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Environmental Page

This page is a forum for discusion.
If you find an error or plain disagree,
I will happily add your interpretation of these issues dancas@gic.net.au
Background to DanCas

Global issues

Local Western Australian issues

Global issues

Ozone layer depletion - the break down of earth's natural sunscreen

Our atmosphere is all that's between us, and the onslaught of radiation crossing space from the sun. The Ozone layer is a major part of our atmospheric protection, forming a thick band in the stratosphere encircling the earth. Within our Ozone layer a constant reaction takes place that absorbs many potentially harmful ultraviolet rays, whilst producing heat to warm our atmosphere.

O2 ---UV---> O + O (1)
O + O2 ------> O3 (2)

This reaction makes Ozone (O3), which is then rapidly broken down by UV radiation to start the cycle again

O3 ---UV---> O + O2 (3)

Around 1930, scientists developed a group of chemicals known as CFCs. These where long lived stable man made chemicals which had many commercial and industrial applications. CFCs have been widely used in refrigeration systems, as propellants in spray cans, circuit board cleaners, and in polystyrene cups just to name a few uses.

Unfortunately these man made wonder chemicals have a large flaw, there is no known natural process for their break down in nature. So once released in the environment they tend to last for 65 - 110 years, and are free to reek havoc which unfortunately they do.

In 1974 chemists Sherwood Rowland and Mario Molina, discovered that CFCs where lowering average ozone concentrations in the stratosphere. With further research scientists began to discover thin patches forming in the polar regions of the ozone layer. These thin patches where monitored and found to grow, forming large holes where UV radiation could freely enter our atmosphere.

Cl + O3 ------> ClO + O2

ozone removed then second reaction allows the process to from (1) to (2) to commence without stage (3) to occur.

ClO + O ------> Cl + O2

Thus the ozone layer becomes depleted and higher UV radiation occurs at the plants surface.

The effects of increased UV (specifically B) include:
*increased number of skin cancers
*increased incidents of eye cataracts
*suppressed human immune system
*decreased food crop yields
*disruption to aquatic systems i.e. reduced phytoplankton growth.

So what can be done?

Basically we need to stop using and emitting these harmful substances into the atmosphere. The sooner the better.
Many Conventions have been signed by countries though out the world all designed to reduce CFC emissions and use, often by the target of the year 2000.

Such conventions include:
The Vienna Convention (1985)
Montreal Protocol of 1987
1992 Copenhagen conference.

Current objectives seem to be to:

Phase out use of CFCs and Halons and CC14 by 2000
Phase out use of Methyl Chloroform by 2005

In Australia, Acts have been commissioned such as:
The Commonwealth Ozone Depletion Act 1989
to implement requirements of Montreal Protocol by controlling supply and use of ozone depleting substances though licensing and quotas on manufacture, import and export.


This article is based on extracts from Miller, T.G. (1994). Living in the Environment. Wadsworth, Inc., California. and Lectures by Dr M.Lund of Edith Cowan University, Western Australia. As part of (SCI 1158) Pollution Sources & Effects.
However there may be errors and erroneous statements within this article which are my own doing.


Response by Jim Baldwin

This is pure baloney. Ozone depletion is cyclic. When Mt. Pinatubo in the Philipines erupted it spued out in one day more that 500 times the amount that man has produced since the production of man-made CFCs (yes, CFCs DO occur in nature). CFC ozone depletion has NEVER been able to be reproduced in a laboratory environment and is only THEORY. Even NASA has stated that they have found no evidence of ozone depletion in their experiments. (No it's not because they want to keep punching holes in the ozone with their launches) Yet, as with Darwin's THEORY of evolution, evolution, has been taught as fact. And we KNOW that all good scientists don't teach theory as fact. It is all part of a catalyst for the new world order and to get the U.S. to cough up more money from it's wealthy coffers to a SOCIALIZED world. There is my "interpretation" your "interpretation" and TRUTH. This is truth.
Jim Baldwin
USA

Well I agree that the natural environment far exceeds our input of nasties to the atmosphere (from time to time in acute quantities), and that this has always occured. However in our very short time on the planet we have chronically added to such phenomena with our own chemical products. Yes you are quite right, science is never certain, rather, it is based on the probability of an event occuring as related to acceptable sampling error. Overall a theory never goes very far without scientific consensous, which has certainly mounted, enough in-fact for governments (such as the Australian Federal government) to sign International treaties such as the Montreal Protocol of 1987, resulting in the reduced useage of CFCs and associated chemicals in countries such as the USA and Australia.
To further answer this question, here is an excerpt from the U.S. EPA web site Questions and Answers on Ozone Depletion

