Natural Hazards Flashcards
What is a natural hazard?
An event beyond human control that could threaten both life and property.
What are 9 natural hazards?
- sandstorm
- earthquake
- tsunami
- volcanic eruption
- thunderstorm
- landslide
- drought
- floods
- tropical storm -> hurricane, typhoon, cyclone
What is a secondary hazard?
A secondary hazard is one that occurs because of another hazard e.g. a tsunami is caused by an earthquake
What are the human factors that affect the risk of natural hazards?
- population density - how crowded, sparsely populated = fewer people so less risk (however getting help may be difficult), densely populated areas have more people so more risk (however emergency services can get you more quickly)
- wealth - less money after to build, preparing buildings/earthquake resistant buildings are expensive
- quality of building
- politics - if war, then buildings already weakened, not enforcing regulations like building codes bc of corrupt government
What are the physical factors that affect the risk of natural hazards?
- Location – more at risk from earthquakes if on a plate boundary
- Frequency – lots of earthquakes means you may not have recovered from one before the next so risk is higher
- Magnitude
- Mountainous/rural – hard to get aid there
- Time of day – if at night, difficult to rescue people or if in your house, it may collapse
- Seasons – if it is cold or wet, those made homeless are more at risk
What are factors that affect volcano risk?
If there is…
- no warning
- no evacuation plan – chaotic response
- buildings very close together
- population density
What are factors that affect tropical storm risk?
- no warning
- no evacuation plan
- population density
- just above or below equator
- time of day
- frequency
- very remote
- lack of education on preparation
What is continental drift?
- The theory that the earths crust is broken into large pieces called tectonic plates, moving a few centimetres each year
- The continents that we know today used to be together and form one supercontinent called Pangea. Over time the plates have moved and the supercontinent broke up.
Who discovered continental drift?
Alfred Wegener
What are the 3 reasons that Wegener thought that continental plates were moving?
- Jigsaw – the continents fit together like a jigsaw
- Fossils – fossils of land animals were found in continents that were separated by the sea
- Mountain ranges – when continents are placed together you can see mountain rages meet up
What is the structure of the earth?
(from the inside to the outside)
- Inner core - very hot, solid
- Outer core - liquid
- Mantle - semi liquid/solid
- Crust - rock, thin (7km - 70km deep)
What are properties of continental crust?
- older
- less dense (than oceanic)
- thick (up to 70km)
- mainly has landmass on it
What are the properties of oceanic crust?
- younger
- denser
- thin (up to 10km)
- mainly has ocean on it
What 3 things makes the plates move?
- Convection currents
- Ridge push
- Slab pull
Why do plates move?
(3 key learning points)
- Convection currents, move plates together or apart or slide them past each other
- At constructive plate boundaries, convection currents and ridge push move the plate apart
- At destructive plate boundaries, convection currents and slab pull move the plates together
How do convection currents happen?
- In the core of the Earth, there is radioactive decay – this produces a lot of heat (7,000°C)
- The particles in the mantle close to the core get heated, so they rise
- As the particles move away from the core, they cool down, and they become more dense so they sink
- The crust will move along because the convectional current drags it
- This movement is called a convection current
What is ridge push?
The process where the plates move because of gravity acting on the plate where it is forced up
How does ridge push happen?
- Plates move apart by convection currents
- The crust is heated and expands so rises to form a slope
- The crust cools down + becomes dense
- The gravity + the weight of the plate also makes it move
- This is called ridge push
What is slab pull?
It is where the plates move faster, because of the weight of the plate and gravity acting on the plate as it is subducted
How does slab pull happen?
- convection currents in the mantle move the plates together - one is oceanic and the other continental (destructive p.b.)
- the oceanic plate subducts because it is denser
- this creates a force and this pulls the plate down further - gravity
What are the four types of plate boundaries?
- constructive plate boundary <— —>
- destructive plate boundary —\ <—
- conservative plate boundary //
- collision plate boundary —><— (don’t need this)
What happens at a constructive plate boundary?
- Convection currents in the mantle cause hot magma to rise, heating the rocks above them 🔃
- The tectonic plates move apart from each other because of ridge push, the molten magma rises in between, cools and forms new rock.
