What determines climate?

With a recent spell of sunshine and warm temperatures here in England, I thought it would be interesting to look at the mechanism behind the Earth and the wider solar system in order to see what influences climate in different locations throughout the world. There are several factors which affect this.

The eccentricity, obliquity and procession of the Earth change slowly over time, which causes changes in the proportion of solar energy which reaches the Earth. These are known as Milankovitch Cycles and are so called due to the Serbian mathematician Milutin Milankovitch. He used these cycles as an aid when explaining the retreat of the polar ice caps and, although he was born in the 19th century, many modern day scientists agreed with his early work on this topic and believe that the cycles do in fact have an impact on the climate of the Earth.

Eccentricity is the shape of the Earth's orbit. When planets are in their closest approach to the sun, this is known as the perihelion and the opposite is the aphelion, with eccentricity being a measure of how these differ. The Earth's eccentricity follows a cycle which is repeated every 100,000 years. The larger this eccentricity is, the greater the difference in solar radiation which reaches the Earth when comparing perihelion and aphelion. Eccentricity can vary between 0.0005 and 0.0607, with a current value of 0.017 which is a 6.7% difference. On a long term timescale, changes to the Earth's eccentricity can affect the Earth's climate.

A grpah to show the Earth's eccentricity cycles

The tilt of the Earth's axis is currently 23.5 degrees and, during the seasons, the effect of this tilt changes on different locations throughout the world. In December, the northern hemisphere receives energy from the sun at more oblique angles which results in a 'winter' climate, and in June the axis is now tilted towards the sun so less oblique angles of energy are received and a warmer climate is experienced. We can see from this that the distance from the sun is not a major determining factor for seasons. The obliquity of the Earth's axis follows a 40,000 year cycle, with a minimum obliquity of 22.1 degrees and a maximum of 24.5 degrees.

The Earth's procession completes a 26,000 year cycle which has resulted in the Earth's axis currently pointing at Polaris (our Northern Star), so therefore we can expect that in half a cycle, 13,000 years, it will point towards the star Vega. Procession is caused by the gravitational effects experienced by the Earth from the sun and moon.

A graph to show the Earth's procession cycles

As mentioned earlier, the Milankovitch cycles result in long-term fluctuations in energy which reaches the Earth. Although there is evidence to suggest that the changes in insolation have had an influence on the world's climate, these changes alone are not enough to explain patterns in past climate.

A graph to show global temperature changes using deuterium isotopes from the Vostok ice cores

Varying Aspects of Global World Health - 2

This is the second instalment of the 'varying aspects of global world health' post; I will once again be using pictures from Worldmapper. All images belong to them.

Stillbirths

Stillbirths

Stillbirths are much more of an issue in MEDCs than maternal mortality or infant mortality, though once again it is an LEDC (Mauritania), which has the highest rate. In the developed world, there is a greater knowledge and understanding of pre-natal issues meaning warning signs can be picked up more easily by the mother and at frequent checkups which are available in these areas in the world. For example, a mother would know that if her foetus has not kicked in a few days there may be an issue and if at a scan the doctors can see all is not well an emergency caesarean can take place to deliver the baby before it dies inside the womb. In LEDCs they simply do not have the knowledge or healthcare measures to monitor pregnancies and prevent stillbirths from occurring. The UK and other MEDCs are larger in this map than they have been with others because stillbirths can still occur late in a pregnancy for reasons unknown to medical professionals.

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Infant Mortality

Infant Mortality

Infant mortality refers to babies who will die within the first year of their lives and in 2002 there were 7.2 million infant deaths worldwide. As can be seen in the map, it is once again MEDCs who experience this the most, with Sierra Leone having 165 per 1000 live births dying before the age of one. There are many contributing factors which affect infant mortality, with a lack of medical care and postnatal care being the most significant. In countries such as India, there are widespread diseases such as cholera and in Africa malaria, which means newly born infants are highly susceptible to life-threatening illnesses at a critical point in their life as there are little measures in place to prevent the spread of disease. When ill, there are few and widespread medical centres which have little medical resources to deal with such issues and return the children to full health, relying heavily on aid. Therefore, it is only in few cases that the child will live long after one year after developing or catching an illness or disease. Therefore, we can conclude that infant mortality rates are low in MEDCs, such as Sweden who have one of the lowest amounts of infant mortality, due to little or no epidemic type diseases being present in the country and the developed medical system to return ill children back to good health.

