Climate Change: A Natural Hazard?: Book Launch Address

William Kininmonth

Peter Walsh, John Zillman, Ladies and Gentlemen

Before talking about the book, Climate Change: A Natural Hazard, there are a number of people that I must thank. Without their support there would not have been a book to launch.

Firstly, I must thank my family who have been supportive in this and many previous ventures associated with my indulgences in climate. Over the years my wife, Elaine, has been very understanding, as I have travelled the world increasing my knowledge of the global climate. More recently I have disappeared into my study for long periods to research and write. The task would never have been completed without her support and consideration.

The Lavoisier Group provides a forum for discussion and debate in Australia on the climate change issue, even when the public has been led to believe that the science of climate change has been settled. I sincerely thank the Lavoisier Group for having arranged this launch of the book, and also for the assistance and encouragement that has been provided, especially by Ray Evans.

I particularly thank John Zillman for taking on the role of formally launching the book. Our professional association in the Bureau of Meteorology goes back three decades but it was about 15 years ago that we were actively working towards achieving a National Climate Program for Australia. Seventy percent of natural disasters are associated with weather and climate extremes. As Director of Meteorology, John took the lead to ensure that the climate observing infrastructure, climate research and the range of services available to this country met our national needs.

Unfortunately, at the same time as the sober National Climate Program initiative was being prepared the prospect of dangerous anthropogenic global warming became an international environmental issue. Alas, greenhouse global warming became the prominent climate issue and a National Climate Program was never formally considered.

John Zillman, as Vice-President of the World Meteorological Organization, played a key role in establishing the Intergovernmental Panel on Climate Change (the IPCC) that was created within the UN system to provide an authoritative international statement of scientific opinion on climate change.

Nearly two decades later, we are still debating the science of climate change. This only underscores the complexity of the climate system. The book that I have written, Climate Change: A Natural Hazard, describes the important processes that are relevant to variability of the climate system on all timescales. It addresses controversial issues and I will briefly discuss a few of these now.

The Radiation Forcing Hypothesis is Flat-Earth Physics

For the IPCC, the concept of radiative forcing is central to climate change. Radiative forcing emerges from a one-dimensional radiation-convective model of the climate system. Radiative forcing assumes that there was radiation balance at the top of the atmosphere before industrialisation commenced.

Radiative forcing is a simple, seductive hypothesis for how emissions of carbon dioxide, especially burning of fossil fuels, will lead to global warming. If the concentration of carbon dioxide in the atmosphere continues to increase it is suggested that dangerous climate change will occur.

The simple radiation forcing hypothesis cannot be sustained, except in the most qualitative terms. It ignores the energy reservoir of the tropical oceans and the need for deep convection to distribute excess energy of the tropical oceans through the atmosphere. It ignores that the earth is essentially two different regions---the tropics, over which solar radiation is accumulating, and the polar regions, where radiation loss to space is dominating.

If we were to only consider radiation and convection as the dominant processes of the atmosphere then we should expect to observe the tropics getting warmer and warmer and the polar regions getting colder and colder. We know this is not the case.

Ongoing poleward transport of energy by the atmospheric and ocean circulations is vital for a stable climate and global radiation balance. Variations of poleward transport of energy will lead to variations in global temperature.

Variability of the poleward transport of energy can cause major climate change. For example, during the last glacial cycle that lasted about 100 thousand years, the sea level dropped about 130 metres as mountain glaciers and polar ice sheets expanded. Then the sea level returned to its present level as mountain glaciers and polar ice sheets retreated. There is no evidence that the glacial cycle was forced by solar radiation because the annual total of solar radiation received by the earth did not change appreciably on these timescales.

A sustained change in poleward energy transport will cause a temperature change over middle and high latitudes. However, it is not necessarily true that radiation forcing will produce significant climate change.

Rudimentary Computer Models have Gross Inadequacies

The projections of the magnitude of global warming due to increases in atmospheric carbon dioxide concentration are based on computer model simulations. The veracity of those projections depends on the ability of the computer models to simulate the climate system.

