Alevel - AS Geography World at Risk Revision
Alevel - AS Geography World at Risk Revision
Alevel - AS Geography World at Risk Revision
Global hazards
A hazard is an unexpected threat to humans and or their property A disaster is when a natural hazard has serious effects such as large loss of life or property A disaster consists of 2 components Hazardous geophysical event e.g. flood/earthquake/tsunami Vulnerable population: susceptible to humans and or economic loss because of where they live
Risk of disaster
Location do they live on a fault line/near the coast/disaster hotspot: more likely risk of disaster Gender people are more likely to get hurt or injured if they are indoors. Women and children are more likely to be indoors in some parts of the world Quality of buildings better the quality of buildings, the more likely it will survive the hazard Income wealthier people usually have better houses and can afford to live away from high risk areas LEDCs Poor quality buildings, poor disaster management plans and poor prediction abilities
Disaster trends
Impacts of natural hazards vary considerably around the world Asia dominates as being the continent most affected by natural hazards Vulnerability is a big part of the study of natural hazards
Disaster equation
Used to measure hazard vulnerability Hazard vulnerability = capacity of a person to cope with, resist and recover from the impact of a natural hazard
Disaster risk (D) = Hazard (H) x Vulnerability (V) Capacity to cope (C)
Vulnerability based on 3 factors: 1. People HAVE to live in dangerous places cant afford other places 2. Cant afford to build well even if building regulations are enforced 3. Rapid urbanisation forced the poor into high risk areas of cities
Global warming
Some of the largest changes in climate are being seen in the Arctic even though very little of the worlds greenhouse gas emissions come from here. Some areas in arctic cooled whilst others warmed Some will warm more than others Past 50 years the biggest average temp increase has been in Siberia, Alaska and western Canada between 2-3 degrees Largest temp change measured inland North Atlantic cooled by 1 degrees Satellite images from NASA show area of sea covered by summer polar ice cap has decrease by 20% since 1979. Arctic sea ice had thinned by almost half since 1950 Predict arctic sea ice will have disappeared completely by middle of 21st century Sea ice has an albedo it reflects back into space 90% of sunlight which strikes it If the ice disappears it will expose the ocean below which absorbs 90% of sunlight so will heat up more. Sea ice is important in keeping arctic region cool and its loss would accelerate warming in the area Scandinavia and north west Russia could experience average changes of over 6 degrees, Siberia as much as 7 degrees and eastern Canada and Greenland 3-5 degrees Average winter temp in arctic could increase by 10 degrees by 2090 Impact land and marine species, biodiversity and the traditional way of life for humans in the arctic. Also positive impacts
Sea ice
Rising temp lead to reduction of sea ice Later freezing and earlier melting will lengthen period when areas have no sea ice Loss of habitat for polar bears, cold water species of fish such as salmon Can threaten their survival However a decrease in sea ice and an increase in nutrient supply from melting ice will lead to increased productivity at the base of the marine chain as more sunlight reaches phytoplankton, meaning more food for further up the food chain More fish will eat phytoplankton More seals which eat fish Potentially more food for polar bears who eat seals Also more open water benefit some whale species
Siberia
Increase in winter precipitation lead to more snow fall In spring as temp rises, melting occurs, annual fresh water run-off into arctic projected to rise by 14% Greater run-off increases the amount of nutrients and sediment reaching ocean positive and negative effects Coastal & wetland bog ecosystems expected to expand creating habitats Bog ecosystems release methane Methane is greenhouse gas with higher global warming potential than co2. 1kg of methane creates same warming as around 21kg co2 Increase in volume of freshwater into ocean impact ocean currents North Atlantic drift current brings warm surface waters towards the poles while cold water sinks and moves back towards the equator. This current keeps northwest Europe warm Change could impact fish species and climate
Impacts on biodiversity
Rise sea temp exceed thermal tolerance of the some species Loss of biodiversity Impact on seasonal migration by northward shift In Alaska and western Canada biodiversity is high 70% of rare plants species found here occur nowhere else on earth
Impact on humans
Little numbers live in arctic If fish population move, fisheries infrastructure , fish vessels, ports have to relocate which is expensive People using snowmobiles cannot move until first snowfall
Farmers have to grow crops in tin cans because there is too much salt in the ground, the fish are dying because the sea is too warm, and drinking water is harder and harder to find. The small island of Tebua Tarawra has already disappeared, and the islanders of Kiribati and Tuvalu are afraid that more of their land will soon be under water. Most scientists around the world agree that the Earth is getting warmer. They believe that some places are already 2 hotter than they were 50 years ago, and that temperatures will go up another 5 in the next hundred years. This means that the ice at the North and South Pole will melt, the oceans will expand and the sea will rise by as much as one metre.
