A paper delivered to the Lavoisier Group Conference, May 2000

Climate Change: Don't Forget the Science

Bob Foster

Abstract

The scientific underpinning for the Kyoto Protocol of 1997 is Climate change 1995: the science of climate change (edited by J.T. Houghton et al) from the IPCC's Second Assessment Report published in 1996. Even now, the Australian Government recognises this Report "as the most authoritative source of information on the science of global climate change". A summary paper of April 2000 by Graeme Pearman (Chief, CSIRO Atmospheric Research) Progress in climate science and its role in greenhouse policy calls "heavily" on the IPCC Report; and my detailed critique herein of the Pearman Paper is a surrogate for an analysis of the Report's climate-change science. The IPCC Report treats atmospheric science and climate-change science as the same thing; and its self-interested advocacy has led 'policymakers'---politicians and bureaucrats---to accept that:

• the observed global warming over the past century is because of human-caused changes to the composition of the atmosphere---resulting from the emission of greenhouse gases, particularly CO2 from the burning of fossil fuels; and
• sufficiently tight control on GHG emissions would keep both climate and sea-level as they are now.

Both beliefs are almost certainly wrong; and IPCC's advocacy is diverting Australian money and zeal from better-founded and more-pressing environmental needs.

Past climate has shown much natural variability, globally or regionally, at many time-scales. Observed surface warming, over the last half-century at least, is largely in the Northern Hemisphere, in temperate and northern latitudes, on land, and in winter. This warming is related to the ca 1500-year cyclic fluctuation of which the Roman Empire time, Dark Ages, Mediaeval Warm Period, and finally the Little Ice Age of AD 1300-1900, are manifestations. Furthermore, GHGs cause the atmosphere to heat up in the first instance, with subsequent re-radiation of this increased warmth and consequent 'greenhouse warming' at the surface; we now have 21 years of atmospheric temperatures---and there has been little or no warming! But surging ice-sheets with resulting redirection of oceanic warm currents, and also variable solar output, are crucial. Reciting the mantra 'we accept the science' would be a poor substitute for considering the full range of relevant scientific input before Australia ratifies the Kyoto Protocol.

Contents

(Major headings only)

1. Our Changing Climate

2. The IPCC's Scientific Origins

3. Enter Australia

4. UNCED Initiative

5. The IPCC Second Assessment Report

6. Australia Needs a Countervailing View

7. IPCC's Advocacy of Atmospheric Science

8. Taking a Broader View of the Environment

9. Epilogue---Incommensurable Paradigms

Endnotes

1. Our Changing Climate

1.1 Natural changes at many time-scales

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 time, Dark Ages, Mediaeval Warm Period and Little Ice Age episodes are the later 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.

Never forget, we live in an Ice Age. It is our personal good fortune to be here during 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 usually last; our next really big change probably will be in the colder direction.

Indeed, we (or at least, our contemporaries living in the temperate regions of the Northern Hemisphere) are doubly blessed:

First, we live in a warm inter-regnum in an Ice Age with a duration in excess of two million years so far, and no end in sight.

Second, Northern Europe and North America have recently emerged from a period of great, albeit intermittent, suffering---the Little Ice Age. The benign climate we now enjoy is ephemeral.

1.2 Sea-level

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 probably destabilised by the rising sea.

The WAIS 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), mostly in the last 8,000 years. Global sea-level has risen 11 metres as a consequence, and observations confirm current surging speeds in West Antarctic ice-streams of up to 2 km/yr. It appears that this long-running collapse (surging, not melting) continues apace; thus, a sea-level rise of several more metres in this millennium is a plausible expectation.

1.3 Environmental impact of natural change

The World now has the wealth and social institutions necessary for ameliorating 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 we can do little more than maintain as wide a variety of habitats---terrestrial, littoral and marine---as possible, which are as extensive and undisturbed as can be achieved. (In SW Australia, we have one of the world's 'biodiversity hotspots', both rich in endemic species and threatened by human activities.)

2. The IPCC's Scientific Origins

2.1 Very Early Days

Back in the 70s, the greater concern was the possibility of global cooling.(1)

However, it was also in the United States during the late 70s, that the attention of scientists was drawn to predictions by primitive numerical climate-models that increasing emissions of CO2 (arising from the combustion of fossil fuels) would cause global warming

This concern was picked up by the World Meteorological Organisation (WMO) and the United Nations Environment Program (UNEP). Together with the International Council of Scientific Unions (ICSU), these organisations met at Villach (Austria) in October 1985 to discuss this newly-discovered threat to mankind. Seldom has a scientific meeting had such an influence on policy-making.(2) The participants concluded that:

although quantitative uncertainty in models results persists, it is highly probable that increasing concentrations of the greenhouse gases will produce significant climate change.

and

the understanding of the greenhouse question is sufficiently developed that scientists and policy-makers should begin an active collaboration to explore the effectiveness of alternative policies and adjustments.

The Villach Conference recommended that UNEP, WMO and ICSU take action to:

initiate, if deemed necessary, a global convention.

Villach was the high-water-mark of scientific influence. The origins of the concern over global warming appear to have been largely scientific in the best sense---rather than self-serving of either scientists or politicians. But it was a conference of climate scientists sensu stricto---not of climate-change scientists sensu lato. These were atmospheric people, not palaeoclimatologists. Hence, from the beginning, perspective was lacking.

Thereafter, science (although, of course, still important) became increasingly subservient to other influences. For instance, Our Common Future (aka the Brundtland Report) published in 1987, arose from a UN commission---although it relied on Villach for its science. But the global-warming horse had bolted; and fear already had bested science. The Brundtland Report concluded, on the flimsiest of evidence, that global warming:

could cause sea-level rise over the next 45 years large enough to inundate many low-lying coastal cities and river deltas. It could also drastically upset national and international agricultural production and trade systems.

2.2 The 1988 Toronto Target

The Toronto Conference of June 1988, The changing atmosphere: implications for global security, although sponsored by the Canadian Government, was not officially government-sanctioned. Thus, in theory, the government-funded participants attended in their private capacities. As a result, the drafting committee was comprised largely of environmentalist; and for the first time in the global warming saga, activists dominated.

And hyperbole also dominated. The Toronto Conference statement began:

Humanity is conducting an unintended, uncontrolled, globally pervasive experiment whose ultimate consequence could be second only to a global nuclear war. It is imperative to act now.

and recommended a target as follows:

An initial global goal should be to reduce CO2 emissions by approximately 20 percent of 1988 levels by the year 2005. Clearly, the industrialised nations have a responsibility to lead the way, both through their national energy policies and their bilateral and multilateral assistance arrangements.

