36  Unit 6: Closing — Your Solutions, Your Argument

How can we reduce the negative impacts of human activities on the environment while still meeting our needs?

HS-ESS3-2 HS-ETS1-2 Time: 3 Days

🌍 Your Solutions, Your Argument 🌍

37 The Performance Task

37.1 🎯 Unit Driving Question

How can we reduce the negative impacts of human activities on the environment while still meeting our needs?

37.1.1 Your Task

Design a multi-solution proposal that reduces environmental health impacts from at least two of the three human activities you studied (fossil fuel burning, land use change, mining). Your proposal must be evaluated using a computational model.

Your proposal must:

• ✅ Identify a specific community and its environmental health challenges
• ✅ Select solutions from at least two different chapters in this unit
• ✅ Use the interactive model below to test your solution combination
• ✅ Evaluate each solution on cost, safety, and reliability
• ✅ Construct an argument using the CER framework that defends your proposal
• ✅ Be presented as a 3–4 minute oral argument with your model results as evidence

38 Building Your Argument: The CER Framework

38.0.1 📌 CLAIM

A clear, specific statement about which solutions you recommend and why.

Example format: “To reduce environmental health impacts in [community], the most effective approach is to combine [Solution A] and [Solution B] because [brief reason].”

Strong claim: “To reduce health impacts in Appalachian coal communities, combining an economic transition program with enhanced land reclamation would reduce premature deaths by 60% within 15 years while creating net job growth.”

Weak claim: “We should use clean energy and plant trees.” ← Too vague! Where? How much? What impact?

38.0.2 📊 EVIDENCE

Specific data from your chapter investigations and model results. You need at least three pieces from at least two different chapters.

Good evidence is:

• Quantitative — includes specific numbers, percentages, or model outputs
• Multi-source — from your data analysis AND the interactive model
• Connected — each piece supports your claim directly

38.0.3 🧠 REASONING

The scientific explanation connecting your evidence to your claim using mechanisms from this unit:

• How do fossil fuel combustion products (PM2.5, SO₂, NOₓ) reach human bodies and cause disease?
• How do land use changes alter local temperatures, water quality, and ecosystem services?
• How do mining contaminants travel through air and water pathways to communities?
• How do feedback loops amplify or reduce environmental impacts?
• Why do combined solutions create synergy effects?

39 Evidence Review: What You’ve Learned

39.0.1 🏭 From Fossil Fuels Chapter

Evidence	Key Data
Air pollution deaths globally	8.7 million deaths/year from fossil fuel pollution
Regional health disparities	South and East Asia: 4.5M+ deaths; Africa most vulnerable per capita
France vs. US energy comparison	France (70% nuclear) has far lower air pollution deaths
Carbon cycle disruption	Human emissions: ~10 GtC/yr → atmosphere growing by 2+ ppm/yr
Health cascade	CO₂ → warming → heat stress, vector-borne disease, food insecurity
Carbon removal technologies	Direct air capture, enhanced weathering, biochar, reforestation
Transportation solutions	EV transition could cut transport emissions 60–80% by 2050

39.0.2 🌳 From Land Use & Biodiversity Chapter

Evidence	Key Data
NYC Heat Vulnerability Index	Low-income, less green neighborhoods have 3× more heat deaths
Manhattan land cover change	From 80% forest → 70% impervious surface in 400 years
Urban heat island effect	Dark surfaces can reach 60°C vs. vegetation at 30°C
Computational land use model	Every 10% increase in impervious surface → +2°C local temperature
NYC cooling solutions	1M trees + 40% cool roofs could prevent 200+ heat deaths/year
Amazon tipping point	At ~25% deforestation, Amazon could flip to savanna
Combined solution analysis	Multi-criteria evaluation across 5 dimensions

39.0.3 ⛏️ From Mining Chapter

Evidence	Key Data
Appalachian health disparities	Lung cancer +81%, heart disease +79%, life expectancy −6 years
Ecological destruction	100% habitat destruction from MTR; permanent stream burial
Mining method comparison	Underground mining has 1/5 the surface impact of MTR
Air pathway	Blasting → dust → PM2.5 → lungs → disease
Water pathway	Mine drainage → heavy metals → groundwater → drinking water
Solution comparison	4 solutions rated on 6 criteria (cost, effectiveness, speed, jobs, health, ecosystem)
Combined solution synergy	Multiple solutions together create +8% effectiveness per combination

