climates of recent past

Question 1

how do the concentrations of O18 and O16 in ice cores give us clues on past temperatures?

Answer 1

• heavier water is harder to evaporate, if it is cold there is no every available so lighter water is preferred
• O18 is heavier
• during a glacial period, the isotopically heavier water remains in the ocean while the lighter water goes into glaciers
  -> if there is poor concentration of O18, water was evaporated in cool conditions and if there is 018, water was evaporated in warmer climates
  -> we can see the O18 concentrations in ocean based on sediments and shells

Question 2

what are some sources of information on past climates in the natural world?

Answer 2

• ice cores
• sediments from oceans or lakes
• tree rings
• pollen
• fossil remains

Question 3

how did we get out of the last ice age?

Answer 3

there was a boost in solar illumation in the Northern latitudes that helped melt all the ice in the summer (no more ice-albedo effect)