This paper was first written in 1990 - nearly 30 years ago - yet little has changed.

Climate Change

Issues Arising from the Greenhouse Hypothesis

Climate change has wide ranging implications for the World, ranging from its impacts on agriculture (through drought, floods, water availability, land degradation and carbon credits) mining (by limiting markets for coal and minerals processing) manufacturing and transport (through energy costs) to property damage resulting from storms.  The issues are complex, ranging from disputes about the impact of human activities on global warming, to arguments about what should be done and the consequences of the various actions proposed.  The following paper explores some of the issues and their potential impact.

The Causes of Climatic Change 

Climate changes all the time for many reasons.  Many of these effects are long term and plant and animal life has time to evolve to accommodate the changes.  Now, for perhaps the first time in history, climate may be changed very quickly by the impacts of human activity. 

Before the impact of human activity can be isolated the natural drivers of climate must be identified. The Sun is the main planetary climate engine. In the case of the Earth the Sun’s impact on our climate is mitigated by both geological and biological activity.

The Sun’s temperature is not constant year to year (with a peak every eleven years).  There is some evidence that the Sun is now hotter than it was a century ago.  Some scientists suggest that up to half observed global warming in the past 130 years is due to the sun getting hotter[1].

Regular changes in the Sun’s activity have a direct influence the climate. These changes in turn have an impact on biological activity that absorbs energy and converts carbon, oxygen and nitrogen (amongst others) into different compounds and changes the amount of water in the atmosphere and the amount of the Sun’s radiation absorber or reflected. 

Water amplifies or dampens these effects.  Snow and ice reflect the Sun’s energy many times more effectively than soil, plants or oceans.  If the planet warms to the extent that the polar and high-mountain snow and ice cover shrinks, then the planet will start to warm even more quickly. On the other hand higher precipitation rates may deposit more snow where temperatures remain below freezing year round (eg at the poles and on very high ranges).

We are observers of a tiny interval of time. Over geological time, the Earth’s climate and atmosphere has varied significantly.  Sea levels have risen and fallen a number of times in recent history.

The Earth is presently quite cool compared to its lifetime average but a lot warmer than more recently, during the last ice age.  Fossil and other evidence suggests that biological activity is higher when the planet is warmer.

Climate is changed by movements in the Earth’s crust (Australia was once under the South Pole) and temperature. These movements originally allowed liquid water to form. The distribution of the seas and continents changes over time changing the flow of ocean and air currents and limestone, created by biological activity, traps carbon dioxide in deep strata. Ocean currents have a strong effect on the amount of water vapour and heat take up by the oceans. At the present time there is a landmass under the Antarctic but not the Arctic.

The planetary orbit and present location of the continents has a lot to do with long term temperature change. The Earth’s orbit around the Sun is not circular and the earth’s axis is tilted so that one pole points more to the Sun than the other when the Earth is nearest to the Sun - this slowly cycles presenting first one pole to the Sun then the other. Thus it is presently colder in the Antarctic than the Arctic. In addition to cyclical changes there are factors such as the slowing of the Earth’s rotation and the Moon’s orbit.

Catastrophic events can also change the climate. Volcanic activity can change planetary temperature by increasing dust in the upper atmosphere (increasing reflection) and by emitting water and carbon dioxide.  It is estimated that there is more water and carbon dioxide trapped in the Earth’s crust than that in the atmosphere and the oceans combined. From time to time large objects in intersecting orbits (meteors, comets etc) hit the Earth. These cause temporary devastation and are thought to have resulted in past mass extinctions.

Although it is the main source of energy at the surface, the Sun is not the only source of the Earth’s energy.  The Earth’s central core is kept hot by the nuclear decay of elements under the massive pressure of the Earth’s gravity and by the effect of the Sun’s gravitational field.  Thus the Earth’s core is still molten after hundreds of millions of years and we find its decay products, such as uranium and radon gas, on the surface.  Heat energy is constantly leaking to the surface and deep mines must be cooled to allow miners to work in them.  In some places, such as mid ocean expansion zones, this heat is constantly emitted. It is assumed that this activity has been more or less constant for many millions of years but this may not be so.

It is difficult to be sure that changes in the climate are due to any one factor. But there are deep-seated cultural reasons for believing that it is mankind that is responsible for bad weather[2].