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Maternal Mortality

Maternal Mortality

Maternal mortality is linked to infant mortality in the fact that they both occur due to underdeveloped medical systems or the lack of access to what little treatment they can have. Once again on the map it is Africa, in particular Sierra Leone, with the highest rates. India is the most enlarged with developed nations such as the UK and USA being minuscule. In these LEDCs there is not pre-natal and post-natal support available like in MEDCs, meaning health advice is not given and any complications simply are not recognised, with childbirth being the time when the highest percentage of maternal deaths will occur. This is because only few women will have their child in presence of a doctor or health care professional and therefore any unseen issues such as high blood pressure, hemagering or infection after childbirth can easily result in death. 



Thomas Malthus: Pessimist or Realist?

For those of you who don't know, Thomas Malthus was an English clergyman and economist who lived from 1766 to 1834. He is well credited for his text 'An essay on the principle of population' in which Malthus expressed a more negative view on the dangers of over-population.

Thomas Malthus

Human population increases geometrically (2,4,8,16,32 etc), whereas food supplies can only grow arithmetically (2,4,6,8,10,12 etc) so by reading in between the lines it can be seen that population growth is set to exponentially rise above the amount of food which can be supplied. However, according to Malthus, population growth is limited by certain 'checks', which prevent the population increasing beyond the optimum number of people for which resources can support. These are either negative or positive checks, which can further be categorised into 'misery', 'vice' or 'moral restraint'. Malthus went on to predict that, as a result of his research, if the population increased above the carrying capacity of the land, it would have to be controlled otherwise widespread famine would occur as there was no foreseeable way that the demand could be met.

A graph to demonstrate the Malthusian dilema

We of course now know that this is not the case and that food demands, which are beyond what we should be able to meet, have been supplied due to advancements in society. This allows us to identify the limitations of the Malthusian theory:

• He did not take into account the Green Revolution or the Agricultural revolution
• Such remarkable advances in technology and medicine were not predicted
• The increase in agricultural crop yields were not known. Today it is possible to produce enough food for a thousand people from the area the size of a football pitch
• Malthus did not see the improvements in the transport and communication of food which were to come
• He did not even begin to imagine that surpluses of food were even possible, such as the 1992 European surpluses which reached 26 million tonnes

So to conclude, do I believe that Malthus was a pessimist or realist? Well, I think Malthus was an inquisitive man who saw the facts but didn't analyse them, who had a 18th century mind but didn't project it, who worked mathematically and not geographically, but most importantly, a man who needed to realise the capability of the amazing human race. 

Question: Do you believe that Malthus was a pessimist or a realist?

Varying Aspects of Global World Health - 1

Today's post is a reasonably long piece, as I will be exploring certain aspects of varying world health. This post will be aided by the website Worldmapper which is an excellent resource for comparing health situations globally and how they differ in different regions. The website also provides graphics to visually show statistics, providing a clearer perspective. All graphics used are copyrighted to them. The maps you see will show countries to be distorted in comparison to their normal shape and size; this is to show variation. For example, a low life expectancy in Africa will show the country appealing smaller than normal and a comparatively large life expectancy in the UK will show the country to be swollen. 

Life Expectancy



Life Expectancy

Life expectancy follows the general trend that MEDCs have a higher value and LEDCs considerably lower however there can be exceptions to this. The country with the highest life expectancy is Japan, which is arguably an NIC as it is developed in some respects such as its healthcare, accounting for this rank but is underdeveloped, or developing, in terms of its economy. A major factor to Japan having a life expectancy of 81.5 years is the lifestyle choice of its citizens, which contrasts with that of people in the UK, for example. The Japanese have a diet which is proportionally low in processed fat, in particular saturated fats, which means that diseases such as heart disease and associated types of cancer which play a major role in nations such as the UK and North America due to an unhealthy diet and rising rates of obesity. In addition, the Japanese do not indulge in alcohol in a social way as other nations do, reducing liver disease and the other illnesses which come with the toxin. The country with the lowest life expectancy is Zambia, which is an extremely poor, deprived and underdeveloped country within Africa whose other southern nations also have an extremely low life expectancy due to similar reasons. An unequal spread of world resources is a major contributor to this which is linked to the relative climate of each country resulting in famine due to both lack of food and failed crops because of harsh temperatures and a lack of water. Clean water is rarely available and the sources used for drinking result in the wide spread of cholera and diarrhoea. Malaria is also widespread, as well as the other extremes of HIV and Aids. In summary, LEDCs generally have a low life expectancy due healthcare which is underdeveloped and insufficient for the number of patients who are ill due to the other problems of the country as mentioned above. MEDCs have a higher life expectancy due to a vast and developed healthcare system, for example the NHS in the UK, and the education of the nation teaching the importance of a healthy life style, how to prevent disease and most importantly how to cure it.

Question: 'More than a third of babies born in 2010 will live to 100'. Will this be a burden or benefit to future society? 

