China’s economy is currently under threat, following reports that detail the exact costs of environmental pollution.
China’s economy is currently under threat, following reports that detail the exact costs of environmental pollution.
In Peoplequake, Fred Pearce, the English author and journalist, explores the massive demographic transition that this planet is undergoing, as the human population grows exponentially beyond the realms of anything seen before. Continue reading
Tectonic hazards frequently occur the world over but this does not always result in a risk. There are three aspects that eventually cause the disaster and these are: the tectonic event itself, exposure to that event and whether you are vulnerable to its effects or not. Only when all three of these criteria are satisfied does a tectonic disaster occur. The first of the three cannot be mitigated against by humans as we cannot stop a volcanic eruption or an earthquake occurring. The second factor, exposure is becoming an increasingly more worrying issue as global population continues it’s current, rapid rise. As populations increase, settlements start to expand into regions of regular tectonic activity. This close proximity to the tectonic event increases exposure and hence, the risk of a tectonic disaster occurring. Mexico City is a prime example of where rapid population growth has occurred despite the overlying threat of disaster. The city, with a population of over 21 million, has experienced rapid expansion during the second half of the 20th Century despite being built on top of unconsolidated alluvial sediments. These help magnify the effect of seismic waves in the extremely seismically active region which only serves to worsen the impact of potential earthquakes. Over 5,000 people were killed in September 1985 when a category 8 magnitude earthquake hit the region but this did not seem to deter potential immigrants. The third factor that contributes to earthquake risk is the vulnerability to an earthquake and this is the area that can be most easily mitigated against although, an authority’s ability to do so is massively dependent on their economic position.
Mitigation against a tectonic disaster has three components: plan, prepare and respond. In order for a government to be able to do these, they must have first have the correct perception of the event, they must be able to perceive the danger and understand the need for mitigation. They must also have sufficient wealth available to them in order for them to successfully mitigate which is why there are such large disparities between mitigation levels in developed and developing countries.
The surge of tobacco products into developing countries began after World War II when the USA developed its “Food for Peace” scheme where tobacco was one of the export items. In the first 25 years of the initiative, the United States exported in excess of $1 billion worth of tobacco. This was the cause of the developing world’s initial exposure to Western-style cigarettes. The evolution of tobacco markets in these regions by TNCs, was continued from the 1960s onwards through the use of a wide variety of targeted and effective marketing schemes to help widen their customer base and potentially induce smoking habits. Smoking prevalence was increased further through the actions of national tobacco companies. In an attempt to counter the increased volume of tobacco being sold by TNCs in their countries, the national tobacco corporations also developed marketing schemes in an attempt to regain lost sales. As TNCs and national corporations went head to head, the overall expenditure on tobacco marketing increased with a corresponding rise in tobacco consumption. 
Beginning with an analysis of the problems facing the world’s population and those trying to mitigate the impacts of earthquakes, Musson draws attention to the key factors in the level of damage caused by seismic events. The book is full of examples, and one that is particularly enlightening is the contrast between the 316,000 death toll of the 2010 Haiti Earthquake, which had a magnitude of 7.0Mw, and the 8.8Mw earthquake that occurred in Chile just a few weeks later. The reasons for this disparity in impact are multiple. Chile is more economically developed than Haiti and hence buildings there were able to be constructed to a higher standard with consideration of seismic hazard, Haiti is one of the poorest countries in the world and the 97,294 houses which collapsed due to the earthquake were built simply with the intention of minimising cost rather than maximising safety.
Musson then provides a succinct explanation of the principal factors that differentiate earthquake impact, focussing on four key terms: risk, the chance that loss will occur; hazard, the chance and likely strength of shaking in an area; exposure, the level of population and property that could be affected by shaking; vulnerability, how susceptible that population and its buildings are to damage from shaking, given education levels and the quality of building codes.