The different computer models developed in the various research centres around the world have differences in their construction and specification of internal processes. They produce a range of estimates of future global warming. The performance characteristics of the various computer models have been examined within the framework of the Coupled Model Intercomparison Project (CMIP).

IPCC has drawn on the model intercomparison in its Third Assessment Report. The apparent ability of the computer models to simulate many of the characteristics of the current climate system is the basis for the IPCC confidence in their use.

However, the intercomparison also identifies some significant weakness in the computer simulations. On average, the rate of mass overturning of the tropical atmosphere is more than 20 percent less than observed for the atmosphere. This means that there are gross errors in the poleward transport of energy by the computer models.

The peak poleward transport of energy by the atmosphere is known with confidence from satellite and other direct observations. A decrease in the transport by only one percent would allow the volume of Arctic sea ice to more than double in ten years. It is surprising, therefore, that the gross underestimation of poleward energy transport by the computer models is not reflected as cooling and expansion of the ice sheets over the polar regions.

The computer models have compensating gross errors in the latitudinal distribution of net longwave radiation at the surface. There is too much radiation loss over the tropics, thus cooling the surface, and not enough radiation loss over polar regions, thus retaining energy in the surface. The magnitude of the radiation errors in the computer models is up to five times the expected radiation forcing from doubling carbon dioxide concentration.

The magnitude of global warming projected by the computer models cannot be considered reliable because of the errors in poleward energy transport and net surface longwave radiation.

Recent Global Warming

The IPCC claims that the global warming observed over the past 50 years has been due to human activities. This claim is based on the apparent ability of computer models, when forced by natural and anthropogenic factors, to simulate the global surface temperature record of the 20th century.

There is, however, an essential discrepancy between the computer simulations and observations. The computer models project warming of the atmosphere, especially over the tropics. Contrary to what the computer models project, over the past two and a half decades there is no evidence of warming of the tropical atmosphere. This is a period when accurate satellite observations have been available and we can directly compare the simulations by the computer models with observations.

The projection of atmospheric warming is the basis for claims of a positive feedback through water vapour, a natural greenhouse gas. Overall, the effect of water vapour feedback in the computer models is to amplify the direct effect of carbon dioxide several times over. By this mechanism, the computer models exaggerate the magnitude of anthropogenic greenhouse warming.

The IPCC conclusion that most of the warming of the past 50 years is attributable to human activities is not soundly based.

The Mythology of Runaway Global Warming

One of the fears raised in relation to continued burning of fossil fuels is that it will lead to runaway global warming. Sir David King, Chief Science Adviser to the British Government, has been quoted as saying that human induced climate change is a bigger danger than global terrorism. That is a big call.

We can be confident that the prospect of runaway global warming is a mirage conjured up by activists and propagandists. It is based on the spurious idea of positive feedbacks.

Bill Priestley, a former Chief of the CSIRO Division of Atmospheric Research, published a paper in 1966 on the limitation of temperature by evaporation in hot climates. From a study of worldwide surface temperature data he showed an upper limit of 33 ºC over well-watered vegetation. The study and its findings were in the context of agriculture and irrigation planning but the physics has universal application. In a passing comment, Priestley noted that 30 ºC represented a practical upper limit to surface temperatures over the ocean.

Observations of sea surface temperatures from the equatorial western Pacific Ocean, extending over the past two decades, confirm that the warmest ocean waters have fluctuated in a narrow temperature range about 30 ºC. At this temperature it is evaporation that dominates the energy exchange between the ocean and the atmosphere. Any reduction in net longwave radiation at the surface due to enhanced greenhouse gas concentration will be compensated by increased evaporation without an increase in surface temperature.

There has been no observed trend in the temperature of either the warmest ocean surface or the tropical troposphere. Nor should we expect any trend in the future. Temperatures of the warmest ocean surface and the tropical troposphere are constrained by natural upper bounds.

The Climate System does have Internal Variability

IPCC has claimed, based on analyses of computer models, that recent global warming is unlikely to be due to internal variability of the climate system. That is, the warming of the past 50 years is due to human activities.