Global Cooling
The Thermohaline circulation system transports heat around the world through oceanic currents Some of these currents are surface, warm water currents e.g. the gulf stream circled Others are deep water cold currents e.g. the north Atlantic deep water For this conveyor to work warm, salty water sinks south of Iceland powering the current However if a large amount of cold, fresh water is deposited in this area the conveyor will weaker or stop glacial retreat This has occurred in the past last time 14 000 years BP. These events are called Heinrich events These events in the past were caused by ice sheets melting over Canada and caused Europe to return to the ice age Today it is believed that if large areas of the Greenland ice sheet melt or the rainfall increases over Russia that this could happen again
I think the world is a more hazardous place as the graph showing natural disasters reported from 1900 to 2008 shows an increase of natural disasters. From 1900 to 1960 there has been a gradual increase of natural disasters whilst from 1970 to 2000 there has been a dramatic increase in natural disasters reported Some people may disagree and say the world is not a more hazardous place as technology has improved over the years so hazards are easier to measure which could be the reason there are more natural hazards reported.
Building on dangerous places Building dams/levees can cause drought/increasing floods CHINA flooding in 1998 caused more than 4000 deaths, effected 223,000,000 people Inundated 61,000,000 acres of crop land and cost well over 36 billion. Led to logging and agriculture 85% loss of forest left places bare Trees didnt intercept water Heavy rains Flood plain built on Reduced capacity of Yangtze water shed to absorb rain. Greatly increased speed and severity of remaining run off US Pacific northwest 94% of landslides due to clear cuts and logging roads Indonesia 1997-1998 burnt forest size of south Korea to grow palm oil Effecting 70mill people from smoke and haze Economic damage to area 9.3bill Schools/airports shut down Crops burnt by fires Dams/reservoirs dramatically increase flooding by increased rate of flow Bangladesh summer 1998, 2/3 country inundated for a month 1300 people dead, 31mill left homeless 10mill miles of road damaged Heavy rain fall and heavily logged areas Ran off from extensive development upstream
El Nino
El Nino conditions tend to be the opposite of normal in the Pacific. El Nio appears, usually every 37 years. An El Nio is a temporary change in the climate of the Pacific Ocean, in the region around the equator. You can see its effects in both the ocean and atmosphere, generally in Northern Hemisphere winter. Typically, the ocean surface warms up by a few degrees Celsius. At the same time, the place where hefty thunderstorms occur on the equator moves eastward. Although those might seem like small differences, it nevertheless can have big effects on the world's climate.
Effects of El Nino
As well as drier conditions in SE Asia and Australasia and wetter conditions on the west coast of South America, El Nino has other, global effects: It causes severe droughts in the Sahel, southern Africa and the Indian subcontinent. It causes extremely cold winters in central North America. It causes stormy conditions with floods in California. It causes exceptionally wet, mild, windy winters in the UK and NW Europe. It is believed to suppress the hurricane season in the Caribbean.
La Nina
Cooling of surface water in the west of the Pacific Ocean and conditions are above the normal level and is the opposite of El Nino. In El Nino the sea water would move to the right but, with La Nina the waters move to the left towards Indonesia, Australia and New Zealand. The Pacific Ocean temperature drops by 3-5oC below the normal temperature and the central, eastern part of the Pacific cools down. Happens by the convection currents moving in the opposite direction warmer water being pushed to the west more clouds are formed over Australia, Indonesia and New Zealand as the low pressure causes the air to rise and condense, increasing the rainfall over these regions.
