Oceans, Carbon & Climate — Investigation · Earth & Space Science, Grade 9
Connect climate evidence with ocean circulation, carbon budgets, and Earth-system feedbacks.
Compare Carbon-Budget Scenarios
Investigate
How do changed carbon flows affect a model atmospheric carbon store?
Plan three teaching sessions: define the model and comparison; run or analyze repeated supplied/collected records; then graph, explain, revise and submit the notebook. These independent home-study routes do not certify the school’s mandated investigations or laboratory minutes.
Materials
- Calculator
- Graph paper
- Supplied scenario table
Before you begin
This is a paper-and-data investigation. Use supplied illustrative data or teacher-approved observations. Do not enter hazardous sites to collect evidence.
Plan a fair test
Compare net human carbon input and net land/ocean uptake over equal one-year steps. Start both scenarios with 100 model units. These units and constant flows simplify real carbon cycling; they are not climate forecasts.
Method
- Define the atmospheric store and the flows crossing its boundary.
- Calculate each scenario’s annual net change as input minus uptake.
- Build a five-year table beginning at 100 model units at year zero.
- Plot both stores over time and compare the slopes.
- Predict how a decrease in uptake would change the result.
- Explain why a carbon-store graph alone cannot predict a particular place’s temperature.
Open the investigation data (illustrative)
Illustrative data created for this activity; these are not measurements from an actual site or an official reference table.
| Scenario | Input (model units/year) | Net uptake (model units/year) |
|---|---|---|
| A: constant higher input | 8 | 5 |
| B: reduced input | 4 | 5 |
Analyze and explain
- Find both atmospheric stores after five years.
- If warming lowers uptake from 5 to 3 while input stays 8, how does the annual change respond?
- What processes are missing from the constant-flow model?
- Identify the system boundary, units and conditions held comparable.
- Explain how the graph or figure supports the mechanism rather than merely repeat its trend.
- State one uncertainty or scale limitation and design a follow-up comparison that could challenge the explanation.
What a strong explanation includes
- Correct system boundary and flow units
- Shows annual net changes and five-year stores
- Explains amplification when uptake falls
- Separates illustrative scenario results from an actual forecast
- Keep observations separate from model-generated or supplied illustrative records.
- Explain a revision using the evidence and a stated model limitation.
Parent / teacher guide: discuss after the investigation
A gains 3 units/year and reaches 115; B loses 1 unit/year and reaches 95. With input 8 and uptake 3, the gain becomes 5 units/year. If warming caused that uptake decrease, the resulting extra atmospheric carbon could amplify warming: a positive feedback. The model omits changing reservoirs, variable uptake, other forcings, heat storage, and regional circulation. A complete notebook also specifies the boundary, measurement units and matched conditions. Describe a mechanism connecting the pattern to the claim, then state a limitation and an additional comparison. Supplied illustrative outcomes are not a claim about your collected results; differences must be interpreted rather than corrected to match the example.
Compare this model with the learner’s actual evidence. Different measurements can support a different conclusion; check the reasoning and limitations, not matching wording.