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Source Notes

This curriculum keeps student-facing pages readable by using a lightweight source system instead of dense inline citations. Use this page when you want to verify a factual claim, update a time-sensitive number, or see where an approximate figure came from.

How To Use These Notes​

  • When a lesson says "about," "roughly," or "approximately," that is deliberate.
  • Current-policy and current-data claims should be checked annually.
  • Classroom heuristics, such as the "10% rule," are presented as teaching models rather than universal constants.
  • Product claims, sponsored eco-friendly messages, before-and-after photos, and viral environmental posts should be checked with the same calm routine used elsewhere in the course.
  • AI-generated or AI-edited images, charts, maps, summaries, wildlife photos, captions, and videos should be treated as checkable information, not as automatic proof.
  • If a figure changes meaningfully over time, update the lesson text and this page together.

Last checked: May 2026.

Environmental Information, Media, And AI Note​

Facilitator reminders:

  • Some environmental messages use strong emotion, dramatic imagery, or simplified captions to get attention. That does not always make them wrong, but it does mean the message may need more checking.
  • Green product claims often highlight one helpful feature while hiding missing context about packaging, shipping, energy use, durability, or disposal.
  • Before-and-after photos, disaster videos, animal images, maps, and screenshots can be cropped, edited, mislabeled, or AI-generated.
  • AI-written summaries can be useful starting points, but they may leave out uncertainty, tradeoffs, or source quality.

When facilitators model source checking, keep the questions steady:

  • Who made this?
  • What evidence or data is shown?
  • Is another trusted source saying something similar?
  • What might be missing?
  • What should be checked before sharing or acting on it?

Week 4: Water Distribution And Reservoirs​

Use these for freshwater distribution, major reservoirs, and water-cycle framing.

Facilitator note:

  • The exact percentages shown in different educational summaries are rounded differently. Keep the big idea stable: most water is in the oceans, most freshwater is in ice or groundwater, and only a very small fraction is in lakes, rivers, and the atmosphere.

Week 5: Atmospheric CO2, The Keeling Curve, And Climate Evidence​

Facilitator notes:

  • NOAA listed the Mauna Loa monthly average at 431.12 ppm for April 2026 and 429.64 ppm for April 2025 when these notes were checked.
  • The preindustrial benchmark used in the curriculum is approximately 280 ppm.
  • The greenhouse-effect discussion in Week 5 is supported by standard physics and the NASA evidence summary above.
  • Whole-Earth carbon reservoir tables vary depending on whether a source is counting only active-cycle reservoirs or including sedimentary rock and other long-term stores. Keep the student-facing lesson focused on relative scale, not false precision.

Week 6: Nitrogen, Fertilizer, And Downstream Loads​

Facilitator notes:

  • Our World in Data summarizes the often-cited estimate that just under half of the people alive today are dependent on synthetic fertilizers.
  • The exact share varies by method and source. In student-facing discussion, it is safer to say that synthetic fertilizer supports a very large share of modern food production.
  • Gulf hypoxia area estimates change year to year. If you want the current seasonal size, check the latest NOAA Gulf hypoxia forecast or measured-zone update before teaching.

Week 7: Plastics, Recycling, And Microplastics​

Facilitator notes:

  • The course should emphasize durable ideas over shaky single numbers: plastics persist, many waste systems leak, and plastic recycling is partial rather than complete.
  • Country-specific PET bottle recycling rates change by year and by reporting method. If you want a current U.S. PET container number, consult the latest annual PET recycling report before teaching.
  • Bottle-to-bottle recycling can happen in cleaner collection systems, but downcycling into fiber or lower-grade material is also common. Avoid saying PET always or never returns to bottles.
  • For microplastics, the safest classroom claim is that larger plastics fragment into smaller pieces that persist in water, soil, food webs, and human environments. Avoid overloading the lesson with uncontextualized human-exposure headlines.

Week 8: Carrying Capacity Case Studies​

Facilitator note:

  • Historical carrying-capacity case studies are often retold with rounded population figures. Use them as structure-rich examples, not as memorization targets. If you want to emphasize a particular case, compare at least two ecology references before treating a number as fixed.

Week 9: Population Dynamics Examples​

Facilitator note:

  • Predator-prey cycle graphs in school settings are usually simplified versions of longer ecological records. The key lesson is the shape of the feedback relationship, not an exact numeric dataset.

Week 12: Circular Design And Aluminum​

Facilitator notes:

  • The commonly repeated claim that about 75% of all aluminum ever produced is still in use is an industry estimate that is useful for teaching long material lifetimes.
  • The same source also summarizes the familiar claim that recycling aluminum uses about 95% less energy than producing primary aluminum.
  • Week 12 should still present aluminum as a strong technical-nutrient example, not as a perfect material with no costs.

Week 13: Right to Repair Policy References​

Facilitator notes:

  • U.S. state repair laws change quickly. The earlier NCSL 2023 legislation page used in this repo is now outdated and should be replaced with a current tracker or current state legislative pages before naming an exact list of states. Needs future verification.
  • The EU material is best used to confirm the direction of policy: more access to repair, spare parts, and repair information for covered goods.

Optional Week 1: Feedback Loops, Permafrost, And Tipping Points​

Facilitator notes:

  • Optional Week 1 should treat tipping points as active areas of research, not countdown claims.
  • If you want to deepen the climate science, use current IPCC summaries or NASA overviews and keep the classroom claim modest: some climate subsystems may contain thresholds beyond which change becomes self-reinforcing.

Optional Week 2: Pinatubo, SRM, DAC, And CDR​

Facilitator notes:

  • NASA describes Mount Pinatubo as injecting about 15 million tons of sulfur dioxide into the stratosphere and contributing to about 1 degree F (0.6 degrees C) of global cooling for almost two years.
  • The National Academies source is useful for explaining why carbon dioxide removal is technically real but constrained by scale, cost, energy, and storage requirements.
  • Geoengineering figures change quickly and are easy to misuse. Keep the lesson centered on mechanism, tradeoffs, and risks rather than on debating a single number.

Annual Update Checklist​

Check these before each new teaching year:

  1. Atmospheric CO2 value in Week 5.
  2. Any fertilizer-dependence or Right to Repair policy language in Weeks 6 and 13.
  3. Any recycling-rate examples used in Week 7.
  4. Any current-event framing in the optional extension weeks.
  5. Any media, product, AI-generated, or source-checking examples used in project materials or current-event extensions.