global warming & climate change Flashcards
climate:
average temperature and rainfall over 40 years
weather
temperature, rainfall, wind in 1 day
hottest part of world?
equator
evidence for past climate:
- tree rings
- ice cores
tree rings:
each ring is 1 year
when warmer rings are wider
when cooler rings are narrower
ice cores:
-ice sheets contain layers
-each layer is 1 year of snowfall
-to find past temperature
= measure CO2 from ice
main green house gas:
carbon dioxide
global warming:
humans produce GHG
more heat is trapped
warming the earth
how do humans increase GHGs?
-factories and cars release CO2
-deforestation
(less trees to absorb CO2)
impacts of global warming:
- thermal expansion (sea level rise)
- 90% of world glaciers shrinking
- artic shrunk
impacts of climate change:
- frequent floods (ice caps melting)
- stronger storms and hurricanes
- changes to farming
- change to animal habitat
- polar bears die out (polar ice caps melting)
- forest fires
greenhouse effect:
‘the process where gases trap heat in the earths atmosphere, causing the world to heat up’
what happens in the greenhouse effect?
- heat from sun enters atmosphere
- some is reflected back into space
- some are trapped by our GHGs
how much did the global temperature rose by?
1180-2012
0.85*
how much did the sea level rise by?
1870-2012
210mm