The Greenhouse Hypothesis

Increasing carbon dioxide (CO₂) and other gases including methane (CH₄), oxides of nitrogen (NO_X) and CFCs may result in global warming[3] (the Greenhouse Effect) which may cause other serious effects threatening the planet. These include ocean warming and higher levels, due to expansion and ice melting, and changed weather patterns.  These in turn may effect our ability to grow food, may result in the inundation and destruction, by storms, of homes and productive land and may cause increasing levels of extinction of plants and animals.

Many scientists today support the hypothesis that carbon dioxide is the main causal factor in planetary warming. Carbon dioxide increases the absorption of solar radiation by restricting the passage of reflected or re-emitted solar radiation that would otherwise be radiated back into space (see diagram). But the actual rate of warming due to carbon dioxide is unknown and can only be estimated with the aid of computer models.

Carbon dioxide presently makes up about 0.034% of the Earth's atmosphere. It is produced by the oxidisation of carbon, previously fixed by living things, and by release from the Earth's core. Although there have been many changes in this level in the past, for many millions of years these have been slow and the planetary carbon cycle has been in approximate equilibrium. As carbon dioxide increases (following volcanic activity or climatic change) so plant growth on land and in the sea increases to absorb it.

The relationships involved are very complex. Carbon dioxide is not the only gas responsible for the greenhouse effect.  Other gasses and water vapour also play important roles. Water vapour (particularly as clouds) reflects incoming radiation.  Water vapour (humidity) is in much higher concentrations than carbon dioxide and is far more variable in concentration, as we all know (sometimes its clear, sometimes its cloudy, sometimes dry and sometimes raining).  The median amount of atmospheric water vapour can be expected to rise as the planet warms.

One of the pieces of evidence for the greenhouse effect is a strong correlation over the past 100,000 years between carbon dioxide levels and atmospheric temperature. Although it is possible that higher temperatures result in higher carbon dioxide levels (warm oceans dissolve less CO₂) or that both resulted in the past from some common cause (such as volcanoes) many scientists believe that this is evidence that higher carbon dioxide levels will indeed result in planetary warming.

According to a majority of qualified scientists, the present increase in carbon dioxide in the atmosphere, due to the increased demand for energy, is an important factor of change in the predicted warming of the planet and consequent climatic change (the greenhouse effect).  Experts assert that an effect that is now barely perceptible against the natural fluctuations in climate may become catastrophic if left unchecked.

All currently accepted models predict that increased absorption of solar energy will make some change in the Earth’s climate.  Some existing plants, animals, peoples, businesses, industries and nations will suffer. Others may secure an advantage. The extent and rate of such changes is not yet known.  If the changes are large and/or rapid, many more will suffer than will gain advantage[4].

Sources of Carbon Dioxide

At the present time, carbon dioxide is dumped into the atmosphere from power stations, industrial plant, vehicles and domestic heating, just as we might dump sewage into the ocean.  Up until recently this has caused very little impact on the global environment.  This is because carbon dioxide is a natural part of the planetary carbon cycle and because coal, oil and gas are carbon dioxide extracted from the air or sea and fixed by past plant or animal life. 

Coal, gas and oil represent only a small fraction of the total carbon resources of the planet.  Most of the carbon resources are held in the ocean and in minerals.  The eco-system of the planet is constantly absorbing and emitting carbon dioxide.  Atmospheric carbon dioxide provides the basis for plant growth.  The sun provides the energy used by plants to absorb carbon dioxide and this energy is released to fuel the cell activity of plants and animals that consume the plants.  Some of this biomass (timber, straw etc) can also be burnt to release the stored energy. Any remainder can become compacted and eventually converts, typically to coal.

Burning previously fixed carbon dioxide (coal, oil, gas and timber) can upset the delicate equilibrium established in the carbon cycle of the planet.

Because carbon dioxide forms a very small fraction of the atmosphere, a relatively small amount resulting from the burning of fossil fuels represents a large percentage increase and can have an impact on the relatively vast volume of the atmosphere surrounding the planet.  This can in turn have a very significant effect on the rate of absorption of solar energy.

In the past twenty years, carbon dioxide in the earth's atmosphere has increased by about 9%.  The principle cause of the recent rapid increase in carbon dioxide has been burning carbon-based materials for energy.  These carbon-based materials, including coal, oil, gas and wood products, currently supply about 90% of the world's energy requirements.

The imbalance in carbon dioxide is being made worse by the removal of a large number of trees (which previously absorbed carbon dioxide) particularly in third world countries, and possibly by the pollution of lakes and oceans preventing the absorption of carbon dioxide by algae. 

