paper 1, section a, challenge of natural hazards Flashcards
what are natural hazards?
a natural event that has a social impact
what are geological/tectonic hazards?
an extreme natural event in the crust of the earth that pose a threat to life and property
what are atmospheric hazards?
they occur as a result of processes in the atmosphere
what are some examples of atmospheric hazards?
- rain
- lightning
- drought
- snow
- hurricanes
- tornadoes
- wind
what category does flooding fall under?
not atmospheric or geological - hydrological
what are some examples of geological hazards?
- volcanoes
- landslides
- mudflows
- avalanches
- earthquakes
what factors affect risk?
- urbanisation
- poverty
- climate change
- farming
how does poverty affect risk?
poverty may force people to live in areas at risk
e.g. in Lima in Peru or Caracas in Venezuela there is a shortage of housing means people have had to build on unstable slopes prone to floods and landslides
how does climate change affect risk?
in a warmer world the atmosphere will have more energy leading to more intense storms
e.g. places may become wetter with an increased risk of flooding or drier and prone to droughts and famines
what are the two types of tectonic plates?
oceanic plate/crust
continental plate/crust
how are the two types of plates different?
oceanic plates are thinner and denser whereas continental plates are thicker and less dense
what mechanisms drive plate movement?
- they move due to convection currents which are currents of heat
- gravitational sliding which includes two mechanisms
what are the two mechanisms of gravitational sliding?
ridge push and slab pull
what is ridge push?
it happens at constructive plates; two plates are pushed apart by the injection of new magma
what is slab pull?
it happens at destructive margins where gravity acts upon the thicker, denser plate = sinks under its own weight
what happens at destructive/convergent plate boundaries?
- where the plates meet, a deep ocean trench is formed
- the dense oceanic plate subducts below the less dense continental plate
- friction between the plates creates strong earthquakes
- the subducted oceanic plate melts, creating less fluid magma (high viscosity)
- eruptions from the steep-sided composite volcanoes are often violent and explosive
what happens at constructive/divergent plate boundaries?
- magma forces its way up to the surface
- when the magma breaks through the crust it can cause small earthquakes
- upon reaching the surface it forms volcanoes
- the magma is hot and fluid (low viscosity) and results in broad, flat shield volcanoes
what happens at conservative/transform plate boundaries?
- friction between these plates causes earthquakes
- earthquakes happen as stresses build up gradually over many years
- they can be very destructive as they occur near the earth’s surface
- there are no active volcanoes at this tectonic plate margin
when and where did the earthquake occur in Nepal?
April 2015, in Gorkha
when and where did the earthquake occur in Italy?
April 2009, in L’Aquila
what was the magnitude of of the earthquake in Nepal?
7.8
what was the magnitude of of the earthquake in Italy?
6.3
how many deaths occurred due to the earthquake in Nepal?
8,841 (19 on Mount Everest)
how many deaths occurred due to the earthquake in Italy?
308
how many people were made homeless by the earthquake in Nepal?
1 million
how many people were made homeless by the earthquake in Italy?
67,500
what was the cost of damage of the earthquake in Nepal?
US $5.15 billion
what was the cost of damage of the earthquake in Italy?
US $1.1 billion
what were the primary effects of the earthquake in Nepal?
- 8,841 dead
- over 16,800 injured
- 1 million homeless
- 26 hospitals and 50% of schools were destroyed
what were the secondary effects of the earthquake in Nepal?
- started an avalanche on Mount Everest which impacted Everest Base Camp and therefore affected tourism
- earthquake occurred right before monsoon season which is when rice is planted; rice is Nepal’s ‘staple diet’ and since 2/3 of the population rely on farming, it’s very important; rice seed which was stored in homes was destroyed which caused food shortages and loss of income
- in 2014, tourism was reported to be 8.9% of Nepal’s GDP and was expected to increase by 5.8% in 2015; however, until Nepal recovers from the earthquake, tourism, employment and income will shrink
what were the short-term responses for the earthquake in Nepal?
