1.2 Natural causes of climate change Flashcards
What are the four different natural factors that have caused world
climates to change over the last 400,000years?
A. Solar output, volcanic activity, radiation, tilting of earth
Notes:
Solar output variation = (sunspots) periods when solar output is reduced, may cause earths climate to be cooler
Volcanic activity = volcanic eruption eject material into atmosphere also ash
Asteroid collisions = more dust in atmosphere which reflects heat and light
Orbital change = shape of earths orbit changes as it gets more circular, the earth is slightly warmer
B. Solar output variation
Volcanic activity
Asteroid collisions
Orbital change
Orbit, Tilt and Wobble – what are these and why do they cause
variations?
A. They are all cycles of the earths orbit (what it does to get e.g. night and day)
Extra notes:
Milankovitch cycle (word of cycle) = All stuff to give seasons (tilt)
Gives us day and night (wobble)
Makes earth slightly warmer (orbit)
Why is the emission of dust v. important in volcanic eruptions and
asteroid strikes and causing a cooler climate?
A. Its important because volcanic activity and asteroid collision causes dust to be released into the air and will reflect on the sun rays causing cooler climate change.
Extra notes:
Dust/ash reflect heat and light
reflects sun rays
causing climate change to become cooler
Is a sun spot hot or cold?! How often does this vary?
A. Sun spot is hot as it spots in the sun (black spots)
Notes:
Sunspots are solar energy being fired out from the sun - earth
Number of sunspots changes from year to year
Cycle length = 11 years
B. Sunspots are very hot as they are solar energy being fired out from the sun to earth, also they vary from year to year
How does ice cores in Antarctica tell us about previous temperatures in the most recent quaternary (2.5million years)?
A. Scientists use the ice cores to look at the air bubble which tells you the temperature
Extra notes:
Ice contains bubbles of air from each year
You can learn about the temperatures for each year
Scientists analyse how much CO2 each layer contains
How can trees and historical sources help with this too?
A. If you cut a tree we can see the ring pattern on it which tells you if conditions were good or not as the ring grows in better conditions. Also historical source can help tell us about previous temperatures as they contain extreme weathers we had (e.g.River Thames froze)
Give three pieces of evidence which show the earth’s climate was:
a. Warmer b. Colder
A. Warmer
Roman warm period
Medieval warm period
The modern era of modern climate
B. Cooler
Little ice age
Dark ages cold and wet
Great frost
