General Manager Marketing at BHP Petroleum in Melbourne.  He is now a consultant in energy economics in Melbourne and can be contacted through
2.  This document develops and updates two earlier papers:
 Robert J. Foster 1999, “Climate-change debate: geoscientists wanted”, Transactions of the Royal  Society of Victoria v 111 no 2, pp lvii-xciv;
 Bob Foster 1999, “Climate-change science: too much imagination block”, pp 152-61 in  Proceedings of the National Conference of the Australian Institute of Energy (on 24/25  November), Melbourne 311 p.
Both these papers are a critical response to the contribution of Working Group I to the Intergovernmental  Panel on Climate Change’s Second Assessment Report:- Houghton, J T et al Eds 1996, "Climate change 1995: The science of climate change", Cambridge University Press 572 p.

In the past, climate change was externally influenced by solar radiation, and internally driven by ice, oceans and atmosphere acting in concert - particularly by recurrent ice-related extreme events.  But the computer-models on which IPCC relies for its projections of climate are atmosphere-oriented and uniformitarian, ignoring intermittent ice surges and consequent abrupt variations in oceanic heat transportation.

Furthermore, atmospheric science and uniformitarianism cannot address the fundamental question: are human-caused GHG emissions, on balance, good or bad for humanity and for the biodiversity of which we are custodians?  Obtaining an answer will take time.  But time is not yet pressing, because sensitivity to anthropogenic emissions is less than previously expected.  A GHG-caused warming of 0.8 0C per decade was invoked at the Toronto Conference in 1988, reduced to 0.3 0C for Rio in 1992, and then to 0.2 0C for Kyoto in 1997.  Even the last could be an exaggeration.

In the meantime, the campaign to mitigate human-caused global-warming is diverting attention from other threats to Australian biodiversity; and a decision to meet Australia’s Kyoto commitment would mean less money for our more-pressing environmental responsibilities.  Already, OECD countries curtail entry for our low-cost food exports; and we now risk setting at naught the advantages of low-cost energy in adding value to our mineral exports - for no known countervailing benefit to the environment.

Ratification of the Kyoto Protocol by Australia would be appeasement of protagonists in the EC/US ‘greenhouse war’; and collateral damage to our LDC-like economy is the inevitable outcome.  If it is indeed crucial that anthropogenic GHG emissions be curtailed, far more is needed than a ratified Protocol; LDCs, notably China and India, must be included.  Alternatively, if the early return of harsher climatic conditions (firstly, to the northern North Atlantic Basin region) is the greater threat, GHG emissions are no longer a problem.  The warm/wet, high-CO2 world of pre-sapiens times would be a distinct improvement on the cold/dry, conditions which preceded the present Interglacial.

1.  Prologue
We humans can’t ensure that climate stays as it is now - any more than we can command the seas to keep their present station.

Natural climate change is often large, often abrupt, and often relatively short-lived.  It occurs at many time-scales: ranging from (long) Glacials and (short) Interglacials on a 100,000-year cycle, which are of global reach; through the ca 1500-year cold/warm/cold cyclicity in the North Atlantic Basin mega-region, of which the Roman Empire, Dark Ages, Mediaeval Warm Period and Little Ice Age episodes are the latest manifestations; down to El Niño warm events (centred in the equatorial eastern Pacific, but with a multi-regional influence) with an irregular frequency of less than a decade.

It is our good fortune to live in an Interglacial (the Holocene), a period of benign climate (cf the previous many tens of millennia) of some 10,000 years so far.  This is about as long as Interglacials last; our next big change probably will be in the colder direction.

Sea level has risen some 120 metres since the Last Glacial Maximum about 20,000 years before the present; and most of this rise took place between 14,000 and 6,000 yBP, as the great ice-sheets of northeast North America and northern Eurasia melted in the Interglacial warmth.

However some of the rise (that derived from the decay of the West Antarctic Ice Sheet) occurred later. Unlike the continental ice sheets on Greenland and East Antarctica, the WAIS is founded on a submerged shelf, and was destabilised by the rising sea.  It has already lost 2/3 of its mass (the sheet’s grounding line in the Ross Sea embayment has retreated 1300 km along the foot of the Transantarctic Mountains).  Global sea-level has risen 11 metres as a consequence, and observations confirm that the collapse continues apace.  A rise of several more metres in this millennium is a plausible expectation.

Fortunately, the World now has the wealth and social institutions necessary for ameliorating somewhat the human suffering which natural variability will surely bring.  But what about the biodiversity of which we are all custodians, and the variety of  complex ecosystems on which it depends?  It may sound naive but, realistically, we can  do little more than try to maintain as wide a variety of habitats - terrestrial, littoral and marine - as possible, which are as extensive and undisturbed as can be achieved.  In Australia, we are not doing enough.

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Posted 13, October, 2000
Updated 7, November
© 2001  Bob Foster
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