- This forms part of the new oceanic plate.
- The new plate sometimes fractures as it is moved, causing shallow, usually small, more nonviolent earthquakes.
- Much of the magma never reaches the surface, but it can push the crust upwards to form ridge and rift features.
- Where magma does erupt onto the surface it produces a lava that is runny and spreads out before solidifying.
- This produces after many eruptions a shield volcano. 🌋
What happens at a destructive plate boundary?
- At a destructive plate boundary plates move together because of convection currents in the mantle and slab pull
- When they meet tension builds up in the plate
- If the plates slip, then energy is released as seismic waves, causing an earthquake
- At destructive plate boundaries oceanic plates meet continental plates
- The oceanic plates subducts because it is denser
- As it sinks into the mantle it melts forming magma
- This magma is formed under pressure so forces its way through cracks in the rock above
- So will explode at the surface as lava forming a violent composite volcano.
- This causes hazards like lava flows and ash clouds 🌋
What happens at a conservative plate boundary?
- Pressure builds up at the margin as the plates are being pulled along by a plate being moved by convection currents
- Eventually, the pressure becomes too great, the rock fractures in an earthquake and jolts into a new position. (snag)
- Land is neither created nor destroyed, and so there are no volcanoes.
What is an example of a constructive plate boundary?
The Mid Atlantic Ridge
What is an example of a destructive plate boundary?
The Pacific ring of fire
What is an example of a conservative plate boundary?
San Andreas Fault
What are the 2 types of crust?
oceanic + continental
What heats the mantle?
radioactive decay in the core
Why do the particles in the mantle rise?
they are heated and then they expand + become less dense
What type of crust is the densest?
Oceanic crust
What is the process where the oceanic crust goes under the continental crust?
Subduction
What type of volcanoes are found at destructive plate boundaries?
composite volcanoes
What type of volcanoes are found at constructive plate boundaries?
shield volcanoes
Which type of crust is younger?
oceanic
When plates are moving together what builds up in the rock?
elastic energy + pressure
Where do convection currents occur?
in the mantle
What is a primary effect?
(give 3 examples)
They are the immediate impact caused by the hazard itself
e.g. death, buildings collapsing and injuries
What is a secondary effect?
(give 3 examples)
They happen later on often as a result of the primary effects
e.g. starvation, lower economy and spreading disease
What is an immediate response?
A response in the days and weeks immediately after a disaster has happened
What is a long-term response?
Go on for months and years after disaster
What is short term aid?
It is the aid that is given immediately (decreases secondary effects)
What is long term aid
It is the aid that is given weeks or months after after the hazard and should help the country recover
What are the 2 earthquakes that we compare?
New Zealand (2016) and Nepal (2015)
both suffered a 7.8 magnitude earthquake
What were the primary effects of the New Zealand earthquake?
- 2 people died
- Over 50 people were injured
- Tens of thousands of homes were damaged and some were destroyed
- 60 people needed emergency housing
- The total cost of damage was around US $8.5 billion
- Over 200 km of road and over 190 km of rail line were destroyed
- Communications, water, sewerage and power supplies were cut off
What were the secondary effects of the New Zealand earthquake?
- The earthquake triggered up to 100,000 landslides, which blocked major roads and rail routes
- A major landslide blocked the Clarence river, leading to flooding and the evacuation of 10 farms
- The earthquake generated a tsunami with waves of around 5 m, leaving debris up to 250 m inland
What were the immediate responses of the New Zealand earthquake?
- A tsunami warning was issued quickly, and residents of coastal areas were told to move to higher ground
- Hundreds of people were housed in emergency shelters and community centres
- 200 of the most vulnerable people were evacuated from Kaikoura by helicopter within 24 hours after the earthquake
- Powers was restored in most places within a few hours + temporary water supplies were set up
- International warships were sent to Kaikoura with supplies such as food, medicine and portable toilets
What were the long-term responses of the New Zealand earthquake?