Plot = require("@observablehq/plot")
d3 = require("d3@7")

40 Your Integrated Solution Model

Use the model below to test different solution combinations across all three environmental challenges.

viewof fossilSolution = Inputs.select(
  ["None", "Switch to nuclear (like France)", "Carbon capture + storage", "Electrify transportation", "All fossil fuel solutions"],
  {label: "🏭 Fossil Fuel Solution:", value: "None"}
)

viewof landSolution = Inputs.select(
  ["None", "Plant 1M urban trees", "40% cool roof coverage", "Protect remaining forests", "All land use solutions"],
  {label: "🌳 Land Use Solution:", value: "None"}
)

viewof miningSolution = Inputs.select(
  ["None", "Enhanced reclamation", "Advanced filtration", "Economic transition", "All mining solutions"],
  {label: "⛏️ Mining Solution:", value: "None"}
)

viewof timeHorizon = Inputs.range([5, 30], {label: "📅 Time Horizon (years):", step: 5, value: 15})

{
  // Calculate impacts
  let fossilHealth = 0, fossilEco = 0, fossilCost = 0;
  let landHealth = 0, landEco = 0, landCost = 0;
  let mineHealth = 0, mineEco = 0, mineCost = 0;

  if (fossilSolution === "Switch to nuclear (like France)") { fossilHealth = 35; fossilEco = 15; fossilCost = 40; }
  else if (fossilSolution === "Carbon capture + storage") { fossilHealth = 15; fossilEco = 25; fossilCost = 30; }
  else if (fossilSolution === "Electrify transportation") { fossilHealth = 25; fossilEco = 20; fossilCost = 25; }
  else if (fossilSolution === "All fossil fuel solutions") { fossilHealth = 60; fossilEco = 50; fossilCost = 80; }

  if (landSolution === "Plant 1M urban trees") { landHealth = 15; landEco = 30; landCost = 5; }
  else if (landSolution === "40% cool roof coverage") { landHealth = 20; landEco = 10; landCost = 10; }
  else if (landSolution === "Protect remaining forests") { landHealth = 10; landEco = 40; landCost = 15; }
  else if (landSolution === "All land use solutions") { landHealth = 40; landEco = 65; landCost = 25; }

  if (miningSolution === "Enhanced reclamation") { mineHealth = 15; mineEco = 30; mineCost = 5; }
  else if (miningSolution === "Advanced filtration") { mineHealth = 25; mineEco = 10; mineCost = 10; }
  else if (miningSolution === "Economic transition") { mineHealth = 35; mineEco = 35; mineCost = 50; }
  else if (miningSolution === "All mining solutions") { mineHealth = 60; mineEco = 60; mineCost = 55; }

  // Count active domains
  const activeDomains = [fossilHealth > 0, landHealth > 0, mineHealth > 0].filter(Boolean).length;
  const synergy = activeDomains > 1 ? (activeDomains - 1) * 10 : 0;

  let totalHealth = Math.min(95, fossilHealth + landHealth + mineHealth + synergy);
  let totalEco = Math.min(95, fossilEco + landEco + mineEco + synergy);
  let totalCost = fossilCost + landCost + mineCost;

  // Time adjustment
  const timeFactor = Math.min(2, timeHorizon / 15);
  totalHealth = Math.round(Math.min(95, totalHealth * timeFactor));
  totalEco = Math.round(Math.min(95, totalEco * timeFactor));

  const livesSavedPer100K = Math.round(totalHealth * 4);
  const speciesSaved = Math.round(totalEco * 3.2);

  const width = 750;
  const height = 480;
  const svg = d3.create("svg").attr("width", width).attr("height", height);

  svg.append("rect").attr("width", width).attr("height", height).attr("fill", "#f8f9fa").attr("rx", 12);

  svg.append("text").attr("x", width/2).attr("y", 28).attr("text-anchor", "middle")
    .attr("font-size", 18).attr("font-weight", "bold").text("Your Integrated Solution Model");

