Hazardous Earth Flashcards
What creates a low and high pressure belt?
At the equator the sun warms the Earth, which transfers heat to the air above causing it to rise, creating a low pressure belt. As the air rises, it cools and condenses forming clouds and rain. The cool air sinks, creating a high pressure belt with cloudless skies and very little rainfall
What are ocean currents?
Large scale of movements of water that transfer heat energy from warmer to cooler regions
How is heat transferred by ocean currents?
Surface currents are caused by winds and help transfer heat away from the equator.
Name the four natural causes of climate change?
Orbital changes
Volcanic activity
Solar output
Asteroid collisions
Orbital changes
Eccentricity - orbit of the earths shape has changed over long time. Meaning sometimes the Earths orbit around the sun is circular, making us a little warmer. Sometimes the Earths orbit becomes more elliptical, making the earth cooler
Tilt - North and South Poles are not exactly aligned at the top and bottom of the Earth. They are 23 degrees tilted, which create our seasons
Precession (wobble) - as the earth rotates it wobbles, this creates big or small difference between a summer or winter
Asteroid collisons
They are large cosmic material which could impact the earths surface. Producing large amounts of dust in the atmosphere and block sunlight leading to glacial periods.
Volcanic activity
They produce ash, sulphur dioxide gas. They can spread around the atmosphere. Ash can block sunlight and cool the earth.
Solar output
Astronomers recorded sunspots over 2000 Years ago. The sunspots. They tell us how active the sun is.
Evidence for natural climate change comes from many sources. Name them.
Tree Rings
Ice cores
Historical sources
Tree rings
Each ring shows a hear of growth. Changes in shape and size of tree rings can show conditions during that year. Bigger tree rings mean warm weather, thinner tree rings mean colder weather
Ice cores
Ice contains bubbles of the air from each year. Scientists analyse bubbles in each layer to see how much Co2 they contain. They can learn about temperatures by measuring relative amounts of different types of oxygen atoms in the water
Historical Sources
Old photos, drawings, written records, diaries. Often not accurate because they were not intended to recored climate. However they can give us some evidence of recent climate trends
What are the human activities making the greenhouse effect stronger?
Farming
Industry
Energy
Transport
How is Farming enhancing the greenhouse effect?
Live stock produce a lot of methane
Trees absorb and store Co2. When land is cleared of tree for agriculture it stops absorption of Co2, which leaves more Co2 in the atomosphere.
How is Industry enhancing the greenhouse effect?
Industry uses a lot of energy. Industrial waste may end up in landfill sites where it decays, releasing methane
How is energy enhancing the greenhouse effect?
Co2 is released into atmosphere when fossil fuels like coals, oil and natural gas are burnt
How is Transport enhancing the greenhouse effect?
Most cars, lorries, ships and planes run on fossil fuels, which release greenhouses gases when burnt. Car ownership increasing in countries developing meaning more cars, more congestion meaning engines running longer.
What evidence is there that human activity is causing climate change?
Declining Arctic Sea
Sea Level Rise and Warming Oceans
Global Temperature rise
Extreme weather events
Climate changes have serious impacts on people
Less crops could increase malnutrition, ill health and death from starvation, particularly in lower latitudes.
Death due to heat
Some areas could become hot and dry and difficult to inhabit
Features and structures of tropical cyclones
The centre of the cyclone is called an eye. The eye is surrounded by the eye wall, where there is strong winds. Towards the edge of the cyclone the wind speeds fall, clouds become smaller and more scattered, the rain becomes less intense and temperature increases.
What physical hazards are caused by tropical cyclone?
High winds Storm surges Intense rainfall Land slides Coastal flooding
What impacts does physical hazards have on the environment?
Trees are uprooted by high winds which can damage or completely destroy wooded habitats.
Storm surges can erode beaches and damage coastal habitats
When experiencing a cyclone some countries may be more vulnerable than other. Name physical vulnerabilities.
Low lying coastlines are vulnerable to storm surge flooding as well as large waves caused by the high winds.
Areas in the path of the tropical cyclones hit more frequently
When experiencing a cyclone some countries may be more vulnerable than other. Name economic vulnerabilities.
Many people depend of agriculture which is often badly affected - leads to loss of livelihoods
People may not have insurance to cover the costs of repairing damage cause by cyclones
When experiencing a cyclone some countries may be more vulnerable than other. Name social vulnerabilities.
Buildings are poorer quality so more easily damaged
Little money for flood defences or training emergency teams
Harder to rescue people because of poor infrastructure