- $5.3 million of funding was provided by the Kaikoura District Council to help with rebuilding the town’s water systems and harbour
- Most road and rail routes repaired and reopened within two years
- The Kaikoura mayoral earthquake relief fund was set up to help residents who couldn’t afford basic supplies, and donations were received from around the world
- By March 2017 (in 4 months), a permanent watermain had been laid in Kaikoura. The new pipe was designed to move with any future earthquakes so it won’t break
What were the primary effects of the Nepal earthquake?
- Around 9,000 people died
- Over 22,000 people were injured
- Roughly 800,000 buildings were damaged or destroyed
- 4 million people were left homeless
- The cost of damage was over US $5 billion
- Roads and bridges were destroyed
- Water tanks and pipes were destroyed, leaving 2 million people without access to clean water and sanitation
What were the secondary effects of the Nepal earthquake?
- The earthquake triggered avalanches on Mount Everest which killed 18 people
- Many mountain roads were blocked by landslides, preventing emergency aid from reaching remote areas
- Lack of clean water caused outbreaks of typhus, which killed at least 13 people
What were the immediate responses of the Nepal earthquake?
- India and China sent teams to help residents rescue people trapped by debris, but a lack of tools and machinery slowed rescue efforts
- People tried to recover the dead and treat the injured, but damaged roads made it hard for emergency workers and aid to get through
- Charities such as Oxfam provided medicine, food and temporary water supplies
- The Red Cross set up emergency shelters for 130,000 families who had lost their homes
- It took rescue teams 7 days to reach rural places in Nepal
What were the long-term responses of the Nepal earthquake?
- The World Bank group financed $500 million worth of projects to build earthquake resistant housing, and repair roads and irrigation systems - some projects are still ongoing
- The road from Nepal into Tibet was reopened 2 years after the earthquake, but many other routes remain damaged
- Many Heritage sites were reopened in June 2015 (2 months later) to encourage tourists back into the area
- Water supply is being restored, but 2 years after the event, many people still didn’t have access to clean water
- NGOs are working with residents to increase their resilience to disasters, for example by providing alternate energy sources
What percentage of Nepal’s GDP did the damage account for?
1/3
What percentage of New Zealand’s GDP did the damage account for?
1%
Why were the effects so severe in Nepal?
- The buildings were badly built so many of them collapsed
- There was no preparation so there was a chaotic response so people didn’t know what to do so more people died
- Many people lived in rural areas so it was harder for emergency services to reach them
- The landscape is mountainous so there were landslides which killed people
- It is a poor country so people don’t have money to repair buildings
- Water tanks were destroyed so there wasn’t any clean water so people died from typhus
What are the advantages of living in tectonic areas?
- Creates geothermal energy – will make energy bills lower and is good for energy industry - also better for environment as no CO2 is produced
- Volcanoes are major tourist attractions – creates jobs like tour guides which generates money (foreign exchange)
- Ash makes soil fertile - so farmers can grow more crops, so they can make more money - they may grow enough to export, so also generates foreign exchange, so the countries become richer
- Precious stones + important minerals are found near volcanoes - getting them out of the ground generates jobs so the locals become wealthier
What are the disadvantages of living in tectonic areas?
- Ash pollutes local rivers – may be where local people get their water + food
- If it erupts then houses might be destroyed by lava (however volcanoes don’t erupt badly very often)
- Volcanoes can be deadly (though, few people die from volcanoes because they are usually evacuated in time)
What are advantages of living in tectonic areas?
(shortened)
- geothermal energy⚡️ = lower energy bills💵 + good industry 🏭
- tourism 📸 = money 💵
- ash good for soil 🌱 = good for farmers🧑🌾
- precious stones 💎 = jobs + money 💵
What are disadvantages for living in tectonic areas?
- ash pollutes rivers 🏞️ = where locals get water 💧
- eruptions destroy houses 🏘️
- can be deadly 💀
How much of Iceland’s energy comes from geothermal energy?
30%
What are the things you can do to reduce the effects of tectonic hazards?
- monitoring
- prediction
- protection
- planning
What is prediction?
Attempts to forecast when and where are natural hazard will strike
What is monitoring?
Recording physical changes to help forecast when and where a natural hazard will strike
What is protection?
Actions taken before a hazard strikes to reduce it’s impact
What is planning?