  // Synergy info
  if (synergy > 0) {
    svg.append("rect").attr("x", 200).attr("y", 35).attr("width", 350).attr("height", 24)
      .attr("fill", "#00b894").attr("rx", 12).attr("opacity", 0.2);
    svg.append("text").attr("x", width/2).attr("y", 52).attr("text-anchor", "middle")
      .attr("font-size", 12).attr("fill", "#00b894").attr("font-weight", "bold")
      .text(`✨ Cross-domain synergy: +${synergy}% boost from addressing ${activeDomains} activity types`);
  }

  // Domain breakdown bars
  const categories = [
    {label: "Fossil Fuel Health", value: fossilHealth, max: 60, color: "#e17055"},
    {label: "Land Use Health", value: landHealth, max: 40, color: "#00b894"},
    {label: "Mining Health", value: mineHealth, max: 60, color: "#6c5ce7"}
  ];

  svg.append("text").attr("x", 15).attr("y", 85).attr("font-size", 14).attr("font-weight", "bold").text("Health Impact by Domain:");

  categories.forEach((c, i) => {
    const y = 95 + i * 30;
    svg.append("text").attr("x", 20).attr("y", y + 15).attr("font-size", 11).text(c.label);
    svg.append("rect").attr("x", 180).attr("y", y + 2).attr("width", 350).attr("height", 18)
      .attr("fill", "#dfe6e9").attr("rx", 4);
    svg.append("rect").attr("x", 180).attr("y", y + 2)
      .attr("width", (c.value / c.max) * 350).attr("height", 18)
      .attr("fill", c.color).attr("rx", 4);
    svg.append("text").attr("x", 540).attr("y", y + 15).attr("font-size", 12)
      .attr("font-weight", "bold").attr("fill", c.color).text(`${c.value}%`);
  });

  // Totals
  svg.append("line").attr("x1", 15).attr("y1", 195).attr("x2", 735).attr("y2", 195)
    .attr("stroke", "#dfe6e9").attr("stroke-width", 2);

  svg.append("text").attr("x", 15).attr("y", 220).attr("font-size", 14).attr("font-weight", "bold")
    .text(`Combined Results (${timeHorizon}-year projection):`);

  const totals = [
    {label: "Total Health Improvement", value: totalHealth, max: 95, color: "#e17055", text: `${totalHealth}%`},
    {label: "Total Ecosystem Recovery", value: totalEco, max: 95, color: "#00b894", text: `${totalEco}%`},
    {label: "Lives Saved (per 100K)", value: livesSavedPer100K, max: 380, color: "#6c5ce7", text: `${livesSavedPer100K}`},
    {label: "Species Protected", value: speciesSaved, max: 304, color: "#0984e3", text: `${speciesSaved}`},
    {label: "Total Investment", value: totalCost, max: 160, color: "#fdcb6e", text: `$${totalCost}B`}
  ];

  totals.forEach((t, i) => {
    const y = 235 + i * 35;
    svg.append("text").attr("x", 20).attr("y", y + 15).attr("font-size", 12).text(t.label);
    svg.append("rect").attr("x", 210).attr("y", y + 2).attr("width", 380).attr("height", 22)
      .attr("fill", "#dfe6e9").attr("rx", 4);
    svg.append("rect").attr("x", 210).attr("y", y + 2)
      .attr("width", Math.min(1, t.value / t.max) * 380).attr("height", 22)
      .attr("fill", t.color).attr("rx", 4).attr("opacity", 0.8);
    svg.append("text").attr("x", 600).attr("y", y + 18).attr("font-size", 13)
      .attr("font-weight", "bold").attr("fill", t.color).text(t.text);
  });

  // Grade card
  const grade = totalHealth >= 80 ? "A" : totalHealth >= 60 ? "B" : totalHealth >= 40 ? "C" : totalHealth >= 20 ? "D" : "F";
  const gradeColor = totalHealth >= 80 ? "#00b894" : totalHealth >= 60 ? "#0984e3" : totalHealth >= 40 ? "#fdcb6e" : "#e17055";
  const costEfficiency = totalCost > 0 ? (livesSavedPer100K / totalCost).toFixed(1) : "0";

  svg.append("rect").attr("x", 15).attr("y", 420).attr("width", 720).attr("height", 45)
    .attr("fill", gradeColor).attr("rx", 10).attr("opacity", 0.15);
  svg.append("text").attr("x", 25).attr("y", 448).attr("font-size", 14).attr("font-weight", "bold")
    .text(`Overall Grade: ${grade}  |  Cost Efficiency: ${costEfficiency} lives saved per $B invested  |  Solutions active: ${activeDomains}/3 domains`);

  return svg.node();
}

40.0.1 📝 Test and Record Your Model Results

1. Try at least 4 different combinations and record the results:

Combination #	Fossil Fuel Solution	Land Use Solution	Mining Solution	Health %	Ecosystem %	Cost	Grade
1
2
3
4