The impetus which Toronto gave to environmental concern has never waned.(3)

2.3 Hyperbole from those who should know better

Moberg looks at the pressures on politicians and scientists to dramatise areas of complexity and uncertainty:

... it is ... quite in order that the governments of the world are seeking to do something about this threat to the global environment.... However it is also perfectly possible that the threat is exaggerated and that governments give it emphasis in order to further their own interests.

and

Political science has given increasing prominence to the idea that politicians are not just governed by considerations of the public good but are also affected by motives of self-interest.... It could be equally well argued that the same also applies to research and researchers.... Since most types of research require substantial funding, it wouldn't be unreasonable to assume that researchers who produce results or work in areas that meet with the approval of the government will have a better chance of survival than those who don't.(4)

Böttcher provides the real-life examples:

In the summer of 1988 the US suffered from a heatwave. The testimony of James Hansen, a NASA climate modeller, to the Senate Energy Committee that "the greenhouse effect has been detected and it is changing our climate now" made front page news, coming as it did at the height of the heatwave.... James Hansen should have known better because every meteorologist knows that regional heatwaves have nothing to do with climate change.

and

Even George Bush used it ... in his election speeches a few months later: "Those who think we are powerless to do anything about the greenhouse effect are forgetting about the White House effect. As President I intend to do something about it".

2.4 The Intergovernmental Panel on Climate Change

The IPCC was created by the World Meteorological Organisation and the United Nations Environment Program in order to:

(a) assess available scientific information on climate change;

(b) assess the environmental and socio-economic impact of climate change; and

(c) formulate response strategies.

This group held its first meeting in November 1988, electing Professor Bert Bolin of Sweden as chairman, and establishing three working groups:

Working Group I on science, chaired by the United Kingdom;

Working Group II on impacts, chaired by the Soviet Union; and

Working Group III on response strategies, chaired by the United States.

The underpinning for the planned work of IPCC was scientific. Following publication of its First Assessment Report in 1990, which co-ordinated the work of hundreds of specialists around the world, IPCC has taken both the scientific and intellectual lead on the greenhouse issue.

But WG I on science is not as 'scientific' as it seems. We now hear much of "the consensus of 2500 of the world's top climate scientists" in the findings of the IPCC; but surely, there is more to science than consensus. Böttcher puts it this way:

A new and dangerous principle has been introduced in science based policy making, namely decisions based on scientific consensus by majority vote, achieved by a group of scientists.... How do we know that what is proclaimed to be a 'consensus' really is a consensus view? And how do we know that this view comes anywhere the truth?

IPCC's 'climate science' was, right from the start, advocacy for atmospheric science.

3. Enter Australia

3.1 In from the beginning

Australia played a significant role at Villach, and in IPCC's formation; and continues to play an important role in scientific research on the climate-change issue. CSIRO's Cape Grim atmospheric base station supplies a crucial real-time input for the data-short Southern Hemisphere. In addition, individual Australian scientists, particularly from CSIRO and the Met Bureau, have played a prominent part from the beginning in the IPCC's Working Group I which deals with the science of climate change.

3.2 The Commission for the Future

During the time of Minister Barry Jones, the Melbourne-based but Federally-funded Commission for the Future made the early running on publicising the greenhouse issue. Staffer Phil Noyce was allocated to the task; and his work culminated in Greenhouse 88 at Dallas Brookes Hall---with a video link to audiences at venues in other states.

The program offered an address by "young outspoken climatologist" Dr Stephen H Schneider,(5) brought to Australia for the purpose. He and James Hansen (see Section 2.3) were the two main greenhouse activists in the science community of the time.

The evening's program was padded out with local speakers, none of them climate specialists: Professor Ian Lowe (then head of the Commission), Carmel Travers, Philip Adams---and Yours Truly.

The event filled a need, of that there can be no doubt, attracting as it did 800 paying customers in Melbourne and smaller, but not insignificant, audiences interstate. A part of the well-educated segment of the Australian community had found a new cause.

Who were these people? Some were undoubtedly Greens keen to extend their area of environmental knowledge. But remember, this was 1988. It is likely that many were not Greens sensu stricto, but those inherently anti-capitalist intellectuals for whom Soviet Man and the glory of socialist labour were wearing a bit thin. There appear to be more well-educated people supporting the greenhouse cause in Australia, and elsewhere in the capitalist world, than other more-pressing green causes. A new market has been tapped.

3.3 Australia's 1990 Cabinet response

3.3.1 The October statement

Following considerable Green pressure to endorse the Toronto target, and without any detailed examination of the physical steps which would be needed to give effect to such a policy, on 11 October 1990 Federal Cabinet:

agreed to adopt an interim planning target of stabilising emissions of greenhouse gases (e.g. carbon dioxide, methane and nitrous oxide) ... based on 1988 levels, by the year 2000, and reducing these emissions by 20% by the year 2005.

However, a balance was maintained between concern as a world citizen, and national self-interest. Thus, an important caveat was provided; and the Cabinet:

while recognising the need to restrict greenhouse gas emissions and to aim for a 20% reduction, agreed that Australia will not proceed with the adoption of response measures which have net adverse economic impacts nationally or on Australia's trade competitiveness, in the absence of similar action by major greenhouse gas producing countries.

Which are the "major greenhouse gas producing countries" in Cabinet's caveat?

3.3.2 CO2 emissions---and their growth

First of all, carbon dioxide is the single most important anthropogenic greenhouse gas, and fossil fuel production and use represent about three quarters of man-made CO2 emissions. Therefore, there is little doubt that Cabinet had CO2, and specifically that from fossil fuels, in mind. Rankings for the top ten emitters in 1990 are given in Table 1 in terms of million tonnes of carbon; also shown is growth or decline in emissions to 1996.(6) Equivalent data from Australia are included for comparison.

* Note that the available IEA statistics do not include 1990 figures for individual
member-republics of the former Soviet Union; the figures above for Russia and Ukraine are my estimates.

Table 1 reveals a remarkable story. Since 1990, there has been a collapse of energy use in the former Soviet Union (and the other CPEs of Eastern Europe), and explosive growth in the Asian LDCs as exemplified here by the PRC and India; these occurrences are reflected in their CO2 emissions.

In addition, serendipitous changes in Germany (closure of fuel-inefficient industry in the former DDR) and UK (replacement of coal by gas in power generation) have caused slightly reduced emissions over the period, in contrast to the rise in almost all other OECD nations.

3.3.3 Feeling good, but ...

It did not take long for the wheels to start falling off the vehicle of Australia's enlightened self-interest. In a review entitled "Australia's international role in protecting the environment", presented to the OECD Environment and Development Minister's Meeting in Paris on 3/12/1991, the Australian Minister for the Arts, Sport, the Environment and Territories, Ros Kelly, said of greenhouse:

There has been enough research. The IPCC Report has made things very plain. There is an urgent need for the developed countries which caused the problem to take the actions necessary to solve it.

Here was a national politician posturing on the international stage, heedless of the pain to Australia's economy and work-force which would be the direct and inevitable outcome of the 'necessary actions' she was proposing. Important to the theme of this paper, note how dismissive Minister Kelly was of the part to be played in future by science.

4. UNCED Initiative

4.1 The 1992 Rio Conference

The United Nations Conference on Environment and Development, held in Rio de Janeiro in June 1992 resulted in a Framework Convention on Climate Change with the ultimate objective of stabilising greenhouse gas concentrations in the atmosphere at an acceptable level. 'Acceptable' would mean that anthropogenic emissions are held below the point where they interfere with the climate system.