Having looked at how earthquakes occur and the reasons for their level of impact in different cases, Musson addresses the key issue of the book: how to prevent the “million death quake” that is expected within our lifetimes. I found the section on prediction particularly fascinating, both in the difficulty in determining between a small earthquake and the foreshock for a larger earthquake to come, but most of all in the unforeseen impacts of seismologists trying to predict earthquakes in certain cases. In particular, I was struck by the example of Brian Brady, a theoretical theorist who applied his theory of rock bursts to earthquakes and determined that there would be an earthquake on June 28, 1981 of over 9Mw off the coast of Peru on the basis of the 1974, 8.1Mw Lima Earthquake. He estimated a death toll of hundreds of thousands and complete destruction of Lima, the capital city of Peru. Understandably, this caused widespread alarm in Peru and despite the attempts of a panel of American seismologists to discredit Brady’s methodology, the prediction had a major impact on the economy of Peru – tourism slumped; workers quit their jobs to be with their families; and property prices plummeted. No major earthquake occurred in the summer of 1981 in Peru and soon after Brady withdrew his predictions, but real and significant damage had already been done to the Peruvian economy.
Overall, the book is very optimistic in tone – Musson strongly believes that through education programs and scientific development a seismic catastrophe can be avoided. His work is an enjoyable read, providing a strong grounding in the principles governing earthquakes whilst remaining accessible for readers of any level of geological knowledge, and is therefore definitely worth reading.
Written by Ben Williamson
Plate tectonic theory is a scientific theory that describes the large scale motion of the Earths lithosphere. The theory of plate tectonics was initially developed by Wegener in 1912. His report put forward the idea of continental drift whereby he proposed the continents were once connected in one supercontinent, Pangea. This was suggested after he noticed the continents have a jig-saw fit, evidenced by South America and Africa. Plates have moved apart since Pangea, and this continental drift is what leads to seismic and volcanic activity. The lithosphere is made up of 8 main plates, and numerous small ones, which float on the earth’s asthenosphere, a highly viscous region at the top of the earth’s mantle. As these plates move, they interact with each other leading to seismic and volcanic events. Thus, a developed understanding of plate margins and their interactions can help us to understand the distribution of such events. This is particularly true as the majority of seismic and volcanic events occur at plate margins.
Evidence supporting Wegener’s theory includes fossilised remains of the mesosaurus being discovered on the coasts of Brazil and Gabon (West Africa) and also the same fossilised pollen species and rock sediments on these coast lines. Wegener’s theory was initially criticised as Wegener could not explain how the supercontinent he proposed split into different ‘jig-saw’ pieces. However, plate tectonics theory was built upon, furthering our understanding of tectonic events. Sea floor spreading was discovered, the formation of fresh areas of oceanic crust which occurs through the upwelling of magma at mid-ocean ridges and its subsequent outward movement on either side. Sea floor spreading provides evidence for the existence of plates and plate boundaries since new rock was being created and destroyed. An example of sea floor spreading was shown in the Atlantic. Here, as the Eurasian and North American plates are moving apart, magma rises through a rift and cools on the surface creating new plate material and the mid-Atlantic ridge, a ridge of volcanoes. This is a constructive plate boundary, a linear feature that exists between two tectonic plates that are moving away from each other. Recent great advancements in technology means we can also use advanced methods to develop our understanding of tectonics. Carbon dating means we can assess the age of oceanic crust, which increases as you get further away from the mid-Atlantic Ridge and evidence from paleomagnetism equally proves sea floor spreading. Palaeomagnetism occurs as metallic rich rocks align in the crust towards the poles before they harden, after hundreds of thousands of years these poles flip and new bands of rock align in the opposite direction. Therefore, each band of the opposing aligned elements in the crust represent several hundred thousand years of crust that was created in that time. Sea floor spreading and the creation of new oceanic crust means that a plate must be being destroyed somewhere else, which brings me onto subduction zones and the consequent distribution of seismic and volcanic events.
