Humanity and the Environment

I gave a talk with the title Morality and the Environment to the Atheist Society in Melbourne in 2008. A later version was printed in the Australian Rationalist journal with the misleading title A charter for Survival. That version was used by the Education Department in Victoria as a teaching aid. The text below is the latest (November 2013) version.


“Protection of the environment” has become a moral issue in the minds of an increasing number of people. But what, specifically, is the environment, what actions are good or bad for it and what moral issues apply to it? I will discuss this by thinking of the environment as the entire planet, or as the home of Earth’s sentient beings, or as the home of Homo sapiens.

Morality concerns what people should do and not do according to some religious or secular principles. Such principles may include an explicit or implicit duty of custodianship for the environment, and more specifically, compassion towards some or all species. This discussion will consider what might be justified as the right, or moral, thing to do concerning the environment, noting differing individual beliefs about morality and about the significance of our actions on the environment. But first it will be useful to look at some relevant aspects about the workings of the environment.


Interactions and Consequences

All life on Earth needs close limits of conditions, such as temperature, availability of a specific range of substances, absence or avoidance of a specific range of substances, and continual presence of other organisms including other members of their own species. All life, in its processes of existing, continually alters its immediate environment. Billions of years ago, organisms called cyanobacteria excreted oxygen into the atmosphere, eventually causing the extinction of many other species of that era. However, this new chemically reactive environment pushed evolution onto a much more dynamic course.

This was just the operation of natural processes, and one key element happened to be a particular species of living organism. But it shows that from a early stage the Earth’s surface, including its climate, has been continually and significantly affected by its inhabitants. Some later effects were: covering the land with plants, which, among other things, increased the concentration of oxygen; production of calcium carbonate; and the decomposition of rock by bacteria, plants and fungi.

These effects were produced in conjunction with inorganic factors: fluctuations in the strength of the sun’s radiation; continual movement of the earth’s crust; the impact of large objects and radiation from outer space; gravitational effects of the sun and the moon; and the rotation and revolution of Earth around the sun and of the moon around Earth. Together these caused great extinctions, generated new kinds of organisms and affected the form, temperature and behaviour of the land, seas and atmosphere.

Human activity has had its own specific effects, starting with hunting and grazing of animals, then agriculture and use of fire. Now, thousands of years later, with the immense power of modern technologies, and the huge increase in human populations and their appetites, the impact is very significant.

Continued human action, it has been suggested, could lead to the extinction of humanity itself. Would this be a good or a bad thing? We might think it bad, but from the point of view of many other species the extinction of humanity could be a good thing. Pre-human extinctions cleared the way for our present existence, so our possible demise might be thought of as just part of an ongoing process.

I think it is unlikely that humanity would be completely extinguished by its effects on the environment. We are too widespread around the earth, too resourceful and resilient, too diverse in culture and belief, and our gene pool – while not as diverse as that of most other mammals – is diverse enough for us to survive many likely adverse environments. But some real possibilities that are short of extinction are still very dire.


What are We Actually Doing to the Environment?

Humanity is seriously harming the environment in many ways: using up resources; poisoning the air, water and land; destroying the habitats of other species; and warming the surface of the earth and the atmosphere.


The increasing human population and its demand for ever higher “standards of living” are using up many essential resources: fresh water, arable land, food species (notably fish), plants and carbon-based fuelsd. Most are vital not only for humanity but also for other species Many species have already been extinguished, and many others are being threatened.

Depletion of resources is being caused by:

  • carelessly wasteful collection and use, in virtually all of our activities;
  • extravagant use, arising from extravagant lifestyles and aspirations;
  • use in a way that does not consider probable environmental requirements.

But even if we used resources sparingly, our sheer numbers might still cause us to consume some of them at an unsustainable rate.


Thousands of recently developed substances have already been introduced into the water, air and land, and more are continually being added. Many of them have been shown to be noxious to humans and other species. The full effects of most of them are still not known. Some are slow-acting, so that their effects are not discovered until years or decades after contact or ingestion. Some are benign in themselves but have been shown to be dangerous in combination with others. These substances are created by:

  • manufacture and use of chemicals and materials for industrial, agricultural, medical and personal use;
  • use of engines and other equipment that emit noxious gases and/or particles;
  • trying to extinguish “troublesome” species.