In NSW, power stations produce over 45 million tonnes of carbon dioxide a year. NSW has explored a number of alternative sources of electrical energy (including wind and solar). The Snowy Mountains scheme and all other non-coal sources together, contribute less than 10% of the State’s needs.  The only known and presently practical alternative to coal is nuclear power, not a political possibility in NSW in the foreseeable future. At current growth rates, NSW power stations are projected to produce over 80 million tonnes of carbon dioxide per year by 2010.

Coal burning power stations are only one source of carbon dioxide.  Petroleum fuelled vehicles not only produce huge volumes carbon of dioxide (over 2 kg for every litre used) but also other gasses and particulates that pollute our cities. 

Metals smelting (iron and steel, aluminium, copper etc) glass making and other materials using high temperature processes are also significant, particularly when carbon is used both for energy and to reduce metallic ores. In the case of aluminium for example, a combination of coal sourced electrical energy (35% thermal efficiency) and consumable carbon electrodes (obtained from petroleum coke at high-energy cost) is used to reduce alumina to aluminium metal.  All these processes produce large quantities of CO₂.

Another major source of carbon dioxide is cement manufacture from calcined limestone. In this process limestone is heated by coal or other fossil fuel and carbon dioxide released both from the fuel and the calcination.  To produce one tonne of cement nearly two and a half tonnes of carbon dioxide are released. This figure does not include transport fuel. A major use of cement is in concrete. About one tonne of CO₂ is released for every 5 tonnes of concrete. Thus each large building, road or concrete structure represents many thousands of tonnes of carbon dioxide released to the atmosphere[5].

Limiting the Production of Carbon Dioxide

Carbon dioxide production is linked directly to burning fossil fuels (coal, peat, oil and natural gas), biomass (wood, straw etc) and garbage for energy.

Countries in the developed world (including Australia) typically consume over ten times the energy per capita of people in the third world.  There is growing international pressure on developed countries to reduce their carbon dioxide emissions[6].

It was therefore decided by the Keating administration that Australia should adopt the Toronto Target, which proposed a reduction in carbon dioxide emissions by 20% from the 1990 level by the year 2005, for all greenhouse gasses combined, to the extent that this can be achieved without adverse economic impact.  This was subsequently modified at Kyoto in 1997 where most first world countries agreed to a 5.2% reduction on their 1990 emissions of greenhouse gasses by 2008 – 12 (with a large number of conditions and tradeoffs agreed to).

The Howard administration took the view that the Toronto goal could not be met without adverse economic impact.  As a result, at Kyoto, Australia successfully negotiated an 8% increase from the 1990 emission levels (representing a substantial reduction in projected emissions). 

Arguments against Toronto target included:

• Australia can’t comply without disproportionate economic harm (relative to other developed countries) because of:Australia’s high proportion of energy intensive exports (coal and metals);
  • our extended transport distances;
  • our moral stance against nuclear power (many first world countries generate between 10% and 80% of their electricity by nuclear means and can comply by building more reactors).
• Our relatively small population (making negligible difference to the planetary generation of carbon dioxide).
• Australia’s very large area for absorption of the carbon dioxide we generate.
• Unless the developing countries also comply, any effort will be useless anyway (we should instead be looking for advantage from the change).
• The whole thing may be a scientific ‘storm in a tea cup’ and we should wait and see what happens before restructuring our economy.

Arguments for compliance included:

• Only developed countries have the potential to lower greenhouse gas production;
• If all developed regions adopt the same attitude nothing will be done;
• If Australia’s economy is structured to be more than usually carbon dioxide intensive, then this is an argument for more effort to restructure, not less;
• Australia’s economic model, showing high unemployment resulting from compliance, was suspect;
• If we wait, by the time we see the effects it will be too late;
• Australia stands to suffer more than some other areas from global warming and should be arguing for, not against, the Toronto Target.

Even the small increase in emissions negotiated at Kyoto represents a significant cut back on projected production and will force Australia to restructure the economy.  We need to consider how this might be done to advantage.

The rate of energy consumption per person is tied to economic growth, while the overall growth in energy consumption is tied to population growth times the energy consumption per capita.

For example, in NSW the standard of living (measured by consumption per capita) is increasing far less rapidly than in developing countries. The population growth is modest by world standards (the birth rate is lower than replacement rate and growth [about 1% pa] relies on immigration and ageing). Yet the combined impact of these two forces is projected to double electrical energy consumption in NSW within two decades.  This could be a conservative projection if there is increased processing of primary products in regional NSW or more ways are found to replace petroleum fuelled vehicles with electric vehicles.  Compliance with the Kyoto target, for example, could spell the death of electric vehicles as a means of reducing air pollution in our major cities.

