Climate History

Question 1

Pleistocene/Holocene

Answer 1

-the Pleistocene is the geological series that lasted from about 2.5 million to 11,700 years ago, spanning the world’s recent period of repeated glaciations
-Pleistocene refers to the ice age
-there were ice sheets in the northern and southern hemispheres

Question 2

Glacial–Interglacial

Answer 2

a geological interval of warmer global average temperature

Question 3

How do we know the Temperature over the last 850,000 years?

Answer 3

Ice-core Isotope Dating, O16 is lighter and cold, O18 is heaving and hot
-when it’s warm there is a lot of O18 in the ice cores, when it’s cold you don’t have a lot of O18 in the ice sheets

Question 4

Sediment Cores: Pollen Analysis

Answer 4

-after glaciers recede, forests grow by lakes, the wind blows the pollen from the trees into the lake, the pollen sinks to the bottom of the lake and then freezes in the sediment, then creates different layers of sediment
-when you remove the dirt, you are analyzing fossil pollen, each type of pollen looks different under a microscope, then you count the number of tree species from the pollen

Question 5

What happened with the ice sheets and land bridges?

Answer 5

they have melted over time with increases in temperature

Question 6

Tree Cores: Temperature and Precipitation

Answer 6

-when it’s a wet or warm year, tree rings are bigger
-when the is less precipitation the rings are thinner
-fires scars on rings can show the frequency of fires in the past

Question 7

Sangamonian (warmer than today)

Answer 7

-it was warmer in the last interglacial period than it is today
-however the temperature is increasing at a faster rate than normal

Question 8

Evidence that the Earth is warming

Answer 8

Temperature gauges, Greenland is melting, Glaciers in South America, Sea-level is rising, the Last 4 years are the hottest on record