Module 2 overview and learning objectives

1. The bookmarks indicated the following six events:
· Formation of the earth and moon 4.6 billion years ago
· Earliest life, 3.9 billion years ago
· Early land plants 420 million years ago
· Largest mass extinction 248 million years ago
· Dinosaur extinction 65 million years ago
· "Lucy", early hominid, 4 million years ago

2. In the Archaean period, there are cyanobacteria and stromatites.

3. The three periods of time that are described as eras are the Paleozoic, the Mesozoic, and the Cenozoic.

4. There are five mass extinction events listed. They are:
End-Orcovician, where many types of ocean life became extinct including trilobites, brachiopods, and graptolites. The Late Devonian, stromatoporoids, brachiopods associated with reefs and more trilobites all became extinct, as coral systems suffered heavy losses. The End-Permian extinction saw some corals, trilobites, and types of brachiopods, orinoids and shelled cephalopods all became extinct at this time. The End-Triassic extinction hit many of those same groups, along with corals, and the land-dwelling phytosaurs. The End-Cretaceous killed off the non-avian dinosaurs, pterosaurs, mosasaurs, some groups of cephalopods and bivalves.

5. The End-Cretaceous appears to have been caused by an asteroid that hit the earth that created a dust cloud that circled the entire planet, greatly reducing the amount of sunlight reaching the earth's surface. The End-Triassic extinction was caused when Pangaea split, which created substantial volcanic activity, filling the atmosphere with carbon dioxide, leading to global warming.

Part II. Global Climate Change
6. The four greenhouse gases that are being measured by the simulation are carbon dioxide, water vapor, methane, and nitrous oxide.

7. The average temperature in the "Today" simulation is 59-60F. Adding clouds appears to do little, maybe up one degree. In 1750, the average temperature was around quite a bit lower, around 53-54F. The gas levels are as follows:

H20
CO2
CH4
N20

Present Day
70%
388ppm
1.843ppm
0.317ppm

1750
70%
280ppm
0.73 ppm
0.27ppm

Ice Age
?
180ppm
0.38ppm
0.215pm

During the ice age, the average temperature was a lot lower, bouncing around the 30sF.

8. The effect that greenhouse gases in the atmosphere are having is to increase the temperature of the planet. As the concentration of greenhouse gases in the atmosphere increases, the planet gets warmer. This reminds of the Ed-Triassic extinction, where volcanic activity released massive amounts of CO2 into the atmosphere, which led to that major extinction.

Part III. Drawing Conclusions

There is a clear conclusion to be drawn from this. It is that as the concentration of greenhouse gases in the atmosphere continue to increase, the planet will continue to get warmer. This will have strong impacts on our ability to survive – past mass extinctions occurred when the climate changed. This is because life can take time to adapt to new realities, such as changes in the food supply, or weather patterns.

What remains unanswered, really, is how we can stop contributing more greenhouse gases into the atmosphere. When we look at the causes of these emissions, our entire society is based around the things that cause greenhouse gas emissions. So this is a pretty major challenge, but our survival as a species depends on it, or on a lot of adaptive capabilities. References
Extinctions in the recent past and the present day. (2017). Sam Noble Museums. Accessed on August 15, 2016, at http://samnoblemuseum.ou.edu/understanding-extinction/extinctions-in-the-recent-past-and-the-present-day/

The greenhouse effect. (n.d.). PhET Simulations. Accessed on July 26, 2017, at http://phet.colorado.edu/en/simulation/greenhouse

University of California, Berkeley, Museum of Paleontology. (n.d.). Geologic time. Accessed on August 8, 2014, at http://www.ucmp.berkeley.edu/education/explorations/tours/geotime/gtpage1.html.