Even though UNCED was a political event, its stated objective on greenhouse (albeit, exceedingly ill-defined) still was science-based. However, the global warming prediction of 0.8 ºC per decade, as used at Toronto, had been reduced by IPCC to 0.3 ºC per decade by Rio. More work on the science had shown the global warming threat to be less pressing than had been thought; but it was already too late to turn the ship.

Böttcher puts UNCED, and its FCCC, in context:

Global warming has obtained the status of the most important environmental issue. This remarkable feat came about through the well-orchestrated efforts of an inner circle of science-policy makers within the Intergovernmental Panel on Climate Change (IPCC). They predominated the scientific discussion in order to achieve the necessary 'scientific consensus' for politicians to take action.... [Thus] the striking attention to a subject as complex as climate change could trigger the signing of an international climate treaty after less than five years preparations---a unique event in the annals of international negotiations.

4.2 Australia's first national inventory

The FCCC commits all Parties to the Convention to:

develop, periodically update, publish and make available to the Conference of Parties ... national inventories of anthropogenic emissions and removals by sinks of greenhouse gases....

In March 1994, the Convention had been ratified by sufficient Parties to bring it into being. Australia, and the other industrialised countries, were then required to provide a greenhouse gas inventory, and predictions as to progress in reducing emissions, prior to the first Conference of Parties under the Convention (COP 1, Berlin) in March 1995.

Senator Faulkner, Minister for the Environment, Sport and Territories, released on 7 September 1994 a summary of Australia's National Communication (of six volumes) as required under the Convention.

In particular:

• Total greenhouse gas emissions in 1990 were estimated to be equivalent to 572 million tonnes of carbon dioxide.
• Of the three main greenhouse gases---carbon dioxide, methane and nitrous oxide---carbon dioxide emissions accounted for almost three-quarters of total emissions.
• The single largest contributor to emissions is the energy sector, which produces about half of Australia's total greenhouse gas emissions.
• In this sector, power generation (primarily coal based) was the main source of emissions. Transport was the next largest source.
• Specifically, if we took no action, our emissions would grow from 572 million tonnes carbon dioxide equivalent in 1990 to 654 million tonnes in 2000.
• This represents an increase of 82 million tonnes, or 14 per cent.

In the terms of Table 1 (above), total greenhouse gas emissions in 1990 of '572 million tonnes of carbon dioxide equivalent' is 156 MtC. Therefore, CO2 emissions from the combustion of fossil fuels was some 46% of estimated total GHG emissions in 1990.

Senator Faulkner had intended to bring to Cabinet during February 1994 a proposal for a 'small' carbon tax (A$2.50/tonne of CO2, ie $9.20/tonne of carbon) or "environmental levy". However, strong lobbying from industry (which saw this tax as a first step toward a bigger tax) and the opposition of economic Ministers (Collins, Cook and McMullan) caused a rethink.

A united industry and relevant Ministers worked together here, with success. Call it lobbying if you like; but this was democracy in action.

5. The IPCC Second Assessment Report

5.1 Climate Change 95

5.1.1 The Report

The contribution of Working Group 1 to the Second Assessment Report of the Intergovernmental Panel on Climate Change (J T Houghton et al., eds, 1996), entitled Climate Change 1995: the Science of Climate Change, is IPCC's current assessment of climate-change science.

When I write of the 'IPCC Report' or the 'Report' herein, I mean the first 50 pages or so of the WG 1 Report encompassing Preface, Summary for Policymakers and Technical Summary. Although the Report comprises 572 pages in all, I doubt whether policymakers---be they politicians or public servants---would have time to venture into the detailed technical chapters.

A 'mainstream' account of the full 3-volume IPCC Report,(7) including inter alia the WG I volume on the science of climate change, is as follows:

How can science advice on controversial issues effectively feed into the policy-making process? One pioneer has been the IPCC.... Its reports have a direct influence on global climate policy. The latest 3,600-page report ended a long-running controversy on whether human activities, such as the burning of fossil fuels, were responsible for the rise in average world temperatures.

The conclusive tone of this article has its source in the Preface of the WG I Report. Here, the principal scientific emphases are the statement that:

the essential message of this report continues to be that the basic understanding of climate change and the human role therein, as expressed in the 1990 report, still holds ...

and

Further, that observations suggest "a discernible human influence on global climate", one of the key findings of this report, adds an important new dimension to the discussion of the climate change issue.

Firstly, the Report further reduces to 0.2 ºC per decade the estimate of future global warming arising from anthropogenic greenhouse gas emissions. This is a far cry from the 0.8 ºC prediction at Toronto in 1988, or even the 0.3 ºC of the 1990 report---and it could still be a substantial over-estimate. This reduction is not mentioned in the Preface.

Secondly, 'discernible human influence' depends on the identification of 'fingerprints' in the climate. Thus the Preface (of just over a page in length) highlights a 25-year warming trend in balloon-borne thermometer (radiosonde) measurements of temperature in the lower atmosphere at 30-60ºS latitude---which corresponds to climate-model predictions. But the full run of available radiosonde data, including the five previous and eight subsequent years, shows no such trend. IPCC's most prominent scientific conclusion(8) is an artefact of the years chosen(9) for study. Advocacy got the better of science here!

But the Nature article also contains a useful account of IPCC's methodology:

The IPCC is divided into three working groups.... Working groups are ... headed by a team of 'lead authors' drawn from independent research institutes.... The work ... is reviewed by a different group of independent experts, government scientists, and non-governmental organizations before being finalized by the lead authors. Government scientists are then responsible for a line-by-line approval of a 'summary for policy-makers' of the entire IPCC report.

The important point is that the 'summary for policy-makers' is the responsibility of a narrowly-defined group---all on government pay-rolls. When one hears of a 'consensus', how broad is it? Responsibility for the Preface must be at least as narrow as for the Summary for Policymakers. It is doubtful if anyone really knows(10) whether there is a :

consensus of 2500 of the world's top climate scientists that there is already 'a discernible human influence on global climate'

5.1.2 Too much 'imagination block'

Misleadingly, the IPCC Report introduces its Technical Summary with the claim that:

... the summary presents a comprehensive, objective and balanced view of the subject matter.

On the contrary, the Report as here defined (ie its first 50 pages) suffers from an acute case of 'imagination block'---because it ignores the well-demonstrated natural variability of mega-regional climates in response to ice surges, ocean-circulation changes, and fluctuations in solar output.. For instance:

Sadly, the IPCC Report is not science. It is advocacy; and it is advocating a line which is almost certainly wrong. The Report is a partisan document---supporting the self-serving theorem that atmospheric science and climate-change science are the same thing.

5.2 The 1997 Kyoto Conference

The Report provided the scientific underpinning for the Third Conference of Parties to the United Nations Framework Convention on Climate Change, held at Kyoto in December 1997. This was a political conference, run by politicians and bureaucrats, not scientists; nevertheless, IPCC's version of climate-change science was the driver.