- temporary shelters were set up: the Red Cross gave out tents for 225,000 people
- the UK’s disasters emergency committee and the US raised US $126 million by September 2015 for emergency aid and to help begin to rebuild the worst-affected areas
- several companies did not charge for phone calls
what were the long-term responses for the earthquake in Nepal?
- Nepal’s government (as well as the UN, EU etc) carried out a post-disaster needs assessment and found 23 areas required rebuilding e.g. housing, schools, agriculture etc
- the durbar square heritage sites reopened in June 2015 and Mount Everest reopened for tourists by August 2015
- six months later, the FAO started a recovery phase; people were trained how to repair and maintain irrigation systems damaged by landslides from the earthquake to help crop production
what were the primary effects of the earthquake in Italy?
- est. 308 people killed
- 1,500 injured
- 67,500 homeless
- approx. 10,000-15,000 buildings collapsed e.g. churches, San Salvatore hospital, National Museum etc
what were the secondary effects of the earthquake in Italy?
- aftershocks set off landslides and rockfalls which damaged transport and houses
- the amount of students at L’Aquila university decreased
- a lack of housing caused rent and house prices to increase
what were the short-term responses for the earthquake in Italy?
- 40,000 tents given out and shelter for 10,000 provided in hotels
- British Red Cross raised £171,000 to help
- Italian Red Cross searched for survivors- with seven dog units, 36 ambulances and a temporary hospital
what were the long-term responses for the earthquake in Italy?
- residents didn’t have to pay tax in 2010
- students were allowed free public transport, discounts on educational equipment and exemption from university fees for 3 years
- homes took several years to rebuild whilst historic centres were estimated to take 15
why do people choose to live in hazardous areas?
- earthquakes and volcanic eruptions don’t happen very often, they are not seen as a great threat in most people’s lives
- better building design can withstand earthquakes so people feel less at risk
- more effective monitoring of volcanoes and tsunami waves enable people to receive warnings and evacuate before events happen
- some people may not be aware of the risks of living close to a plate margin
what are the benefits of living on a plate margin?
- access to hot water
- dramatic landscapes which increase tourism and increase employment
- volcanic rocks (building materials)
- geothermal energy which is used to produce electricity
what is an example of where people benefit from living in a hazardous area?
Iceland
how to people in Iceland take advantage of the environment?
- hot water from within the earth’s crust provides heat and hot water for nearly 90% of all buildings in Iceland
- geothermal energy is used to generate 25% of the country’s electricity (most of the rest is generated by hydroelectric power)
- volcanic rocks are used in construction for roads and buildings
- Iceland’s dramatic landscape with waterfalls, volcanoes and mountain glaciers has become a huge draw for tourists; tourism provides jobs for many people
what are the four main management strategies?
- monitoring
- prediction
- protection
- planning
what is monitoring?
the use of scientific equipment to detect warning signs
how is monitoring used to manage the risks of volcanic eruptions?
- remote sensing (satellites)
- seismicity (seismographs)
- ground deformation (laser beams measure the ground)
how is monitoring used to manage the risks of earthquakes?
- occur without warning most of the time
- bulging of the ground
- raised groundwater levels
what is prediction?
the use of historical and scientific research to predict when and where
how is prediction used to manage the risks of volcanic eruptions?
- linked to monitoring, allows more accurate predictions and effective evacuation
how is prediction used to manage the risks of earthquakes?
- impossible due to lack of clear warning signs
- however, historical records can help determine probability and help plan for them
what is protection?
designing buildings or shelters to withstand events
how is protection used to manage the risks of volcanic eruptions?
- little can be done to protect houses, but diversions can be used for lava (embankments)
how is protection used to manage the risks of earthquakes?
- drills help keep people alert and prepared
- earthquake-resistant construction is the best way to reduce risk
what is planning?
identifying and avoiding places most at risk
how is planning used to manage the risks of volcanic eruptions and earthquakes?
- areas are mapped to assist with identifying areas to practice evacuation or restrict building
what is global atmospheric circulation?
- the cruising altitude (height) of an aeroplane is around 10km above the ground surface; at this altitude, the majority of the atmosphere’s mass is below you
- the atmosphere is a highly complex, swirling mass of gases, liquids and solids; these include: water droplets, water vapour, ash, carbon dioxide and oxygen
how does global atmospheric circulation work?
