ENSO: a kind of synopsis

It looks like we are going to be doing a lot of purely Human Geography for a while and so, as well as writing a post about what I learnt about development this week I thought I would write a post on ENSO, a purely physical topic, that, if I am honest, really really fascinates me but is unfortunately no longer on the A-level syllabus. Just incase you don't manage to get to the bottom of this post, I am planning on writing up atleast one detailed case study that could be used in our essays (sorry to remind you all!) and so I am looking for some suggestions on which one to do - I have a few ideas but any suggestions would be greatly appreciated!

So, anyway, this one is for all you Physical Geographers out there!

What excatly is the El Nino Southern Oscillation (ENSO)?
The term 'El Nino' has been applied, in the past, to somewhat different oceanographic events in the tropical Pacific but, nowadays, is commonly used to describe the anomalous warming of the sea-surface temperatures (SST) that occurs every few years in that region, although typically focused in east-central equatorial Pacific. El Nino events last several months and are associated with widespread changes in the climate system (dominating climatic flucuations observed on interannual timescales). These climatic changes have huge socio-economic impacts on countries, affecting agriculture, infrastructure, health, energy and, of course, development.

What is La Nina and the ENSO cycle?
La Nina is the term used to describe episodes of cooler than normal SST in the tropical Pacific (easiest way to think of it is the opposite of El Nino). The Southern Oscillation bit of ENSO is the term used for the atmospheric changes that occur in the tropical Pacific and accompany El Nino and La Nina events. Both events involve strong interactions between the oceans and atmosphere and tend to alternate (although not always the case) and this whole process is referred to as ENSO cycle. The ENSO cycle is not regular with various sizes and durations in both events but ENSO is a natural phenomenon and proxy evidence (principally from coral growth rate measurements) suggests ENSO has existed for thousands of years.

What causes El Nino?
As simply as I can put it, the ENSO cycle is the consequence of slow acting feedbacks in the ocean-atmosphere system, helped by strong air-sea interactions in the tropics that permit long-lived long-range connections to operate in the system.

Normally, the equatorial Pacific ocean has a pool of relatively warm water in the upper ocean to the west and a shallower layer of relatively cool water in the east; easterly surface winds are intrinsic to the maintainance of this balance. The first few tens of metres of oceans are well-mixed and lie above a thin thermocline, with cold water below.

The exact trigger of El Nino events is still debated and, due to a lack of observations, not a great deal can really be said about them with much certainity.There are a few possbile triggers though - Raised SSTs in central/east Pacific can be caused either through the action of westerly windbursts (short-lived storm-like events in West Pacific), or the gradual development of the ocean waveguide which moves the thermocline. Increased SST influences the atmospheric winds which, in turn, influence the upper ocean and the thermocline such that the SST is further increased = positive feedback. Only when the conditions are favourable will this feedback generate an El Nino event  where you get increased SSTs, reduced easterly winds and a 'flatter' (for want of a better word) thermocline across east to west Pacific.

La Nina

El Nino events then also cause gradual changes throughout the tropical Pacific ocan which develop in such a way that the SST across the equator slowly returns to normal, thus ending this event. However, the system normally overshoots and the feedbacks act to amplify small cooler anomalies, initiating a La Nina - as said before, it is basically the opposite with strengthened easterly winds and a increase in thermocline gradient. As this process is self-limiting the cycle continues....

What are the meteorological consequences?

Global impacts of El Nino

If you have managed to stick with this to this point, this is probably the bit that will interest you the most - bringing in a bit of Human Geography you could even link this to the development essay as ENSO has, arguably, hindered development in countries across the world!

 During El Nino events changes in SST, alterations to atmospheric circulation, temperature and precipitation occur; with these alterations, via atmospheric dynamics, extending far beyond the tropical Pacific region. As the impacts vary with location, it is practically impossible to identify a general pattern but generally speaking the eastward shift of precipitation in western Pacific tends to provoke huge deficits in the Philippines, Indonesia, north and east Australia, whilst central Pacific experiences increased rainfall.


