Review summaries of Kling lectures

Paleoclimate and the Ice Ages

---

Main Terms:

1. “Relationships” in Science – Variables, Mechanism, Correlation, Causation

“Relationships” in science are basically about “interactions” between people, or, between “things”. Of course when scientists make measurements they don’t call “things” “things”, they call them “variables”.

Variable - A variable is an object, or a measurement of an object. For example, if I measure the temperature at various locations on campus, the temperature is then a variable. And because some places are warmer and some cooler, this variable is not a “constant” (part of the definition of a variable). Typically we measure variables in order to understand how something works or operates – that is, we want to understand the mechanism of the behavior of that variable (i.e., Why is it warmer or colder in certain places?)

Mechanism - A mechanism can be thought of as “how does something work”. For example, in our example with temperature, the mechanism that causes warmer temperatures in sunny locations is the absorption of energy in the form of solar radiation.

Correlation - Correlation means that there is a consistent relationship between two phenomena or two variables. For example, when variable goes up so does the other.

Causation - The phrase “correlation is not causation” is commonly heard in science. It means that just because two variables behave similarly, it does not mean that they are “mechanistically related”. That is, there might not be a mechanistic explanation for the correlation. Consider that papers have been published noting that the birth rates in the Netherlands are correlated with the number of stork sightings. Based on this correlation it is (or it used to be…) common to tell small children that “storks bring babies”, rather than delving into an explanation of the actual mechanism.

2. Paleoclimate and Paleoclimatology

3. Weather versus Climate

4. Ice Age

5. Methods used in paleoclimatology

* Isotope geochemical studies

* Dendrochronology

* Pollen distribution

6. Oxygen isotopes

7. Isotope fractionation

8. Milankovitch orbital cycles

Main Concepts:

1. Be able to explain the causes of climate change

Long-term causes - Including the effects of solar luminosity, shifting continents and weathering, and greenhouse gases.

Medium-term causes - Including variations in Earth’s orbit around the sun, the “Milankovitch” cycles.

2. Be able to explain how the use of isotopes of oxygen and hydrogen can determine the temperature of past environments on Earth, either from the analysis of ice cores or ocean sediments.