Pollution, Carbon & Climate Evidence — Chapter quiz · Physics & Environmental Science, Grade 12

Connect pollutant transport, carbon chemistry, radiation balance, and long-term evidence.

Problem 1

Which of these is a major air pollutant produced by burning fossil fuels?
  1. Water vapor from clouds
  2. Sulfur dioxide and nitrogen oxides
  3. Pure oxygen
  4. Argon gas
Answer and explanation

Sulfur dioxide and nitrogen oxides

Burning coal and oil releases sulfur dioxide and nitrogen oxides, which cause smog and acid rain; oxygen and argon are normal, harmless components of clean air.

Problem 2

A persistent contaminant is .2 mg/kg in algae. In a supplied model each feeding transfer multiplies tissue concentration by 10. Algae→insects→fish has two transfers. Find fish concentration.
Answer and explanation

20 ppm

.2×10²=20mg/kg. This is a hypothetical trophic-transfer model, not uptake from water.

Problem 3

Excess fertilizer washes into a bay and triggers an algal bloom; when the algae die and decompose, the water's oxygen is used up and fish suffocate. This process is called
  1. condensation
  2. the greenhouse effect
  3. eutrophication
  4. biomagnification
Answer and explanation

eutrophication

Nutrient over-enrichment that fuels blooms and then oxygen-robbing decomposition is eutrophication, the cause of aquatic 'dead zones.'

Problem 4

Which gas contributes most to human-caused global warming?
  1. Helium
  2. Oxygen
  3. Nitrogen
  4. Carbon dioxide
Answer and explanation

Carbon dioxide

Carbon dioxide from burning fossil fuels is the largest driver of human-caused warming; oxygen, nitrogen, and helium are not significant greenhouse gases.

Problem 5

For a supplied comparison, CO₂ rises from 280ppm to 420ppm. Find the percent increase relative to 280ppm.
Answer and explanation

140 ppm

(420−280)/280×100=50%.420 is a supplied comparison value, not a claim about today.

Problem 6

Explain why scientists rely on many independent lines of evidence — temperature records, shrinking ice, rising seas, warming oceans — rather than a single measurement to conclude that the climate is warming.
Answer and explanation

Any single measurement could contain errors or be affected by local factors, so on its own it could be questioned. But temperature records, melting glaciers and ice sheets, rising sea level, warming oceans, and earlier spring events are gathered independently, and they all point to the same conclusion. When many separate lines of evidence agree, the conclusion that Earth is warming becomes very difficult to explain any other way.

Problem 7

Explain the following claim and supply a valid example or counterexample: Uptake from water is bioconcentration; magnification compares feeding levels.
Answer and explanation

Each feeding transfer increases tissue concentration tenfold in the supplied model. It is not a rule for all substances. Uptake from water is bioconcentration; magnification compares feeding levels.

Response criteria

  • State a scientifically accurate conclusion.
  • Show the calculation or mechanism that supports it.
  • Include units, conditions, or limits where relevant.

Problem 8

Independent chapter check: An outlet flows200 L/min at3 mg/L. Find pollutant mass emitted in1 h. Treatment captures80% into sludge with no chemical destruction; find waterborne and captured mass.
Answer and explanation

Initial mass=200×60×3=36000 mg=36 g. Waterborne residual=7.2 g; captured mass=28.8 g. The captured material remains in the full system account.

Initial mass=200×60×3=36000 mg=36 g.

Waterborne residual=7.2 g; captured mass=28.8 g.

The captured material remains in the full system account.

Response criteria

  • Use the stated measurements or conditions, with correct units.
  • Connect the result to the physical or environmental mechanism or evidence relationship.
  • Identify the assumption, model limit or further evidence requested.

Problem 9

Explain the following claim and supply a valid example or counterexample: The greenhouse effect is not the ozone-hole mechanism; fixed CO₂ examples must have dates or be labeled models.
Answer and explanation

It changes infrared absorption/emission and radiative escape, causing system temperatures to adjust; evaluate multiple observations and forcing mechanisms. The greenhouse effect is not the ozone-hole mechanism; fixed CO₂ examples must have dates or be labeled models.

Response criteria

  • State a scientifically accurate conclusion.
  • Show the calculation or mechanism that supports it.
  • Include units, conditions, or limits where relevant.

Problem 10

Independent chapter check: A model Earth absorbs242 W/m² and emits240 W/m² for10 s. Find stored-energy increase per area and explain why this alone does not give a surface-temperature change.
Answer and explanation

Increase=(242−240)×10=20 J/m². Temperature change also needs heat capacity, depth/distribution of storage and coupled responses; this is a supplied short model interval, not an actual climate measurement.

Increase=(242−240)×10=20 J/m².

Temperature change also needs heat capacity, depth/distribution of storage and coupled responses; this is a supplied short model interval, not an actual climate measurement.

Response criteria

  • Use the stated measurements or conditions, with correct units.
  • Connect the result to the physical or environmental mechanism or evidence relationship.
  • Identify the assumption, model limit or further evidence requested.

Problem 11

How can adding H⁺ affect carbonate ions?
Answer and explanation

Some convert to bicarbonate, altering carbonate availability for calcification.

Response criteria

  • State a scientifically accurate conclusion.
  • Show the calculation or mechanism that supports it.
  • Include units, conditions, or limits where relevant.

Problem 12

Why are pH alone and one species response insufficient to describe all ocean effects?
Answer and explanation

Buffering, temperature, oxygen, species differences, and interacting stresses matter.

Response criteria

  • State a scientifically accurate conclusion.
  • Show the calculation or mechanism that supports it.
  • Include units, conditions, or limits where relevant.

Problem 13

Independent chapter check: A seawater sample changes frompH8.1 topH7.9. Estimate the[H⁺] ratio and explain whether that proves a58% carbonate decrease.
Answer and explanation

[H⁺] increases by10^0.2≈1.585, about58.5%. It does not prove the same carbonate decrease; alkalinity, dissolved carbon and coupled-equilibrium conditions are also required.

[H⁺] increases by10^0.2≈1.585, about58.5%.

It does not prove the same carbonate decrease; alkalinity, dissolved carbon and coupled-equilibrium conditions are also required.

Response criteria

  • Use the stated measurements or conditions, with correct units.
  • Connect the result to the physical or environmental mechanism or evidence relationship.
  • Identify the assumption, model limit or further evidence requested.

Problem 14

Temperature 15.4°C, baseline 14.8°C. Find anomaly.
Hints

Write the relationship first; substitute with consistent units.

Answer and explanation

0.6 °C

15.4−14.8=.6.

Problem 15

How can a baseline change affect trends?
Answer and explanation

A fixed baseline shift changes all offsets equally and does not change the trend slope.

Response criteria

  • State a scientifically accurate conclusion.
  • Show the calculation or mechanism that supports it.
  • Include units, conditions, or limits where relevant.

Problem 16

Independent chapter check: Two absolute global temperature estimates are14.6°C and15.0°C. Their baseline is14.0°C, then changed to14.2°C. Find both anomaly pairs and show whether their difference changes.
Answer and explanation

Original anomalies are0.6 and1.0°C; new anomalies0.4 and0.8°C. The difference remains0.4°C, so a uniform baseline shift changes offset rather than physical change.

Original anomalies are0.6 and1.0°C; new anomalies0.4 and0.8°C.

The difference remains0.4°C, so a uniform baseline shift changes offset rather than physical change.

Response criteria

  • Use the stated measurements or conditions, with correct units.
  • Connect the result to the physical or environmental mechanism or evidence relationship.
  • Identify the assumption, model limit or further evidence requested.

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