- air that is sinking towards the ground surface forms areas of high pressure, winds on the ground move outwards from these areas
- low pressure areas on the ground are formed when air is rising from the ground surface e.g. at the equator
- winds on the ground move towards areas of low pressure
how does global circulation affect the world’s weather?
it drives the world’s weather e.g. trade winds in the tropics push tropical storms across these regions
how does it explain cloudy and wet conditions in the UK?
- the UK is about 55 degrees north, just below the 60 degree north line of latitude
- this mens the UK is near the boundary of cold polar air which moves down from the north and warm sub-tropical air from the south (moving up)
- the boundary between these is unstable (rising air and low pressure belts)
- rising air cools, condenses and creates clouds and rain
- warm and wet conditions are brought to the UK by winds from the south-west
- cold polar air moving down from the north moving down bringing snow and very cold winter weather
how does it explain hot and dry conditions in the desert?
- +- 30 degrees north and south of the equator
- air is sinking = high pressure (sub-tropical high)
- lack of clouds as air isn’t rising and little rainfall
- lack of clouds = very hot during the day and cold at night (heat lost in the ground)
how does it explain hot and sweaty conditions at the equator?
- 0 degrees, the air is rising = low pressure (equatorial low)
- hotter than the UK (with the sun directly overhead)
- equatorial regions, such as central Africa and south-east Asia, experience hot, humid conditions
- it is often cloudy with high rainfall
- this is the region where tropical rainforests are found
what is the name for tropical storms in the USA and Caribbean?
hurricanes
what is the name for tropical storms in south-east Asia and Australia?
cyclones
what is the name for tropical storms in Japan and the Philippines?
typhoons
where do tropical storms form?
- over warm oceans (above 27 degrees celsius)
- in the summer and autumn (when sea temperatures are highest)
- 5-15 degrees north and south of the equator (because at the equator there is not enough ‘spin’ from the rotation of the earth)
- in tropical places intense heat causes air to be unstable and rise rapidly; unstable conditions are important in the formation of hurricanes
what are the wind speeds for each category on the Saffir-Simpson scale?
5 - >252km/h
4 - 209-251km/h
3 - 178-208km/h
2 - 154-177km/h
1 - 119-153km/h
what is the distribution of tropical storms like?
- over the last few decades, sea surface temperatures in the tropics have increased by 0.25-0.5 degrees celsius; the changing patterns and areas of sea surface temperatures will influence the location of tropical storms
- in the future, tropical storms may form and affect areas outside the hazard zone (tropical belt), tropical storms may also become more powerful
what is the frequency of tropical storms like?
past recorded data and computer models indicate that the frequency of tropical storms may decrease but their intensity will increase
what is the intensity of tropical storms like?
hurricane intensity in the North Atlantic has increased in the last 20 years; this is most likely linked to the increase in sea surface temperatures; however, comparing current events with past data is unreliable as we have not been accurately measuring tropical storms for long enough
how do tropical storms form?
- a strong upward movement of air draws water vapour up from the warm ocean surface
- evaporated air cools as it rises and condenses to form thunderstorm clouds
- as the air condenses it releases heat which powers the storm and draws up more and more water from the ocean
- several smaller thunderstorms join together to form a giant spinning storm; when surface winds reach an average of 120km/h it becomes a tropical storm
- the storm develops an eye in the centre where air descends rapidly; the edge of the eye is the eyewall, where the most intense weather (strong winds and heavy rain) is
- as the storm is carried across the ocean by prevailing winds, it gains strength
- when it reaches land, the storm’s energy supply (evaporated water) is cut off; friction with the land slows it down and it begins to weaken
when and where did Typhoon Haiyan occur?
November 2013, Philipppines
how did Typhoon Haiyan form?
- originated as a low-pressure area in the federated states of Micronesia (in the western Pacific Ocean)
- the storm moved westwards
- by 4th November, it had gradually developed into a tropical storm
what were some primary effects of Typhoon Haiyan?