Reducing Greenhouse Gas Production in NSW

Together, coal burning and transport generate most of the State’s greenhouse gasses.

World-wide, oil produces more greenhouse gasses than coal but in NSW coal is our major energy source supplying about twice-as-much energy as oil and gas combined.  The production of carbon dioxide from coal burning therefore outweighs the production of oil sourced greenhouse gasses.  47% of this total energy is consumed by industry, most in primary metals and materials production.

In New South Wales, coal-burning power stations are the biggest consumer of coal - the next biggest consumer being the steel industry. Much of the industrial power generated in New South Wales is used by the aluminium industry.

Whereas most industrial and domestic energy is produced by coal (predominantly in the Central Coast, Hunter and Central Western regions), oil (petroleum) is the principal energy source for the transport sector. Cars consume 50% of petroleum fuels, trucks and vans 27%, aircraft and ships 17% and public transport and other minor users 6%. 

37% of New South Wales’s energy is consumed by the transport sector which also produces 26% of the carbon dioxide[7], and in addition, produces most of the carbon monoxide and nitrogen oxides[8].

Under present technology, coal produces more carbon dioxide per unit of electric power output than other fossil fuels (and of course very much more than non-fossil sources). The reason that petroleum based fuels produce less carbon dioxide than coal for a given energy output is twofold.  Coal is not pure carbon and some of its other constituents reduce combustion efficiency (and produce ash – approximately 25% by weight depending on coal type).  Petroleum contains about 27% hydrogen that efficiently burns to water.

 Although at first impression it would seem that transport is relatively blameless in the greenhouse picture (as opposed to electricity generation or industrial burning of coal) when conversion efficiencies are taken into account this is not the case. 

Present vehicles consume more than four times the energy that is actually delivered as mechanical energy to the wheels.  Many commentators believe that vehicle efficiency gains of up to 50% are feasible (but at a cost that is currently prohibitive using existing technology). The inefficiency of internal combustion engines also contributes to excessive weight and materials consumption.  Savings in these areas would lead to a significant reduction in the industrial energy consumption involved in manufacturing and processing the materials and in manufacturing the vehicles themselves. 

In addition, a great deal of energy is currently wasted because of less than ideal traffic design and the inadequacies of the present road system.  These produce variations in traffic speed, requiring frequent braking and acceleration, and impose other inefficiencies, such as steep gradients and poorly designed corners.  These factors are very evident in comparisons of town and country fuel consumption rates[9].  The large number of ageing and poorly tuned vehicles on our roads also contributes to this waste and accompanying pollution.

The impact of burning fossil fuels for energy goes beyond small contributions to the global greenhouse effect and include; ozone layer depletion, the production of SO2 and NO_x pollutants leading to acid rain, the warming of streams and lakes, and radioactive emissions from flue gas and ash. Emissions from coke ovens exacerbate the local environmental impacts of steelworks.

New South Wales has a multi-billion dollar investment in large-scale conventional coal burning power stations and metallurgical plants.  Coal exported to overseas power stations and steel works is a major employer and the nation's principal export.  In the coming decade these will increasingly come under pressure as a major contributor to greenhouse gas and other pollutants. 

Alternative Sources of Energy

At present, the practical large-scale sources of global energy are coal, oil and gas and nuclear power with some additional remaining hydroelectric resources yet to be exploited. 

While Australia has significant reserves of uranium, these are not as plentiful as coal and impose other problems.  There are obvious risks involved in encouraging the proliferation of nuclear power in third world countries.  India acquired nuclear weapons within a few years of gaining their first reactor and even the Soviet Union has proven to be an unreliable manager of nuclear power plants.

There are many potential sources of energy appropriate to the domestic energy needs of small regions or communities, including hydroelectric power, geothermal power, tidal power and wind power.

Most of the World's energy use is consumed by industry manufacturing and moving materials[10]. At the current level of technology, only nuclear power provides an alternative source of energy to fossil fuels on sufficient scale to be able to meet the world's energy requirements.  But nuclear power poses other threats, already identified above. 

There are many that propose that solar power or perhaps wind energy can contribute in a substantial way to the world's energy needs.  But this is not possible in many locations using present mechanical or electrical technology. Energy balance analysis shows that, in many parts of the globe, the energy used to manufacture the materials used in energy collectors exceeds the energy that those collectors could collect within their expected lifetime.  The use of solar and wind collectors will result in net energy consumption if their production energy can't be collected within their practical lifetime. 