Global Impacts of La Nina

I was fornutate enough to get to quiz an ENSO researcher at the Met Office,  about everything related to ENSO and I saw lots and lots of similar maps to those opposite - one question that instantly came into my mind was why excatly do the maps suggest that ENSO has no impact whatsoever on Europe. Well, in short, the European region is only relatively weakly effects and there is substantial variability in the observed conditions. Therefore, only when you analysis a long historical record of events will you see the impacts. Such analysis suggests that there is a clear late winter response associated with moderate strength El Nino events; with the tendency for cold conditions in northern Europe and mild southern Europe, with an increased precipitation in a wide band across central Europe (accompanied by decreases elsewhere). Due to this though, it is hard to distinguish between the different factors, with El Nino just one, that are capable of generating such climatic anomalies.

What are El Nino 'flavours'?
I had never, ever heard of this idea of El Nino 'flavours' before and my knowledge is limited to what I am about to write (definetly requires a bit of further indepth research on my behalf!) but I thought I would mention it anyway as its quite an interesting idea. This topic has recieved quite a bit of attention in recent years, due to the slightly differing impacts. The 'normal' El Nino witnesses SST warming in eastern and central Pacific, while the 'dateline' or 'modoki' (apparently Japanese roughly translating to 'similar but different') type primarily experiences warming in the central equatorial Pacific. It has been suggested that the main difference is the influence in Atlantic tropical storms, with such storms typically fewer in 'normal' El Nino years, with 'modoki' events not reducing hurricane activity.
So, I think that is probably the basics of ENSO and I think, before I move on to talking about modelling it and how is it measured, I will probably have to write a post on the basics of climate modelling (it will be the real basics as all this modelling stuff is like a totally seperate science which I won't be able to tell anyone about in any great detail - trust me, its tricky stuff!) and, when I get my head around some scientific papers on ENSO the Met Office provided, I will also write a post on extrinsic forcing factors that effect ENSO. Just one last think to leave you with, follow the link to see up to date measurements taken in the Pacific as part of the Tropical Atmosphere Ocean project.

Taken yesterday (14/09/2011)

I am guessing that most are probably aware that we have just come out of a La Nina (cause of flooding earlier this year in Australia etc.) but at the moment scientists are divided over what will happen next as, although SSTs in Nino 3.4 started to rise again, they have since started to fall again - causing a split amongst researchers as to whether we will remain in the 'normal' state or go back into a La Nina (no one really seems to think we are going to go immediately into an El Nino). If you are interested and catch me around college, I have some plots, and ensemble forecasts which illustrate this.

I hope this made some sense (and was interesting), let me know if you didn't quite get everything as I realise that I am not great at explaining things but I am more than happy to try my best to explain it in a more understandable way if necessary. I am quite intrigued by the idea of El Nino 'flavours' and so if anyone knows anything more about it, please let me know!!! Especially things like what dictates whether an El Nino turns out to be of the 'normal' type or 'modiko' type?

There is some development stuff on the way, along with a few book reviews and a post primarily for all the new AS Geographers on 'Flooding, Farming and the Future'. Millie has emphasised the importance of knowing some case studies really well, with reference to development and colonialism, so I thought I would try and write a post on atleast one, sometime over the next few days, so let me know which one you would most like me to write about - its up to you!

Is there a link between climate patterns and conflict?

Peru's civil war erupted during an El Nino year

Ok, so this summer holidays I had planned to try and link various topics to development but, so far, I havent got very far down my lists of ideas and, as we go back to college fairly soon, I thought I had better start! Here goes for one of my first, the link between climate and civil conflict which, of course has/had a knock-on impact on development.......

A recent study has made the first link between global climate patterns, specifically ENSO, to the onset of civil conflict and, perhaps most interestingly, a factor that is being placed on a par with poverty. Researchers at Princton University have been looking at conflicts that have occured between 1950 and 2004 that killed more than 25 people a year and then compared those years with whether or not we were in a El Nino or La Nina. The analysis included 175 countries and 234 conflicts, with more than half being responsible for 1000 deaths, and concluded that the risk of conflict in tropical countries rose by 3% during La Nina to 6% during El Nino; with this affect being absent in those countries who only experienced a small impact thanks to the climate cycles (essentially countries with a temperate climate). This study has shown that 1/5 of the conflicts that have erupted since 1950 are a result of the cyclical changes in climate which have, primarily, triggered reductions in food production.