- about 6,300 people killed, most drowned by the storm surge
- over 600,000 people displaced and 40,000 homes damaged or flattened, 90% of Tacloban city was destroyed
- Tacloban airport terminal badly damaged
- the typhoon destroyed 30,000 fishing boats
- strong winds damaged buildings and power lines and destroyed crops
- over 400mm of rain caused widespread flooding
what were some secondary effects of Typhoon Haiyan?
- 14 million people affected, many left homeless and 6 million people lost their source of income
- flooding caused landslides and blocked roads, cutting off aid to remote communities
- power supplies in some areas cut off for a month
- ferry services and airline flights disrupted for weeks, slowing down aid efforts
- shortages of water, food and shelter affected many people, leading to outbreaks of disease
- many jobs lost, hospitals were damaged, shops and schools destroyed, affected people’d lives and education
- looting and violence broke out in Tacloban
what were some short-term responses for Typhoon Haiyan?
- international governments and aid agencies responded quickly with food aid, water and temporary shelters
- over 1,200 evacuation centres were set up to help the homeless
- French, Belgian and Israeli field hospitals set up to help the injured
- the Philippines Red Cross delivered basic food aid, which included rice, canned food, sugar, salt and cooking oil
what were some long-term responses for Typhoon Haiyan?
- the UN and countries including the UK, Australia, Japan and the US donated financial aid, supplies and medical support
- rebuilding of roads, bridges, and airport facilities
- ‘cash for work’ programmes; people paid to help clear debris and rebuild the city
- rice farming and fishing quickly re-established; coconut production, where trees may take 5 years to bear fruit, will take longer
- aid agencies such as Oxfam supported the replacement of fishing boats, a vital source of income
what preparations were made for Typhoon Haiyan?
- hours before the typhoon hit, philippine authorities moved 800,000 people to evacuation centres, many of these structures could not withstand the winds or water though
- many people didn’t panic as they were used to typhoons
- inadequate preparations
- weak buildings
- philippine officials didn’t anticipate the 20 foot storm surges
- some people ignored the evacuation
what are some key statistics for Typhoon Haiyan?
- category 5 storm on Saffir-Simpson scale
- winds up to 275km/h
- waves as high as 15m
- about 6,300 killed
- over 600,000 displaced
- typhoon destroyed 30,000 fishing boats
- 14 million people affected
- Province of Leyle took full force
- most of Tacloban’s 220,000 inhabitants left homeless
- over 1,200 evacuation centres were set up to help the homeless
- one of the strongest storms ever recorded
how is the area affected by the Typhoon now, a few years on?
- ‘resettlement sites built north of the city aided in recovery, but also displaced farmers that had been working on the lands for generations; many are now experiencing dramatic changes to their land security, housing, and ability to pursue their livelihoods’ (2019)
- costs to rebuild in the Philippines were estimated at $5.8 billion
what are some examples of effective monitoring/prediction/protection/planning?
- monitoring and prediction: in the US, two levels of warning systems; hurricane watch and hurricane warning
- protection: in Bangladesh, 2000 cyclone shelters built
- planning: in the US, there is a National Hurricane Preparedness Week
that is hurricane watch and hurricane warning?
hurricane watch: advises hurricane conditions are possible
hurricane warning: advises hurricane conditions are expected and people should take immediate action
why was Bangladesh a success story?
- early warning system
- cyclone shelters
- greater awareness
these things helped reduce death tolls from 500,000 deaths in 1970 to 4,234 in 2007
what is the difference between weather and climate?
weather - day to day conditions of the atmosphere
climate - average weather over a long period; data used over 30-year period to describe the climate of a place
what is weather driven to the UK by?
by south-westerly prevailing wind
what are some weather hazards which occur in the UK?
- thunderstorms
- prolonged rainfall
- drought and extreme heat
- heavy snow and extreme cold
- strong winds
what are some examples of extreme weather events in the UK?
2003: heatwave
- the UK recorded its highest ever temperature of 38.5 degrees celsius in Kent; over 2000 people died due to the heat , railway tracks buckled and in places the roads melted
2009: heavy snow
- parts of south-west and south-east England were affected by heavy snow with 20cm falling in the capital
2013/14: floods
- severe floodng occurred across southern England causing the River Thames to burst its banks and vast areas of the Somerset Levels to become inundated; it was England’s wettest winter in 250 years
where are the Somerset Levels?