Domestic solar hot water provides an example.  Although modest sized solar units can provide an energy boost to the average family home by supplementing hot water, the CO₂ equivalent the materials used in their manufacture is significant.  Energy collected is small. It is typically many years before the CO₂ equivalent of the energy usefully collected by these units exceeds carbon dioxide generated in their manufacture, transportation and erection.  In many locations and aspects, break even may not be achieved in their lifetime. Where this is the case the use of these units will increase global CO₂ production above that which would have resulted if conventional fossil fuels had been used.

If there was significant investment passive solar hot water units, global world CO₂ production would be driven up by the energy demands of solar unit production and sufficient savings in energy may never result to “pay back the debt”.  Further, because solar units collect energy at a non-peak period for electricity generation, they increase the “lumpiness” of electricity demand and have potential to adversely affect the efficiency of the electricity grid and the utilisation of generation equipment.  If they became commonplace, there would be a hidden additional energy cost to the electricity generation system, which would also translate to additional CO₂ production.

Photovoltaic solar collectors are far more promising.  Costs of production are falling and new materials may result in lower materials and fabrication energy costs.   While photovoltaic solar collectors have a significant and growing place in communications, domestic and building energy supplies, particularly in rural Australia and other dry temperate climates, they will never be a replacement for large-scale high intensity industrial or transport energy sources for much of the world. 

Most of the world's population is concentrated in high latitude countries or in tropical countries with high levels of cloud cover.

Maximum theoretical energy conversion efficiency for a solar collector is only about 40% and less than 20% is typical in practice. Total solar incidence is already exceeded by energy consumption in several large northern industrial cities of the world.  That is, even at 100% conversion efficiency and total coverage, there is not enough sun to meet existing energy needs in those areas. As a British Steel scientist once remarked, “it would be very cold and dark under the collector”.

Wind generators may many years to generate the energy consumed in their manufacture[11]. Wind generators can theoretically run night and day.  But in reality few locations have continuous winds of over 55 km/h[12].  Below his level, or at very high wind speeds, present commercial wind generators will not deliver full output.

The energy required to make the materials and to build the solar collectors or wind generators is predominantly obtained from fossil fuels and is required at the outset, whereas the energy received is collected over an extended period.   A large expansion of solar collector or wind generator manufacture world wide would therefore result in a substantial additional net energy drain on the planet's fossil energy resources while growing “green” energy needs were being met.

At present levels of technology of the energy produced by some so called “green power” sources may be insufficient, simply to replace the fossil energy consumed in their manufacture and installation, let alone fuel the system's own expansion.

Similar problems confront tidal and wave power and geo-thermal collectors.  Biological solutions including bioengineered fuels and biomass could provide transport and industrial fuel in the future but these require further technological development.

The solution lies not just in finding new energy sources but also in solving the problems caused by the existing sources. 

Increased Absorption

One solution was suggested in a brain storming session hosted by the Hunter Technology group in Newcastle in 1990. This was to increase absorption of carbon dioxide in economic crops near to large point sources. 

The principal greenhouse gas, carbon dioxide, is naturally absorbed in nature.

The planet has an existing, very large solar collector, plant life. From this collector almost all our existing energy requirements are originally derived. Solar energy is consumed reducing carbon dioxide back to carbon rich compounds.

Carbon dioxide and water are combined through photosynthesis in the leaves of plants to produce sugar and other carbohydrates used by the plant for tissue growth, and in doing so release oxygen. This is a highly complex process involving a large number of processes but can be simplified to the following equation.

If the process of carbon dioxide absorption by trees and crops could be accelerated, then much of the lost plant growth could be replaced, additional crops could take up additional industry produced carbon dioxide, and problems associated with the burning of fossil fuels would be reduced.

The only long term and practical solution to carbon dioxide consumption from the gases must be biological.  Chemical gas scrubbers to remove carbon dioxide require more energy input and therefore increase fossil fuel consumption.  The scale of any biological solution and the need for energy input, preferably solar, precludes the possibility of large structures (such as glass houses) through which the gas is processed (unless this problem becomes so acute that large sums can be expended for environmental reasons alone).

Hundreds of millions of years ago when the carbon dioxide level was higher in the atmosphere due to volcanic activity, the rate of plant growth was far higher than it is today.  In the carboniferous period, large amounts of plant growth were laid down to become coal and this process continues on a smaller scale today, where peat and other organic materials are being absorbed.