Subduction is the process that takes place at convergent boundaries by which one tectonic plate moves under another tectonic plate and sinks into the mantle as the plates converge. Subduction zones involve the oceanic lithosphere of one plate sliding beneath the continental lithosphere or oceanic lithosphere of another plate due to the higher density of the oceanic lithosphere. Deep sea exploration has proven areas such as the Pacific Ring of Fire is at a destructive margin. The Pacific Ring of Fire has a high concentration of earthquakes and volcanoes due to deep ocean trenches (e.g Marianas Trench) running close by parallel to these boundaries that show evidence of plates subducted beneath them (destroyed). Here a denser oceanic plate would subduct a continental plate- the plate would melt inside the mantle creating a pool of magma which would rise through the cracks in the rock forming a volcano. This development in plate tectonic theory helps explain firstly why volcanoes are always found along plate boundaries which are constructive (due to rising magma) and now also at destructive plate boundaries – due to plate melting.
Thus, plate tectonic theory explains why seismic and tectonic events occur at plate boundaries, what before any understanding, were perceived to be imaginary lines. However, there are some issues with this statement. Firstly, mountain building accompanied by seismic events can occur at plate boundaries instead of volcanic events; an example of this is along the Eurasian/Indo-Australian plate boundary. Here there are no volcanoes, but instead there are high mountain ranges such as the Himalayas. Two continental plates of the same density meet, leading to fold mountains being created whereby the two plates converge upwards as neither plate is denser than the opposing one. Pressure builds and eventually the plates fault upwards (Fracturing), adding to the creation of the mountains Explaining another way plates can be destroyed. Sudden faulting explains the seismic activity along this boundary, such as in Bam, Iran in 2003.
Another issue with the proposed distribution of seismic and volcanic activities is that intra-plate volcanoes do not correspond with the theory that volcanoes are found along plate boundaries. This is the case for the volcanoes of Hawaii and Yellowstone for instance. This does not weaken my proposed distribution however, as Tuzo Wilson came up for an explanation of this with his Hawaiian hot spot theory. He suggested hot spots were formed by magma plumes in the mantle which created melting of the crust at a particular point forming a volcano. The plume was stationary and the crust moved over it, creating a series of volcanoes called the Emperor sea mountain chain. As the crust moves, the plume would no longer build a volcano there and instead a relic feature would be left on the crust. Some of these old volcanoes have transformed into coral reeds after being eroded by the wind and sea until submerged in the sea. From this, we can conclude that intra-plate hot spots actually strengthen the theory of plate tectonics and plate movement.
A final issue with the distribution of seismic and volcanic events is that there is evidence of volcanoes away from plate boundaries. This is evident in the UK, such as at Arthur’s Seat in Edinburgh (extinct volcano) and the Whin Sill Dyke in England. However, similarly to Hawaiian hotspots, these also proved plate tectonic theory as well. They indicate temporal change of the position of plate boundaries that have moved away due to plate movement. Evidence from sea floor spreading, hot spots, subduction and convection currents in the earth’s movement driving movement have proven this case.
Plate tectonic theory has proved that there is a general correlation of the location of seismic and volcanic locations and their proximity to a plate boundary. However this information is rather dubious as plate tectonic theory cannot tell us where along a plate boundary an earthquake will occur which are thousands of kilometers long. Moreover, while plate tectonic theory can help us understand the distribution of seismic events; this information can also be of little use as the effects of an earthquake can be felt far away. For example, after the 2011 Virginia Earthquake, the effects were felt as far North as Quebec, despite it being unusual for Quebec to feel any seismic activity due to it being away from any plate boundaries. The usefulness of plate tectonic theory is also limited due to some people’s perception of the causes of earthquakes and volcanic events. Poorly educated people in LEDC’s may still believe tectonic events are from Gods, and so plate tectonic theory would be incomprehensible to these people who may not even be aware of plate tectonics.
To conclude, plate tectonic theory that has developed relatively recently in tectonic terms, has improved our understanding of the distribution of tectonic and seismic events. Through the understanding of how tectonic plates move, scientists have been able to assess the regular distribution of earthquakes and volcanoes found along these pate boundaries.