- Somerset is a county in south-west England
- the Somerset Levels and the Somerset Moors form an extensive area of low-lying farmland and wetlands bordered by the Bristol Channel and Quantock Hills to the west and the Mendip Hills to the north
- the area is drained by several rivers (including the Tone and the Parrett) which flow to the Severn Estuary via Bridgwater
- flooding has occurred naturally here for centuries, as the area has been developed for farming and settlement, many people are no at risk from extreme flood events
what were the social impacts of the flood?
- over 600 houses flooded
- 16 farms evacuated
- residents evacuated to temporary accommodation for several months
- villages such as Moorland and Muchelney cut off; this affected people’s daily lives, e.g. attending school, shopping etc
- many people had power supplies cut off
what were the economic impacts of the flood?
- Somerset County Council estimated the cost of flood damage to be more than £10 million
- over 14,000 ha of agricultural land under water for 3-4 weeks
- over 1,000 livestock evacuated
- local roads cut off by floods
- Bristol to Taunton railway line closed at Bridgwater
what were the environmental impacts of the flood?
- floodwaters were heavily contaminated with sewage and other pollutants including oil and chemicals
- a huge amount of debris had to be cleared
- stagnant water that had collected for months had to be deoxygenated before being pumped back into the rivers
what were the immediate responses to the flood?
- as the floodwaters spread out over the Somerset Levels, homeowners coped as best they could
- villagers cut off by the floods used boats to go shopping or attend school
- local community groups and volunteers gave invaluable support
what were the longer-term responses to the flood?
- a £20 million Flood Action Plan has been launched by Somerset County Council who will work together with agencies such as the Environment Agency to reduce the risk of future flooding
- in March 2014, 8km of the Rivers Tone and Parrot were dreaded to increase the capacity of the river channel
- road levels have been raised in places to maintain communications and enable businesses to continue during future flood events
- vulnerable communities will have flood defences
- river banks are being raised and strengthened and more pumping stations will be built
- in the longer term, by 2024, consideration will be given to a tidal barrage at Bridgwater
what caused the flood in 2014?
- it was the wettest January since records began (1910)
- a succession of depressions (areas of low pressure) driven across the Atlantic Ocean brought a period of wet weather lasting several weeks; about 350mm of rain fell in January and February, about 100mm above average
- high tides and storm surges swept water up the rivers from the Bristol Channel; this prevented fresh water reaching the sea and it spilled over the river banks
- rivers had not been dredged for at least 20 years, and had become clogged with sediment
what are some key statistics for the Somerset Levels case study?
- about 350mm of rain in Jan and Feb
- rivers hadn’t been dredged for 20 years
- over 14,000 ha of agricultural land under water for 3-4 weeks
- over 600 house flooded
- Rivers Tone and Parrot were dredged in March 2014
- over 1,000 livestock evacuated
- 16 farms evacuated
- flood damage estimated at more than £10 million
explain why extreme weather events may be on the rise
e.g. devastating floods in Pakistan (2010), intense heatwaves in Russia (2010), and severe droughts in western USA (2014)
- scientists believe that a trend over many years could be linked to a warming world: more energy in the atmosphere could lead to more intense storms; the atmospheric circulation may be affected, bringing floods to normally dry regions and heatwaves to normally cooler areas
could our weather patterns be getting stuck?
the Hadley and Ferrel cells are expanding poleward leading to a warming Arctic, this may slow down the atmospheric circulation in the northern hemisphere mid-latitudes resulting in weather sticking for long periods of time (this could explain the recent heatwaves and floods experienced in the UK)
what is the recent evidence for climate change?
- shrinking glaciers and melting ice
- rising sea level
- seasonal changes
what are some global effects of climate change?
- melting of glaciers and ice caps
- islands are under threat
- flooding of agriculture
how is evidence collected?
