Unit 9 Resources

Since unit 9 makes up 15-20% of the exam, I recommend taking your time and really covering each of the 10 topics in class thoroughly. However, some of the topics are more complex and heavier in terms of Essential Knowledge outlined in the Course and Exam Description, so you may want to devote numerous days or longer days if you have a variable-length/block schedule to these topics.

I don’t go through the topics in this order, but this is the order I would prioritize spending in-class time on them based on complexity/volume of essential knowledge:

9.5 (Global Change) - Evidence for climate change, effects across numerous spheres, polar amplification, positive feedback loops, this is just a beast of a topic. I recommend doing some gold old fashion direct instruction, aka lecturing, to ensure that you explain some of the more complex topics here. Feel free to use my slides/video for 9.5 or AP Daily videos for the topic. Even with a flipped classroom, I still walk through the more complex aspects of this topic in class, especially the destabilization of the jet stream, thermohaline disruption, polar amplification, and widening of the Hadley cells.

As for student-directed activities, I have my students fill out this “effects of climate change” table using our Fridland text, which I think does an awesome job of succinctly explaining HOW climate change impacts such a wide range of systems on Earth.

I’ve also used this ESRI GeoInquiries activity in the past.


9.9 (Endangered Species) and 9.10 (Human Impacts on Biodiversity) - I don’t think these are as complicated as ocean acidification or ozone depletion, but between them, the CED outlines a lot of information that students are expected to know. I really like using the North Atlantic Right Whale Case Study from Science Outside for teaching these two topics together. It also provides students with some math and data analysis practice along with review of topics from units 1, 3, and a bit of 8.

This is also where I cover the Endangered Species Act as well as CITES, two of the ten pieces of required legislation that students need to know. Nothing fancy, just a quick run through of the information on my slides for this unit. If you’re concerned about covering legislation, I made a short video briefly describing the 10 pieces of legislation students need to know for the exam.

In addition, many folks in the Facebook group have shared versions of a popular activity called “Endangered Species Trading Cards.” While I’ve never had the time to do this activity with my students, it looks fun, so check it out there if you’re interested.


9.1 (Stratospheric Ozone Depletion) and 9.2 (Reduction of Stratospheric Ozone Depletion) - It’s a little PG-13, but I like to use the “distracted boyfriend” meme that was popular on the internet a few years ago to tell the story of the destructive chlorine atom that leaves its relationship with a CFC to break up ozone relationships over and over again. My Instagram page has these two memes, but I’ve taken screenshots of them here in case you’re interested in using them in class. 

In addition to this little story, we do Kristi’s ozone table drawing in class, which is a nice way to review tropospheric ozone formation as well.

Recently, I’ve seen what looks like an awesome Ozone depletion activity using marshmallows and toothpicks shared in the Facebook group. I’m not sure who it originally came from, but here’s a popular version shared by Dan Moylan.


9.6 (Ocean Warming) and 9.7 (Ocean Acidification) - I grouped these together in this blog post because I like to start with this Gizmo activity to introduce how coral reef ecosystems are impacted by warming, acidification, overfishing, and invasive species, the day before we get into acidification.

After laying the groundwork for ocean acidification with the Gizmo and a brief review of the chemistry (just my first 9.7 slide), students design an investigation based on Kristi’s Ocean Acidification lab. This is an awesome opportunity to review experimental design as well as content, so I would try and prioritize using class time to have students conduct this lab.

I just discovered these NOAA resources over the weekend and they look awesome, however, I haven’t had the chance to try them out with my students yet. I did peruse them a bit and they look like they could be a great way to explore part of 9.5 as well as 9.6 and 9.7.


9.3 (Greenhouse Effect) and 9.4 (Increases in the Greenhouse Gases) - I like to start by showing this section of the recent Crash Course episode to review the basics of the greenhouse effect. Then I show students how to use this PhET simulation and have them spend a few minutes playing around with it before asking them to draw their own model of the greenhouse effect.

To help students explore impacts of rising GHG concentrations and start exploring the impacts of climate change, I love this $4 virtual lab from Kristi’s TpT page.


9.8 (Invasive Species) - While I’ve never shown the full documentary, it’s an APES right of passage to have your students watch at least part of the cinematic masterpiece that is Cane Toads: An Unnatural History. Highlights include 16:47 (old man explaining the noise of Cane Toad mating), 25:00 (vengeful man explaining hatred for the toads with the camera far too close to his face), 40:20 (man purposely running over toads with his car), and 44:18 (outro song).

After that, we create invasive species wanted posters (not sure who this came from originally, but this is a version I copied from someone in the Facebook group.)


And just like that, we’re through all 99 topics and it’s time to review for the exam! I really try to make a point of congratulating the students on all the work that they’ve put in up to this point in the year. I have yet to encounter another AP course that has more than 99 topics outlined in their CED, which is part of what makes APES a challenging course to teach from a pacing and planning standpoint. If they’ve maintained one notebook or binder for notes throughout the year, have them get it out and flip through it for a minute, just to admire the sheer volume of information they’ve been exposed to and interacted with. This can be a great way to build positive momentum headed into the final weeks/days of the course leading up to the exam on May 2nd.

As always, don’t hesitate to reach out if you have questions or concerns as you plan out unit 9 and your exam review. (apesvsverybody@gmail.com)

🏔️ Jordan

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