The Kyoto Protocol, once ratified, will establish a legally-binding obligation on Annex B Parties to the Convention (such as Australia) to limit average anthropogenic GHG emissions in the 2008-12 period to a fixed proportion of their 1990 emissions.

Australia will have an obligation to limit its emissions to 108% of the 1990 level during the commitment period. Although most Annex B Parties will have more stringent limits than ours, this target is very demanding in Australia's particular circumstances. There are a few countries with more-liberal targets: Iceland 110%, Spain 115%, Greece 125% and Portugal 127%. Also, Russia and Ukraine with targets of 100% are well treated, considering their sharp decline in energy consumption since 1990 (see Table 1). LDCs (eg China, India, Korea and Turkey, all with fast-growing emissions) have no target.

6. Australia Needs a Countervailing View

6.1 Letter to Canberra---and the response

I wrote a letter to Prime Minister Howard in the naive hope that someone not in the Canberra environmental bureaucracy might read it. My assertions were that:

As I had feared, the response came from the Australian Greenhouse Office, saying:

Thank you for your letter of 4 February 2000 concerning the science of climate change and ratification of the Kyoto Protocol.

and

The Australian Government recognises the Second Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) as the most authoritative source of information on the science of global climate change.

Canberra suffers from 'group-think' on climate-change science; and individuals who press a countervailing view are not heard. This is why the Lavoisier Group is needed.

6.2 Dominant paradigm updated the Pearman Paper

In April 2000, Graeme Pearman (Chief, CSIRO Atmospheric Research) provided an update of the dominant paradigm as espoused in the IPCC Report.(11) The Introduction to the Pearman Paper says:

On the scientific side, a mechanism has been established by which periodic assessments of the state of the science are made by a panel called the Intergovernmental Panel on Climate Change (IPCC) comprising several thousand scientists around the world. This Panel has already delivered two assessments (1990, 1996).

and

In this presentation I will call heavily on the IPCC Second Assessment Report. However, this is a field of rapid change and I will also refer to recent outcomes of CSIRO research.

and, finally

In this paper, as a climate scientist, I will speak mostly about the underpinning science of "greenhouse"....

It is in the area of the 'underpinning science' that I will put a countervailing view to that espoused by IPCC.

7. IPCC's Advocacy of Atmospheric Science

7.1 Climate processes

7.1.1 Greenhouse gas emissions

The Pearman Paper, discussed below in some detail, calls "heavily" on the IPCC Report. Thus I am, in essence, disagreeing with the Report when I disagree with the Paper. The Paper begins its discussion of the science with a section headed Climate Processes. This first describes the role of the atmosphere (including the greenhouse effect, but without referring to it by name), saying:

These processes include the radiative absorption process that causes energy from sunlight to be absorbed or trapped in the atmosphere or at the earth's surface and that influence the exchanges of thermal long-wave radiation.

I think it is worth spending a little more time on greenhouse fundamentals before proceeding.

Human-caused emissions of greenhouse gases (CO2 from the combustion of fossil fuels is the most important) accumulate in the atmosphere. Because these GHGs are transparent to incoming short-wavelength radiation (in the visible range) from the sun, these GHGs do not reduce the incidence of the sun's heat at the Earth's surface. However, the Earth radiates back to space a portion of this incoming heat at longer (infra-red) wavelengths---and the GHGs are not transparent to this returning lower-temperature radiation.

Thus, more of this out-going heat is trapped in the lower atmosphere than previously---because of the increasing concentration of anthropogenic GHGs. The lower atmosphere, as a consequence, becomes warmer; and some of this extra warmth is re-radiated to the Earth's surface. The subsequent extra warming which we detect at the Earth's surface is the "greenhouse effect"---whose amelioration is the sole objective of the Kyoto Protocol.

The most fundamental point to make when discussing "the underpinning science of 'greenhouse'" is that greenhouse is a phenomenon of the atmosphere. Put another way, if GHGs are not warming the atmosphere, obviously, that warmer atmosphere can't then cause warming at the surface. Remember, it is this resultant surface warming which we call the 'greenhouse effect'. I return to greenhouse later (See section 7.4).

7 1.2 Aerosol emissions

The Pearman Paper covers, albeit briefly, another important atmospheric issue, that of the sulphate aerosols also emitted from burning fossils fuels, saying:

... the properties of microscopic particles on which water droplets form influence the reflectivity of clouds.

This means that anthropogenic aerosol emissions increase the reflection to space of incoming heat from the sun. Hence, they are a cooling influence at the Earth's surface, and have the opposite impact to (warming) GHG emissions.

There is a crucial point of comparison to be made here. The major GHG (CO2) has a residence time in the atmosphere of many decades. Thus, irrespective of where the emissions are sourced, their warming impact is global---because the GHGs have time to equalise concentrations around the world. (Although there still are small local and/or seasonal variations.) Greenhouse warming is a global phenomenon.

On the other hand, aerosols emitted from the combustion of fossil fuels have a residence time in the atmosphere of only a few days---much too short for concentrations to equalise around the globe. Aerosol cooling is regional not global.

Furthermore, most fossil fuels are consumed in the Northern Hemisphere; and also, the sulphur content of fuels produced there is often higher than that of fuels originating in the Southern Hemisphere. (For instance, Australia's coal, natural gas and crude oil have a relatively low sulphur content.)

We can go further, aerosol cooling as a result of fossil fuel consumption should be a Northern Hemisphere phenomenon---because about 90% of these aerosols are emitted in the north, mostly in temperate latitudes, mostly over land, and with a greater incidence in winter than summer.

I will also return to aerosols (see Section 7.5).

7.2 Climate modelling

7.2.1 Computer-model-based experiments

Under this heading, the Paper makes a contentious point:

We are continuously improving climate models and gaining confidence in their ability to represent the climate system in a mechanistic way and thus their capacity to be able to respond to experimental changes, such as increased levels of greenhouse gases, in a realistic and predictive manner.

This statement is a worry. Computer models are being used as a substitute for observational and deductive science. Predictions are being made, and policy is being formulated, based on experimental changes 'such as increased levels of greenhouse gases' in numerical models. Such model-based predictions are soon divorced from the assumptions made by the modeller who produced them. Inadequate input is not recognised, or is soon forgotten; but the resulting output, however spurious, lives on.

Have the mathematicians who built the models to which the Paper refers incorporated all relevant influences such as those which cause the continuing ca 1500-year cyclicity of climate in the temperate and northern regions of the Northern Hemisphere---of which the Little Ice Age is the last cold period? Have they incorporated in realistic fashion the increased strength of the sun over the past 150 years? And what of the inertial effects on ocean heat transport of ice-stream surging such as is now happening in Antarctica?

That the answer is 'no', regarding the incorporation into the models of longer-term (and of particular importance to my thesis, non-atmospheric) influences, is evident from a later piece in the same section:

It is also clear that these trends in climate will occur against a backdrop of the usual variability of climate (the year by year differences).

