Global Hazards Flashcards
What were the social impacts of tropical cyclone Aila on Bangladesh?
- Several villages destroyed by a storm surge
- 190 people killed
- 750,000 made homeless
What were the economic impacts of tropical cyclone Aila on Bangladesh?
- Embankments washed away
- A lot of crops killed by salt water
- 59,000 animals (including livestock) killed
What were the environmental impacts of tropical cyclone Aila on Bangladesh?
- Loss of animals (no animal dung source of cooking fuel) which led to deforestation for firewood
- Sickness (fresh water contaminated)
- Endangered tigers drowned
How does Bangladesh prepare for cyclones?
- Weather forecasting
- Satellite technology
- Warning systems
- Evacuation strategies/shelters
Pros and cons of weather forecasting in Bangladesh
Pros:
- In 2009 there were lower death rates for those households with radios
- In the capital city of Dhaka, many people have TVs and radios
Cons:
- There are only 50 phones per 100 people in 2014
Pros and cons of satellite technology in Bangladesh
Pros:
- Enables accurate and quick tracking
- Can track cyclones
Cons:
- It’s expensive
Pros and cons of warning systems in Bangladesh
Pros:
- There are over 45,000 cyclone warning volunteers spreading awareness and information
Cons:
- Some people are illiterate and can’t read the posters and leaflets
- Some people don’t pay attention to them due to previous false warnings
Pros and cons of evacuations strategies/shelters in Bangladesh
Pros:
- People who use them usually survive
- 3500 built
Cons:
- More are needed
What are the 4 natural causes of climate change?
- Volcanic eruption
- Sunspot theory
- Orbital theory
- Surface impact (asteroid)
How do volcanic eruptions contribute to climate change?
They produce ash and gas that spread and form huge clouds (like a blanket) which stops sunlight from reaching the earth’s surface, making it colder
How does the sunspot theory contribute to climate change?
Sunspots are black areas on the sun’s surface and more of them means that more solar energy is being fired from the sun towards earth which makes the temperature on earth warmer but fewer sunspots make it cooler
How does the orbital theory contribute to climate change?
Over very long timescales, there have been big changes in climate and scientists think they are due to the way the earth orbits around the sun - sometimes it’s circular (meaning it’s closer to the sun) but sometimes it’s more ecliptal (oval shaped, meaning further away from the sun)
How do asteroids (surface impact) contribute to climate change?
Asteroid impacts can only alter the earth’s climate if they’re big, blasting millions of tonnes of dust and ash into the atmosphere causing the climate to cool as dust blocks the incoming sunlight
What level cyclone was cyclone Aila (Bangladesh)?
1
What level hurricane was hurricane Katrina (USA)?
3
How was the preparation for the cyclone different in Bangladesh vs the USA?
In Bangladesh an estimated 500,000 (only around 25% of the population) people were evacuated whereas in the USA, 80% of the population left
How was the response to the cyclone different in Bangladesh vs the USA?
- In Bangladesh, the Red Cross supplied water purifying tablets (NGOs also distributed dry clothes) and water was rationed so everyone had something to drink but in the USA, people in the superdome were trapped with limited food and water
- The government set up camps for people to stay and NGOs started teaching people to design cyclone proof houses (although they were quite expensive) however in the USA, FEMA (the Federal Emergency Management Agency) were unprepared for the scale of destruction causes
What is the greenhouse effect?
The sun’s energy passes through the atmosphere in short wave radiation. The energy deflects from the earth as long wave radiation. Some energy is trapped by the atmosphere while some escapes. As more greenhouse gases are released, the atmosphere becomes thicker. This causes more of the radiated energy to become trapped and the climate of the planet increases.
What are the human causes of climate change?
- Deforestation (releases CO2)
- Transport (releases greenhouse gases)
- Factories (burn fossil fuels)
- Cattle ranching (produces methane)
What evidence is there for climate change?
- Tree rings
- Ice cores
- Sediment cones in the oceans
- Thermometer (instrumental records)