- temperatures are measured using a thermometer
- scientists use indirect data stored as a fossil record
- scientist study the oxygen in ocean sediments or water molecules to calculate temperature
- ice cores have been used to reconstruct temperature patterns as long as 400,000 years ago
what are the three parts of the milankovitch cycles/orbital changes?
- eccentricity
- axial tilt
- precession
what is eccentricity?
- describes the changes in the path of the earth’s orbit
- it changes from being almost completely circular to being elliptical
- the changing of this cycle takes place over 100,000 years
what is axial tilt?
- the earth tilts at an angle of 23.5 degrees
- however, over 41,000 years the tilt moves from two extremes
- these extremes are 21.5 and 24.5 degrees
what is precession?
- this describes the natural ‘wobble’ of the earth
- a bit like a spinning top
- these ‘wobble’ cycles take around 26,000 years to return to a state of normality
how does the natural greenhouse effect work?
- the sun warms the earth
- the earth reflects some heat away
- the earth’s atmosphere contains greenhouse gases
- some heat can’t escape into space, some is trapped by gases such as carbon dioxide; this keeps earth. warm enough for living things to survive
how does the enhanced greenhouse effect work?
- heat from the sun enters our atmosphere, some is reflected back into space and some is trapped
- the energy is trapped by greenhouse gases such as CO2
- as human activity has produced more of these greenhouse gases, more heat is trapped
- over time, this means the earth has gotten warmer
what are the human factors contributing to greenhouse gases?
- use of fossil fuels
- agriculture
- deforestation
how is the use of fossil fuels contributing to greenhouse gases?
- a fossil fuel is formed by natural processes, such as the decomposition of buried dead organisms such as plants
- when burned to create energy in the form of heat, CO2 and other greenhouse gases are released into the atmosphere
- since 1960, carbon emissions from fossil fuels have risen fast, reflecting increased global energy demand
- the IPCC has found that emissions from burning fossil fuels are the dominant cause of global warming, accounting for 89% of global carbon dioxide emissions in 2018
- coal is the ‘dirtiest’ fuel, responsible for over 0.3 degrees celsius of the 1 degree celsius increase in global average temperatures since 1880
- today, about 1/3 of the world’s total carbon emissions come from burning oil and 20% from natural gases
how is agriculture contributing to greenhouse gases?
- agriculture emits about 30% of all greenhouse gas emissions and 40% of methane emissions
how does agriculture produce carbon dioxide?
- land use change (e.g. land drainage and deforestation) and soil disturbance (ploughing releases carbon in soil)
- energy is used for heating and transportation on the farm and in distribution
how does agriculture produce methane?
- livestock digestion releases methane (mostly through burping); the average ruminant (herbivorous mammal) produces 250-500 litres of methane a day
- anaerobic decomposition is paddy rice cultivation accounts for 5-20% of total methane emissions from human sources
how does agriculture produce nitrous oxide?
- agriculture emits 75% of all nitrous oxide, mostly from manure and nitrogen-rich fertilisers
- highly managed grasslands produce large volumes due to fertiliser use and soil disturbance
how is deforestation contributing to greenhouse gases?
- deforestation means cutting down or burning trees, usually to clear land for farming, settlement or industry
- carbon stored during photosynthesis (when green plants convert light energy to chemical energy) is re-released into the atmosphere as carbon dioxide
- deforestation in tropical regions accounts for about 20% of annual global greenhouse gas emissions
- since 2000, Indonesia has lost almost 10% of its tree cover, mostly for the commercial production of palm oil
- the main reason for recent increases in emissions is growing demand for, and trade in, agricultural and forestry commodities, mainly palm oil, soy, cattle and timber products (including paper)
- in the amazon rainforest, 70% of deforestation is to create grazing land for commercial livestock
what is mitigation?
the action of reducing the severity, seriousness, or controlling something
what is adaption?
responding to changes and adjusting accordingly in order to survive
what are 4 ways to mitigate the impacts of climate change?
- alternative energy production
- carbon capture and storage
- planting trees
- international agreements
how does alternative energy production mitigate the impacts of climate change?
