1. How did scientists use glaciers and ice caps for data?
? Drill into large sheet of ice (Antarctica and Greenland)
? Measure ancient greenhouse gas concentrations from the gas bubbles trapped in the ice (they are same as in the atmosphere in which they were formed).

2. On slide 16 (notice that the data is in thousands of years ago)-describe how CO2 levels and temperature change were related PRE-HUMAN? What is the significance of this?

3. Has it been proven that earth’s temperature is dependent upon CO2 alone?
No. CO2 and temperature follow each other, but that does not mean that
CO2 causes global warming. Could be other factors.

4. List how much each of these gases has increased since pre-industrial times: CO2, CH4, NO2
CO2 levels have increased by 30% since preindustrial times.
CH4 has increased 145%
NO2 has increased 15%

5. How fast have ocean levels raised in the last century?
Ocean levels have risen 1cm/ decade for last century.

6. What conclusions did the powerpoint make? See slides #28, 29?
There were significant climate changes before humans were around and
there will be non-human causes for climate change in the future.
There is no doubt humans have caused a large increase in the atmospheric
greenhouse gases
- Increases that would naturally be occurring over centuries by
normal processes have been duplicated in less than a century because of human activity
These gases contribute to global warming (they always have, even before
humans).