2. Which combination has the best health improvement per dollar spent (cost efficiency)?
3. What happens when you extend the time horizon from 5 years to 30 years? Why?
4. Why does addressing multiple domains give a synergy bonus?
5. Select your final recommended combination for your oral argument.

41 Cost vs. Impact Tradeoffs

tradeoffData = [
  {solution: "Plant urban trees", health: 15, cost: 5, domain: "Land Use", size: 30},
  {solution: "Cool roofs", health: 20, cost: 10, domain: "Land Use", size: 20},
  {solution: "Forest protection", health: 10, cost: 15, domain: "Land Use", size: 40},
  {solution: "Nuclear transition", health: 35, cost: 40, domain: "Fossil Fuels", size: 35},
  {solution: "Carbon capture", health: 15, cost: 30, domain: "Fossil Fuels", size: 25},
  {solution: "Electrify transport", health: 25, cost: 25, domain: "Fossil Fuels", size: 25},
  {solution: "Reclamation", health: 15, cost: 5, domain: "Mining", size: 30},
  {solution: "Water filtration", health: 25, cost: 10, domain: "Mining", size: 10},
  {solution: "Economic transition", health: 35, cost: 50, domain: "Mining", size: 35}
]

Plot.plot({
  title: "Cost vs. Health Impact of All Solutions",
  subtitle: "Bubble size = ecosystem benefit. Best solutions are upper-left (high impact, low cost)",
  width: 700,
  height: 420,
  marginBottom: 50,
  x: {label: "Cost ($B)", domain: [0, 55]},
  y: {label: "Health Improvement (%)", domain: [0, 40]},
  color: {
    domain: ["Fossil Fuels", "Land Use", "Mining"],
    range: ["#e17055", "#00b894", "#6c5ce7"],
    legend: true
  },
  marks: [
    Plot.dot(tradeoffData, {
      x: "cost",
      y: "health",
      fill: "domain",
      r: "size",
      fillOpacity: 0.6,
      stroke: "domain",
      strokeWidth: 2,
      title: d => `${d.solution}\nHealth: +${d.health}%\nCost: $${d.cost}B\nEco: ${d.size}`
    ,
        tip: true}),
    Plot.text(tradeoffData, {
      x: "cost",
      y: "health",
      text: "solution",
      dy: d => d.solution === "Electrify transport" ? -22 : -18,
      fontSize: 9,
      fontWeight: "bold"
    }),
    // Highlight the "best value" zone
    Plot.rect([{x1: 0, x2: 15, y1: 15, y2: 40}], {
      x1: "x1", x2: "x2", y1: "y1", y2: "y2",
      fill: "#00b894", fillOpacity: 0.07,
      stroke: "#00b894", strokeDasharray: "5,5"
    }),
    Plot.text([{x: 7, y: 38}], {
      x: "x", y: "y", text: d => "💚 BEST VALUE ZONE",
      fontSize: 10, fill: "#00b894", fontWeight: "bold"
    })
  ]
})

41.0.1 💡 The Best Value Isn’t Always the Cheapest

Look at the upper-left corner of the chart — that’s where you find solutions with the highest health impact per dollar. But notice:

• The cheapest solutions (trees, reclamation) have moderate health impact but great ecosystem benefits
• The most expensive solutions (nuclear, economic transition) have the highest total impact
• Some mid-range solutions (cool roofs, water filtration) are highly cost-effective

Your argument should explain why your combination balances these trade-offs for your chosen community.

42 Argument Structure Guide

42.0.1 📋 Oral Argument Outline (3–4 minutes)

Opening (20–30 seconds): State your community, its challenges, and your overall claim.