- the burning of fossil fuels contributes to 87% of all CO2 emissions
- to reduce CO2 emissions, many countries are turning to alternative sources of energy
- they don’t emit huge amounts of CO2
- some are renewable, thinking about the future
- nuclear power uses uranium to generate electricity but does not emit CO2 as a by-product
UK aims: 15% of its energy from renewable sources by 2020; investments made- e.g. end power
what is an example of alternative energy production?
- hydro-electricity HEP
- nuclear
- solar, wind and tides
- new nuclear plant built in Hinkley Point, Somerset
are there any negatives to alternative energy production?
uranium is not renewable
how does carbon capture and storage mitigate the impacts of climate change?
- coal is the most polluting of all fossil fuels
- countries using large amounts of coal for electricity are:
China (80%), India (70%), USA (50%)
CCS: - using technology to capture CO2
- possible to capture up to 90% of COO2 emitted into the atmosphere
- once captured, carbon gas is compressed and transported by pipeline to an injection well
- injected into the ground to be stored in suitable geological reservoirs
what is an example of carbon capture and storage?
- Tata-owned Cheshire plant to turn 40,000 tonnes of CO2 a year into useful products
are there any negatives to carbon capture and storage?
not economically viable yet
how does planting trees mitigate the impacts of climate change?
- trees act like carbon sinks, removing CO2 from the atmosphere through photosynthesis
- they also release moisture, producing more clouds and so reducing incoming solar radiation
- tree planting is well established in many parts of the world
- plantation forests are more effective than natural forests at absorbing CO2
what is an example of planting trees?
- Great Green Wall, across the Sahara Desert
are there any negatives to planting trees?
no
how do international agreements mitigate the impacts of climate change?
climate change is a global issue that requires global solutions; governments are negotiating towards a more sustainable future:
2005: The Kyoto Protocol
- 1st international treaty
- over 170 countries agreed to reduce carbon emissions by an average of 5.2% below their 1990 levels by 2012
2009: Copenhagen Accord
- pledged to reduce emissions with financial support for LICs to help them cope with the impacts of climate change
- however, there was no legally binding agreement for this
2015: Paris Agreement
- 1st legally binding global climate deal
- aims to limit global temperature increases to 1.5 degree celsius above pre-industrial levels
are there any negatives to international agreements?
there is criticism that agreements are often promises rather than commitments (deadlines are often not met)
what are 3 ways to adapt to the impacts of climate change?
- agricultural adaption
- managing water supply
- reducing risk from rising sea levels
what is agricultural adaption?
- climate change is believed to have a huge impact on agricultural practices worldwide
- rainfall and temperature patterns to change
- extreme events more common (heatwaves, droughts and floods)
what are examples of agricultural adaption in lower latitudes as well as mid latitudes?
lower latitudes:
e.g. Gambia
- expected to be the worst affected here
- to tackle this, several adoptions have been made such as new irrigation systems and educating farmers
mid latitudes:
- warmer climate in Europe and North America could lead to increase in production of crops like wheat, vines and olives could thrive in the UK
who will be worst impacted by the impact on water supplied due to climate change?
climate change has and will continue to impact our water supplies, both in quality and quantity; the worst impacted will be the vulnerable in rural parts of LICs
why does water supply need to be managed in the Himalayas?
millions in Asia depend on the glacial meltwater rivers; the 16,000 glaciers are receding rapidly, threatening water security
How is water supply being managed in the Himalayas?
- artificial glaciers will supply villages in Ladakh, India
- water is collected in winter through diversion canals and embankments and freezes in spring, it melts to provide water to locals
why does risk from rising sea levels need to be reduced?
having already risen by 20cm since 1900, rises of up to 1m by 2100 are possible, this will:
- threaten important agricultural land in countries like Bangladesh, India, Vietnam
- increase rates of coastal erosion and damage from storm surges
- contaminate freshwater supplies with saltwater
what is an example of somewhere that is reducing risk from rising sea levels?
Maldives:
- the Maldives are building houses that are raised off the ground and on stilts, constructing sea walls around the capital (Male) with sandbags, constructing artificial islands, restoring coastal mangrove forests because their tangled roots trap sediments and offer protection from storm waves
- ultimately, the entire population could be relocated to Sri Lanka or India
