Climate change and its causes

Another addition to the revision for the geography unit 1 exam for Edexcel.

Don't use this as your sole revision tool.

Good luck for your exam! :)

?
L J T X V V Q T P G R W R V E W V G B V
E R U P T I O N T H E O R Y D B H Y S G
B B K R H C K K Q V Q G C V R L R M H W
N O P R D I R O M T H O M F X O T H Y I
S R Q V M W Y W V Q N R I O E N R R J A
J B T S E N N D V M E F E H S W O T W Q
V I G H D O Y W P T U I T W W E M M P F
S T R O I B R H G X J D O T H B O K W H
O A E R U E D N K W I C T T D N R J L I
J L R T M U O R B O W H T I U A L M Y U
T T N T T L S G R P X O C C B U P W X W
J H O E E B D E F W P U A P G F G X E G
E E M R R B T G M S J I K F D N T W C P
K O W M M S C A N B L O L U O L N J X N
N R E L A X R U A B V K M U B H Y S A R
T Y A E S F S Q Q E W L L V G Y I U M I
O H R I V G Q N B Q P F F T V B R O L H
J D A B M H D E C I G U U U I B J V L O
X D G O W V Y O Y O J A D R C R J P A X
F I Q E U F X D B D A T O X M S V K J V

Clues

  • Every 50 to a 100 million years, an asteroid hits the Earth large enough to cause planet devastation. This accounts for the extinction of dinosaurs 65 million years ago. (8, 6)
  • Pollen analysis (they become trapped in sediment and scientists can compare the plants as pollen can be dated), sea level change (the volume difference as beaches can be dated) and ice cores (a layer created each year, traps gases and shows temp). (4, 4)
  • The orbit varies every 100,000 years and changes every 41,000 years. This affects glacial cycles. Deep sea samples show that over 800,000 years the Earth has had 8 inter glacial cycles. (7, 6)
  • This causes variations in solar energy and this accounts for the cooler periods such as the Medieval period and the little Ice Age. (7, 6)
  • Tree rings (one is formed every year and if the climate was good then the ring will be thick), historical records (indirectly show the changes in conditions) and retreating glaciers (the change in temp by rocks dating and glacier size). (6, 4)
  • Volcanoes produce ash and Sulphur Dioxide. This rises into the stratosphere and the high level winds form a blanket reducing UV rays. E.g. Mount Pinatubo, 1991 produced 17 million tonnes of Sulphur Dioxide and this cooled the Earth by 0.5% a year. (8, 6)
  • Weather records (detailed change in the climate), polar ice melt (reduction at both poles because of global warming) and ecosystem changes (the changes in availability of food and shelter). (5, 4)

Comments

No comments have yet been made

Similar Geography resources:

See all Geography resources »See all Pollution and health risks resources »