First of all, it is important to address the impacts of salmon on our health, central to the argument over its consumption. Omega 3 is almost universally accepted to be beneficial for our health, and is associated with a reduced risk of heart disease and possibly stroke. However, recent research has highlighted another component of farmed salmon which can be dangerous for our health: PCB’s (polychlorinated biphenyls). In Richard Girling’s book, Sea Change, he states that ‘The levels of PCB’s in the salmon were so high that, according to some analysts, two portions a month was all it would take for a child or pregnant woman to exceed the World Health Organisation’s recommended safety limits for dioxins and dioxin-like PCB’s.’ Although, results are not conclusive PCB’s have been linked to both severe liver damage and non-Hodgkin’s Lymphoma Disease, making eating the two portions of fatty fish a week, including farmed salmon, recommended by the Food Standards Agency a serious health risk.
Economically, the farmed fish industry has done as much harm as good. Though the farms are often located in very inaccessible areas of Northern and Western Scotland and hence provide crucial jobs to isolated communities, these benefits are becoming increasingly undermined by damage in other ways. Aside from the wages from these jobs, very little of the money generated from the industry is retained within the local economy. The vast majority of farms are now owned by the Norwegian mega-company Pan Fish who rake off any profits and all feed is sourced from abroad. Moreover, Ian MacKinnon, a Scottish journalist specialising in the subject, has highlighted that ‘The low cost high-volume approach [to salmon farming in Scotland] is socially unsustainable as it has already cost hundreds of jobs in remote rural communities in the last five years’ and that the takeover of Pan Fish has worsened this situation. The farmed salmon industry is also directly hurting other key industries of these remote areas. Interbreeding between escaped farmed salmon and wild salmon in Scotland’s rivers is severely hurting the freshwater angling industry in Scotland, which could be worth as much as £150m annually. And, the large-scale pollution from salmon farms into the pristine environment of the Highlands and Outer Hebrides – the amount of effluent from salmon farms is now equivalent to double the sewage output of the entire 5.1m human population of Scotland – is of great cost to tourism revenue in the area, another major part of the local economy.
Environmentally, salmon farming has been a catastrophe. The huge levels of pollution outlined above are tarnishing the pristine landscape and the numbers of escaped salmon from farms now means that farmed salmon outnumber wild salmon ten to one in Highland rivers. Additionally, the farmed salmon are fed fish meal – made of grounded down fish from less sought-after species – and Girling points out in Sea Change that ‘to grow one kilo of farmed salmon, you need to catch four kilos of wild fish’. This is not only a severe waste of resources, many of the fish species used in fish meal are severely endangered. For instance, WWF-Norway issued a report stating that ‘In Europe, the situation for the blue whiting, a species primarily used as ‘industry’ fish, is depressing. A total collapse is expected if the current fishing practice continues’.
The overwhelming weight of evidence now shows that farmed salmon is socially, economically and environmentally unsustainable. Therefore, given it is illegal to catch wild salmon for commercial purposes, isn’t it time that we all stopped eating salmon?
“Antimicrobial resistance in a ticking time bomb…for the UK”, says Sally Davies, Chief Medical Officer for the UK. As she states, a major part of the growing health crisis is the problem of increasing bacterial resistance to current antibiotic treatment. This can be attributed to the natural evolutionary process, but also the misuse of drugs by the common person. People are consistently being given a course of medication and stopping the course prematurely, once their symptoms have died down. Already we, as a society, are experiencing some of the effects of this resistance. Dr Ibrahim Hassan, a consultant microbiologist from Manchester, reported to the BBC that “we’re beginning to see that in some hospitals, patients coming in with this infection with no antibiotic that can be used to treat them”. A further factor in the problem of drug resistance is the effect of the increasing privatization of drug production. This has greatly incentivised the production and development of drugs that can act as palliatives to chronic diseases, where the drug will be used for decades, whilst deterring research into new antibiotics which have a short-term use. The fact that no new class of antibiotics has been developed since the 1980’s is a clear indication of the dire current state of antibiotic production, and consequently the dire state of the future of antibiotic treatment.