Actions taken to enable communities to respond to and recover from natural disasters
Draw the global atmospheric circulation
ADD PIC OF PAGE 28 OF NATURAL HAZARDS BOOKLET THAT I DREW
What is a Tropical Storm?
It is an intense low pressure system that is formed over tropical waters
Where do Tropical Storms occur?
Either side of the equator - between 5° and 20° North and South
What three things does a tropical storm need to form?
- Warm sea (27°C or more)
- Low pressure
- Coriolis effect
Which way do winds bend in the northern hemisphere?
To the right
Which way do winds bend in the southern hemisphere?
To the left
What is the coriolis effect?
- winds blow from areas of high pressure to areas of low pressure
- as the earth rotates, it causes the winds to bend
- this is known as the coriolis effect
Why don’t tropical storms occur on the equator?
the Coriolis effect is not strong enough there to make the storm spin
What is an advantage of monitoring and prediction of tropical storms?
it gives people and governments enough time to take action (e.g. evacuation) to reduce the impacts of tropical storms and help protect lives
What are advantages of protection against tropical storms?
- reduces building damage if the protection is effective
- if you use a sea wall, protects people living by the sea from sea surges
What are advantages of planning for tropical storms?
- training people + emergency services how to react reduces risk of chaotic response which can reduce no. of deaths
- planning evacuation routes can allow people to get away from the storm quicker
What direction do tropical storms spin in the northern hemisphere?
- When tropical storms form they have a low pressure centre, and a high pressure outside
- So, air is travelling towards the centre from the outside (as surface winds always blow from high to low pressure)
- So, in the northern hemisphere, the Coriolis effect causes the wind to bend to the right towards the middle, so hurricanes swirl anticlockwise
(look in book on page 33 if confused)
What direction do tropical storms spin in the southern hemisphere?
- When tropical storms form they have a low pressure centre, and a high pressure outside
- So, air is travelling towards the centre from the outside (as surface winds always blow from high to low pressure)
- So, in the southern hemisphere, the Coriolis effect causes the wind to bend to the left towards the middle, so hurricanes swirl clockwise
(look in book on page 33 if confused)
Draw the world with the directions of the surfaces winds on them
remember:
- winds blow from high to low pressure
- in the south, winds bend to the left
- in the north, winds bend to the right
look up “global surface winds” and check
How does a tropical storm form?
- Hurricanes draw the energy from warm seas and can only occur over areas of warm water 27°C or more.
- Because the surface water is very warm it evaporates, rises and condenses into storm clouds.
- The rising air creates low pressure which pulls surface winds in from the edges of the storm.
- Where “vertical wind shear” is low, the clouds are prevented from breaking up as they rise. (vertical wind is the when the top and bottom of the storm have different speeds/times they are spinning in??)
- The storms spin because of the Coriolis effect.
- As the storm moves over the ocean the energy from the warm water strengthens the storm so the wind speeds increase.
Why do Tropical Storms die out?
- When they hit cold water they lose their energy source (warm water) and so begin to die out
- As they pass over land, friction slows them down
What is the structure/features of a tropical storm?
- In the middle of the tropical storm there is the eye – the calm part
- The eye can be 50 km across - here air is descending, causing high pressure, light winds, no clouds or rain and higher temperatures
- coriolis effect causes winds to spin
- the eye wall - around the eye - there are fast convection currents
- warm moist air from the tropical seas rise up the tropical storm
- at the bottom of the tropical storm there is high hurricanes speed winds and heavy rain occur
- Towards the edges of the storm, the wind speed falls, the clouds become smaller and more scattered, the rain becomes less intense and the temperature increases
- the top edge of the storm, there is cool dense air
What is the case study for a tropical storm?
Typhoon Haiyan (2013)
What is an overview of Typhoon Haiyan?
- It happened in the Philippines in November 2013
- It was category 5 on the Saffir-Simpson scale (a scale of 1-5)
What are the primary effects of Typhoon Haiyan?
- 90% of the city of Tacloban was destroyed
- 50% of the houses were destroyed
- 4.1 million people made homeless
- Over 6,000 people died
- US, $12 billion of damage
- Damage to rice cost US $53 million
- 1.1 million tonnes of crops were destroyed
- 75% of farmers + fishermen lost their income
- There was an 800,000 litre oil leak
What are the secondary effects of Typhoon Haiyan?