Interesting article here

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HIV/AIDS Prevalence

I apologise for generalising these two different states of health as one, unfortunately they are often grouped when in the media and therefore some resources do not distinguish between the two. I studied HIV/AIDS at school and found it to be a fascinating topic with an interesting and somewhat questionable origin. Before we look more deeply into the global patterns, here are a few key facts about HIV/AIDS:

• HIV stands for Human Immunodeficiency Virus
• AIDS stands for Acquired Immune Deficiency Syndrome
• AIDS was believed to first appear in Central Africa in 1959 but wasn't fully recognised until 1981
• Swaziland is the area in the world which is most affected by HIV - with a prevalence of ~30%
• There are more than 100,000 people living with HIV in the UK
• In the world more than 33 million people are living with HIV/AIDS

HIV/AIDS Prevalence

HIV is most prevalent within the continent of Africa, with Southern Asia being the nation with the second highest amount of records. In Africa, there is little contraception used due to being unable to access them or the fact that such methods are against the religion of some settlements. Even if contraception is provided by aid groups/NGOs or subsidised by governments trying to lower the birth rate or reducing the spread of HIV, people are not always aware of how to use contraception due to a lack of education and therefore its effectiveness is lost. As a large proportion of sexual intercourse is unprotected, HIV is spread as a STI (sexual transmitted infection) and as it is often culturally normal for polygamy to occur; one man can infect a number of women who may have more sexual partners. It is now becoming more frequent for children to be born with HIV, as it is an infection of the blood, if their mother is a carrier of the disease. In the Western world, the number of HIV cases is rapidly rising, particularly in the UK. The first initial cases were normally within the gay communities as condoms were sparsely used and HIV passed between them as an STI however as casual sex and unprotected sex are now occurring more often, HIV is prevalent between all groups and sexualities of society. Ironically, this is once again due to contraception not being used, just like in LEDCs, even though these nations have high levels of education and knowledge as to why contraception is important. However, the occurrence of death due to HIV/AIDS in these countries is significantly lower than LEDCs as they have the advanced medicine to prolong the life of people with HIV.

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HIV/AIDS Related Deaths

HIV/AIDS Related Deaths

It is clear to see from this map that Africa has the largest amount of deaths due to HIV and AIDS as well as the highest prevalence of HIV. In 2002 nearly 80% of the 2.6 million deaths from AIDS occurred in sub-Saharan Africa where the disease, usually untreated, caused more than 6000 deaths every day and accounted for almost one in five of all deaths and half of the deaths of adults aged 15 to 59 years. This is primarily due to the fact that there is a lack of medicine and treatment available to people who are infected with HIV to prolong this stage and stop AIDS developing which is when death can occur. In 2002 HIV/AIDS caused 40% of deaths in children under 15 years old, who are most likely to be born with it due to blood genetics. Though cases in the developed world are rising, the deaths are significantly less frequent due to superior medical care to stop AIDS developing and prolong life.

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Click here for a link, which will take you to a 'Geofile' which is addressing Aids in the 21st Century - a great piece of extended reading which gives a broad overview of this vast topic.

Question: Do you think AIDS, as a communicable disease, has more of an impact on development of a country than a non-communicable disease such as obesity?

Outwash Plain Stop Motion Film

In a geography lesson a couple of months ago whilst studying the Cold Environments module for the AS examination, we were asked to make a fluvioglacial landform using play-dough and to make a stop motion film - something a little different. I thought I would share with you my attempt at re-creating the sequence of an outwash plain.

Enjoy!

A School Field Trip to the Lake District

Between the 25th and 29th of March, the whole of year 12 who take geography went on a field trip to Grange-over-Sands in the Lake District. I've never been to this area of the country as I've always gone West rather than North however I was excited to visit a new place and the Lake District is always said to be a beautiful place to go. We stayed in a study centre called Castle Head, enjoying fieldwork ex situ during the day and classroom work at the centre in the evenings to consolidate what had been learnt in order to prepare us for the Unit 2 exam in the summer.

Day 1 - Windermere

Lake Windermere

After an extremely long coach journey, which seemed to take an age, we arrived in the Lake District. The focus of day one was to look at tourism so we stopped at the popular tourist destination of Bowness in Windermere to carry out surveys on the public and take in the area, seeing how it provided for the tourist industry. It was a lovely town that sat on the edge of Lake Windamere, with frequent boat trips which focused on the wildlife and outstanding natural beauty of the landscape. In addition there was a high street with a mixture of chain and one-off local shops providing the needs of both residents and tourists like myself. There was a certain charm about the place and with previous snowfall still being on the ground, it was a lovely place to be.