Damage to habitats of people and other species is caused by:

  • clearance of land for crops, grazing, urban and industrial areas, roads and other transport infrastructure, mining, and storage of water;
  • cutting through or breaking habitats into small areas by roads and other uses;
  • introduction of exotic species – weeds, predators and pathogens;
  • human intrusion;
  • poisoning.

Global warming.

Human-induced global warming is caused by direct or indirect emission and release of “greenhouse gases”, notably carbon dioxide and methane, from:

  • industry;
  • transport;
  • agriculture;
  • clearing of land;
  • civic and household use of energy.

Once started, global warming can induce other processes that increase it.e

It is most unlikely that we will avoid severe and widespread consequences of global warming, but immediate drastic action would delay and reduce the damage. Warming itself may not be the most dangerous threat to humanity, but until some new equilibrium is eventually reached it will increase the spread of disease and the depletion of resources and habitat.


Is This Just Doomsday Scare-Mongering?

Some people dismiss the need for any action on these environmental issues, saying that they:

  • don’t believe these environmental degradations are real;
  • don’t believe the situation is as bad as painted – or technology will fix it, “as it always has”, or whatever God wills will happen anyway;
  • don’t think it is urgent – other issues are more important or pressing;
  • don’t want to believe the situation is a problem – it would spoil lifestyle, position or aspirations;
  • don’t think anything can be done about it – it’s just too late or too hard;
  • don’t know what to do about it;
  • don’t think individual people can make a difference.

So why don’t we all just accept our situation and optimise the new world that is being introduced by new technologies?

There are several issues here:

  • how sound is the case for imminent disaster?
  • are there other more urgent issues than the environment?
  • will such development make the situation worse?
  • is such development necessary to provide an acceptable standard of living worldwide?
  • is wealth necessary for human happiness?
  • will new technology protect us from possible adverse environmental effects of economic and industrial development?

As for the approaching doomsday, we see unprecedented longevity and wealth in many countries, despite the allegedly terrible new chemicals we are now exposed to, and despite occasional economic slumps. Increases in health and material prosperity seem to be unstoppable And we remember previous unfulfilled dire predictions, from Malthus in the early 19th century to the Club of Rome in 1972.

But this time it looks like a bubble about to burst. During recent decades computer models have been predicting that the earth would become increasingly warmer as a result of increasing emissions of greenhouse gases, and have suggested the effects that this would have on the climates of different parts of the earth. But the models and their predictions kept changing. Critics dispute some of the evidence of global warming and point to flaws in the models, which in the past did not use data that was precise enough nor complete enough to represent the very complex and chaotic behaviour of the environment.

But later models are giving more precise predictions. We also have clear, measurable, warnings – shortage of potable water, disappearance of glaciers, melting of Antarctic, Arctic and Greenland ice, increases in ocean temperatures – that global warming is more advanced than the models predict. Further, there is the disappearance or endangerment of food species, and the increasing acidification of the oceans (with CO2), that things are going wrong. Meanwhile, populations and personal consumption continue to increase.

There are indeed other serious problems that need immediate attention, such as war, private use of increasingly powerful weaponry, and poverty. These should not be ignored, but neither should the environment, and most of them make the environmental problems more severe, and vice versa.

The hope, or expectation, of continued economic development has been fostered by progress in science, the industrial revolution and the success of capitalism. Wherever it is kindled it is driven by well-known human traits. Governments like it: it pleases voters and increases international influence. So, although it generally worsens the environment in many ways, development usually gets priority over environmental issues. More efficient and sustainable technologies will be likely to reduce the adverse impacts of development, but are not likely to be sufficient by themselves.

Equalisation of distribution of goods and services, ie., “bringing the poorer nations to a higher standard of living”, is often said to make further economic development essential. But, contrary to this argument, new technology and development usually benefit the rich much more than the poor. What is really needed is better sharing of resources, not greater exploitation.

