Climate Change Interactive Homework

From the reading, you know that isotope information can be used to determine past temperature conditions. As the ice in ice sheets is made from successive snowfalls over thousands of years, ice cores taken from these ice sheets record layers of different climate conditions.

Two different temperature histories are shown below from two different Antarctic ice cores (blue and green lines). Note that “today” (and the top of the ice cores) is at the right side of the graph, and that the ice is older as we move towards the left side of the graph. A relative change in temperature, in degrees Celsius, is shown on the left side of the graph. The zero (dashed) line is today’s temperature (so if there was no change over time, the green and blue lines would be the same as the dashed line). If the line is above or below the dashed line it means that the temperature in the past was higher or lower than today.

Note that changes in global ice volume are highly correlated with changes in the observed temperature.

Figure from Ice Age Temperature

According to this data, in the last few hundred thousand years the Earth (choose all that apply):

If the present average temperature is 15 degrees Celsius (about 60 degrees Fahrenheit), what was the temperature about 25,000 years ago, and about 120,000 years ago?

Using the graphs for sea level change, we can say that: (check all that apply)

NASA also discusses scientific uncertainty in the article The study of Earth as an integrated system. The uncertainties are divided into two categories – forcings and feedbacks. Using the information here, and perhaps from a small amount of further research, answer the following: Burning coal can both increase and decrease temperatures. Why could it cause an increase in temperature? Why could it cause a decrease in temperature? Check all that apply.