Although ENSO has wide and varied effects, I think it is quite unsettling to think that cyclical short term variations in climate can seem to have such an impact when the predicted changes as a result of global climate change are likely to be much more extreme and long lasting - so just how are we going to adapt to those???

Is it just coincidence that cyclical climatic changes have occured
just before the eruption of civil conflict in many developing
countries?

Anyway, this doubling of the risk of conflict is quite large, and the study seems to suggest that the imapct of El Nino is immediate, with the onset of conflict erupting within months of the start of an El Nino event - a correlation independent of other local weather events which are also capable of generating tension. The study related outbreaks of violence in countries from southern Sudan to Indonesia and Peru to the cuts in food production triggered by El Nino. Using southern Sudan as an example, warfare broke out during 1963 (an El Nino year) and then again in 1976 (again an El Nino year) and then in 1983 (a very intense El Nino year), with the conflict lasting for more than 20 years and leaving more that 2 million people dead and millions displaced. In contrast, Australia, whose climate is also controlled to some extent by ENSO has had no civil conflicts which suggests that less developed countries lack the resourcse to adapt to the varability generated by these cyclical climate changes and so are more vulnerable to its impacts - a fact that suggests that climate still hinders the development of countries today.....

Hopefully provides a general idea of the varying
impacts of El Nino on the climates of many
countries

So, what is it about El Nino that increases the risk of conflict? Well, the study is yet to explain this and doing so is going to be hard due to the global variability in the impacts of El Nino. Best guesses, at present, seem to point towards increased temperatures in some regions leading to droughts, thus reducing crop yields which, in turn, would provoke a hike in global food prices - something that, thanks to the international market, would spread the climate signal around the world. Although most believe it is the impact on food production that triggers the violene, other ideas include a rise in unemployment and an increase in natural disasters.

This seems to be the first clear link between civil conflict and climatic cycles and I think it only reinforces the idea of our dependency on climate and the dictatorial role it has played and, perhaps, continues to play in terms of development (post on this idea hopefully on its way soon!). I must admit that it does concern me that if ENSO, an example of a short term cyclical climatic change which we are forever understanding and predicting better, can have such an impact on social unrest; how is mankind going to cope with the sea-level rises, droughts, famines, more natural disasters etc. that are predicted to accompany global climate change - a change in climate whose impacts are going to be much further reaching...........

Some external forcing factors with the ability to distrupt the general ocean circulation

As I have briefly discussed before, with reference to Heinrich events, the current ocean circulation pattern that exisits has not always do so and alterations to it in the past have resulted in huge shifts in the worlds climate. As well as those previously mentioned, there are some other external forcing factors that have the ability to affect the oceanic and atmospheric circulation. I think some of this stuff, like volcanic influence and Milankovich, comes up in the A2 syllabus although I don't know how much detail we go into - probably a bit more than I have done here, but hopefully the basics will still be useful!

At varying points in time, external forcing factors have and will continue to provoke variability in the ocean circulation. Understanding them is, again, crucial as some explain the past changes that occurred, whilst others endorse future predictions.

There are two types of Precession: this diagram illustrates Axial Precession
 and this alters the hemispheric distribution of insolation. For more on
Milankovich and the individual cycles see seperate blog post on
The race for a million year old ice sample 