“The effect of projected climate change indicates that a prolonged transmission season is as important as geographical expansion in correct assessment of the effect of changes in transmission patterns” of infectious disease. As highlighted here by a recent article from The Lancet, global warming is another significant factor in the growing prevalence and effects of disease on the world’s population. For instance, a recent BBC report from Nairobi found that this city, previously protected by its altitude, is now suffering from malaria for the first time. In addition, diseases like malaria are anticipated to spread to higher latitudes, with southern European countries potentially at risk by the end of this century.
A final complicating factor in the fight against disease this century is the fast rates of urbanisation taking place globally. This has had a particular effect on the transmission of infectious diseases as more concentrated human settlement has allowed for easier transmission of disease. Rural to urban migration is a trend only set to continue during this century, making this an ever-growing problem. Moreover, the prevalence of slums with poor sanitation and living conditions in the major cities of LIC’s (Low Income Countries) provides perfect breeding conditions for many vectors, such as mosquitoes, increasing the risk of vector-borne diseases like malaria.
Therefore, it is clear that, along with climate change, terrorism and population growth, global health is one of the biggest issues we must tackle in the 21st century. Unless we act upon the failings of the current global health movement, it is possible that, as Dame Sally Davies reports, “if you get an infection in your bloodstream, in about 10, 20 years it might be untreatable”.
Contributed by Ben Williamson
Currently, flooding poses a very serious annual threat to the UK. Over 110 flood alerts were issued last week 2, whilst the Environment Agency has reported that flooding cost the UK “between about £260 and £620 million”3 in the period of April 2012 and April 2013. Global warming is widely predicted to greatly increase the risk and severity of flooding in the UK, making this one of the most important economic and social issues for the UK in the 21st Century. The European Environment Agency predicts that climate change will “increase the occurrence and frequency of flood events…in particular flash floods”, whilst the Government’s own report expects “2 or 4 times” as much river flooding as now by 20803.
Reports like these, as well as the devastation caused by recent flooding, has led to widespread questioning of the government’s plans to cut another £300 million from DEFRA’s budget – the body responsible for flood defence – at a time when it should be increasing it. This is not a new issue either, as the 2004 Foresight Future Flooding report stated a need for yearly increases of £10 – £30 million above inflation to the flood defence budget, until the 2080’s. Although the Environment Secretary, Owen Paterson, has defended his government’s cuts as necessary for overall deficit reduction, the flood defence budget should surely be ring fenced given that “every £1 currently invested…reduces the long-term cost of flooding… by around £8”3.
However, it is not just increased spending that is needed on flood management, but more effective spending. A recent Guardian article revealed the complete mismatch of flood prevention and farming policy in river drainage basins where vast sums of money are being spent on subsidies for upland farmers to create additional farmland by removing vegetation, increasing flood risk4. Bare land has no or little vegetation to intercept rainfall, significantly increasing the risk of flooding downstream. A recent study of small-scale reforestation at Pontbren, near the source of the River Severn, showed that if 5% more land in the river’s catchment was reforested, there would be a 29% reduction in flooding peaks5 downstream.
Flood defence is, of course, only a small part of the work of Owen Paterson and DEFRA (Department for the Environment, Food and Rural Affairs) but it is also just one example of their continued incompetence in managing environmental affairs. The ongoing badger culls vociferously pursued by the Government in Western England present another obvious example. 2,081 badgers are scheduled to be killed in the pilot scheme alone, yet DEFRA’s own figures predict a measly 16% reduction in TB cases in cattle as a result of the badger cull. However, a recent analysis of the Randomised Badger Culling Trial which ran from 1998 to 2005 has shown even this figure to be an overestimate, since in the areas studied only 6% of cows received TB directly from badgers6.