But we know that natural variability occurs at many time-scales beyond 'year by year'. Model experiments can certainly aid our understanding; but they should not be used as a glib substitute for knowledge and thought. I think the IPCC Report and the Pearman update, with their over-reliance on results from modelling, are boosting the importance of the atmosphere vis-à-vis other, longer-term and non-atmospheric, influences on climate.

7.2.2 Frequency of extreme events?

Here, the Pearman Paper departs somewhat from the IPCC Report. The Summary for Policymakers of the Report does a bit of fence-sitting, saying:

Warmer temperatures will lead to a more vigorous hydrological cycle; this translates into prospects for more severe droughts and/or floods in some places and less severe droughts and/or floods in other places.

Intuitively though, a half a century where the warming has been concentrated in high northern regions, would suggest less vigorous and/or frequent climatic events than previously.

This is because the temperature differential between tropical and boreal regions is now less---and the differential is thus a less energetic driver of large-scale activity in the atmosphere. Although comprehensive long-run records are lacking for most regions, the deduction appears to be confirmed in the case of US Atlantic/Gulf Coast hurricanes---which have declined in both frequency and intensity over the past half-century.

The Pearman Paper is a little more definite, based on new information:

New versions of global climate models are now capable of generating even relatively small-scale atmospheric phenomena such as tropical cyclones. Whilst this capability is new and needs substantial improvement, it is encouraging. It suggests that associated with global warming we might expect some increase in the intensity of tropical cyclones and slight increase of latitude to which these events may extend.

But this is not the end of the story. A new paper(12) using the general circulation model 'CSIRO 9' compares a base run with the current CO2 concentration with a run where it is doubled. This model-based experiment finds:

... diminished cyclone activity for the doubled CO2 simulation. For the (Northern Hemisphere), decreases of 10 percent to 15 percent largely follow the storm track (ie across North America) ... Over the (Southern Hemisphere), decreases in cyclone activity are found over the entire hemisphere.

and the paper concludes that:

Doubled CO2 leads to a marked decrease in the occurrence of intense storms ...

I remain a little sceptical about numerical-model-based experiments for the time being---while the modeller's choice of methodology and input assumptions is so obviously crucial to the output.

Obviously, the scientific debate on the likely frequency of extreme events in a warming world remains unresolved. But, just as obviously, the battle for lay hearts and minds on this issue has already been won,(13) and lost---in the popular press.

7.3 Observed change

7.3.1 The 'straw man'

The section of the Pearman Paper headed Observed Change is particularly interesting for its emphases. It begins with a 'straw man':

A significant level of debate has been sustained concerning the evidence that the climate of the planet has already changed.

In my opinion, this is not so.

The miseries of the Little Ice Age (ca AD 1300-1900) are well entrenched in the written history of Europe; and rebound from this period of intermittent severe cold is obvious in the available temperature records. Surely, this means that, at least in Europe, there is no doubt "the climate has already changed".

So far as I know, there is no dispute about the reality of surface warming over the past 150 years in the temperate latitudes of the Northern Hemisphere. Elsewhere, who knows? There was no adequate surface coverage prior to the mid 20th century---and there still isn't any south of about 50 ºS.

The real issue of the debate is not the 'straw man' of whether there has been warming. It is whether or not the observed warming is greenhouse warming.

The Pearman Paper makes two main points in this section:

In the first instance, whether the changes in planetary temperature have or haven't been detected is not the basis of the debate over greenhouse gas-induced climate change. There are scientifically-based expectations that greenhouse gases will increase temperature ultimately.

What's going on here? The IPCC Report of 1996 had as the main feature of its Preface just that point---claiming "a discernible human influence on global climate" as "one of the key findings of this report"! Those in any doubt as to the impact this claim had at the time, should read the three contemporary quotes (see Section 9 below) I have chosen.

We now know that IPCC's claim was based on a spurious trend (see Section 5.1.1). The Paper has thoroughly de-emphasised this "key finding"---but without saying why.

7.3.2 The world is warming

The Pearman Paper continues:

Second, the information that leads us to believe that indeed there has been global warming over the past century comes from a range of observational sources ... These data are overwhelming and suggest that there appears to have been a small general cooling of the surface of the planet up until a century or so ago, with a warming that has vastly exceeded any natural fluctuation.

I guess that the "small general cooling" was the Little Ice Age, although that familiar name is not mentioned here (nor in the IPCC Report) for reasons unknown. The omission might just be an oversight; but the assertion(14) that warming over the past century "has vastly exceeded any natural fluctuation" is different.

This is not science at all. It belongs in the realm of advocacy.

The above piece of hyperbole is contradicted by much evidence; and a specialist in palaeoclimatology states:(15)

The global temperature for the last 100 years is known from direct observations. The temperature was low until 1910; thereafter it increased up to 1940. After a period of slightly lower temperature around 1975, the global temperature has increased.

and, in particular

The temperature changes that have occurred during this (20th) century do not appear to be unique.

In my opinion, the IPCC Report, and the Pearman update, are playing down the importance of ice/ocean/sun-related natural variability in climate-change. Instead, they appear to be championing the atmosphere and, particularly, human-caused changes in its composition. I will expand on this theme in my verbal presentation.

7.4 Satellite-derived temperatures

7.4.1 Asking the right question

The Pearman Paper tells us that the recent satellite debate:

... has had to do with whether satellite measurements in the micro-wavelengths are showing a different trend from that observed at the surface.

This is no 'straw man'. Instead, it is an exceedingly relevant question, both topical and vital. In fact, the (US) National Research Council released a study(16) of it in January 2000, prepared by a panel of eleven scientists with a variety of skills---and outlooks ranging from greenhouse booster to greenhouse sceptic. 'Boosters' could include James E. Hansen (mentioned in Section 2.3, above) and Benjamin D. Santer (of the 'discernible human influence on global climate' paper); and John R. Christy and Roy W. Spencer (long-time proponents of the value of satellite-derived atmospheric temperature measurements) could qualify as 'sceptics'.

The Pearman Paper addresses the satellite-derived data in some detail, and I here quote its contribution to this important topic in full:

Some debate has occurred over whether temperatures deduced from microwave soundings made from satellites can adequately determine surface air temperatures for comparison with measurements made by conventional meteorological methods. Certainly, when first released, there were some unexplained discrepancies. However, such measurements are difficult to interpret due to questions concerning continuity and quality of calibration, satellite altitude, effective measurement altitude, etc. Recent analysis appears to have clarified what such measurements mean and how they can be usefully compared.

This paragraph discusses the wrong question! Granted, it would be useful if satellites could "adequately determine surface air temperatures for comparison with measurements made by conventional meteorological methods" because there is no comprehensive coverage of conventionally-derived surface measurements north of 70 ºN, south of 50 ºS, or for large interior tracts of South America, Africa and Asia.

But this isn't the point of the debate at all. The issue is the discrepancy between trends in observed (and conventionally-measured) temperatures at the surface, and in the atmosphere as evidenced by satellite-derived temperatures---over the 20 years (1979-1998) for which there is also satellite data.

