Topic 1 Flashcards
(48 cards)
How do winds transfer heat from the equator to the poles?
The sun heats the surface unevenly and most radiation is received at the equator
Different temperatures cause different air pressure
Winds blow from high to low pressure and therefore heat is transferred away from the equator
What is high pressure
It is when cool air falls because it is more dense. As it falls, it warms up and leaves behind clear skies with no rainfall.
What is low pressure
It is when warm air rises because it is less dense. When it cools, it condenses and forms clouds and rainfall.
What are the three cells and what pressure zones are they in?
Hadley cell - low pressure
Ferrel cell - high pressure
Polar cell - high pressure
How is heat transferred by ocean currents?
Ocean currents transfer heat from warmer to cooler regions
Surface currents are helped by wind to transfer heat
Deep ocean currents are caused by water density
When water freezes, the surrounding water increases in density
The denser water sinks and the warmer water flows to the surface
This process repeats over and over again
What are the natural causes of climate change?
Orbital changes
Volcanic activity
Solar output variation
Asteroid collisions
What are orbital changes and how do they cause climate change?
They are variations in the way the Earth moves round the sun
Stretch : the earth’s orbit changes from an almost perfect circle to an oval every 96,000 years
Tilt : the earth’s angle at which it faces the sun changes every 41,000 years
Wobble : the earth wobbles on a cycle of 22,000 years
How does volcanic activity cause climate change?
Major volcanic eruptions eject material into the atmosphere. These particles reflect the sun’s rays back into space and the earth’s surface cools. This may cause short-term changes.
How does solar output variation cause climate change?
The sun’s output of energy changes every 11 years. Sometimes there is less output which causes the earth’s climate to be cooler.
How do asteroid collisions cause climate change?
When large asteroids hit the earth’s surface, it can throw up huge amounts of dust into the atmosphere. This partially blocks the sun’s energy and causes global temperatures to fall.
What is evidence for natural climate change?
Tree rings
Ice cores
Historical evidence
How can tree rings be used as evidence for climate change?
Trees produce one ring per year
The thicker the ring, the warmer and wetter the year was
How can ice cores be used as evidence for climate change?
A layer of ice is formed every year
These contains bubbles which scientists analyse and can tell the temperature for that year as well as the amount of carbon dioxide.
How can historical evidence be used as evidence for climate change?
Old photos, drawings and diaries can all be used as evidence. However, it is not as accurate and less likely to be used.
What human activities make the greenhouse effect stronger?
Farming
Industry
Energy
Transport
How does farming make the greenhouse effect stronger?
As the population increases, so does the demand for food. This means the population of cows also has to increase to supply this food but as they fart, they release methane. On top of this, trees absorb and store CO2 but deforestation has increased due to the need for more space for agriculture.
How does industry make the greenhouse effect stronger?
Most industries use a lot of energy. The demand for customer goods is constantly increasing and more energy is required to make these items. The waste may end up in landfill sites where it decays and releases methane.
How does energy make the greenhouse effect stronger?
New technology demands more energy. This has resulted in more energy being produced by burning fossil fuels. This releases CO2 into the atmosphere.
How does transport make the greenhouse effect stronger?
Cars, ships, lorries and planes all require a lot of fuel which releases greenhouse gases when burnt. Also, car ownership is constantly increasing which leads to more fossil fuels being burnt. On top of this, more cars leads to more congestion which means the cars are on for longer and release even more greenhouse gases.
What is evidence that human activity has caused climate change?
Declining arctic ice
Temperature rise
Sea level rise
Extreme weather events
How is declining arctic ice used as evidence for climate change?
Sea ice forms in the winter when ocean temperatures are less than -1.8°C. For the past 35 years, the amount of ice being made has decreased by over 3% per decade.
How is sea level rising used as evidence for climate change?
Ice melting : Warmer temperatures are causing glaciers to shrink and ice to melt. When the ice on land melts, the water goes into the oceans and causes the levels to rise.
Thermal expansion : As water gets warmer, it expands. This means that as the temperature increases, it warms the oceans and causes the amount of water to also increase.
How can climate change affect people?
Deaths
Loss of housing
Crops suffering
Lower crop yields - malnutrition and sicknesses
How do tropical cyclones form?
The sea temperature has to be at least 26.5°C
They mostly occur in between 5° and 30° north and south of the equator
Warm air rises which releases huge amounts of energy which makes the storm more powerful
Rising air increases surface winds
The earth’s rotation causes the cyclone to spin
As the cyclone travels on warm water, it keeps getting stronger
As it hits any land or cool water, it loses strength