Evidence Block 1 (40–60 seconds): Present evidence from your first chapter’s data. What did the data show about the current problem?

Evidence Block 2 (40–60 seconds): Present evidence from your second chapter’s data. Include specific numbers.

Model Evidence (30–45 seconds): Show your model results. What was the predicted health improvement, ecosystem recovery, and cost?

Reasoning (30–45 seconds): Explain the scientific mechanisms that make your solutions work. Why do they address the root cause?

Counterargument (20–30 seconds): Acknowledge one limitation, cost concern, or opposing viewpoint. Explain why your proposal still holds.

Closing (15–20 seconds): Restate your recommendation and what it means for the community.

43 Addressing Counterarguments

Counterargument	How to Address It
“Your solutions are too expensive”	Compare costs to the cost of doing nothing — medical bills, lost productivity, environmental cleanup all cost money too.
“Transition programs cause job losses”	Short-term disruption, but long-term the new industries create more and safer jobs. Include a transition timeline.
“Technology isn’t ready yet”	Many solutions (trees, roofs, regulations) are available now. Combine ready solutions with developing tech.
“One community’s solutions won’t fix the global problem”	True — but every community taking action creates momentum. And local solutions have immediate local benefits.
“People won’t change their behavior”	That’s why a mix of regulation, incentives, and infrastructure works better than relying on individual choices alone.

44 Peer Review & Feedback

44.0.1 👥 Peer Feedback Protocol

After each oral argument, rate your classmate on:

Criterion	Rating (1–4)	Comments
Claim is clear, specific, and addresses the driving question
At least 3 pieces of evidence from at least 2 chapters
Evidence is quantitative (includes specific numbers)
Model results are included and explained
Scientific reasoning connects evidence to claim
Solutions evaluated on cost, safety, and reliability
At least 1 counterargument addressed
Delivery is clear and within time limit

Scoring: 4 = Excellent | 3 = Proficient | 2 = Developing | 1 = Beginning

45 Reflection: Connecting It All Together

45.0.1 🔄 How Has Your Thinking Changed?

At the start of this unit, you saw data about premature deaths from environmental causes. Now you understand the mechanisms behind those deaths and the solutions that could prevent them.

Answer these questions in your notebook:

1. At the start of this unit, what did you think was the biggest environmental health threat? Has that changed?
2. What was the most surprising connection you discovered between human activity and health?
3. Which solution from this unit do you think would have the biggest impact if implemented worldwide? Why?
4. Environmental justice question: The communities most harmed by fossil fuels, land use change, and mining are often the poorest. How should that affect which solutions we prioritize?
5. What is one thing you can do in your own community to reduce environmental health impacts?
6. What new questions do you still have?

46 Unit 6 Summary: What You Figured Out

Driving Question	What You Figured Out
How do human activities cause health impacts?	Fossil fuels, land use change, and mining release pollutants that travel through air and water to reach human bodies
Why are some communities more affected?	Environmental injustice — poverty, proximity to pollution sources, less green space, less political power
How does burning fossil fuels harm health?	PM2.5, SO₂, NOₓ cause 8.7M deaths/year; CO₂ drives warming → cascading health impacts
How does land use change affect communities?	Removing vegetation → urban heat islands → heat deaths; deforestation → biodiversity collapse, tipping points
How does mining poison communities?	Air (dust, PM2.5) and water (heavy metals, mine drainage) pathways carry contaminants to people
How do we evaluate solutions?	Use computational models; evaluate on cost, safety, reliability; combine solutions for synergy
What makes a solution “just”?	It prioritizes the communities most harmed and doesn’t create new inequities

46.1 🎓 You Did It!

You’ve completed a deep investigation into how human activities affect environmental health — and what we can do about it. You can now:

• ✅ Trace pollution pathways from human activities to health outcomes
• ✅ Analyze data to identify patterns and disparities
• ✅ Use computational models to test and compare solutions
• ✅ Evaluate solutions using multiple criteria (cost, safety, reliability)
• ✅ Construct evidence-based arguments using the CER framework
• ✅ Consider environmental justice in your recommendations

These are the skills of environmental scientists, public health researchers, and policy makers. The problems are real. The data is clear. The solutions are in your hands. 🌍