Many proxy-climate records suggest that the Milankovich ‘pacemaker’ has driven alterations in the oceans, atmosphere and the cryosphere; due to the moderation in the hemispheric distribution of insolation provoked by the three cycles, precession (23ka and 19ka), obliquity (41ka) and eccentricity (100ka). The spectral analysis of d¹⁸O variations present in marine carbonates over the last 10Ma, contain signals of all three cycles moderating high northern latitude insolation variations.  Milankovich used this to explain the initiation and termination of ice ages and his theory states that the alterations in high-latitude insolation in the Northern Hemisphere are crucial in regulating the survival of snow through successive summers to warrant ice accumulation; a theory authenticated by the coincidence of glacial terminations and rapid increases in the solar insolation values of high latitudes in the Northern Hemisphere. The control Milankovich cycles exercise over hemispheric insolation distribution therefore dictates, although on a delayed timescale, the extension/shrinkage of ice masses (whether that be sea ice or ice-sheet/shelves) and it is because of this that they alter ocean circulation; although it is believed that precession has the largest influence. Generally speaking, the cycles range between two extremes, one favouring glaciation and the other deglaciation. When they favour glaciation, the THC is forced to downwell further south and thereby reduces northwards heat transfer and the associated ablation processes, to only further accelerate cooling. During glacial termination, the opposite is true and baseline increases in NADW intensity, beginning approximately 18ka, that parallel increasing Northern Hemisphere insolation, have been inferred from the RC11-83 South Atlantic Ocean floor sediment core. Many believe that it is the alterations provoked by this extrinsic forcing factor to the thermohaline circulation that drives, all atleast contributes, to the temperature changes that occur during transitions between glacial and interglacials.

Spectral analysis of variations of the chemical composition of ice cores have revealed that cycles shorter than those of Milankovich have occurred (periodicities of 11100, 6100 and 1470 years); with these sub-Milankovich cycles believed to be overtones generated within the climate system due to the influence longer cycles. The sub-Milankovich cycles can also be classed as an external forcing factor and can be attributed to shorter, abrupt alterations to the oceanic circulation. Precessional-driven climate alterations are believed to be linked to the 11100 year cyclicity which is being held responsible for temperature maximums being experienced every 11100ka in continents straddling the tropics. The 6100 year cyclicity seems to have a relationship with Heinrich events and other coolings such as the Little Ice Age and it is thought to only be amplified by ice-sheet presence. The shortest periodicity, because of the lethargic nature of ice-sheets, presumed to communicate readjustment of atmospheric circulation, is possibly due to solar output variations; something suggested by ¹⁴C records in tree-rings. When the sun is at its most ‘’energetic’, the Earth’s magnetic field is strengthened, blocking more cosmic rays. ¹⁴C is formed when cosmic rays hit plants, therefore measured in tree rings; with high levels of ¹⁴C suggesting an ‘inactive’ sun. Bond documented increases in icebergs and ice drift coinciding with the increase in ¹⁴C, indicating the sun was weaker at such times. Alterations in the volume of ice-rafted debris, in North Atlantic, also coincide with the 1470 year cyclicity, although are only 1/10 the size of the inconsistencies witnessed during the last glacial. Overall, there is agreement amongst scientists that these millennial-scale cycles, which have also been detected within ENSO, have a solar inception affiliated to the THC.

Volcanic eruptions, principally those that disperse ash and SO₂ into the stratosphere which are most commonly high latitude (due to lower tropopause) explosive eruptions, can provoke a period of cooling that can last for a few years; like Pinatubo did after it erupted in 1991, releasing 20 million tonnes of SO₂, cooling the Northern Hemisphere 0.5°C over  5 years.  Despite their apparent ability to affect the climate, the effect they have on ocean circulation is debatable due to the variability produced by GCM. Some models show a connection between volcanic eruptions and a reduction in MOC intensity. However, these reductions appear to be small and short term and, this fact combined with other models not picking up the link above, suggest that the impacts of volcanic eruptions on ocean circulation, if there is one at all, is of little consequence and do not seem to pose a threat to the stability of the ocean circulation.

UN officially declares a famine in Somalia

Last week, the UN officially declared a famine in two regions of southern Somalia. This is the first famine to hit Somalia since 1992 and although it is currently contained in the regions of Bakool and Lower Shabelle, there are fears that this famine could spread throughout the rest of the country. The UN estimates that 2.5 million people in Somalia are in desperate need of assistance so why exactly has it taken so long for it to be officially classed as a famine?