Increasing the wealth of the poor while curtailing the consumption of the rich seems like an impossible hope. None of the major religions has had any success in achieving it. But happiness brought by wealth is only transitory. Any long term happiness or feeling of wellbeing depends on temperament, on engaging in satisfying activities, and having hope of reaching goals.

New technologies often produce effective substitutes for depleting resources – such as for energy, or minerals with specific applications – and may continue to do so for many of our needs. Nuclear fusion, or more likely capture of sunlight, may become our primary energy source, for example, and hydroponics might substitute for arable land. Such solutions are generally only partial substitutes, and new technical capabilities often have unexpected serious side effects. Similarly, careful husbandry of agricultural land and forests could greatly increase their productivity. But we can no longer sustain another “green revolution” similar to the previous one, which required vastly increased amounts of water and fertiliser, and caused depletion of land and destructive run-off into waterways.

It is likely that some serious problems can be fixed, but none that anyone can be sure about. And the longer prosperity and longevity continue, the more serious all the problems will become and the more vulnerable communities will become to periodic climate changes. Archaeological evidence strongly suggests that earlier civilisations collapsed for similar reasons. Earlier, there was usually somewhere else for the survivors to go. But now there isn’t.


Moral Implications

What moral issues arise from these human impacts on the environment? A central issue in most people’s morality is the welfare of human beings – our selves, our family, nation, and, depending on our fears, compassion and generosity, all of humanity. Some of us would extend our morality to the welfare of all sentient organisms, or to Gaia – the dynamically interdependent system of the earth’s crust, oceans, atmosphere and the organisms that live in these places – or the planet as a whole. So, to the extent that the environment affects the welfare of any of these, the “welfare” of the environment is a moral issue.

But how do we justify human welfare – which is not the same as affluence – as a moral objective? The evolutionary process shows no respect for individuals or species – those not equipped to withstand changes to their environment die out. If humanity is the result of an evolutionary process, then the continuation of the evolutionary process may seem a desirable end in itself, even if it results in the extinction of humanity.

If humanity allows its own demise, then that’s evolution. Some people think there is some inexorable tendency (perhaps even a planned tendency) towards the evolution of increasingly marvellous species or towards increasing intelligence, with Homo sapiens as the current high point.

The usual assumption is that the next high point will be an enhanced form of humanity. But previous trends in evolution had inherent limits, which were surpassed by new species that arose from different lineages. Perhaps our combination of emotions and intelligence may limit our ability to evolve as organisms – although we might enhance ourselves as cyborgs. And, as suggested above, our nature or our actions might lead to our partial or total destruction. But, when we look at how people determinedly survive in all kinds of harsh conditions, it is obvious that there is an inherent human will to survive.

I think almost everyone would regard prevention of the destruction or severe harm to humanity to be an important moral consideration. And, in general, prudence would be regarded as morally preferable to self-indulgence.

So then, where do we apply moral considerations to the environment?

Earth’s continuation as a planet is dependent on the rest of the universe, not on anything we can yet do.

For as long as Earth’s condition allows, Gaia will continue to work out its own consequences. In the past this has often been at the expense of many of its species. Gaia has been regarded as a thing of beauty, a place of worship, an entity to worship or just an economic asset. (It has also been regarded as an organism, but while it contains many living organisms, it is not itself alive.) Since Gaia’s condition is crucial for the existence and wellbeing of all species, including us, its continued operation in a way conducive to our continued (tolerable?) existence must be a moral issue.

All of Earth’s biota is interdependent. This means that groups of very different species form ecosystems, in which each species has a niche role in providing food and shelter for other species in some sort of balance. As external conditions change – climate, earthquakes, new species arriving, dying out of “key” species – ecosystems are disrupted and may change to adapt to the new conditions or else die. The adaptations may include new predator and competitor species, and may result in the disappearance of some member species. So ecosystems everywhere, from the tiny to the vast, are continually developing, changing and dying.

