Archive for October, 2010

Geo-engineering – To use or not to use

October 24, 2010

One of the most topical debates going on at present is on the subject of Geo-engineering.  Should or should it not be used to prevent global warming and if so which methods are most appropriate.

It is certainly true that we humans have historically justified our pollution of the earth on the grounds that “Oh it is only a little drop of ‘Chemical X’ that we are adding to the huge volume of the earth’s oceans/water bodies/atmosphere/soil etc.”  The idea being that the recipient medium is so huge that it really will not make any difference.  Now alas, we know for certain that this is not the case.  Whereas, what goes into the soil is usually broken down sooner or later by the soil’s bacterial cocktail, if it reaches a water body or the atmosphere, the story is very different.  For example:  PCBs (polychlorinated biphenols) turn up in unexpected places, having being concentrated by the oceans’ currents.  They then lodge in fish oils and the fats of marine mammals and the associated human communities.  Once in animal bodies, we do not even now know the full extent of their effects; but we do know that they seem to have a bad effect on the reproductive system.   The chemicals released to our atmosphere, are similarly dissipated and not only travel around the globe in the Trophosphere, but some also seem to affect the gaseous mix in the Stratosphere.

However, I am against Geo-engineering for the following reasons:

Firstly, because the suggested strategies are relatively easy to put in place, but virtually impossible to remove, should the situation swing too far in the other direction.  The need to be able to fully control anything that we do, is not so daft as it may seem.  Already the planet has proved to be unstable in its circa 4.6bn year history.  Geological records and the volcanologists tell us that we are due for a reversal of the magnetic poles; though it was thought that this was a process that would take thousands of years, the latest information suggests that it in the past it has occurred over a mere 4 years!  We know for certain that in the history of life on earth, parts of the planet have been a lot warmer, a lot wetter and a lot colder than they are now.  NB there are huge aquifers under parts of the Sahara and records of predators that could not have survived without large herds of herbivores that in turn could not have survived without grasses and shrubs.  So whatever we do our strategies must be adaptable; and I suggest that we should begin by moving to renewable energy supplies, stop use of fossil fuels unless we are prepared to reconvert the carbon dioxide and water to hydrocarbons, and do what we can to clean up the toxic chemicals that we have released into our oceans and prevent further releases.  The following are my comments on some of the Geo-engineering strategies that have been suggested.

Carbon capture and storage, actually means storage of carbon dioxide (CO2) produced by the process of combustion in our atmosphere.  Thus for every 44gms of CO2 stored we would be removing 32gms of oxygen (O2) from our atmosphere.  Mammals have fairly advanced and efficient lungs but cannot abstract anything like 100% of the O2 inhaled. Invertebrates and Fish etc. are far less efficient and the 20% O2 in our atmosphere is likely to be necessary to provide high enough levels of dissolved Oxygen in the water to support its life forms, especially the Zooplankton.  Storing the carbon on its own would be OK, but better still: why not convert the CO2 back to hydrocarbons or electricity.  A number of research projects are already showing a lot of promise – from solar furnaces to electrochemical cells.

Seeding the ocean with Iron/fertilizers is equally daft.  We already know a lot about the effects of algal blooms due to ‘accidental’ release of fertilizers into the seas and freshwaters of the planet. The increased surface algae die and sink, meanwhile the decomposers get to work and in living remove large amounts of Oxygen from the water; with the result that it becomes too deoxygenated for the survival of the waters fish and their larval stages.

Global warming will, under the normal laws of physics, give rise to higher evaporation rates from the water’s surface.  So there should be no need for the expensive practice of spraying seawater up into the clouds!

The placing of trillions of tiny solar reflectors in space to prevent a percentage of the sunlight from reaching Earth, seems equally fraught.  How are these to be controlled, removed, repositioned etc. We have a complex series of temperature inversions that are not well understood in the atmosphere.  Moving up through the Trophosphere the air cools to well below freezing point at approx 16km up at the equator and 7km at the poles; it then warms up in the Stratosphere until it reaches 0oC at approx the boundary with the Mesosphere at an approximate height of 50km.  However, by the middle of the Mesosphere it has cooled to -90oC, finally warming up to a deep blanket of between 570o – 1570o (night & day and summer & winter temperatures)as it moves up through the Ionosphere, over the next 800 or so kilometres.  I strongly feel that we should not tinker with things that we do not fully understand; just because it seems to be OK if we consider one set of criteria, does not mean that it will be OK if we considered the full as yet unknown set.

Finally, there is the suggestion to release sulphate particles into the stratosphere (approx. 16 – 45km high).  Again, how is it proposed that we control the actual position of these, either around the globe or in terms of their placing in the stratosphere?  What is the chemical effect of placing sulphate particles in our upper atmosphere?  It has been suggested that doing this would be no more damaging than the effect of a large volcanic eruption on the surface of the planet, despite the fact that In general the effects of volcanic eruptions are not welcomed on the surface.  Plus if we are intent on blocking the sunlight, then we also reduce the possibility of power from photovoltaic panels.  This could push the planet towards nuclear power i.e. the use of a very finite resource and one with a very high invisible medical and genetic risk at every stage of its use from mining through to waste storage.  There are simply too many questions that remain unanswered, yet they need to be fully considered by experts in all the branches of scientific knowledge and research, before there is any move to carry out the procedure, or even to trial it.