Within the limits indicated (less than 0.05%), many plants try to absorb all the carbon dioxide they can get, provided they also have sufficient water and other trace nutrients.

It can be seen from the above equation that if fully absorbed, the 44 million tonnes of carbon dioxide produced by NSW power stations each year would produce in excess of 31 million tonnes of additional plant carbohydrate production. About 18,000 megalitres (ML) of additional water would be required. This is significant but well within the water resources of the Hunter region (potential ground water resources of the Hunter exceed 278,000 ML per average year).

Solar input is also adequate over the area contemplated (as much as 500 sq kilometres in areas near the five major Hunter power stations would be treated). The area treated would become a huge biological solar collector.

In practical terms the carbon dioxide would be distributed over a very large area in the open. Not all carbon dioxide produced would be absorbed. Although carbon dioxide is 1.53 times heavier than air and would be distributed over a very wide area, there would be losses due to wind and diffusion. The distribution system would also need to avoid areas of high loss or natural build up and monitor and cut supply if excessive losses or build up occur. Different rates may be required for different types of vegetation.

The gas could add very significantly to economic crop production. The most probable crops to be accelerated initially would be C4 plants with a leafy canopy or dense foliage that will serve to contain the carbon dioxide and include trees, high grasses (wheat corn, sugar etc), sunflower and grapes. A number of aquatic plants may also have potential. Some of these might be genetically modified to absorb more CO₂.

In areas where water is relatively plentiful, the soil is fertile and sunlight is adequate for agricultural growth, such as the Hunter, the introduction of additional carbon dioxide to crops will increase plant growth.  This new growth can be used to produce additional building materials for an expanding world population, for food and fibre production. 

The absorption of carbon dioxide would, of course, have to happen in rural areas and would have to be associated with large sources of carbon dioxide, such as power stations and steel plants. Here coal has an advantage over oil used in transportation.  Unlike oil, most coal is burnt in large stationary power stations and industrial plant and this may give coal an advantage as the energy source of the future. 

The catch to the idea of using crop growth and solar energy to absorb coal-sourced carbon dioxide is that carbon dioxide from industrial furnaces is often hot and dirty and contains trace gases that are harmful to crop growth.  Cleaning the gas and delivering it to the crops so that it is not blown away may also be difficult and costly.  But this may be a small cost to pay (like the cost of sewage treatment plants) for the benefits to the environment and to the future of the coal industry that such cleaning technology may provide.

If ways can be found to clean the carbon dioxide so it can be used for agricultural purposes, the location of major coal burning plants in a region may become a major asset to the local agricultural industries.

World Population Growth

At the root of the world’s carbon dioxide problem is the greatest challenge facing the planet: over-population.  Recent human population and technology growth has been so high, we are in danger of outrunning the ability of natural mechanisms to compensate for the environmental impact. In the 20th century the population of the world has already increased four times over. World population is certain to at least double in the next twenty years, driven by higher than replacement birth rates and longer life spans.

This situation is alarming, as it is not possible to slow world population before it doubles to around twelve billion.  Some demographers believe that after that point population decline in the first world combined with resource depletion and disease will cause a, perhaps rapid, decline in global population.

Over 90% of world energy is presently obtained by burning carbon based materials such as coal, oil and wood products (including garbage) all resulting in increasing carbon dioxide production.  At the same time the ability of biological systems to respond to higher carbon dioxide levels is being reduced by land clearing, soil degradation and pollution of rivers seas and oceans, particularly in coastal areas, as a result of excessive human population pressures.

It is possible that changes in lifestyle, domestic technology, industrial processes and improvements in combustion efficiency and distribution methods could offset population growth and stabilise consumption of carbon based fuels, including coal in a few developed countries.

Hope remains that it might be possible to meet the Toronto target in some developed countries.  In parts of Europe the closure of “Rust Belt” industries in East Germany and the old “Iron Curtain” countries, combined with a move to nuclear power in others has made the Target achievable (depending on which year is taken as the base).  This has not so much depended on stabilising or reducing energy consumption between now and the year 2005 as on closing older industries and converting from fossil fuel based energy to alternatives, in particular, nuclear power. 

A 20% reduction in production in countries like Australia would require a substantial switch to alternative energy sources.  In developing countries such a Target is not achievable.

But by the year 2005 the world's population will have inevitably grown to around six billion people and, at the same time, many now developing countries will have substantially increased their energy consumption per capita. 

The energy consumed by this vast population is increasing per person at the same time.