The welfare of the various “useful” species is a moral issue because of our interdependence with them. And what about the others? The wellbeing of some other species has been justified as a moral issue because of their ability to feel pain and emotion, which has been amply demonstrated. The rights implied in this are:

  • not to be killed;
  • to be treated humanely, ie., not cruelly;
  • to be treated fairly;
  • to be able to gratify innate feelings and urges.

If we accept this, then cruel use of animals generally regarded as sentient (not only the “warm and cuddly”) for food, for other use of their body parts, for their muscle power, for entertainment and for companionship might be regarded as immoral – as indeed it is by many people.

This view is, of course, not universally accepted. Most people assume they have a natural or God-given right over other species. The cruelty of the food chain and of droughts, floods, earthquakes, etc., is often referred to as part of the natural order, with the claim that our actions are also merely part of that order. Indeed, predators are essential in maintaining the balance of ecosystems. But a large part of human endeavour is protection against the natural order, and the purpose of morality is to regulate “natural” human tendencies, such as rape and stealing, when they are considered harmful.

It may be argued that we have a right to be able to follow our “natural” lifestyle, unimpeded by consideration of other species which are all less intelligent and less aware of their situation than us. The same is often claimed about people with intellectual impairments. Indeed, people with unimpaired intellects but with lower social status or wealth are often denied the rights expected by people of greater status or wealth. But whatever is concluded about this, it seems very selfish to deny sentient animals at least some moral consideration.

In addition to this, some apparently “useless” species may have an unexpected key role in the ecology that we are dependent on. How far can this be taken? It would be hard to argue for protection of the bacteria that cause diseases, or to such pests as mosquitoes, or various noxious fungi or plants. So judgment and common sense are needed in drawing a line on what aspects of the environment to protect.


Possible Environmentally Moral Approaches

It is one thing to have moral objectives and another to know what to do to fulfil them. Even slowing down the damaging effects of our present lifestyles would be a great achievement. The idea of sustainability, that is, consuming no more than the earth can restore, seems out of reach. We would need to change our lifestyles immediately, and just being alive with our present world population puts a strain on the environment. Moving towards previous conditions, such as “Australia before the Europeans arrived”, is not an option because some of the changes we have caused are irreversible.

There is no agreement among experts or lay people about what are the most urgent problems to address, nor about what are appropriate or effective ways to tackle them. It is not uncommon for large-scale attempts at resolving problems to be counter-productive or to introduce new problems that are just as serious.

So we cannot expect to have the environment saved by grand projects while we just go on living our lives. While some such schemes might help, history tells us that we should be wary of them. And actions effective to one area will not necessarily work in others. It is only by whole populations taking individual and collective actions to alter lifestyles that the damage to the environment and to humanity can be reduced, or its increase delayed. We might then even hope that much of the damage may be reversed.


A Few Specifics

The actions needed to be taken on a global scale if humanity is to avoid or delay environmental disaster are to have:

  • the human population increase reversed;
  • individual consumption of goods and services reduced;
  • waste products mostly recycled;
  • production of noxious substances eliminated;
  • habitats of humanity and other species made liveable;
  • causes of global warming dramatically reduced.

Such drastic and extensive changes will not happen without a widespread acceptance of a moral obligation and an aspiration to achieve them.

Certain aspects of lifestyle would need to be addressed, as follows.

Personal attitudes

Personal aspirations and care would need to be directed towards the community and the environment rather than the person or family.

Human compassion should extend to other communities and to other species.

Corporate attitudes

The aspirations and actions of corporations and other organisations, both private and public, would need to give at least as much weight to the welfare of the environment as they give to shareholders and to profits.

Human population and wellbeing

Population levels need to decline, so family planning and small families should become universally acceptable and promoted. However, care should be taken in not discriminating against the inevitable larger families.

Also, influential transnational corporations, “rogue” nations and criminal syndicates would violate

Excess consumption

It should be immoral to waste or excessively consume resources, including potable water, food and non-renewable energy.

Since a vegetarian diet incurs the use of much less water, land and energy than a carnivorous one, high consumption of meat should become morally questionable. To a lesser extent this applies to milk.