More recent ocean research suggests that the global warming of recent decades can be directly linked to natural interactions between the oceans and the atmosphere.

A change in the surface wind field over the tropical Pacific Ocean has reduced the shallow overturning in the ocean surface layer since the mid-1970s. Reduced upwelling of cold water has altered the surface energy balance and caused the area with surface temperatures near 30 ºC to expand and for ocean surface temperatures elsewhere to warm. Overall, evaporation of water vapour from the oceans and the supply of latent energy to the atmosphere have increased.

An observed increase in the overturning tropical circulation during the past two decades can be directly attributable to the enhanced latent energy supply from the warmer tropical ocean. The more vigorous atmospheric circulation has increased the poleward transport of energy. Warming middle and high latitude temperatures and contracting ice mass are to be expected.

Satellite observations confirm that there has been an increase in the emission of longwave radiation to space from the tropics, consistent with warmer ocean surface temperatures. The increased radiation to space, however, is contrary to IPCC's radiation forcing hypothesis, which predicts that increased concentrations of carbon dioxide will reduce the emission of longwave radiation to space.

The oceans are the flywheels of the climate system as they have large thermal capacities and relatively long inertial periods. Each ocean circulation has characteristic inertial periods whose timescales reflect basin topography. The inertial periods range from the decadal to the millennial and are excited by changing surface wind stress.

The surface temperature patterns and energy exchanges from the oceans drive the atmospheric circulation. The atmospheric circulation responds rapidly to changing energy input from the oceans. This is clear from El Niño events and the more persistent tropical forcing since the middle 1970s. We should expect variations of local and regional climate that have timescales that are characteristic of the inertial periods of the ocean circulations.

Fluctuations of climate on a range of timescales are consistent with internal variability of the climate system.

Climate Change and Future Policy

The spectre of dangerous anthropogenic climate change has come to dominate government and business policy, especially across the energy and environment sectors. Decisions are being formulated and implemented based on the climate change projections endorsed by the IPCC. In particular, the Kyoto Protocol and its impending ratification mean that reduction of greenhouse gas emissions is an objective that takes priority over economic efficiency, international competitiveness and, in a number of sectors, job creation.

The science underpinning climate change projections is not settled. The book, Climate Change: A Natural Hazard, exposes serious defects in the IPCC Third Assessment Report and its climate change projections.

• The radiation-forcing hypothesis is a poor construct for the climate system. Its simplicity focuses unduly on radiation processes and ignores the natural interactions of the ocean and atmospheric circulations that also affect climate.
• The computer models of the climate system are seriously flawed and the projections of anthropogenic global warming are exaggerated. The prospect of runaway global warming is a mirage.
• The past climate has fluctuated because of natural internal variability and external forcing. Global temperature patterns, rainfall distributions, ice volumes and sea level have varied on a range of timescales. We must anticipate and be prepared for such variability continuing into the future. The twentieth century was probably neither the warmest century nor the 1990s the warmest decade of the last millennium.

Weather and climate extremes are hazards that continue to threaten life and property and will not go away by reducing greenhouse gas emissions. It is important that scarce resources are applied to the development of community infrastructures that are resilient and provide protection against weather and climate extremes.

Climate Change: A Natural Hazard challenges widely held assumptions and highlights uncertainties of the science that tend to be conveniently ignored. I have also tried to ensure that the scientific arguments are clearly described and free from jargon to enable policymakers to participate in the important debate. It is not a debate that should be confined to the circles of the scientific elite. We must ensure a strong connect between the science and the dependent policy outcomes.

I thank everyone who has come to this occasion and, again, to John Zillman for doing me the honour of its launch.

The book is available for purchase tonight from my lovely daughters-in-law who are assisting The Avenue Book Store of Middle Park.

Thankyou.

To read Dr John Zillman's's launching speech for Climate Change: A Natural Hazard, please click here

For details of how to order Climate Change: A Natural Hazard, please click here