Weather Hazards and Climate Change Flashcards
Define climate change.
The changing of the average climatic conditions of the planet over time.
What are interglacial and glacial periods?
Interglacial = warmer
Glacial = colder
What is the Global Atmospheric Circulation System?
The pattern of the movement of air across the planet and how it affects climate
When did the Quaternary Period begin?
~2.6 million years ago
What is a typhoon?
A tropical storm in the Indian or Western Pacific Ocean regions.
What is a tropical cyclone?
Large, rotating storm that forms over oceans in tropical areas
What is eccentricity?
The path of the Earth as it orbits the sun - it departs from a perfect circle at certain periods
How does eccentricity affect climate?
Circular movements cause interglacial periods, whereas elliptical cause glacial - further from sun.
Every 100,000 years, the Earth’s orbit goes from circular to elliptical and back again.
What is the axis tilt?
Earth changing on its axis between 21° and 24.5°.
How does the axis tilt affect climate change?
Earth on greater angle = greater variation between summer and winter.
What are precession cycles?
The natural “wobble” of the Earth. A cycle takes around 24,000 years.
How do precession cycles affect the climate?
Closer to sun = more solar radiation so hotter, affects seasons
What causes precession cycles?
Tidal forces exerted on Earth by the moon and sun
How do solar variations affect the climate?
Sunspots:
More sunspots = higher temp.
Less = lower temp.
How does volcanic activity affect the climate?
Eruptions can blast huge amounts of ash, gas and liquid into the atmosphere.
1. Ash blocks sun = reduces temperatures.
2. Droplets are created which act like tiny mirrors, reflecting radiation from the sun.
What is the Coriolis Effect?
The effect of the Earths spinning on its axis.
How does wind affect heat circulation/climate?
When hot air rises, wind is drawn in. It is typical of low pressure.
How do jet streams affect heat circulation/climate?
Bands of fast-moving air:
More jet streams = area has more variation in weather.
Less = area has more similar weather for longer periods of time.
How do oceans affect heat circulation/climate?
- Ocean currents: North Atlantic drift carries warm water, creating warmer climate in West.
- Warm water is less dense so rises, heats at the equator and moves towards the poles
- This water sinks and moves towards equator.
Why is there low pressure at the equator?
Hadley cells meet - warm air rises, cools and condenses to form clouds.
What sort of climate is created by areas of low pressure?
Rainy
What sort of biome is along the equator?
TRF
What sort of biome is created where the Hadley cells meet the Ferrel cells?
Desert
What happens where the Hadley and Ferrel cells meet?
- Cold air from Hadley cell sinks
- Which traps warm air beneath - cannot rise
- Warm air cannot form clouds so there is no rainfall
- Forms deserts
What latitude are desert found at?
30° north and south
What happens where the Ferrel and Polar cells meet?
- Warm air rises, cools and condenses to form clouds
- However, it is colder than at the equator so deciduous forests are formed instead of TRF.
What happens where the Polar cells meet?
- Cold air sinks, trapping warm air
- Creates areas of high pressure and there are low temperatures
- So cold desserts are created
How do tree rings work?
Rings in trees can be used to make judgements about climate:
1. Wider ring = climate warmer and wetter
2. Smaller = climate colder and drier
3. The number of rings shows the age of the tree.
Name a disadvantage of tree rings.
Tree has to be cut
How do ice cores work?
Cores of ice can be used to make judgements about climate:
Ice cores show temperature of ice for last 400,000 years.
Also contain volcanic ash, microbes, etc.
Name a disadvantage of tree rings.
Expensive
How does pollen work? (measuring climate change)
Pollen can be used to make judgements about climate:
1. Plants can only survive in certain conditions
2. So pollen shows climatic conditions at the time
Name a disadvantage of using pollen to measure climate change.
Pollen travels across distances, can be easily damaged so often unreliable
How do historical records work? (measuring climate change)
Descriptions in diaries, newspapers, religious records, etc.
Name a disadvantage of using historical to measure climate change.
Cannot be scientifically proven, only go back so far
When was the Little Ice Age?
14th-19th Century
What was the Little Ice Age?
A period when Europe experienced colder climates and severe winters
Why did the Little Ice Age happen?
Extreme volcanic eruptions, decrease in solar radiation
When was the Medieval Warm Period?
11th-late 15th Century
What was the Medieval Warm Period?
Temperature changed to support growth of grapes
Why did the Medieval Warm Period happen?
Increased solar activity, low volcanic activity
When and where was Hurricane Katrina?
New Orleans, August 2005
What was the strength of Hurricane Katrina?
Category 4
How many died due to Hurricane Katrina?
1833 dead
How much of New Orleans flooded due to Hurricane Katrina?
80%
How did Hurricane Katrina increase racial tension?
Many victims were African-American
Give 2 ways that America or other nations responded to Hurricane Katrina.
$500 million given by Kuwait, 80% evacuated before hurricane hit, $34 billion set aside to rebuild houses/establishments
Give 2 causes of the drought in California.
- Low rain and snow
- Shares Colorado River with 6 other states
- Waste and overusage of water
Give 2 impacts of the drought in California.
- Seawater drawn inland mixed with freshwater
- Wildfires - lowered biodiversity, cost of damage, etc.
- Damage to infrastructure
- Cost $2.7 billion a year
Give 2 responses to the drought in California.
- Government regulations - cut 25% of water
- Homeowners encouraged to check for water leaks
- Public education campaigns
(California drought) Give an example of a public education campaign.
Save Our Water
What was the cause of the drought in Ethiopia?
Longer dry season - hot and little rain
Give 2 impacts of the drought in Ethiopia.
- Malnutrition - illness, death
- 260,000 deaths
- Girls having to walk further to get water, could not go to school
Give 2 responses to the drought in Ethiopia.
- USA sent $129 million in 2015
- Oxfam and Unicef increased access to water supplies
- Large charity events to raise money + awareness
(Ethiopia drought) Give an example of a charity event.
Live Aid
How much did the USA send in aid to Ethiopia to help with the drought?
$128.4
How do tropical cyclones cause intense rainfall?
As they travel, they collect moisture from oceans. This leads to large releases of rain.
How do tropical cyclones cause storm surges?
Large areas of low pressure so sea levels rise. There are also high winds. This causes large amounts sea water to be forced inland.
(Tropical Cyclones) How do storm surges affect areas?
Can damage coastal defences, erode beaches, etc.
(Tropical Cyclones) How does intense rainfall affect areas?
Causes flooding, property damage, injury, etc.
(Tropical Cyclones) How do strong winds affect areas?
Cause severe damage to infrastructure, trees uprooted, smaller buildings can be moved, injury, death, etc.
Where was Typhoon Haiyan?
The Philippines
What was the strength of Typhoon Haiyan?
Category 5
When did Typhoon Haiyan take place?
November 2013
Name 3 impacts of Typhoon Haiyan.
- 7000 dead
- Population in less affected areas doubled due to refugees
- 30,000 fishing boats destroyed
Name 2 responses to Typhoon Haiyan.
- Oxfam replaced fishing boats
- Red Cross supplied 1.1 million with clean water
- 1200 evacuation centres set up.