Wherever practicable, we should use our brains and muscles instead of material resources to provide comfort and convenience in our lifestyles, and perhaps learn to prefer self reliance to pampering.

Noxious substances

Industrial, agricultural, pharmaceutical, cleansing and beauty products whose manufacture, packaging, use or disposal releases substances that adversely affect the environment should be identified, shunned by users and phased out by the manufacturers. Benign alternatives should be sought by users.

Global warming

It should be regarded as immoral to continue to provide or use energy from sources that emit large amounts of greenhouse gases.

There should be a reduction in other processes that cause emission of greenhouse gases, such as in agriculture, logging, etc.


All the above affect the habitats of both human populations and other species. The habitats of both should be restored or replaced wherever possible. Any human intrusion into the habitats of other species should take full regard to their specific needs for wellbeing.


What Are the Chances?

Many of these moral values contradict aspirations, established ideas, entrenched religious principles and cultural traditions. So there would be strong dissent and opposition, probably becoming violent wherever the inevitable disruption started. Types of employment, transport, accommodation, eating and other aspects of life would need to change. For some time after the changes were begun the environmental effects would continue to worsen. Although global warming will continue, there will be places where the climate will become cooler as a result, and this will strengthen the resolve of people who do not accept that warming is occurring. Those in privileged positions, ie., the wealthy, would need convincing that their impact on the environment should decrease to equal the rising impact of the less privileged. This applies to nations as well as to individual people.

Also, some influential transnational corporations, “rogue” nations and criminal syndicates could try to violate any rules that were designed to protect the environment. It could be very difficult to monitor and prevent such actions.

A strong sense of community and mutual help would need to be developed within and between societies if there were to be any widespread acceptance of these moral issues.

Actions related to care of the environment will include attending to the desires of some people at the expense of others or of a living generation at the expense future generations. Current examples are the production of noxious waste and the depletion of scarce resources in the course of meeting demands for goods and services. Future generations would probably adjust to, and accept as normal – although perhaps not happily – conditions that we in developed countries would regard as adverse. Many populations around the world do this now, and the ancestors of most of us have done so.

What would need to be done to get the suggested moral principles adopted? Would they then work if they were adopted?

First, a lot of disbelief would need to be overcome. Usually we don’t realise what impact our every-day actions have on the environment. And we seldom, if ever, consider the environment in the hundreds of decisions we make each day. So widespread educating would be necessary. But that by itself would not be enough to change habits.

Emotional, not just intellectual, conviction, and willingness to share the short-term disadvantages, would be needed. Since the measures would involve considerable inconvenience, and would often appear to worsen the situation, many people would never be convinced.

The action would work only if it started soon and if a sufficient proportion of the world’s population, particularly of the richer countries, were actively engaged. This will not happen until enough people become very scared about the effects of what is happening to the environment.

When is soon enough, and what proportion of the world would need to be involved? Who knows?



Addendum: A note on global warming

Some of the people who have criticised the science that supports the claims of human-induced global warming genuinely believe that it is unsound. They have arrived at this conclusion through beliefs based either on what they regard as common sense or on their expertise in a particular branch of science. Their specific claims are that:

  • there is no evidence that the surface of the earth is getting warmer;
  • periods at least as warm as the present time occurred within recorded history before there was much human-induced emissions of greenhouse gases;
  • cases of recent extreme weather are just examples of cyclic climatic processes;
  • the warming effects of greenhouse gases will soon reach a maximum despite increasing concentrations in the atmosphere;
  • processes other than greenhouse gases are the real causes of global warming;
  • the effect of human-induced greenhouse gases is insignificant compared with that from geological sources;
  • feedback mechanisms, such as increased cloud cover, will prevent further increases in greenhouse-induced warming;
  • any rises in sea level that result from warming will be minimal compared with those resulting from the effects of continental drift;
  • scientists involved in global warming studies are falsifying their results.

These claims will now be addressed.