Well, the main reason is that to define a famine is slightly more complex than simply a shortage of food, as some may think. In 2005, the UN established criteria to provide guidance to those needing to declare a famine and to help them allocate their limited resources. Therefore, the UN ranks food security into 5 stages, with famine being the fifth and most severe. They created 3 conditions that have to be met before a famine can be declared:-

- 20% of the population must have fewer than 2100 kilocalories of food available per day
- More than 30% of the children must be acutely malnourished
- 2 deaths per day in every 10,000 people or 4 deaths per day in every 10,000 children must be caused by a lack of food

National Governments have the responsibility to declare a state of famine but, due to the fear of the long term detrimental impact doing so could have on the way the country is perceived, many governments are reluctant to do so. In the case of Somalia, the UN had to step in and take control of the situation as there is a lack of central government in the country.

Until this month, aid agencies had been banned from working in quite large parts of Somalia by the Al-Shabab group, who exercise control over much of southern and central Somalia. It is hoped that the declaration of famine in southern Somalia will provoke greater international efforts to help tackle the situation, which is only likely to get worse without international intervention.

The worst drought in over half a century being experienced in the horn of Africa is to blame for the famine. So, what has created this bad drought?

Think back to the really bad floods experienced in Australia, Sri Lanka and Brazil earlier this year. Well they were caused by La Nina, however, La Nina does not increase rainfall across the globe and in fact, in some areas, it can drastically decrease rainfall. This is the effect that La Nina is having on the horn of Africa and it is one of the principal reasons why this area is experiencing a drought. The hope is that once the switch to El Nino occurs the rainfall will start again but at present, it could be a while until this switch occurs as there are no apparent signs that this is happening. Another factor that is believed to have made this drought so bad is the fact that the temperature of the Indian Ocean is warmer than it has been in previous years. This has provoked an increase in the precipitation over the sea which has reduced precipitation over the land. The rains have failed for three successive rainy seasons and two should occur each year (May to March and October to December).

The drought is, perhaps, the most influential contributory factor that has generated the famine but it is not the only reason…….

Conflict in the area has generated thousands upon thousands of refugees who further increase the population density of the area, meaning that there are more mouths to feed. Many of these refugees have been forced into Kenya and Ethiopia who, respectively, have a predicted 3.5 million and 3.2 million people in need of immediate assistance and this has only acted to increase the food and water shortages in these two neighbouring countries. Conflict, combined with other factors, has led to increases in both food and fuel prices, thereby meaning that affordable food is more and more of a problem. Farmers currently have to sell 5 goats to enable them to buy one 90kg bag of maize. One of the biggest issues is that around 65% of the population are Pastoralists and so make their living by raising and grazing livestock. The drought has caused many of their animals to die of dehydration, thus depriving people of their only food source and income. The lack of development in Somalia is responsible for leaving the Pastoralists vulnerable to such climate extremes as that currently being experienced as a lack of infrastructure, primarily roads and market centres, has closed off their easiest route to prosperity – something which many believe would insulate them from climate extremes.          

The conflict and control exercised over many regions of Somalia has slowed, and in some cases prevented, the aid getting through to the people who clearly so desperately need it. The UN has announced that they will begin airlifting food to Somalia on Tuesday and the World Bank has pledged $500 million in monetary aid - $12 million of which is being used for immediate assistance to the worst hit areas in East Africa. With more than 10 million people estimated to be at risk of starvation; the aid effort needs to be an internationally united one if it is to have the required effect. However, the aid effort cannot stop as soon as the food shortage has been solved. Money needs to be spent on making farming practices in Somalia more sustainable and productive so that food shortages are not a problem in the future. It is true that climate extremes such as the current drought, which has been triggered by La Nina, cannot be prevented but their impacts could be reduced. Improving transport links and infrastructure between rural and urban areas would allow for easier and more effective trade – something which would help prevent people for being isolated by similar climatic extremes.