All this goes to show that a government policy of cutting and misspending the flood defence budget is no effective policy at all in mitigating against the increased flooding that will be brought about by global warming. Though this damage may not affect the PM or his colleagues living in the Home Counties, it will bring devastation to 900,000 other homes in the UK by 20503.
While Margaret Young and thousands of others continue the cleanup operation after the recent flooding, the threat of severe flooding to their and others’ properties will be getting ever worse, thanks in large part to the incompetence of our coalition government.
Contributed by Ben Williamson
1. The Guardian, http://www.theguardian.com/uk-news/2014/jan/07/uk-floods-chesil-beach-sirens
2. Met Office, flood alert chart for 08/01/14.
3. Environment Agency, http://a0768b4a8a31e106d8b0-50dc802554eb38a24458b98ff72d550b.r19.cf3.rackcdn.com/LIT_8443_200ddd.pdf
4. The Guardian, http://www.theguardian.com/commentisfree/2014/jan/13/flooding-public-spending-britain-europe-policies-homes
5. Howard Wheater et al 2008, http://nora.nerc.ac.uk/5890/1/ur16_impacts_upland_land_management_wp2_2_v1_0.pdf
6. PLOS, http://currents.plos.org/outbreaks/article/the-contribution-of-badger-to-cattle-tb-incidence-in-high-cattle-incidence-areas/
News.nationalgeographic.co.uk. 2010. “Guns, Germs and Steel”: Jared Diamond on Geography as Power. Available at: http://news.nationalgeographic.co.uk/news/2005/07/0706_050706_diamond.html.
Nybooks.com. 1997. ‘Guns, Germs, and Steel’ by Jared Diamond | The New York Review of Books. Available at: http://www.nybooks.com/articles/archives/1997/jun/26/guns-germs-and-steel/?pagination=false.
Swadling, P., Wagner, R. and Laba, B. 1996. Plumes from paradise. Coorparoo DC, Queensland Australia: Papua New Guinea National Museum in association with Robert Brown & Associates.
Jarosz, L. 2003. A Human Geographer’s Response to Guns, Germs, and Steel. Seattle: Blackwell Publishing. p. 7. Available through: http://www.uky.edu/~tmute2/geography_methods/readingPDFs/jarosz_diamondCrit.pdf.
Contributed by Krishan Sivaneson
This research, led by João Duarte, involved mapping the seafloor off the coast of Iberia and has led to the discovery of a 186 mile long subduction zone in the Atlantic Ocean, 120 miles from Portugal. Put simply, the Earth’s crust consists of a number of tectonic plates, which move across the surface of the mantle, driven by convection currents deep within the Earth. When two plates collide, the denser plate subducts underneath the other, which is less dense, forming a subduction zone.
The newly discovered subduction zone is not yet fully developed and is instead in ‘an embryonic’ stage, in the words of Duarte. The crack that is forming in the ocean floor will lead to the Eurasian splitting into two parts, one continental and one oceanic. The denser Oceanic section will then subduct underneath the Continental plate, leading to the Atlantic Ocean shrinking as North America and Europe are pulled together. Eventually, the two continents will be joined together and the resulting collision will lead to a new mountain range forming and a supercontinent, similar to Pangea, could potentially develop. This process will not be a fast one and the first significant changes will only begin to manifest themselves after roughly 20 million years. In approximately 220 million years the Atlantic Ocean should have closed up completely.
Scientists have been mapping the Atlantic Ocean seabed near Portugal for many years now for signs of potential tectonic activity and this discovery marks the first significant evidence that a subduction zone is indeed forming. The area has experienced relatively regular earthquakes, the most destructive of which was the 1755 earthquake, which had an estimated magnitude between 8.5 and 9. The primary impact of the earthquake and the series of tsunamis that were created by the seismic energy combined to destroy an ill-prepared Lisbon, killing 60000 people. It is predicted that earthquakes will become more common and increase in magnitude in the area around the subduction zone as it develops.