Evidence of Warming

Because temperatures around the surface of the earth vary greatly from place to place and from time to time, making an overall judgment of whether global warming is occurring is not a simple matter. Measurements of the land surface are made at regular intervals by sensors in satellites that circle the earth. The oceans are measured at very many locations and at various depths using thermometers from research ships and strung from buoys. Various levels in the atmosphere are measured using balloon-mounted thermometers. And the temperatures are measured at various depths of the ice in Antarctica and Greenland.

Overall, temperatures are rising. But some areas on land and some levels of the atmosphere have recently become cooler. The areas that are cooler have little effect on the overall warming and can be explained by well-understood wind and ocean systems. The oceans are warmer overall despite being cooled by the ice that is melting in Antarctica, Greenland and the Arctic Ocean.

The recent warming has caused many species that are able to change their habitat to move further from the equator or to higher altitudes. The species include land animals, birds and insects, fish and other sea-dwelling animals, and plants with short life cycles and seeds that are easily transported. Some large trees, such as conifers in California, are starting to die out in their present habitat; their seeds are unable to get to cooler areas quickly enough to regenerate.

Earlier Warm Periods in Recent History

There have indeed been reported cases of very hot and very cold weather from several parts of the earth over the past several centuries. There were no thermometers then, so it is not known precisely what the temperatures were or how widespread they were. But the reports suggest they were sudden, so they may have been local or short-term concurrences of several factors. The present period of warming has been progressive and widespread, Examination of ice cores from Antarctica and Greenland show that present global temperatures are higher than those of earlier periods in recorded history. But over geological time there have been higher temperatures than human beings could survive in.

Cyclic Effects

There appears to have been a recent increase in extreme weather events, droughts, rainfall and winds. Some people attribute these events to global warming. Others say they are just a continuation of the cyclic patterns that have been observed for a long time.

There are many well-known long-standing cycles – such as the North Atlantic cycle, El Niño and the trade winds – that bring rain and sometimes drought. They vary in intensity, depending on how much energy is in the system driving them. Their energy is usually represented by the latent heat in the water vapour in the atmosphere, and this is increased by higher temperatures. So while the events themselves are the well-known cycles, if they are more severe than previously this can be attributed to global warming. Additionally, it appears that some of the events are now appearing at times of the year when they previously did not. One effect of global warming is to change the mechanics of the systems that drive these cyclic patterns.

The Greenhouse Effect is Now Close to Maximum

Claims have been made in scientific papers that the effect of greenhouse gases will not increase much further because it is reaching a saturation point. These appear to have been the conclusions from experiments. However, realistic experiments would have to be conducted with a vast volume of the atmosphere using concentrations higher then the present levels, which would be impracticable. There is a concentration of the various greenhouse gases where all the energy radiated by the earth was redirected back to the surface. But at present concentrations of carbon dioxide, methane, cloud and water vapour, and other gases of smaller consequence are a long way short of the limiting point. Actually, for the gases, the process is not a reflection like that which occurs from surfaces, but the absorption of radiated energy by individual gas molecules, and then the re-radiation of the absorbed energy. This re-radiated energy can go in any direction, not just back to the earth.

Other Processes Also Cause Global Warming

Many different processes cause warming and cooling of the earth’s surface. The amount of energy emitted by the sun varies from time to time. The orbit of the earth around the sun is elliptical, so the earth moves closer to the sun at some times of the year and then further away at other times.

The earth’s axis of rotation is tilted, that is, at right angles to the plane of its orbit. So the polar regions have periods where they are pointing away from the sun and have no sunlight for six months of the year. This allows permanent ice to form and build up in the polar regions. And ice reflects sunlight better than other surfaces, so polar regions do not absorb as much radiation in the summer as they would with no ice. The more tilted the axis, the greater area that has six months of darkness. The tilt of the earth’s axis is not fixed, so this is another influence on global warming and cooling.

Other factors affect the amount of the sun’s radiation that is reflected by the earth. The oceans reflect less radiation than the land areas, that is they absorb more. Different kinds of vegetation have different degrees of reflection. Deserts reflect more than vegetation but less than ice. Most of the radiation emitted by the sun is unaffected by greenhouse gases. This applies also to solar radiation reflected by the surface of the earth. It is the infra-red radiation emitted by the earth that is affected by greenhouses to cause global warming.