- Infection + disease spread due to contaminated water + surfaces
- Power supplies were cut off for a month in some areas
- Many schools were destroyed, affecting peoples education
- The fishing industry was disrupted as the leaked oil from the barge contaminated fishing waters
- Flooding caused landslides and contamination of surface and ground water.
- The airport was badly damaged, and roads were blocked by trees and debris
- 10 hectares of mangroves were contaminated by the oil leak
What were the immediate responses of Typhoon Haiyan?
- The government televised, a warning for people to prepare and evacuate
- Authorities evacuated 800,000 people,
- Emergency aid supplies arrived 3 days later by plane
- The government imposed a curfew 2 days after to reduce looting
- Celebs and companies like the Beckhams, Coca-Cola and Apple used their status to raise awareness + donations
What were the long-term responses of Typhoon Haiyan?
- A ‘cash for work’ work program paid people to clear debris + rebuild the city
- Over US $15 billion was pledged in foreign aid to help
- The government declared a long-term recovery plan ‘build back better’ so buildings could be upgraded
- Mangroves were replanted
- A new storm surge warning system was installed
- Re building was slow - 100,000 families still in temporary housing in 2015!
What are advantages of monitoring and protection of tropical storms?
- Satellites monitor cloud patterns – of tropical storms and also higher altitude rain clouds
- NASA monitors weather patterns in air craft
- Supercomputers give five days warning and predict a location within 400 km
- Early warnings are issued by National hurricane centres around the world
What are disadvantages of monitoring and protection of tropical storms?
- Monitoring equipment is expensive
- Relies on good communication
- Might not have the ability to communicate information to people who are likely to be affected
- Might evacuate people who don’t need to be evacuated
What are advantages of protection of tropical storms?
- Reinforces buildings
- Develop coastal flood defences
- Create ‘no build zones’ in low-lying areas
What are disadvantages of protection of tropical storms?
- Expensive to build lots of protection
- Not everyone has access to resources to help protect (e.g. metal shutters)
What are advantages of planning for tropical storms?
- Prepare disaster supply kits
- Ensure vehicles are fuelled
- Know where evacuation shelters are
- Plan what their family will do
What are disadvantages of planning for tropical storms?
- If people are in remote areas, it is harder for supply kits to be transported to them or they are very far from evacuation shelters
- If people are not warned about tropical storms, they don’t have time to plan
- Poorer countries don’t have money to stockpile
- Has to have an organised plan
What is a fact for monitoring + prediction from Typhoon Haiyan?
The government televised a warning for people to prepare and authorities evacuated 800,000 people
What is a fact that relates to protection from Typhoon Haiyan?
After Typhoon Haiyan, in July 2014, the government declared a long term recovery plan called ‘Build Back Better’ where buildings were upgraded to be better at withstanding tropical storms
How will climate change affect tropical storms?
it will affect their:
- frequency
- strength
- distribution
How will climate change affect tropical storms’ frequency?
Oceans will stay at 27°C for longer, so may mean that there are more storms as there is a longer time when they can form.
e.g. in the Atlantic the number of tropical storms has increased each decade
How will climate change affect tropical storms’ distribution?
As temperatures rise, more areas might be 27°C or more, so they may occur in more areas
How will climate change affect tropical storms’ strength?
- Higher sea surface temperatures means more evaporation
- SO more cloud formation
- SO more energy
- SO storms could be more powerful
e.g. intensity expected by 2-11% by 2100
What extreme weather hazards happen in the UK?
- high winds
- droughts
- heatwaves
- flooding
- snow
- hail
- fog
- ice
What are some examples of extreme weather hazards in the UK?
- Storm Desmond (2015) brought heavy rainfall and severe gales to southern Scotland, north of England, Wales and Northern Ireland
- About 5,200 homes were flooded because of this
- 3 people died due to storm Desmond
. - In 2018, the ‘Beast from the East’ led to 50 cm of snow in areas such as Dartmoor and Exmoor
- This cost the UK economy at least £1 billion a day - as companies had to close
What are the social effects of extreme weather in the UK?