The discovery of this newly forming subduction zone, could contribute significantly to the field of plate tectonics, as further monitoring will allow for a greater understanding of how subduction zones initially form and the way in which supercontinents develop as oceans disappear. Duarte has suggested a possible cause behind this being that the subduction cycles of the African and Eurasian plates, which were previously being driven into one another, have subsided, resulting in the mountain ranges stretching from west to east across Europe and into Asia. There is existing evidence for this idea, as when the plates in the Pacific began to decrease in movement, two subduction zones, similar to one seen of the coast of Portugal, formed, one in the North Atlantic and the other near Antarctica.
Despite the fact we will never see the impacts of this subduction zone, as is inevitable with most geology and plate tectonics, it is fascinating to see how the series of supercontinents that have formed over time were made and how they broke apart, with this discovery in the Atlantic Ocean shedding new light on the field.
Contributed by James Axton
The area that we now call Dartmoor is a site of huge historical importance, with over 500 sites referenced by Jeremy Butler and over 3000 stone and 6000 wooden round houses estimated by Petitt. The general consensus is that there are many more sites to be discovered, with extensive ancient field boundaries or Reaves dividing up the land, hinting at the type of existence that these people lead. However, radiocarbon dating has shown that most of the Reaves were built within a 200 year period; and only in use for between 200 and 400 years. The abandonment of the Reaves and the upland moor has been put down to Geographical issues such as a change in climate at the time, a drop in temperature and an increase in dampness, however there are other more minor factors that also contribute to the departure of man from the moor, and the current lack of extensive settlement in the area today.
Contributed by Chris Cockerill
Silchester (or Calleva) and Colchester (Camulodunum) were both Iron Age fortified settlements. After the Roman Conquest in 43CE they became influential, defended Roman towns of a high status; as proved by the unusual wall construction at Silchester, and the fact that Colchester was the capital of Britain until the Boudiccan revolt of 61CE. However, after the Romans left Britain in 410CE their fortunes diverge. Colchester was resettled by the Anglo Saxons by 450CE, and gradually developed once again into an important commercial centre. Population estimates for the town based on recording from the Domesday Book suggest that about 2,000 people were living there in 1086, whilst by the year 1400 this had increased to 8,000 people. Silchester on the other hand was not re-settled by the Anglo Saxons, instead the nearby former roman town of Dorchester on Thames was chosen. The small village which had been on the site of Silchester was abandoned in around 1400, possibly due to the Black Death. A key reason why Silchester was not re-settled in any meaningful way by the Anglo Saxons was that it was 10 miles away from the nearest river. This meant that it was not on a good communications or trade and so was not suitable for the Anglo Saxon way of life. This stunted the town’s rejuvenation, and contributed heavily to it being abandoned later. Colchester on the other hand had been an important trade port under the Romans (due to its location on the river Colne). The Anglo Saxons were also then able to trade from this settlement, and it grew once again, becoming one of the country’s principle towns. Therefore on the basis of this comparison it appears that ease of trade was a key determinant of which settlements would prosper in the Anglo Saxon and Medieval periods, and that rivers (and easy access the coast) were more important for trade than roads during this period. This lead to towns with good road connections but poor waterway access declining (Silchester for example), whereas towns with good road access which were close to rivers and the sea developing further (Colchester).
Contributed by Matthew Cockerill
Botswana is severely affected by HIV/AIDS, but due to its largely peaceful recent history, it receives little international attention. AVERT says that, as of 2009, 320,000 people live with HIV/AIDS in the country. This is 24.8% of the population, meaning that Botswana has the 2nd highest rate of infection in the world. As a result, life expectancy in the country has fallen from 65 in 1990 to 53 in 2009; however, this most recent figure is far higher than in 2000-05, when it was less than 40. This is in stark contrast to the country’s estimated life expectancy without the disease, which would be 74.4 according to the United States Census Bureau (the highest of all Sub Sahara African nations).