Effects
Weather Cycles - La Nia are responsible for weather extremes in various parts of the world that are typically opposite to those associated with El Nio. La Nia features unusually cold weather in the Northwest and (to a lesser extent) northern California, the northern Intermountain West, and the north-central states. Farther south, higher than normal temperatures are slightly favoured in a broad area covering the southern Rockies and Great Plains, the Ohio Valley, the Southeast, and the MidAtlantic States. La Nia's cooler temperatures also affect Canada from British Columbia's west coast, through the Prairie Provinces and into Ontario. Southern BC receives more snow than average; much of southern Canada will receive higher precipitation of all types. Fishing is also affected: Sockeye salmon will travel through the Strait of Juan de Fuca thanks to the preferred lower temperatures. This allows American fishing vessels to share the catch. Drought in East Africa Also Due to La Nia. Globally, La Nia is characterized by wetter than normal conditions west of the equatorial central Pacific
Water shortage is common in large areas of California. Due to earthquake risk, the state is also at risk from tsunamis. Intense winter rain storms can cause flash floods in LA Local wind Santa Ana spreads bush fires
Brush wood becomes highly flammable every autumn when hot and dry.
California experiences between 100 and 150 earthquakes large enough to be felt by humans each year. In the last 25 years, more than 100 Californians have lost their lives to landslides which are triggered by intense rainfall. Estimated that in past 1000 years there have been 12 volcanic eruptions in the area The likelihood of a volcanic eruption occurring in any given year is less than 1%. California, hill region covered in sandy soil. Subsidence: when ground slips due to drilling down for oil along the coast. Ground sinks into the sea causing rising sea level
In 1991, Mt Pinatubos eruption caused large pyroclastic flows and widespread lahars and caused 1000s of people to evacuate. The Philippines experience considerable seismic events Cyclone activity exposes islands to strong winds and rain
Faces the pacific ocean which is the most prone to tsunamis in the world
GDP in 2006 was US $5000 Per capita The Philippines has a number of large volcanoes The Philippines have experience a number of very intense earthquakes in recent years In 2003, 200 people were killed in landslides. In 2006 a local earthquake triggered a 3m high tsunami. Humans have caused deforestation of many mountain forests
Greenhouse effect
The greenhouse effect and the enhanced greenhouse effect are below.
Time:
Geological time is split into smaller periods The quaternary is the name given to the past 2.6million years It is then split into Pleistocene and Holocene the Holocene is past 10,000 years Geographical time is measured as BP (Before present) This is the number of years before 1953
Glacial period of widespread glaciation (cold period) Interglacial warmer period with reduced or no ice cover
Positives: The sequences of sea level change links very closely with oxygen and carbon dioxide Can trace changes in temperature and atmospheric gases over a very long stretch of time
Negatives: Very expensive to extract and analyse Only found in cold places
Positives: Cheaper than ice cores Available more widely Anywhere in world
Negatives Accurate pollen reconstructions rely on good preservation of pollen Long pollen sequences are rare Vegetation change may lag behind climate change Relies on habitat of modern pollen sets plants may have evolved over time
Positives: A good source of temperature data Better in places with old trees
Negative: Tree records only give localized records Deforestation means tree data has been lost
Negative Unreliable these sources did not set out to record climate change and must be used with care They are usually local Difficult to generalized Anyone could have painted or written them
Positives: Reliable good records stretch back to around 1880, before this the record is patchy
Negatives Glaciers may be reacting to internal mechanisms completely unrelated to climate change.
Negatives: Many measuring devices have been moved over their life span, often from towns to rural areas causing an artificial temperature change.