This situation is far from being remedied and so if I were you I would monitor it and the effectiveness of the aid effort – this is an issue that could be linked easily to the Development and Globalisation module.

Dealing with the aftermath of flooding

This is slightly off topic (if you can bear the length there is a link to climate change right at the end) but I have been trying to keep ontop of some of the population and rivers stuff and so I thought I would try and write a blog post which discussed how different countries deal with the aftermath of flooding. I have also tried to explain how the La Nina oscillation caused extreme rainfall in Australia and Sri Lanka but it is rather complicated - don't fret it is no longer on the syllabus!

Over the past few weeks the news has been filled with stories about flooding across the globe. It is believed that they have all been caused by the same thing – the La Niña oscillation. This oscillation is rather complicated and scientists don’t really understand why or how it happens but I am going to try and explain some of the basics (as I understand them). La Niña occurs when the surface temperature of the water in the eastern Pacific cools and the western waters get warmer. This increase in surface temperature to the west means that the water has more energy and so heavy rainfall and storms become more frequent. The cold water from the deep depths of the ocean gradually rises upwards and collects off the west coast of South America. Strong easterly trade winds pull the cold water across the Pacific. This causes warm water and high pressures to build up along the east coast of south-east Asia and Australia where it becomes trapped which results in heavy rainfall. La Niña has varying impacts on the climate in different parts of the world. Usually the parts of the world that normally experience dry weather become drier and those with wet weather become wetter. The Atlantic and Pacific hurricane activity often increases with La Niña and the effects of severe droughts are likely in those already dry parts of the world.

Although it is believed that the recent floods in Australia and Sri Lanka were caused by the same weather system; the precipitation that fell has had very different impacts on these regions and the two different countries have taken very different approaches to deal with the aftermath of the flooding. Brazil has also experienced floods but it is unclear if this was caused by La Niña as the Met Office claim that La Niña should have made Brazil drier this year. This is an example of how scientists are still unsure about La Niña and also El Nino which has the opposite effect on the climate. The El Nino Southern Oscillation is created when the trade winds that blow along the South American coast from the south east weaken and the temperature of the sea along the South American coast begins to rise. The atmospheric pressure decreases in the eastern Pacific and rises in the western Pacific which causes the warm air and water to move to the eastern side of the Pacific where it replaces the colder water supplied by the Humboldt current. Usually this causes increased levels of precipitation for the western and southern areas of South America and, the lower ocean temperatures create exceptionally dry weather in the countries in the Indian Ocean and the western Pacific. It is unclear what causes the switch between a La Niña and an El Nino and scientists don’t really know if there is any pattern to when they switch.

In Australia the floods, so far, are believed to have claimed 35 lives but there are still some people missing. The floods forced thousands of people to abandon their homes and their belongings. The flooding was caused because the annual monsoon rains coincided with La Niña. These two different weather phenomena do not usually occur simultaneously but, as I am sure you are all aware, when they did the impact on Australia was vast. Last year Australia experienced many bush fires and droughts and the conditions required to provoke these events were created by the El Nino Southern Oscillation. This meant that the ground was extremely dry and so flash floods became a possibility if enough precipitation fell in a short time. As you are all aware, this is exactly what happened as the La Niña oscillation at the beginning of the year, which has been suggested to be the strongest one on record, created an awful lot of rain. Australia experienced its wettest December on record in Queensland with around four times the average rainfall in places and between 400mm and 1200mm (up to 4ft) of rain fell during that four-week period in coastal areas of Queensland. It is not just Queensland that has been hit by flooding. The south eastern state of Victoria has also experienced floods. The Victorian floods are estimated to have killed at least 6,000 sheep and washed away 41,000 hectares of crops, costing the agricultural sector as much as $2 billion in lost production and damaged infrastructure. The impacts of the flooding in Australia vary from the destruction of infrastructure and the loss of materialistic items to the impacts it will have on the Great Barrier Reef. Fortunately only a small percentage of people who were affected by the flooding have lost their lives but, especially in developing countries, this is often not the case. The next problem facing the Australian government is how are they going to deal with the aftermath of the flooding and ultimately who is going to pay for the massive clean-operation.

