PALEOCLIMATES Click to edit Master subtitle style Ancient
PALEOCLIMATES Click to edit Master subtitle style Ancient climates 12/30/2021
Click to edit Master subtitle style 12/30/2021
12/30/2021
Earth’s climate history � Has always been changing
Earth’s climate has always been changing 12/30/2021
HOW DO WE STUDY PAST CLIMATES? ? ? 12/30/2021
Fossils Certain critters only live in WARM climates Trilobites Corals (Petoskey stones) dinosaurs 12/30/2021
Glacial evidence • Indicates COLD climate – Grooves – Erratics • Misplaced boulders 12/30/2021
Ice cores • Ancient air bubbles are trapped in the ice • Can analyze ancient air! 12/30/2021
18 O/ 16 O • 18 O is heavier- harder to evaporate • More 18 O when climate is hotter • Seen in ice cores 12/30/2021
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Tree rings Wider rings represent warm wet climate 12/30/2021
Coral reefs • Corals add layers every year – Like tree rings – Bigger layer= warmer 12/30/2021
NATURAL CAUSES OF CLIMATE CHANGE
VOLCANOES �Lava type= Emit CO 2; warms- long term (need a lot!) �Ash type= emit SO 2 - blocks heat- cools- short term
Impact events (space rocks) � 1) Stirs up dust= colder
Milankovitch cycles � Earth tilt changes ◦ Less tilt= less seasons �Cooler in mid latitudes �Ice age! �OR �Earth’s orbit becomes �More oval= colder
Variation in Solar output � Sunspots ◦ Cause solar storms ◦ Make earth hotter
Land vs. sea ice � Melting of sea ice (icebergs) will NOT effect sea level � Melting of land ice will effect sea level ◦ Antarctica/ Greenland also cause global cooling (Day After Tomorrow) � Could
Global warming can cause global cooling? �
Rising sea level by 2080 (projected)
Current state of glaciers
Glacier national Park, Montana 1938 vs. 2005
Alaska 1917 vs. 2005
Greenland notice 2002 -3
Carbon footprint � Your � Extra impact on GHGs. credit!!
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