Countries with high rates of HIV/AIDS cases suffer what is known as a negative feedback or a vicious circle. This cycle leads to larger and larger numbers of people becoming HIV positive, which makes the situation worse:
HIV/AIDS leads to poverty if untreated
Antiretroviral drugs are the only treatment for HIV, but they are not a cure. These expensive drugs maintain an individual’s white blood cell count so that their immune system is not weakened by the disease, and so people do not become ill as easily. If these drugs are not available, the infected individual is unable to work and so falls into poverty. This is also true if one or both parents in a family die, leaving their orphaned children unable to support themselves effectively.
Poverty increases chances of infection
When in poverty, infection rates rise due to several factors. Firstly, children cannot afford to be educated and so are not aware of the dangers of the disease and how it spreads, meaning that they are more likely to become infected. Secondly, many women are forced into sex work in order to sustain their family. Thirdly, as less people work due to sickness, the government receives less tax income, meaning that it cannot increase education rates or afford more antiretroviral drugs. These lead to more people falling into poverty and more becoming infected by the virus.
The government of Botswana have tried to break this feedback loop through several health and education initiatives since the first case of the disease in 1985. First, blood donations for transfusions were screened to prevent people becoming ill through medical care. In the 1990’s the focus shifted to education. This reached urban populations far more effectively than rural populations, as well as those who were not in poverty (as they were able to go to school for example). Due to the fact that many children do not attend school due to poverty, or having to look after sick parents, there is still a lack of understanding of the disease, and many inaccurate perceptions such as only sex workers and homosexuals being able to get the disease. Another scheme which was tried was an ABC campaign which had been effective in Uganda. This encouraged people to Abstain, Be faithful, and ‘Condomise’ (use a condom). This campaign however was also ineffective as public behaviour did not change despite the number of messages.
Despite this, huge government investment, as well as money from non-governmental organisations and charities, has meant that the country’s most recent attempts at treating HIV/AIDS have been reasonably successful. In 2007 the government spent US$31.3million on providing Anti-retroviral drugs to all those in need of them, whilst providing universal treatment access (available to 80%+ of the population). This ‘Masa’ scheme (‘Masa’ being a Setswana word meaning ‘a new dawn’) is the first of its kind in Africa. It aimed to: enable people to live longer and healthier lives; lower the rate of transmission; decrease the numbers of children orphaned by HIV/AIDS every year; and maintain skills in the workforce so that the country can develop. 161,219 people were being treated by MASA in 2010, which is 93% of the needy population. This national treatment programme has been so successful it is now seen as a model for other African nations to follow.
‘Masa’ has provided a break in the positive feedback loop experienced by many in Botswana, as the Anti retroviral drugs mean that infected individuals are able to remain economically active. This means that these people in many cases are able to improve their living conditions and send their children to school. This reduces the chances of further HIV infections. However, in order to reach the government’s ambitious target of having no new infections of HIV by 2016, it must be coupled with effective prevention schemes. In Botswana these include:
• Increasing Public education & awareness
• Increasing AIDS education for young people
• Condom distribution & education
• Targeting of high risk adult populations
• Improvement of blood safety
• Prevention of mother-to-child transmission of HIV (PMTCT)
In order to achieve no new infections by 2016 huge levels of funding must be provided, focused on successful prevention schemes, not just treatment. This will be a significant challenge for a country with a GNI per capita of US$6890, and will need large levels of international aid in order to be successful. However, it has the potential to succeed, although it may take time.
Botswana has been able to break the negative feedback loop created by large infection rates of HIV. Effective treatment due to large levels of investment has meant that infection rates are slowing, whilst the levels of development in the country are increasing. In order to prevent further infections, investment must now be focused on increasing the effectiveness of preventative schemes rather than just focusing on treatment. However, Botswana has taken very large steps forward in its fight against HIV/AIDS, which have meant that it has been able to break the vicious circle it found itself in.
All statistics are from AVERT and UNICEF
Contributed by Matthew Cockerill