The clean-up operation is going to be a gigantic task as houses will have to be cleaned, redecorated, refurnished and have all the electrical systems replaced. Fortunately, in developed countries, most insurance companies will provide the funds for most of this. This will have to be done in every house in every one of the 80 communities that was affected by this flooding. Also other infrastructure, especially bridges and roads, will have to be repaired and the cost of this is going to huge. The backbone of the recovery effort is being provided by aid assigned by the Government, charitable donations and help from the military but this is not enough to rebuild the areas hit by the floods. To help foot the bill the Australian Government, from the 1^st July, is implementing a 12 month flood tax for all those who earn over A$50,000 and who were not affected by the floods. The new tax will charge an extra 0.5% on those earning A$50,000-A$100,000 and 1% more on those earning more than A$100,000 and this tax is expected to raise about A$1.8bn. Australia is developed country and so has the resources, and economy, to recover fairly quickly on their own but for other, less developed countries, it is a different story………….

Sri Lanka also experienced wide scale flooding over the last few months. It is believed that as many as 390,000 people have been driven from their homes and at least 3,744 houses have been destroyed, according to the country's Disaster Management Centre. Although, at present, only 37 people have been killed; in developing countries the secondary effects are often worse than the primary effects. It is believed that 400,000 children could starve as the floods have destroyed 21% of the rice crops in the country and so food shortages are an impending issue. Developing countries often have very poor sanitation and so the spread of water borne diseases, like cholera, is likely. Once the water supplies become contaminated it is very difficult to contain the spread of the disease and this is exactly what happened in Haiti and the outbreak has killed over 1000 people. In terms of the cost of repairing the damage, in Sri Lanka it is a lot lower than the cost of rebuilding the Australian states affected. The cost of rebuilding Sri Lanka is estimate to be around £315 million but the country cannot afford to foot this bill. The reason for such a difference in the cost of repair is due to the fact that the damage done in Australia was mainly to the infrastructure which is costly to rebuild. In Sri Lanka the damage to infrastructure would be minimal in comparison as there is not as much developed infrastructure in the country. However, in Sri Lanka, the human cost is going to be a lot higher. In developed countries insurance companies pay out to provide the money need for the cost of repair to houses and taxes are then used to pay for the repair work needed on infrastructure etc. In Sri Lanka this is not the case and instead they have to rely on aid from other countries. So far medical units have been sent to the area to help those who have sought shelter in crowded relief camps and the government have sent military helicopters to distribute aid and used transport aircraft to move aid from the capital, Colombo. Four camps have been set up to help flood victims and troops have been deployed to distribute food and medical supplies. India has sent a plane loaded with food supplies as well as blankets and water purification tablets. The US said it was sending aid and has supplied boats to rescue the stranded and distribute bottled water, cooking materials and tarpaulins. Reaching those in remote areas is often an issue and countries often rely on the helicopters and boats provided by countries like the US to reach those in danger as they, themselves, do not have the resources to do so.

Australia will recover a lot quicker from the flooding than Sri Lanka will. The flooding that occurred in Pakistan 6 months ago is still causing problems in the country today. Over 1000 people died in Pakistan itself and around a 100 more in neighboring Afghanistan whilst thousands lost everything. The biggest issues provoked by the floods were the spread of diarrhoea and cholera and shortages of food and clean water. Pakistan had to depend on aid from other countries in a similar way in which Sri Lanka are doing so now. The UN provided £6.5 million in aid for the relief effort and the UK provided £10 million. The US also offered aid and as well as $10 million they provided 12 temporary bridges to replace most of those that were destroyed by the floods. The worrying fact is that, 6 months on, people are still dying due to the secondary impacts created by flooding. Some blame Government inefficiency, for example, the Sindh area is in desperate need of around 500,000 blankets but so far the Government has only sent 13,000. So the question is, how long will it take Sri Lanka to recover from the flooding and how sufficient and effective is just sending monetary aid?