Please let a wide understanding, of all the mechanisms and needs involved, over-rule uncontrollable geo-engineering and further waste of resources with unknown consequences.  Please let tigergreen.co.uk know how you feel about this topic.  A knee-jerk reaction now could, by chance, have an excellent result, but is more likely to cause a catastrophic reaction either for us or future generations.

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Wilderness to Farmlands to Towns – can we afford this change to be inevitable?

October 14, 2010

Wilderness to Farmlands to Towns – can we afford this change to be inevitable?

This topic is often on my mind and it was recently magnified when I read “Among the Elephants” by Iain and Oria Douglas-Hamilton.   Iain’s study sets out to establish how best the African elephant can be managed in the limited areas of the National Parks.  In the final chapter, he comes to the crux of the problem.

Very simply the rapidly increasing human population has resulted in the spread of rural and urban development into areas that were once solely the territory of wildlife and nomadic tribes.  This is actually a worldwide problem; however, this book highlights the problem in Africa.

For millennia elephants have roamed all over Africa from the Mediterranean to the Cape and from East to West. Between 11,000 and 5,000 BC, humans were observing them and they were featured in rock etchings, some of which have been found in Algeria.  Wherever the right mix of grass and trees existed, there too were the elephants.  As they passed, they ate the bark, young branches, fruits and seeds together with grass which they cut with their toe nails i.e. they do not normally pull it up in chunks and if this happens accidentally, they avoid eating the soil and roots. Many of the tree species in particular have seeds that will only germinate if passed through an herbivore’s gut; and since the elephant then deposits the seeds with a liberal amount of dung, the young trees germinate into an ideal growth medium, rather than into the frequently nutrient poor surrounding soil.  When the elephants have opened up an area of woodland so that there is no-longer an ideal mix, and grassland starts to take over, they move on – providing there is the space to do so.  The spreading grassland areas become savannah and can then support vast herds of grazers e.g. the Wildebeest and associated species.  Eventually, droughts and wildfires thin the grass, returning the essential trace elements to the soil, and the grazers turn to a fresh swathe of savannah.  Meanwhile the seeds that have remained dormant in the soil get a chance to germinate, usually in the vicinity of the few remaining trees, and gradually woodland builds up again.  Finally the cycle restarts with the return of the elephants.  In other words, the elephants act just like early humans with their practice of ‘slash and burn’, crop and move on, agriculture.

The problem for elephants now is not that they are hunted by humans per se; it is simply the level of hunting and the restriction of their ancient ranges by human infrastructure.  The African elephant has been hunted, for both ivory, meat and even domestication, for many centuries.  As far back as the 3rd century BC, Ptolemy set up a school for African elephants beside the Red Sea, for the specific purpose of using them with his armies!  However, in those days the population of Africa was very low and scattered, there were none of the huge urban developments and areas of cultivation that exist and are still extending to-day.  This meant that the elephant herds had the run of a whole continent to manage in their own way.

However, from the Douglas-Hamiltons’ book, it is quite clear that even in the Africa of 1975, cultivated crops were being planted right up to the boundaries of the National Parks wherever there was sufficient water for crop growth.  This conflict of land use had been started in past decades by the white settlers, but now that many were leaving, the conflict was being continued to an even greater extent by the ever growing local tribes.  It is an inconvenient fact that if land grows good woodlands, then there is enough water initially for humans to grow good crops.  Where crops can be grown, then towns arise to process them, transport them and provide the necessary infrastructure for a growing non-nomadic culture.  At this point the phrase “enough water initially” becomes crucial.  Inevitably, artesian wells have to be sunk and if water is found then the community continues to grow, if not it eventually moves on.  Unfortunately, the aquifers thus tapped are finite reserves, and their very use may hasten the draw down time for surface waters, thus threatening any remaining surface flows and the wildlife and ecosystems that depend on it.  Where the townships thrive, both the wild animals and indeed the native nomadic tribal peoples become regarded as nuisances; and their lives, harmonious with nature, are restricted to ever smaller areas in the interests of Growth – or should that be Greed.

So, if the change posed in the title is inevitable, then modern humans are faced with yet another dilemma; presuming that they are all agreed that they wish ALL the species on the planet to be able to survive.  Creating a habitat for one species, does not serve the vast mosaic of species that normally co-exist symbiotically.  The best solution is to let wild animals and their vegetation have sufficiently large areas to cycle naturally, in all parts of the globe.  However, this poses the question of how many humans the planet can actually support.  If we and all the other species are to live in harmony, with enough space to be able to enjoy our lives, then we do as individuals need to control our populations.

Traditionally, having long got the better of our carnivorous predators, our population has been controlled by disease and frequent and bloody wars.  However, this latter is a very unpleasant way of behaving and it is to be hoped that diplomacy will always prevail.  But even now, while this happy state of affairs is being established, all national, ethnic and religious groups need to consider how to prevent over population by humans, whilst preserving our varied gene pool and our diversity of thought and culture.  The more numerous we become, the more we encroach on wilderness areas, the scarcer our resources become and the more each diminishing resource costs to use.  In the 1960s water in the UK was still free.  Now we have to pay an ever increasing amount for this commodity so essential to life.  As our population rises so does the cost of living – for how long can we support these increasing costs that actually do nothing to save the species on this planet.