The rate of energy consumption per capita in the world is very uneven.  Under present technology, high energy consumption per capita equates with a high standard of living. 

Each person in the industrialised west consumes around 8 times the fossil energy of each person in developing countries. 

But people in developing countries are much more numerous and their population is growing faster.

In developed countries, growth in energy consumption was continuous from 1900 to 1980 with some fall off since that time.  In developing countries per capita energy consumption has doubled in the past 20 years. Total energy consumption in the developed world doubled between 1950 and 1975. 

Third World countries naturally demand that they be given the opportunity to improve their standard of living.   Nor may it be possible to intervene to substantially limit the demand for energy in either the developed or the developing world without the destruction of world economic and political stability.  Such a destruction of economic stability would very likely result in the deaths of tens of millions of people.

Increasing standards of living and the growing world population are conservatively expected to double world energy demand over the next thirty years (UN Projection).

It follows that the Toronto/Kyoto targets cannot be met world-wide unless very substantial new sources of energy (equivalent to over 3,000 million tonnes of coal per year by 2050) are found, which do not rely on the burning of carbon based fuels. 

Alternatively economic development must stop now and this must be combined with an immediate stop in world population growth.

None of these is likely.

We may well be facing half a disaster, a full disaster may not be apparent, until it is too late.

Other Climatic Concerns

As indicated at the outset the climate of the planet is determined by the interplay of a large number of factors. Present generation computer simulations do not take all of these factors into account and, like all encompassing economic models, have very little predictive accuracy. It is therefore possible that climate changes due to human activity might be for the better, offsetting some otherwise negative natural change.

Climate change has the potential to affect our ability to grow food through flood or drought, to destroy productive land through wind, water, ice or salt build-up and to cause increasing levels of extinction of plants and animals. Ocean warming and higher sea levels, due to expansion and ice melting, result in the inundation of coastal areas and low islands.  The opposite effects may result if the Earth becomes colder. 

Governments need to develop strategies for dealing with the effects of climate change.  Like all disaster plans these need to consider all the reasonable short and medium term contingencies but to leave longer-term considerations to future generations. 

For example if there is a reasonable expectation of higher sea levels within a few years, local planning should prohibit further development in areas subject to potential inundation. Similarly a reasonable expectation of higher levels of storm damage may require building codes to be revisited the storm proofing of emergency services and communications and that some areas of high exposure are avoided.  A large number of such contingencies (100 year floods, dam safety, bridge design and so on) could be drawn up.

Of particular concern to NSW is the impact of more or less rainfall across the State.  More consistent rain in the northern or western parts of the State could be beneficial to agriculture but if this has higher variability it could have negative impact without management.  Greater water use may increase salination and increased land degradation.  Rainfall change may require tree planting or other interventions to correct for rapid climatic change.  Conversely, if Central NSW becomes dryer water management will become even more critical.

What can be done?

We should be aware that climate is changing, possibly quite independently of anything we are doing, and that these changes are, in all probability, irreversible. 

Already excessive human populations make some parts of the planet highly vulnerable to such changes. Some communities already face the spectre of outrunning their available food and energy resources with every minor climate change.  As population increases this will be a frightening catastrophe on two levels, the progressive destruction of land and its fertility and the inevitable death and terrible suffering of unprecedented numbers of personally innocent people.

In many areas it may already be too late to save the suffering and early death by starvation or disease of many just born or about to be born.  It is desirable that the World stops and preferably reverses population growth in the areas most at risk.

Population growth is an issue of more immediate concern than climate change, which (if the greenhouse hypothesis is correct) may be but one of its symptoms.  We must be careful that treating one symptom does not aggravate the disease.

The most acceptable, and so far the only successful way of controlling population growth is to provide economic and social alternatives to having many children.  This requires more, not less, energy.

New extraction technologies and better energy efficiency could make existing power technology cleaner, first world economies could make greater use of nuclear power and work to make other non-polluting energy sources economical.

First world countries do need to work to reduce energy consumed per capita.  Some of the options are well known, better urban planning to reduce travel, energy efficient buildings, reduced materials consumption, increased recycling, improved industrial design and so on.  They can also replace part of their existing fossil energy with nuclear energy.

As technology advances so energy efficiency often improves.  In the future, this may significantly impact on the energy intensity of a given standard of living.  Microcomputers tele-commuting and bio-engineered materials may replace or improve the efficiency of some energy intensive technologies such as transport and materials production. 