"How do we know that natural sources are not responsible for ozone depletion?
While it is true that volcanoes and oceans release large amounts of chlorine, the chlorine from these sources is easily dissolved in water and washes out of the atmosphere in rain. In contrast, CFCs are not broken down in the lower atmosphere and do not dissolve in water. The chlorine in these human-made molecules does reach the stratosphere. Measurements show that the increase in stratospheric chlorine since 1985 matches the amount of CFCs and other ozone-depleting substances released by human activities."


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Enhanced Global Warming

The Greenhouse effect was first proposed by scientists more than 100 years ago. Since this time it has been confirmed by numerous laboratory experiments and the theory has become widely accepted by the science community (Miller, 1994).

Concern today (as I understand it) is based not around the validity of the Greenhouse effect, but the possible occurrence of an Enhanced global warming / Greenhouse effect.

The Greenhouse effect is a natural phenomena where heat (Infra red radiation) becomes trapped within our atmosphere under a blanket of Greenhouse gasses (i.e. Carbon dioxide). This effect is part our planets natural protection from the coldness of space, keeping the temperature of our planet relatively stable (fluctuating 0.5-1oC every 100-200 years) over thousands of years (Miller, 1994).

The Greenhouse effect as it is understood, is believed to be controlled by the levels of certain chemicals within our atmosphere. Scientists are concerned as since the advent of the Industrial revolution levels of carbon dioxide, Nitrous oxide, Methane and more recent additions such as Chlorofluorocarbons (CFCs), have risen altering the natural balance of these chemicals (with the exception of CFCs which are human made) which are found within the atmosphere. Scientists are concerned that the increased levels of these chemicals will cause accelerated warming of our planets atmosphere.
Carbon dioxide (CO2) is thought to be off most concern, estimated by some to contribute around 55% to the global warming greenhouse produced by human activities.
Whilst CO2 is a normal constituent of our atmosphere, the major majority of our planets CO2 normally resides in storage "sinks" such as Coal reserves, Timber*, and Water. Unfortunately humankind has been extracting Coal/Timber faster than these fragile resources are recreated, or than other storage sinks (such as the ocean) can store the excess CO2 released.

So why are scientists as yet still devided, concerning the outcome of Enhanced Global Warming?

The answer seems to be that due to the many associated (and unknown) factors involved, no consensus has as yet been reached by the overall scientific community.
It is however certain that these chemicals are accumulating in our environment exceeding past "normal" levels. Therefore it would seem that something will happen.

Many Scientists predict that ocean levels will rise as the temperature increases, some say 2-4cm per year. Predictions also include the advent of Storms, Heat waves, and Droughts, all of which may be uncharacteristic to many region in which they may occur. Most notable the mid region of the Northern Hemisphere is noted as an area which may suffer from some kind of climate change.
Some scientists however disagree, questioning if the increased water vapor within the atmosphere might lead to higher levels of snow in the polar region creating a cooling effect.
The effects of warming on cloud cover is also unknown. For increased levels of water vapor may reduce levels of heat radiating into our lower atmosphere. Also it is hypothesized by some, that increased CO2 may encourage growth of phytoplankton (algae) in our oceans which may consume CO2 through photosynthesis.

Solutions

Well, the most effective solution would probably be to stop emitting these gasses into the atmosphere immediately. However this is not possible by any stretch of the imagination.
We can however look at more sustainable ways of managing and using our resources. Unfortunately Government through out the world is unwilling to legislate to that effect, as the scientific community is so divided (to much to risk political suicide over).
Many countries however have become signatories to conventions such as Agenda 21, which seek to improve the sustainable use of our resources.

In my opinion, the "Precautionary principle" is the best way to go.
That is to avoid emitting substances into our atmosphere which cause us to exceed natural atmospheric levels (as best we can predict them). For though we do not know for sure the outcome of excessively polluting with these chemicals, it stands to reason (at least to me) that there will be an out come of some description. Why subject our children to that uncertainty, because of our Greed?