Tropical storms:
Form between tropics e.g. North Atlantic, Indian ocean and West Pacific This is because when warm damp air rises, it condenses forming clouds which go on to form the hurricane. Depending on direction of prevailing winds, these storms then travel towards the coast
Avalanches:
Found in cold mountainous regions where it snows Snow falls due to cold air rising over mountains, condensing and hen forming precipitation The snow builds up and when it becomes unstable an avalanche occurs
Volcanoes:
Found along plate boundaries e.g. Japan, Philippines, Italy Along destructive boundaries composite volcanoes are found This is because oceanic plate is forced under the continental plate causing oceanic plate to melt This causes an increase in pressure which will eventually explode to the surface as a volcano. Along constructive plate boundaries (North Atlantic Ridge) the plates are moving apart. As this happens, magma rises to the surface, but not under pressure causing a shield volcano
Droughts
Localised to areas where there is little rainfall This is due to anticyclonic conditions, where air is falling causing high pressure The air is dry because it is falling so it is unable to collect any moisture Anticyclones are stable weather conditions which means they stay in a place for considerable periods of time.
Earths Orbit: Every 100 000 years the Earths orbit changes from spherical to elliptical, changing solar input
Tilt of the earth: The Earths axis is tilted at 23.5o, this changes over a 41 000 year cycle between 22o & 24.5o, affecting solar input, especially in higher latitudes.
Wobbly axis: The Earths axis wobbles, so which way the hemispheres are facing to the sun when closest to the sun varies over 21 000 years. Affecting solar input.
Many scientists argue that the Milankovitch cycle may have been just enough to trigger a major global climate change, but that climate feedback mechanisms are needed to sustain it -Feedback effects are those that can amplify a change and make it bigger (positive) or smaller (negative). An e.g. of positive feedback is snow and ice cover. Small increase in snow and ice raises surface albedo reflecting more solar energy back into space. Resulting in further cooling An e.g. of negative feedback is cloud cover. As CC occurs, more evaporation occurs increasing cloud cover, which in turn may reflect more solar rays back into space diminishing effects of the warming.
3. Natural: Volcanoes
Major eruptions eject material into stratosphere. The sulphur dioxide forms a haze of sulphate aerosols This reduces the amount of sunlight received at Earths surface The eruption of Tambora led to the year without a summer in 1816 as global temperatures dipped by 0.4-0.7 degrees C
Effects Migration Hard engineering Barriers to sea levels rise to prevent flooding Storing food for extreme weather
Mitigation:
Mitigation is the reduction of greenhouse gases emitted into the atmosphere While the climate system would still be changing for a number of decades into the future (a legacy of past emissions), the risk of compounding these changes would be significantly reduced. A complete cut in emissions is unlikely but there are ways of limiting emissions Pros Reducing problem solving it Sustainable Save money on having to adapt Cons Could be expensive Could take longer to effect/make a change Everyone needs to take part
Integrated waste segregation facilities Domestic and small businesses have renewable energy grants scheme Targets ensure that 15% of all energy use in Birmingham is from renewable sources 30% domestic water recycled by 2010 An increase in co2 road transport should be kept to less than the increase in road traffic
National Scale: UK
Cutting emissions Emissions have already fallen 21% below 1990 levels nearly double what was promised at Kyoto In the UK alone, low carbon and environmental goods and services are already worth more than $100billion each year and the sector employs 80,000 people Government has put in place the worlds first ever legally binding target to cut emissions at least 80% by 2050 and a set of 5-year carbon budgets to keep the UK on track. By 2020 emissions will be 18% below 2008 levels Emissions falling faster than before fallen 1% a year since 1990 and will now fall 1.4% a year. All UK government departments been allocated their own carbon budget Produce around 30% of our electricity from renewable by 2020 by substantially increasing the requirements for electricity suppliers to sell renewable electricity Facilitate building of new nuclear power stations Making homes greener by channelling 3.2billion to help households become more energy efficient Rolling out smart meters in every home by 2020 Introducing clean energy cash back schemes so people and businesses will be paid if they use low carbon sources to generate heat/electricity
Recognizing that developed countries are principally responsible for the current high levels of GHG emissions in the atmosphere as a result of more than 150 years of industrial activity, the Protocol places a heavier burden on developed nations under the principle of "common but differentiated responsibilities."