In my group, we approached a mixture of people and asked several questions to determine how far they had travelled to the town, what they believed to be the strengths and weaknesses and why they had visited. In addition, we carried out a car number plate survey which showed the majority of visitors to have come from close proximity in the North-West of England, being aware that this method is not fully reliable due to the re-selling of cars. Our findings were that Bowness is typical of any British tourist honey pot site; there are peak seasons, which are heavily influenced by the weather, and there are sufficient services to provide enjoyment. The public said the main attraction to them personally was walking, however there are frequent boat trips, shops, and exhibitions such as that of Beatrix Potter who I must say seemed like a local iconic figure. However, despite me saying that Bowness fits the typical characteristics of a honey pot site, when compared with Blackpool which is also in the North-West of England, the two locations are quite different but follow the same story. If wanting to analyse this town any further, it could be placed on the Butler Model.

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Day Two - The River Eea

The upper course of River Eea

Our first full day was to be spent taking various measurements at four sites along the River Eea. Having studied rivers at both GCSE and AS level I was keen to prove that certain values changed downstream, which is demonstrated well by the Bradshaw Model and the Schumm Model. Measurements included the wetted perimeter, velocity, width, gradient that were amongst other features which were to change as the river travelled from its source to the mouth. In order to measure the velocity of the water, two methods were used. Firstly, a dog biscuit was put onto the river surface and was allowed to travel a set distance with the time being recorded. The equation 'velocity = displacement/time' was then used to calculate the rate at which the water was flowing. The second method was using a propeller which was rotated down a grooved spiral due to the force of the water and therefore the higher the velocity, the shorter time the propeller took to reach its limit. Of those two methods, the latter is more reliable and accurate as the dog biscuit became trapped and slowed by rocks. It was refreshing to be able to see characteristics and features with my own eyes that had previously been explained to me or read from a textbook and in the evening when we processed our data and presented it, I found myself linking ideas and understanding the topic to a new level.

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Day 3 - Sandscale Haws

Sandscale Haws



I have to say this was my least favourite day of the trip, possibly because of the repetitiveness of taking measurements or the British weather! Sandscale Haws is owned and managed by the National Trust and so due to human influence could be called a plagioclimax, however there is a rich biodiversity with 15% of the British Natterjack toad population being in this area. It was a similar goal to the previous day: gain data to analyse which will show how sand dunes develop as you move inland from the sea. Our hypothesis was 'Abiotic factors do not vary along the sand dune succession and Sandscale Haws does not fit the idealised psammosere model'. Coastal environments and sand dunes are a topic I have not covered at school, however I find it to be a very interesting topic and feel I was so oblivious before to think of sand dunes as mere 'piles of sand'. The measurements taken were a range of biotic factors, such as the percentage coverage of marram grass, and abiotic factors such as wind speed and soil pH levels. The aim was to see how these varied inland from the strand line to the climatic climax, which after a few hours was achieved. The landscape was beautiful and I was surprised to learn that sand dunes only cover 0.1% of the country, with the only other sand dunes I have ever seen being in Le Touquet which, coincidentally, was also on a school trip. If I were to investigate further, I could compare to the Studland sand dunes in Dorset to see if Sandscale Haws was unique in being a prograding landscape.

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Day Four - Coniston Copper Mine Valley

The view from the top of the valley

A tarn in one of the various corries

This was by far my favourite day, as well as being the most strenuous. It was a steep assent all of the way but was made fun by snowdrifts, looking at sheep and enjoying the sunshine. We stopped regularly to look at features of glaciation which I previously had no concept of size and significance. I was struck most by the prominence of hanging valleys, which cut through the land and led into wide valleys once consumed by ice. I was amazed by just how big glaciers were and their presence in the landscape was obvious by the U-shaped valleys left behind all these years later. Though I enjoyed the walk, it was a relief to reach the tarn which was a very peaceful area although I would have liked to have known just how deep it was.

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And that was my trip. This is just a few moments and pictures which I enjoyed the most from an educational and fun experience. 

Question: If another glaciation period were to occur, do you think mankind would survive and what adaptations to life would be most crucial?

An Introduction

My name is Jessica and as the name of this blog gives away, I am going to be posting about the vast and diverse subject of Geography. I am constantly surprised by how geography relates to our everyday living without being necessarily obvious and never fail to be interested and enriched during lessons at school. I plan to write about what I have learnt which interested me, ideas which may be new, debatable topics, my geography experiences and everything in between. I hope to do posts regularly and plan to end each with a related question to get everyone thinking more deeply into the topics discussed. As it says in my profile, I want to do Geography at university and I believe that by creating this blog I will develop more as both a student and a Geographer. I hope that you enjoy the items I post and that they get you thinking in a three-dimensional way. I look forward to this project and am interested to see what The Geography Blog UK becomes!

Thank you for reading