- Death and injury (not very common)
- Inability to travel (limits education)
- Freezing pipes (stops water and heating)
- Damage to buildings and property
- Flooding
- Lower quality of life
- Reduces tourism (storms) or increases tourism (heatwave)
What are the economic effects of extreme weather in the UK?
- Energy bills rise (to heat or cool your house)
- Businesses are forced to close
- Repairs to housing + replacing property if no insurance
- Loss of income.
What is the case study about flooding in the UK?
Somerset levels (Dec 2013 - Feb 2014)
What were the causes of the Somerset levels flood ?
- Several depressions moving across the Atlantic Ocean caused weeks of wet weather
- Saturated soil
- Wettest January on record
- High tides and storm surges came up the rivers from the Bristol channel
- Reduced river capacity (lots of sediment) due to not being dredged for over 20 years
What were the social impacts of the Somerset levels flood?
- More than 600 homes flooded
- 16 farms evacuated
- Temporary accommodation for residents needed for several months
- Some villages were cut off
- Power supplies were disrupted
What were the economic impacts of the Somerset levels flood?
- Over 14,000 hectares of agricultural land flooded for weeks
- Over 1000 livestock evacuated
- Roads were cut off
- Railway line closed
- £10 million of damage estimated
What were the environmental impacts of the Somerset levels flood?
- Contaminated river water with sewage, oils and chemicals
- Large volume of debris deposited across land
- Stagnant water had to be re-oxygenated then pumped back into river
What were the immediate responses to the Somerset levels flood?
- As expected for an HIC, the response to the flood was well organised and rapid
- Boats were used to help stranded people
- 80 homes agreed to evacuate
- The army issued sandbags and distributed food
- 65 pumps were used to drain 65 million m³ of floodwater
- An estimated £15 million was made available by the government to meet the immediate costs
What were the long-term responses to the Somerset levels flood?
- The Somerset levels and Moors action plan was developed, and included measures such as reintroducing dredging, the construction of a tidal barrage and additional permanent pumping stations
- The scheme is part of a 20 year plan for the Somerset levels and will have a total cost of £100 million
What is the short term evidence for climate change?
- Recordings of global temperatures by Met Office, using weather station satellites etc
- Photographs + recordings of shrinking glaciers
- Recordings of sea levels
- Old photographs and paintings and historical documents
What is the long-term evidence for climate change?
- Ice cores
- sediment cores
- tree rings
- pollen samples
How do sediment cores work/what are they?
- Overtime, the ocean has been warmer and colder
- Different animals and plants, live in different temperatures and seas
- Different sediments fall to the bottom of the sea and over time they form different layers
- Then scientists analyse each layer to see the types of sea life and then work out if the sea was warm or cold
How do Tree rings work/what are they?
- Warmer times trees grow more, so the rings are thicker
- Colder times trees grow less, so the rings are thinner
- Scientists can then analyses what years are hotter and which are colder
What are pollen samples/how do they work?
- You find them in peat bogs
- They are wet environments, so living matter decomposes, very slowly
- Scientist can analyse the type of plant and therefore what the temperatures were so we can collect ancient pollen samples.
What are the natural causes of climate change?
- Orbit changes
- solar output
- volcanic activity
What are orbit changes?
- Every 100,000 years, the Earth changes from an elliptical (oval) to a circular orbit
- When it is oval, it is warmer and interglacial
- when it is circular it is colder and a glacial
way to remember: Circular - C - Cold circular
What is solar output?
- Sunspots are dark spots on the Sun surface that radiate out more energy, making the Earth warmer.
- They follow irregular circle
- They last about 11 years
- We have currently had 50 years of low solar activity.
What is volcanic activity? (in terms of causes of climate change)
Major volcanic eruptions lead to a brief period of global cooling
e.g. ash and SO2 blocks the Sun
What are human causes of climate change?
- Since industrial revolution - but only getting very bad in 1960 - as more of the world industrialised, more cars, more planes and we ate more cows and cut down more trees
- The greenhouse gas layer has got thicker, SO it traps more heat so the temperature of the earth is increasing
What are some effects of climate change on people?