Why was it created? The Kyoto Protocol was adopted in Kyoto, Japan, on 11 December 1997 and entered into force on 16 February 2005. The reason for the lengthy time span between the terms of agreement being settled upon and the protocol being engaged was due to terms of Kyoto requiring at least 55 parties to ratify the agreement and for the total of those parties emissions to be at least 55% of global production of greenhouse gases. Every year we are releasing almost 7 billion tonnes of carbon into the atmosphere carbon that had lain buried since the days of the dinosaurs. Remain in the atmosphere for around a century, raising the level of carbon dioxide in the atmosphere and trapping more of the sun's heat. Before the industrial age, the CO2 level was steady at around 280 parts per million. When the Kyoto protocol was drawn up in 1997, the CO2 level had reached at 368 ppm. In 2004, it hit 379 ppm.
Figures released by the UN last month suggest the world is on track to meet its Kyoto targets for greenhouse gases. Countries in Kyoto Protocol have committed to cut emissions of not only carbon dioxide, but of also other greenhouse gases, being:
Methane (CH4) Nitrous oxide (N2O) Hydrofluorocarbons (HFCs) Perfluorocarbons (PFCs) Sulphur hexafluoride (SF6) Countries involved
India and China, which have ratified the Kyoto protocol, are not obligated to reduce greenhouse gas production at the moment as they are developing countries.
Impacts: Among industrialised nations, 16 are on target to meet their Kyoto obligations, including France, the UK, Greece and Hungary, the UN said. Some 20 countries are off-course, including Canada, Germany, Ireland, Italy, Japan, New Zealand and Spain. Nations that miss their Kyoto target in 2012 will incur a penalty of an additional third added to whatever cut they agree under a new treaty in Copenhagen. Has Kyoto worked? "In terms of emission reductions achieved, the answer would be no," De Boer said. "A 5% cut is a pretty small step on what will be a long and arduous journey.
What: The Accord: Developed countries must make commitments to reduce greenhouse gas emissions, and developing countries must report their plans to curb greenhouse gas emissions to the UN by 31 January 2010 Endorses the continuation of the Kyoto Protocol. Underlines that climate change is one of the greatest challenges of our time and emphasises a "strong political will to urgently combat climate change in accordance with the principle of common but differentiated responsibilities and respective capabilities" To prevent dangerous anthropogenic interference with the climate system, recognizes "the scientific view that the increase in global temperature should be below 2 degrees Celsius", in a context of sustainable development, to combat climate change. Recognizes "the critical impacts of climate change and the potential impacts of response measures on countries particularly vulnerable to its adverse effects" and stresses "the need to establish a comprehensive adaptation programme including international support" Recognizes that "deep cuts in global emissions are required according to science" (IPCC AR4) and agrees cooperation in peaking (stopping from rising) global and national greenhouse gas emissions "as soon as possible" and that "a low-emission development strategy is indispensable to sustainable development" The deal does not spell out penalties for any country that fails to meet its promise.
Recognizes "the crucial role of reducing emission from deforestation and forest degradation and the need to enhance removals of greenhouse gas emission by forests", and the need to establish a mechanism (including REDD-plus) to enable the mobilization of financial resources from developed countries to help achieve this. Establishes a Copenhagen Green Climate Fund, as an operating entity of the financial mechanism, "to support projects, programme, policies and other activities in developing countries related to mitigation
How: Reducing carbon emissions - Countries representing over 80% of global emissions have engaged with the Copenhagen Accord. A selection of reduction targets is shown below. All are for the year 2020. Japan: 25% Russia: 15% - 25% Ukraine: 20%
The G77 said that the Accord will only secure the economic security of a few nations Australia was happy overall but "wanted more". India was "pleased" The United States said that the agreement would need to be built on in the future and that "We've come a long way but we have much further to go." United Kingdom said "We have made a start" but that the agreement needed to become legally binding quickly. People's Republic of China's delegation said that "The meeting has had a positive result, everyone should be happy. Brazil's climate change ambassador called the agreement "disappointing". Bolivian president, Evo Morales said that, "The meeting has failed. It's unfortunate for the planet. The fault is with the lack of political will by a small group of countries led by the US.