In terms of development Brazil is probably in between Australia and Sri Lanka. The floods, which then led to landslides, killed over 800 people in Rio de Janeiro and over 500 people are still missing. Brazil is taking a totally different approach to dealing with the aftermath of the flooding. The Government has proposed to build 8000 ‘free’ houses to replace those that were destroyed by the flooding. President Dilma Rousseff has said 6,000 of the proposed homes would be paid for by the state and federal governments and the other 2,000 would be donated by a consortium of construction companies. The houses would be given to families living in shelters after their homes were destroyed and to those who were being removed from areas considered at risk of further flooding and landslides. It is planned that the proposed homes will be built on public land and the construction cost subsidised by the federal government and private companies, with the Rio state government then paying the monthly purchase instalments on behalf of poor families who move in. As well as trying to deal the aftermath of flooding, the Brazilian Government are also trying to implement measures to reduce the impacts if such an event was to occur again. The Government are directing funds to projects which involve mapping out areas that were prone to flooding and landslides and clamping down on unauthorised building in danger zones. Federal money is also being made available to rebuild roads and bridges and fund drainage and hillside stabilisation projects. The hope is that these new measures will reduce the impacts that future floods and landslides will have on the area and the people of Brazil.

These three countries have taken very different approaches to dealing with the aftermath of flooding but is there a right or wrong way to deal with the impacts of flooding? I think that it depends on the area as less developed countries could not implement a temporary tax to foot the bill of the clean-up. Developing countries have to rely on aid to recover after a disaster instead but often monetary aid alone is not enough. Advisors and medics are often needed more than just money to help ensure that the aid actually reaches the people that need it. I think the approach that Brazil has taken to floods is quite sustainable as not only are they trying to deal with the present situation but also prevent a similar one from occurring in the near future. Poor sanitation and unstable buildings in the favelas in areas like Rio de Janeiro escalate the impacts of flooding as they make landslides more likely and the spread of diseases more probable and by making building regulations stricter hopefully the conditions in the favelas can be improved and therefore the secondary effects of future floods less damaging.

Now I am going to try and link flooding to the current module. A recent report that investigated the flooding that the UK experienced during 2000, which damaged 10,000 houses and caused £1.3 billion worth of insurance loss, has blamed climate change for the flooding. This is the first time that anyone has linked a single weather event to climate change since Al Gore implied that human induced climate change caused Hurricane Katrina. Two reports that were released this week have suggested that the increase in greenhouse gas emissions, which has caused the average global temperatures to rise, has significantly increased the risk of flooding as warm air holds more moisture than cold air. Record high sea temperatures are believed to be the reason for La Nina being so strong this year and having such a devastating effect. It is believed that as we increase our greenhouse gas emissions the probability of severe floods occurring across the global will increase. The method used to come to this conclusion was to compare two climate models which were based on two different scenarios. The first one was classed as a realistic scenario and was based on the greenhouse gases that were present in the atmosphere during 2000 whilst the other one was based on a world where humans had not created and emitted any greenhouse gases. The conclusion of the report that used this method was that human greenhouse gas emissions "significantly increased" the likelihood of the 2000 floods and, they claimed, with a 66 per cent confidence level, that emissions nearly doubled the risk of the 2000 floods. http://www.newscientist.com/article/dn20141-blame-human-emissions-for-british-floods.html

 The other report, which was carried out between Canada and the UK, studied the increase in the frequency of extreme precipitation events that occurred in the Northern Hemisphere between 1950 and 2000. They concluded that, although there have been some variations, extreme rainfall events have become more common and the only explanation of this trend is the slow steady increase in temperatures provoked by greenhouse gas emissions. http://www.bbc.co.uk/news/science-environment-12484314

Both of these reports suggest that the possibility of floods, like those experienced in Australia, Sri Lanka and Brazil this year, occurring has significantly increased. This means that countries are going to have to be more prepared and have more efficient ways of dealing with the aftermath of flooding. So, is this really a great time for the government to announce that they are cutting the funds for flood denfences by 8%? http://www.bbc.co.uk/news/uk-politics-12402284