- Deaths due to changing temperature
- In some areas are hard or impossible to inhabit
- Some areas are struggling to supply enough water
- Some crops are suffering and has caused smaller yields
- Some crops are benefiting due to warmer conditions
- Lower crop yields could Increase malnutrition, ill health and death from starvation
- The weather is getting more extreme so more money has to be spent on predicting extreme weather events
What are some effects of climate change on the environment?
- Warmer temperatures = glaciers to shrink and ice sheets to melt so sea levels are rising
- Sea ice is also shrinking leading to the loss of polar habitats
- Rising sea levels mean low-lying in coastal areas will flood more regularly and coastal erosion will increase
- Other species are declining due to warming , e.g. coral reefs 🪸are suffering from bleaching
- Precipitation patterns are changing
- The distribution and quantity of some species could change + biodiversity could decrease
- Habitats are being damaged or destroyed and have to live it higher latitudes (further from the equator) due to warming temperatures
What are the 2 ways to cope with climate change?
Mitigation and adaptation
What is mitigation?
Aims to reduce the cause of the problem by limiting or preventing GHGs and protecting carbon sink (e.g. trees)
What is adaptation?
Responds to the impact of climate change and tries to make people less vulnerable
What are the four mitigation strategies?
- Wind/solar energy
- Carbon capture
- Planting trees
- International agreements
What are the three adaptation strategies?
- Changes in farming
- Managing water supply
- Reduce risk from sea level rise
How does wind/solar energy reduce climate change?
And a fact that goes with it?
Assessment?
Renewable sources of energy do not produce CO2, so there is less CO2 in the atmosphere, so the greenhouse gas layer will not get thicker
In 2022 36% of the U.K.’s electricity was generated using renewables
- They are good, but they are more expensive than fossil feels although they are coming down in price
- If there is no sun or wind you need an alternative source
How does carbon capture reduce climate change?
A fact that goes with it?
Assessment?
Stops CO2 from being emitted by power stations, catches it and taken underground or used for something else. So less goes in the atmosphere
In 2021 44 MT (mega tonnes) of CO2 was captured globally
- It isn’t used very much as it is very expensive
- it is part of the solution, but it isn’t the only thing
- we don’t know the future impact of storing it
How does planting trees reduce climate change?
And a fact that goes with it?
Assessment?
Trees absorb CO2 so there is less CO2 in the atmosphere. With more trees, more CO2 will be absorbed
If we planted 25% more of forest we already have that would absorb 25% of all CO2 in the world.
- It is great but there is not much/not enough space
- They take a long time to grow.
How do international agreements reduce climate change?
And a fact that goes with it?
Assessment?
Large conferences where governments from all countries make pledges and agreed to reduce their carbon emissions (CO2)
196 parties at COP 21 in Paris signed a legally binding treaty on Climate Change.
- It is difficult to get countries to stick to it
- if countries only have bigger priorities e.g. war they would focus on that instead.
How do changes in farming help people adapt to climate change?
And a fact that goes with it?
Assessment?
There are two main methods:
Floating gardens - where farmers can still grow food/crops, but on top of water, so when it floods or rising sea levels won’t affect it
Tolerant + resistant seeds to drought conditions have been invented
With floating gardens, farmers can earn an average profit of $140 per square metres during the monsoon season.
- Floating gardens are cheap, easy and efficient (not really any disadvantages)
- The seeds are quite expensive.
How does managing water supply help people adapt to climate change?
And a fact that goes with it?
Assessment?
There are two main methods:
Drip irrigation is where there are pipes in the ground right next to the seeds slowly feeding it water so less water is wasted.
Hydroponics is when you grow plants in greenhouses in tubes with very little water.
Hydroponics takes 10x less water than regular plants.
- Good ways to manage water
- Drip irrigation isn’t expensive.
- Hydroponics is very expensive.
How does reducing risk from sea level rise help people adapt to climate change?
And a fact that goes with it?
Assessment?
Either building a flood barrier to stop flooding or build houses on stilts.
The Thames barrier has been closed 200 times to prevent flooding
- Barriers are very effective, but very expensive
- Houses on stilts are good and cheap, but if water rises too much, it is ineffective.