Criticism: The BBC immediately reported that the status and legal implications of the Copenhagen Accord were unclear. The accord itself is not legally binding No decision was taken on whether to agree a legally binding successor or complement to the Kyoto Protocol. The accord sets no real targets to achieve in emissions reductions. The accord was drafted by only five countries The deadline for assessment of the accord was drafted as 6 years, by 2015. The mobilisation of 100 billion dollars per year to developing countries will not be fully in place until 2020 There is no guarantee or information on where the climate funds will come from. There is no agreement on how much individual countries would contribute to or benefit from any funds. COP delegates only "took note" of the Accord rather than adopting it.
The head of the G77 has said it will only secure the economic security of a few nations. It shows biases in silent ways such as the promotion of incentives on low gas-emitting countries.
Success: Tony Tujan of the IBON Foundation suggests the failure of Copenhagen may prove useful, if it allows us to unravel some of the underlying misconceptions and work towards a new, more holistic view of things The Copenhagen Accord, for the first time, unites the US, China and other major developing countries in an effort to curb global greenhouse gas emissions. The accord also says developed countries will aim to mobilise $100bn per year by 2020, to address the needs of developing countries. In some parts of the world this is already having impacts - and a Copenhagen deal could not stop those impacts, although it could provide funding to help deal with some of the consequences.
Key players in the Copenhagen agreement: Key player: someone who has power and influence over a situation The key players include US, China, India, Brazil and South Africa. These are the countries that drafted the accord and include some of the countries with most the carbon emissions such as US and China.
Innovative strategies:
End our dependence on fossil fuels Short term aim to use fossil fuels more efficiently Some fossil fuels are clean and should be used more often Transport converted to operate on natural gas which are better for environment
Carbon capture:
Greenhouse gases can be caught before they are released into the atmosphere Carbon capture then stored safely in a designated carbon sink where it is sealed off and unable to enter the atmosphere
Transition to clean sources create range of jobs in diverse areas of new industries By 2050, products that relate to low carbon energy market expected to have a global value of $500billion
Economic Impacts: Weighed up the impact on rising sea level on the Thames estuary where assets are worth 100 billion New developments planned for London are in or bordering the tidal flood risk zone As insurance cover may be withdrawn, it could lead to the collapse of the property market Businesses and finance area in Canary Wharf would be very vulnerable to increasing flood risk Solutions: There is a current effort to upgrade Londons defences by 2030 in the Environment agencies Thames project 2100. Aims to project the capital for the rest of this century New study raises the risk and reinforced the need to upgrade defences in the Thames.
Maldives
Vast use of the island has led to an environmental catastrophe Sea level rise by 0.9cm a year 80% of islands in Maldives are no more than a metre over sea level, within 100 years Maldives would become inhabitable. Countrys 360,000 citizens forced to migrate 60% of population volunteered to evacuate in next 15 years First country to sign up to the Kyoto protocol The capital city is surrounded by a 3m high wall which took 14 years to construct at a cost of 63million dollars Maldives economy is weak and cannot pay this amount which was accepted aid from japan Japan paid 99% of cost No sustainable as not long term Wall only covers and protects 200 inhabited islands against tidal surges Tidal surges flood homes every fortnight Government encourages forestation to prevent beach erosion Coral reef natural barrier against tidal surges
New York
In 2007, IPCC said by 2100 sea levels would rise by 1ft and new York would be effected If Greenland ice sheets melt, new York wont have a large rise in sea level If Antarcticas ice sheet was to melt new York would have a large rise in sea level This is because the Greenland and Antarctica ice sheets pull sea water towards the two countries. When sheets melt, water is pushed away from countries so sea level drops New York will be 20% more affected by sea level ruse than elsewhere.
Bangladesh
If climate changes push sea levels high, people in coastal low lying areas such as Bangladesh could be forced from their homes. In the last century world heated up by 0.6 degrees, Sea level rose from 9 to 20 cm and is predicted to increase to 88cm by 2100 Bangladesh is situated in the low lying Ganges river delta and is one of the most densely populated countries on the earth Char Bangla is one of thousand islands located around the river delta People living here are most vulnerable Rivers are expected to flood, destroying surrounding areas Villagers have built up platforms of mud for their huts to try and keep them out of the water.