Some of the absorbed solar energy is taken up in melting ice and evaporating water. This means that an increase in absorbed sunlight is not all taken up by increasing temperatures, so the ice and the seas form a buffer against rapid changes in overall temperature. If it were not for this, the temperatures around the world would now be higher than they actually are.

Large volcanic eruptions throw vast amounts of fine particles into the air, and these can cloud most of the sky, blocking most of the sun’s radiation from reaching the earth’s surface. Such events have resulted in global cooling, sometimes lasting longer than a year. Fine particles emitted by fires and internal combustion engines, and raised in dust storms also have a cooling effect.

Ice cores have been taken from Greenland and Antarctica to examine the evidence relating to temperature and atmospheric gases during periods before the recent ice ages. These show that high levels of atmospheric carbon dioxide followed global warming by about 700 years. A claim has been made that this demonstrates that greenhouse gases do not cause global warming. In fact, warming that has been caused by processes other than the greenhouse effect will cause an increase in carbon dioxide and other greenhouse gas concentration. But then these increased emissions accelerate the warming until conditions beyond the earth eventually take over to cause cooling.

All the possible causes of global warming and cooling are continually being measured, and the evidence shows that greenhouse gases emitted by human activity are the only feasible explanation for the warming occurring now. Without the current greenhouse warming the earth would have already started its cyclic cooling.

Human-Induced Warming is Comparatively Insignificant

It is sometimes claimed that volcanic eruptions and other geological emissions put much more greenhouse gas into the air than people do. But recent analyses of volcanoes have shown that they produce only a small fraction of the present total global emissions. There are other emissions of greenhouse gases from various biological processes, such as decay and digestion, and from chemical reactions in rocks and soil. For the past few millenniums these have been balanced by other biological processes to provide a rough balance of concentration in the atmosphere and a roughly constant average global temperature. But recently the emissions from human activity have been enough to cause continuously increasing average temperatures.

Moreover, there are large amounts of methane trapped in soil and underground rocks and dissolved in permafrost and undersea ice. Most of the present methane emission from underground seems to be the result of human activity. Global warming is now starting to cause emissions from permafrost. There are fears that warming of undersea ice will soon start to release methane. These effects will accelerate global warming.

All the possible causes of global warming and cooling are continually being measured, and the evidence shows that greenhouse gases emitted by human activity are the only feasible explanation for the warming occurring now. Without the current greenhouse warming the earth would have already started its cyclic cooling.

Feedback Processes Will Stop Global Warming

It has been suggested that just as feedback systems have regulated atmospheric levels of carbon dioxide, other regulatory processes will start to come into effect, prompted by global warming. One mechanism would be that as temperatures rises there will be greater evaporation of water. This will have some cooling effect because of evaporation uses up energy, but it also will increase cloud formation, which will reduce the amount of sunlight reaching the ground and sea. However, as evaporation increases, clouds are more likely to stack vertically than spread horizontally, which means the extra cloud does not reflect a proportionate amount of sunlight.

Also, not all evaporated water forms clouds. Some remains as water vapour, which is an effective greenhouse gas. Also, when water vapour turns into cloud, that is, droplets of water, the cooling effect of evaporation is reversed.

Climate scientists generally think that the feedback processes involving increased evaporation of water will be far too small to have a significant effect on global warming. However, the details of the systems are not known precisely enough for a definitive conclusion to be reached, because the climate system is so complex.

The Chief Cause of Changes to Sea Level is Continental Drift, Not Global Warming

Continental drift, or more precisely, the movement of the tectonic plates of the earth’s crust, has caused the appearance and disappearance of islands, the sinking of cities that were once seaports, and the conversion of other seaports to inland cities. Whether all this action has any major effect on overall sea level is a moot point. In fact, with continents moving and undersea plates subducting under continental plates, the concept of an absolute measure of sea level may be problematical.