*Note by referring to the burning of fossil fuels in particular timber, I should like to clarify that in theory it is okay to burn wood as long as it is sustainable replaced at the same rate by new wood, which is allowed to mature to the same age. This way CO2 at least, is re absorbed from the atmosphere.

Further reading: Greenhouse Effect Links

This article has drawn certain ideas, facts and figures from the following:
Lund, M. (1994). SCI1158 - Pollution Sources & Effects. Edith Cowan University, Perth Western Australia.
Miller, T. G. (1994). Living in the Environment. Wadsworth, Inc., USA.
(I would like to make note, that the article is written according to my understanding of the subject matter, and as such may not be correct or up to date. Views expressed are strictly my own.)


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Local Western Australian issues

Reuse of Grey Water

Roughly around 3% of our water on Earth is available as freshwater for drinking (agriculture etc.). This water is not however situated evenly within the worlds population, and only approximately 0.003% is readily available above ground (Miller, 1994. -similar statistics quoted in most text books).

Therefore the conservation of water is of utmost concern to many communities, such as Perth Western Australia. A large amount of water used by house holds each day does not need to be prime drinking water. For instance much of house hold water is used in :
flushing toilets,
washing clothes,
bathing,
and watering of lawns and gardens.

Current tapped water in many western countries, is treated to a No Risk standard, that is , the water is cleaned (expensively ) with chlorine and other agents so that the water is sterilized. This is undertaken at great expense and the end product is known as potable water (drinking water).

However, do we need to use expensively treated precious high quality water for all our house hold uses?

It has been suggested many times that a dual reticulation system should be introduced in to new suburbs. Where lower quality water (ie clean indirectly used industry waste water, or limited treatment ground water) could be fed through a separate tap to suitable parts of the house. For instance depending on the quality of the water, this grey water could be used for laundry, watering lawns, or at least flushing of the toilet.

Alternately to relive water problems it has been suggested that persons collect there own rain water if not for drinking*, for bathing or possibly irrigation if enough is collected. (*Note, urban rain water may contain unacceptably high concentrations of lead, especially if the first fall of rain after the dry season is collected instead of used to flush the roof clean).

Another grey water suggestion, is the idea of reusing laundry water to flush toilets, or reticulate lawn areas (providing water does not contain bleach etc.) If laundry water was used for reticulate lawns, several problems would be addressed to some extent.
For instance less high quality water would be wasted where low quality water would suffice.
Less water would require treatment by the sewage works, and
additionally, phosphorus from laundry detergents would be absorbed as fertilizer by the lawn (as long as not applied in excess, ie not gallons every day). This would directly help reduce the level of nutrients released by sewage farms into our coastal waters.

However it should be noted that it is officially illegal to reuses grey water for watering lawns in many countries or states such as Western Australia (with the exception of Rottnest island), though this may change in the future. This rises from concerns over the hygiene of water sprayed in public areas and ground water pollution.
It is my opinion that normal laundry water is fine spread over a lawnd area, as it is no more harmful than fertilizer (as long as you give the bleach a miss), but certainly don’t spread any grey water of dubious origin (ie containing chemicals), and of course this is on the assumption that you are not running a Laundry business!!

There are many other ways to save water, and they don’t have to take time away from you or make tasks any harder. Just washing your car on the lawn instead of on the road is a good example. You kill to birds with one stone!

Remember, with initiative there is always ways to wisely use water. The key is to be AWARE of our water usage, so that we can MINIMIZE it. Why use high quality water for tasks that just don’t warrant it?

Check out the DanCas Low Tech & Sustainable ideas page for hints on water usage (more to come).
For further reading, visit the new Albany Wastewater Treatment Plant

Reference made to: Miller, T. (1994). Living in the Environment. Wadsworth, USA


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Response by Eric Bateman

 Dan I enjoyed reading your inventive articles on aquaponics etc. It has concerned me greatly about the way Western Australia's growing population puts a heavy demand on water resources and it is terrific to see a local lad offering options on the internet.

I remember during the late 50's and into the 60's how water was an issue and similar concerns were expressed about how the (in those days approx 400,000 odd) people would survive on those existing resources without a change of attitude to usage. (I'm 46 by the way.)

I was thinking the other day how in the late fifties and into the sixties, Mum would conserve grey water. The way she did that was to run the garden hose into the wash sink and or bath and then drain the 'grey water' into the garden plants. Mostly on the Lemon tree that I remember. Mum would get us kids to connect the hose and hand one end through the laundry or bathroom window, turn the tap on wait a few seconds and then undo our end. Its a pity in our advanced technological society that someone could not invent a simple device that could pump the water from a washing machine or the like into a filtered watering system. I am sure an inventive person could produce such a device.