Surface warming is real enough, despite the imperfect coverage; we all accept that. But the satellites provide a comprehensive global coverage for the first time, and they indicate little or no warming in the lower atmosphere.

It is this discrepancy which is the issue of debate; and it is this issue which was addressed by the NRC Panel.

7.4.2 Greenhouse, where are you?

There are several points to remember here.

First, greenhouse is a phenomenon of the atmosphere. If the lower atmosphere doesn't warm, its extra warmth can't be re-radiated to the surface.

Second, the surface is warming---the evidence is overwhelming.

Third, if the very warm 1998 El Niño year is excluded, there is no warming trend in the lower atmosphere over the 20 years studied by the NRC Panel. Indeed, the 21st year (1999) is now in, and there is still no significant warming trend in the satellite-derived data. There are 12 warmer and eight cooler years than 1999 in this history.

Fourth, balloon data is available back to 1958. Long-run coverage is relatively sparse except over land areas of the temperate Northern Hemisphere but, where there is overlap, balloon and satellite data are in good agreement. For 15 years the balloon-based lower atmosphere temperatures were warmer, and for 27 cooler, than 1999.

We now have 21 year's global coverage of satellite-derived temperatures for the lower atmosphere---with no significant warming trend.

Could you describe the Pearman Paper's failure to report this remarkable fact as being 'economical with the truth'? The paper treats what I see as the most important aspect of the debate relating to satellite-derived temperatures by ignoring it.

Does the discrepancy between surface and atmospheric trends prove that the clear-cut surface warming during this period is not greenhouse-caused? Is this the 'law of empirical disproof' in glorious action? Not so fast!

The observations to date certainly don't hurt the countervailing view that most the global (surface) warming observed over the past 100 years is not caused by anthropogenic changes in the composition of the atmosphere.

However, the greenhouse issue is not yet resolved in the negative. The NRC Panel urges that, to ensure the trend (or lack of it) is statistically robust, we wait until we have 40 years of global coverage for temperatures in the lower atmosphere.

There are still 19 years to go.

7.5 An aerosol-free future?

Under the heading The energy cycle---greenhouse connections the Pearman Paper goes on to predict a "number of significant revisions to estimates of future climate changes" for IPCC's pending Third Assessment Report.

One such is particularly contentious---given what we now know:

One revision is likely to relate to the role of aerosol. Atmospheric aerosol, which is prevalent in industrial regions of the northern hemisphere, limits the extent of localised global warming by scattering incoming solar radiation.

and

Previous estimates have directly linked aerosol emissions with fossil fuel projections. However, it is now believed that efforts to limit aerosol emissions during fuel combustion is likely to result in a much smaller future growth rate in aerosol emissions than previously thought. As a result, masking of global warming by aerosol is likely to be less effective than previously supposed, leading to a slightly greater rate of predicted global warming.

This sounds plausible enough, as it stands; but information necessary for making an informed judgement on the worth of the hypothesis is absent from the Paper.

As mentioned in Section 7.1.2 above, aerosols should exhibit their greatest cooling impact in the Northern Hemisphere---where 90% are emitted.

But in reality, warming at the surface, over the last half-century at least, has been greater in the Northern Hemisphere---exactly the opposite of what the distribution of aerosols would lead us to expect. The problem goes deeper; the observed warming is in the north of the hemisphere (40-65 ºN), not the tropical areas, and over the continents not the oceans. Again, this geographical distribution is contra-indicated by the sources of these short-lived (cooling) emissions. Finally, observed warming is at its greatest in winter---when the emission of 'cooling' aerosols is also at its greatest---and particularly at night.

If natural variability is not the major cause of observed warming over the past century, and if greenhouse warming dominates but is indeed partly masked by aerosol cooling, then the Southern Hemisphere should be warming the faster at the surface. It isn't. Indeed, satellites show the lower atmosphere is cooling in the Southern Hemisphere.

In my opinion, this 'revision' is IPCC boosterism aimed at supporting a prediction of increased future warming (predictions have been reducing ever since 1988 in Toronto, remember); and, although not explained in the Pearman Paper, it is unsupported---even contradicted---by a half-century of observations. Perhaps this is a valid example of the primacy of empirical disproof.

8. Taking a Broader View of the Environment

The IPCC Report encourages those concerned about the environment to believe that "global climate change from increased atmospheric carbon is the single biggest threat facing this planet". Indeed, in his final State of the Union address on 27 January 2000, President Clinton says as much, calling global warming "the greatest environmental challenge of the new century".

Obviously this was, in part at least, a Presidential helping hand for the Gore campaign. But still, this is pretty emphatic stuff; and it is almost certainly wrong.

Does it matter? We all know the precautionary principle---so let's apply it. But it does matter, because there is only so much money and so much zeal available for supporting the environmental cause in all its facets.

By diverting money and zeal to the climate-change issue, we automatically diminish the amount available to a variety of environmental imperatives. In Australia for instance, habitat destruction and consequent erosion of biodiversity is a pressing current problem---and time lost now may never be regained.

What is the relative threat to biodiversity in the longer-term from anthropogenic (or even natural) warming cf the threat here and now from the degradation and alienation of habitat? In Australia, greenhouse not only is diverting attention from the continued clearing of native bush, but from other, and growing, environmental threats such as dry-land salination, draining or filling of wetlands, nutrient run-off from primary production, impending limits on the quantity/quality of our water resources, and the impact of feral plants and animals.

How important is human-caused climate-change? Are anthropogenic factors the only,(17) or even the largest, influence on changing climate?

On balance, are anthropogenic greenhouse gas emissions good or bad for humanity? After all, CO2 is not a pollutant in the accepted sense; and its increasing concentration in the atmosphere is well known for promoting both growth and stress-resistance in plants.

Will our activities hasten or delay the inevitable return of harsher, and more-normal, conditions to the Globe? It is less than 20,000 years since a kilometre of ice covered the site of Detroit, and Central Australia's desert dunes extended as far south as NE Tasmania. Both biodiversity and humanity will suffer when such conditions return.

As a diversion from consideration of all the issues, the IPCC Report is itself an environmental threat.

Furthermore, media hype engendered by the IPCC Report has led the concerned laity to believe that observance of appropriate restrictions on greenhouse gas emissions would keep climate just as it is now. This is nonsense.

9. Epilogue---Incommensurable Paradigms

It has been famously said that scientific paradigms are incommensurable ie "having no common measure with another" (Concise Oxford). What Thomas Kuhn might have meant is canvassed in his obituary:(18)

... scientists cannot decide between alternative paradigms solely on the basis of reason, argument and evidence ... Kuhn even goes so far as to compare scientific revolutions to political revolutions, and no one thinks that the latter are entirely a matter of reason, argument and evidence.

Therefore, old paradigms die hard.