But the very commercialisation of these products and processes depends on demand for them.  This increased demand may well result in more rather than less overall demand for energy.  Whatever new sources of energy are chosen they will need to provide a high ratio of energy to each tonne of carbon dioxide producing materials used in energy production/collection.  This may rule out wind in most locations and some types of solar power.  Perhaps geothermal power or biomass offers a way forward.

Developing economies need energy at the lowest available cost. Coal and oil will remain a low cost fuels, available to meet the planet's energy needs for many decades into the future.  In the absence of a cheap clean source of energy, it seems certain that burning coal and other fossil fuels will continue to supply most of the energy needs of the planet's expanding population.  These fuels will remain essential for the production of food, textiles and building materials for that population and for their transport and distribution into the foreseeable future. 

Thus production of greenhouse gasses will continue to rise. In the face of this reality we must develop a range of strategies to cope with the outcomes.

Large point source generators such as power stations, metallurgical and cement plants offer the potential to concentrate and dispose of carbon dioxide.

Many disposal ideas have been suggested, including pumping it into the deep oceans and into underground mineral seams.  Sequestration is problematic in all but a few locations (eg over empty oil wells). It could be very costly and require significant additional energy. The environmental impact is presently unknown; for example large scale use may result in the release of already absorbed CO₂ or trapped methane.

Increased biological conversion, employing sunlight to reduce the gasses back to carbon seems to be the only process that could be employed on a large enough scale to make a difference. Faster growing and harvesting of C4 plants for materials that will not be burnt (eg for paper or timber for construction) could fix more atmospheric carbon.  Planting more trees has been accepted internationally as a means of earning greenhouse carbon credits but this only works if the area under forest increases and when harvested the timber is not subsequently burnt.  Some food crops might be genetically modified to behave like high CO₂ absorbing C4 plants. Recent work with GM rice could offer the potential of considerable gains in yield using CO₂ enrichment.

Recycling can extend the useful life of plant fibres. Carbon rich materials like paper, garden waste, agricultural materials and even sewage sludge might be preferentially buried in large landfills or open cut mines (from which methane may be obtained as fuel) rather than employing incineration.  This would complete the cycle back to underground carbon deposits or to create new soil for agriculture. Assisted higher absorption of carbon dioxide by crops could minimise the greenhouse effect.

But preliminary ideas on how carbon dioxide might be economically cleaned and distributed for agricultural purposes, and what crops would give the maximum economic benefit to such a project, still need to be proven. 

Some of these methods may give us time, time to find better solutions to world energy needs.  We need to trial a number of these ideas now.

Conclusions

Australian impact on global climate is insignificant. Our main contribution is likely to be indirect by way of diplomatic efforts to change global behaviour or through research into solutions that can be applied globally. Climate is likely to change no matter what we do. In Australia we are all too familiar with the effects of natural climate fluctuations. 

The degree to which human activity changes climate is related to our level of resource utilisation.  Although energy consumption is very important in this equation so too are mineral extraction and processing, farming and land clearing, pollution of oceans and lakes and the shear number of humans and their consequent demands for food and shelter.  Not only does excessive population lead to stresses on the biosphere of the planet; it makes huge numbers of people highly vulnerable to relatively minor changes in that biosphere.

Sudden climate change is just one of a number of a range of potential catastrophes that might befall the planet. It is important that while doing all possible to mitigate the impacts of increasing resource exploitation we:

1. commit more resources to means to respond flexibly to climate change than to trying to prevent it and;
2. treat the disease (over-population) not just the symptoms (like greenhouse gasses).

We need to focus on the possible. An appropriate response is to ensure that resource and transport efficiency is optimised and energy waste is reduced. 

Another is to explore less polluting energy sources. This needs to be explored more critically.  Each so-called green power option should be carefully analysed for whole of life energy and greenhouse gas production against the benchmark of present technology before going beyond the demonstration or experimental stage.

Much more important are the cultural and technological changes needed to minimise World overpopulation. We desperately need to remove the socio-economic drivers to larger families, young motherhood and excessive personal consumption (from resource inefficiencies to long journeys to work). 

Climate change may be inevitable. We should be working to climate “harden” the production of food, ensure that public infrastructure (roads, bridges, dams, hospitals, utilities and so) on are designed to accommodate change and that the places people live are not excessively vulnerable to drought, flood or storm.

Only by solving these problems will we have any hope of finding solutions to the other pressures human expansion is imposing on the planet.  It is time to start looking for creative answers for NSW and Australia now.

Richard McKie                   

October 1990 /March 2000

Footnotes