Obviously some big things have taken place. Unfortunately I haven't lived here for over 25 (of 27) years due to a job I took up in Jan 1970 (back Dec 96) so news in the eastern states about development in the WA water conservation area was not of any priority. We came back for two years in 80/81 and I remember grey water was an issue then. I've only just returned and from your article see that the issue is still under discussion without any real community solutions.

In your studies perhaps it may provide a thinker like yourself to gear a more urgent approach to debate the issue of WA water and its uses on a much wider scale than the yearly government reference to the problem without any real community solution or initiative except restrictions. Certainly ground water has eased some of the burden but how long will that last?

Certainly the recent hot weather spell will make a huge demand on the water supplies not to mention the evaporation percentages. One channel in Sydney during last year informed the viewing public of daily consumption quantities and the dam levels. It had a good community response judging by the figures supplied. I could waffle on for quite a while, so thanks for your page and I will visit again.
Eric.


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Salinity

Salinity has been recognized as a major agricultural problem for many years in Australia. As far back as 1917 a correlation was noticed between land clearing and the rising salinity of ground water, where eairly steam trains on some lines, suffered excessive boiler corrosion. This was linked to the salting of dams which corellated with vegetation removall gradually up the line (Happs 1995).

The build up of salt with in soil has caused much damage to Agriculture. Valuable agricultural areas have been lost, and potential irrigation waters have become saline to the extent where they are no longer useable for agricultural purposes. For instance in 1989 The Australian Bureau of Statistics conducted a survey of farmers in western Australia, and found that 2.83 percent of the 15.7 million ha of the south west’s cleared land was saline (Evans 1995). Clearing for agriculture began earlier in the eastern states of Australia, hence salinity problems tend to be more advanced. For instance in Wakool NSW, 50 tonnes/ha per year of salt would have to be removed before cropping could be practiced again (Happs 1995).

Whilst solutions have been attempted under many different circumstances (ie revegetation with saltbush), they appear largely ineffective in the short term, unless supplemented with Gypsum which with regular application can become expensive in the long term (Happs 1995).

Salinity can be caused by a number of factors, therefore I shall only cover the general basic process here.

salt1.jpg 67.8 K


salt2.jpg 64.3 K


The above diagrams depict the rise in water table after the removal of a substantial proportion of natural vegetation. In general the water table will begain to rise as the long rooted trees (ie Jarrah) are no longer present to pump water up from the ground water table, before transpiring it from their leaves. As the water rises salts held within the soil profile become mobilized with the water until they are percipictated near the surface of the soil due to increased evaporation (no trees to shade soil, or lower water table). The result is usually an increased concentration of salt near or at the soils surface. This area of concentrated salt tends to effectively kill remaining vegetation, and prevent agriculture.
It is important to recognize that salt may arrive on location in different ways which of course effect the severity and form that the salting may take. For instance coastal areas tend to receive salt in the wind from sea spray, where as areas further from the ocean may contain more salt suspended within the soil profile from past sea action or other sources of salts. There is no hard and fast solution for preventing or reversing salinity. In pasture land where salt is forming on or close to the soil surface (where the water table is close to the top soil), measures to prevent water pooling near the surface are sometimes found to be usefull. For instance a Friend of mine owns a farm in the Serpentine catchment area in Western Australia. He has successfully delaid the effects of salting by cutting drains across his affected paddocks. This however has only taken the salt away from the surface by giving saline ground water a place to collect, whilst seasonal rainfall flushes the now effectively raised land of salt. This is not a solution to prevent the salting on his farm, but this solution delays some of the more prominent effects of the salinization. Deeper rooted vegetation however, still appears to be dying off due to the still high concentrations of salt in the upper soil profile.

I am no expert on these matters, rather I am trying to provide a simple description of some of the causes and effects of salinity. There are many farmers and other individuals who could give differing accounts of the same sorts of situation.

Solutions at this time range from the introduction of long rooted salt resistant crops and vegetation with the aim of lowering the water table, to heaverly vegetating reacharg areas for the ground water to prevent less water percolating in. More information on this subject can be found in the Dryland Salinity Series

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