Today's dominant paradigm has its origins in the Villach conference of 1985 (see section 2.2.1, above). This was a meeting of climate scientists, not climate-change scientists. The interest of scientists attending Villach was the atmosphere, not ice and oceans---or sun. Not surprisingly, the dominant paradigm has human-caused changes in the composition of the atmosphere as the major cause of observed trends in global climate, albeit "against a backdrop of the usual variability of climate (the year-to-year differences)".

The countervailing view is that climate is naturally variable at many time-scales from the hundred thousand year cycle of Glacials/Interglacials, which are of global reach, right down to the 'year-to-year differences', acknowledged by the guardians of the dominant paradigm.

Of particular relevance to the greenhouse debate, is the 1500+/-500 year cycle in the temperate latitudes of the Northern Hemisphere of which the Mediaeval Warm Period and Little Ice Age are the latest manifestations. It is this hemisphere which is more prone to abrupt climate change (for reasons of basinal geometry), which has the longer run of written records describing past changes of climate, where the majority of palaeo-climatological work has been done so far, and which has the greater political clout.

In essence, the countervailing paradigm has it that a combination of two (unrelated, but both non-anthropogenic) factors are likely to have caused the observed rebound from the depths of the Little Ice Age---and thus, the greater part of the observed warming which we choose to call "global warming".

First, is (cyclic) strengthening in the flow of warm Atlantic surface water into the Nordic seas. Variations in this flow are associated with horizons of ice-rafted detritus in the sea-bed sediments of the North Atlantic. This suggests that the degree to which warm water penetrates between Scotland and Iceland is influenced by the intermittent surging of continental ice, consequent abrupt rises in sea level, and subsequent inertial effects which alter the trajectory of the ocean current bringing equatorial heat to northern regions.

Second, is an increase in the strength of the sun.

Human impacts, including human-caused changes in the composition of the atmosphere, will also have an effect---but it is likely to be small compared to those above (particularly in the light of the lack of any substantial warming in the lower atmosphere over the 21-year period for which we have global coverage). Thus, there is no justification for saying that, if growing emissions of greenhouse gases were to be stopped, climate and sea level would remain as they are now.

Furthermore, we cannot yet even tell whether anthropogenic CO2 emissions are, on balance, good or bad for the future of humanity.

How will these issues of incommensurability be resolved?

The auguries are not good. I recall reading, about five years ago, a Me and my God piece such as appeared in the Daily Telegraph each Thursday. The writer was Sir John Houghton, and his message was that global warming was a reminder from God that we should take care of our planet.

Sir John (formerly head of the UK Meteorological Office) was the lead editor for IPCC's 1996 Report "Climate change 1995: the science of climate change" which provided the scientific rationale for the Kyoto Protocol. He was the main man in the 'consensus of 2500 of the world's top climate scientists'.

He might be right, or he might be wrong. But how can we tell? Remember, it was Karl Popper's view that science is demarcated from other endeavours by the primacy of empirical disproof. Only theories which can, at least in principle, be found to be wrong by experiment or observation are entitled to be called scientific. Empirical disproof is of no help here.

Is the dominant paradigm on climate-change really 'scientific'? IPCC Chairman Bert Bolin (he was formerly Professor of Meteorology at Stockholm University) certainly thinks so, saying in a letter to Nature of 16/3/95:(19)

Of course no single scientist can be completely objective, particularly about as complex an issue as that of human-induced climate change, but the collective work led by IPCC is generally much more reliable than other attempts to summarize scientific research results for the political process.

In those years, 'science' still had a powerful influence on those in the political sphere---but it had to be the 'right' science. There is no chivalry in scientific contention, no concept of 'may the best man win'. In short, the dominant paradigm dominates. I give below three examples, all relating to the "discernible human influence" conclusion (now known to be spurious) which was the most prominent feature of the IPCC Report. They show what I mean.

After release of the IPCC Report, on 25/7/96, the man who was to be the principal representative of the United States Administration at the Kyoto Conference, Timothy Wirth the Under-Secretary of State for Global Affairs, is reported in a Nature news item as follows:(20)

Wirth described as a 'remarkable statement' the conclusion of the IPCC's latest report on climate change, that 'the balance of evidence suggests that there is a discernible human influence on global climate'. He said the administration took the report 'very seriously'.

but

Wirth described the IPCC's critics as 'naysayers and special interest groups bent on belittling, attacking and obfuscating climate change science'.

Already it is easy to see in the minds of politicians the distinction between the dominant paradigm and the countervailing views of 'naysayers and special interest groups'. In fact, the 'remarkable statement' in the IPCC report to which Wirth refers is untenable (see Sections 5.1.1 and 7.3.1, above)---it is an artefact of the years selected for study.

In the lead-up to the Kyoto Conference, the Editorial in Nature of 12/6/97 "Seizing global warming as an opportunity" (v 387 p 637) was unequivocal:

If agreement is reached, as hoped, at Kyoto on relatively ambitious targets for reducing greenhouse gas emissions, much of the credit must go to the work of the ... IPCC. The panel's hard-fought consensus, published in 1995, that 'the balance of evidence suggests that there is a discernible human influence on global climate', has established a clear reality that cannot be wished away, as even lobby groups representing the fossil-fuel industries have now, reluctantly, come to admit.

A further Editorial in the International Herald Tribune of 23/6/97 was entitled "Take warming seriously". It was picked up from the New York Times; and it said:

One reason why the industrialized nations opted for voluntary targets at Rio (in 1992) was that main-stream scientists simply could not agree whether man-made emissions had contributed to the small rise in global temperatures that began late in the 19th century. In 1995, however, the UN Intergovernmental Panel on Climate Change, consisting of about 2,500 scientists, concluded that they had.... Despite challenges from businesses, which have attacked the science in tobacco-industry fashion, the UN panel has not retreated from its basic findings.

But it is not only politicians and journalists who think they can distinguish 'good' scientists from the contrarians. It seems that some notable scientists have caught the bug.

A recent paper(21) reports a study of doubling the CO2 content of the air in which 13 year old Pinus taeda (loblolly pine, the world's most important plantation timber species) in North Carolina were growing. Three groups, each of about 100 trees, were provided with the enriched air, and were compared with three similar-sized control groups; all groups were within the same continuous pine forest.

The saplings exposed to the higher level of CO2 increased their growth by about 25% over the two years of the study, compared to the nearby trees which continued to grow in ambient air.

Good news? Not so, it seems.

The authors of this paper were rebuked in a letter(22) to Science on 17/9/99 (of which the lead-signatory was the same Bert Bolin, see above), saying:

In the current, post-Kyoto international political climate, scientific statements about the behaviour of the terrestrial carbon cycle must be made with care....

Doubtless these strictures wouldn't have surprised Giordano Bruno, whose auto-da-fé at the hands of the Inquisition took place on 17/2/1600 in Rome; but they are surprising in this enlightened age. Sadly, one of the five signatories to the Bolin letter is from Australia (Research School of Biological Sciences at ANU, Canberra). After 400 years of struggle, science still hasn't escaped its establishment yoke.

I am happy to report that the head of the International Council of Scientific Unions, Mihkel Arber, shot back:(23)

Your letter on the need to temper scientific findings with political considerations, published in Science today, is a chilling testimonial to the current trend to limit objective reason in deference to political ambitions ...