However, after the recent ice age about ten thousand years ago, as the ice melted there was more water to go into the sea, so the area covered by the sea increased and many land areas became sea floors. Something similar but on a smaller scale would occur if the ice of Antarctica, Greenland and the Arctic Ocean all melted. Since so many of the major population areas around the world are near the coast and often on low-lying ground, any significant addition to the water in the oceans will be of major concern.

This is already of concern also to several small island nations in the Pacific Ocean. Many of these islands are built on coral reefs that have grown on the tops of under-sea mountains and ridges. The average elevation of some inhabited islands is only a few metres above sea level. Even if the sea level rises by only a few millimetres, these islands will be increasingly affected by the higher waves that are already occurring as a result of the stronger winds caused by the warmer sea and the warmer air above it. In some cases, if the sea level rises slowly the coral will grow higher at the same rate, but this will not compensate for the stronger winds.

Climate Scientists are Falsifying their Results

The International Commission on Climate Change has published periodical detailed reports on the findings of climate science, and has included forecasts of how warming will affect specific regions around the world. From time to time the forecasts have changed as measurements have become more precise and more numerous, and as new computer models of the global climate have produced different results. Naturally, many people ask how any forecast can be believed if they are being continually changed.

It may seem foolish to publish any forecasts when the models are known to be imperfect. But governments and industry need forecasts in order to plan for future conditions. And it is always believed, perhaps unduly optimistically, that the latest models will be much better than the ones they replaced.

One of the many difficulties with forecasting such a complex “chaotic” system as the global climate is that sometimes small changes in conditions can have disproportionately large effects. Another difficulty is that at each new change of climatic conditions the model has to have all its input details reset and the assumptions that it is based on renewed. Also, it is likely that climatic conditions will keep changing as warming continues. Distrust in the integrity of climate science and the scientists has been aroused also by actions of some of the researchers. Some scientists have on occasion been unwilling to release measurement data or the methodology of interpreting the data. Whether such actions were proper or not, the behaviour of a few scientists does not refute the science. There is keen scrutiny throughout the scientific world, and dubious measurements or interpretations are always contested (as are all new discoveries, new measurements and their interpretations in every field of science).


At any stage of scientific progress, it is necessary to work with the latest findings and build the planning and technology on those aspects that seem more certain. What does seem certain is that the surface of the earth is warming, human activity has been and continues to be a major contributor to this warming, and there will be many changes to climate, some very unpleasant, around the world as a consequence.



a I think any boundary between sentient and non-sentient animals must be arbitrary, and regard sentience as a matter of degree.

b In an earlier essay (Australian Ratinalist No. 74) I discussed five separate justifications for taking moral positions: nature, personal convictions, revelation, logic applied to high principles, and evolving consensus. Some of these could support care of the environment.

c With the extinction of a few key species – and we may not know the identity of all of them – humanity could be put in the position of desert dwellers without being able to employ most of the technology developed during the past few hundred years.

d These include ethanol and “bio-diesel” – derivatives of plants – whose production often diverts the use of already-scarce arable land.

e  The greenhouse effect is only one of the causes of global warming. Others are increases in the emission of radiation from the sun, periods when the earth is closer to the sun, and reduction of the reflectivity of the surface of the earth. Increased emission of greenhouse gases, including water vapour by increased evaporation, is one of the consequences of warming.

One effect of melting ice in the Arctic Ocean, Antarctica and Greenland is to cool the sea, in the process “absorbing” a large amount of heat as latent heat (equivalent to the heat that would raise the temperature of that amount of water by 800C). This has slowed warming and is partly why the global temperature has risen unevenly. The additional evaporation from the warmer seas has a similar effect, which is partly offset by additional rain and snow from the increasingly humid air.

Since the present concentration of greenhouse gases in the atmosphere is enough to melt the ice, the melting could be expected to continue even if we reduce further emissions. The decreased reflection from the decreased ice surface will increase the warming. (This extra precipitation causes an increase of the thickness of continental ice in Antarctica, but also a warming of the ice.)