Arber has hit the spot. In the field of climate change, at least, politics has all but vanquished science. Stray outside the dominant paradigm at your peril!

I hope the Lavoisier Group will be able to help those who wish to speak out but cannot now be heard.

Endnotes

1. For those of you who keep your National Geographic magazines, a measured account of thinking at the time can be found in "What's happening to our climate?" by Samuel W Mathews, November 1976, pp 576-615. A more-populist tone was adopted in "The year the weather went wild" by Thomas Y Canby, December 1977, pp 798-829; for instance:

Looking back on the ordeal, was it (ie 1976/77) really the 'worst winter' it seemed to be? If you live in the Ohio River Valley, the answer is an unequivocal "yes". Cincinnati set an all-time record with a brittle minus 25 ºF ... Snow, too, set records. On January 31 it rested on part of every state of the contiguous 48 for the first time on record. Never had snow fallen as far south as Miami ... By winter's end 200 inches---nearly 17 feet---had fallen on Buffalo ... While Easterners shovelled heavy drifts ... much of the nation was caught up in severe drought. Worst off by far were the northern plains and the West.

and

Predictable or not, extremes of temperature and precipitation will be with us for a while, contend many meteorologists. They believe that the recent decades of benign weather---a period most of us regard as 'normal'---were an era of exceptional mildness. "The unusual thing', says Dr J Murray Mitchell Jr, a NOAA senior climatologist, "is not the variability we have now, but the lack of it between 1950 and 1970".

2. In the opinion of Frits Böttcher, 1999, "The use and misuse of science in policy making" pp 40-9 in Climate policy after Kyoto edited by Tor Ragnar Gerholm, Multi-Science Publishing Co Brentwood UK, 170 p. Much of this section draws on papers in that book.

3. I give but a single typical example, from a letter to The Times of 1/7/97 by Dr Georgina Green of Friends of the Earth (letters in similar vein are myriad):

Global climate change from increased atmospheric carbon is the single biggest threat facing this planet. The increase comes from the use of fossil fuels, and it is that which has to be tackled.

4. Erik Moberg, 1999, "The science and politics of the greenhouse issue" pp 30-9 in Climate policy after Kyoto.

5. Well, not so young perhaps; my quote is from the National Geographic article of November 1976. However at 55 now, he is still outspoken. A News Focus article in Science of 18/2/2000 entitled "Citizen-Scientist Guru" (v 287, p 1189) says in part:

Schneider recommends 'three rules' of advocacy: explicitly stating when one's views reflect values rather than science; using colourful, easy to grasp metaphors; and producing a 'hierarchy of products', ranging from sound bites to op-eds to scholarly papers to lengthy books "where you can put in all the caveats". At the same time, he says scientists shouldn't shy away from painting 'scary scenarios'---such as deadly heat waves in New York City and a dried-up Mississippi River as a possible result of global warming---to get a message across.... And if scientists don't speak up, "who's going to talk about it? Somebody less qualified or with an agenda?"

6. Reproduced from the 1998 edition of the International Energy Agency's "CO2 emissions from fuel combustion", Paris. In my Table, emissions have been recalculated from CO2 to contained carbon (for easier comparison with quantities of fossil fuel). One tonne of carbon is equivalent to 3.7 tonnes of CO2.

7. "Climate panel forecasts way ahead" of 2/1/1997, written by staffer Ehsan Masood (Nature, v 385 p 7).

8. IPCC's ill-founded assertion was supported post-hoc by B D Santer et al ,1996, "A search for human influences on the thermal structure of the atmosphere", Nature, v 382, pp 39-46.

9. The rebuttal is by Patrick J Michaels and Paul C Knappenberger, 1996, "Human effect on global climate?", Nature v 384 pp 522,3.

10. This is the assertion of Sharon Beder, associate professor in Science and Technology Studies at the University of Wollongong, in an article "Ecological double agents" (Australasian Science of February 1998, pp 19-22) criticising 'ecological front groups sponsored by multinational corporations'.

11. G I Pearman, 2000, "Progress in climate science and its role in greenhouse policy", Australian Institute of Energy News Journal, v18 (1) pp 14-19.

12. Mark Sinclair and Ian Watterson, 1999, "Objective assessment of extratropical weather systems in simulated climates", Journal of Climate, v 12 pp 3467-85.

13. An article in The Age of Melbourne of 29/4/2000 says it all. Under the headline "Greenhouse effect leads to disasters: Floods and droughts are pieces of the same ominous jigsaw", is an article (p 27) by Tim Radford of the Guardian; and it begins:

Floods are events of the moment. Droughts are disasters on a slow fuse. Both happen with or without global warming.

But the drought and famine in Ethiopia, the desiccation of Rajasthan, the arid corn land of the United States west, and the towns in Mozambique and Venezuela swept by storms and floods are beginning to look like pieces of the same ominous jigsaw.

'You can't ever say that a hurricane or a flood or a drought is because of global warming', said one disaster expert. 'What you can say is that global warming makes any of these or all of them more likely'.

Deeper into the article is the punchline:

So far events have matched predictions with an eerie precision.

14. The Pearman paper justifies this intemperate (and in my opinion, very much ill-founded) statement by reference to the paper by Michael E Mann, Raymond S Bradley and Malcolm K Hughes (1999), "Northern hemisphere temperatures during the past millennium: Inferences, uncertainties and limitations", Geophysical Research Letters v 26 (6) pp 759-62.

15. Wibjörn Karlén, 1999, "Is the temperature of the last 100 years unique?", pp 52-65 in Climate policy after Kyoto.

16. Panel on reconciling temperature observations (John M Wallace, Chair), 2000, Reconciling observations of global temperature change, National Research Council, Washington 85 p.

17. The hard-line position taken by the IPCC Report and the Pearman Paper on the likely contribution of natural variability to observed warming over the past 50 years (or even 150 years) may weaken in future. Hansard records evidence from Dr Geoff Jenkins, Director of the Hadley Centre for Climate Prediction and Research, UK Met Office, to the Australian Senate Committee hearing of 9/3/2000 on global warming:

Starting off with some work we have done recently on the attribution of climate change, the extent to which the change we have seen over the past 50 years or so is due to human activities is still quite a big scientific question.

18. David L Hull, 1996, "A revolutionary philosopher of science", Nature, v 382, pp 203,4.

19. Bert Bolin, 1995, "Politics of climate change", Nature, v 374 p 208.

20. According to a 1996 news item by staffer Ehsan Masood, "United States backs climate panel findings", Nature, v 382 p 287.

21. Evan H DeLucia et al ,1999, "Net primary production of a forest ecosystem with experimental CO2 enrichment", Science v284 pp 1177-9.

22. Bert Bolin et al ,1999, "Effect on the biosphere of elevated atmospheric CO2", Science, v 285 pp 1851,2.

23. Here quoting from World Climate Report, v 5 (7) p 2, of 13/12/99.