Climate & the Greenhouse Effect — Practice · Grade 9 Science

Chapter: Oceans, Carbon & Climate

What this practice covers

By the end of Climate & the Greenhouse Effect you should be able to:

11 questions, multiple choice and written answer, each with a worked explanation.

Vocabulary used: climate, greenhouse effect, greenhouse gas, global warming.

Problem 1

Which statement correctly describes the difference between weather and climate?
  1. Weather is day-to-day conditions; climate is the long-term average pattern.
  2. Weather and climate mean the same thing.
  3. Climate changes every hour; weather stays the same for decades.
  4. Weather only applies to storms; climate applies to sunny days.
Answer and explanation

Weather is day-to-day conditions; climate is the long-term average pattern.

Weather is short-term (today's conditions); climate is the long-term average over decades.

Problem 2

Which of these gases is a greenhouse gas?
  1. Carbon dioxide
  2. Nitrogen
  3. Oxygen
  4. Argon
Answer and explanation

Carbon dioxide

Carbon dioxide absorbs and re-emits outgoing heat; nitrogen, oxygen, and argon make up most of the atmosphere but are not significant greenhouse gases.

Problem 3

Which factor would most directly give a region cooler average temperatures?
  1. Higher elevation
  2. Being closer to the equator
  3. Being farther from any ocean
  4. Having more greenhouse gases nearby
Answer and explanation

Higher elevation

Temperatures generally drop as elevation increases, since higher places have thinner air that holds less heat.

Problem 4

What keeps Earth's average surface temperature from being far below freezing?
  1. The natural greenhouse effect trapping some outgoing heat
  2. The ozone layer blocking all sunlight
  3. Ocean currents alone
  4. Earth's rotation
Answer and explanation

The natural greenhouse effect trapping some outgoing heat

The natural greenhouse effect traps enough outgoing heat to keep Earth's surface livable; without it, Earth would be far colder.

Problem 5

What is the key difference between the natural greenhouse effect and the human-caused concern often called global warming?
  1. The greenhouse effect itself is natural and necessary; the concern is that human activity is increasing greenhouse gas concentrations, enhancing the effect and raising temperatures further.
  2. There is no difference; they are the same process.
  3. The greenhouse effect only happens at the poles.
  4. Global warming is caused by too much oxygen in the atmosphere.
Answer and explanation

The greenhouse effect itself is natural and necessary; the concern is that human activity is increasing greenhouse gas concentrations, enhancing the effect and raising temperatures further.

The natural greenhouse effect keeps Earth livable. The concern is that burning fossil fuels and other activities have added extra greenhouse gases, intensifying the natural effect and pushing global average temperatures higher.

Problem 6

A classmate says, 'The greenhouse effect is bad and we should get rid of it completely.' Explain what's scientifically incorrect about that statement.
Answer and explanation

The greenhouse effect itself is natural and necessary — without it, Earth would be far too cold to support life as we know it. The real problem is that human activities have increased the amount of greenhouse gases in the atmosphere, enhancing the natural effect beyond its normal balance and causing global temperatures to rise; the goal is to reduce that extra human-caused increase, not eliminate the greenhouse effect altogether.

Problem 7

A region has one unusually cold winter within a 30-year warming record. Are those facts contradictory? Explain the reasoning in your own words.
Answer and explanation

No; the full record, variability and spatial coverage are needed.

Weather varies from year to year.

A long-term trend summarizes many measurements, so an individual cold period can coexist with warming.

Response criteria

  • Use the stated conditions.
  • Show the evidence or calculation.
  • Explain the conclusion and any stated limitation.

Problem 8

Why is a snowy surface's albedo relevant to climate? Show the reasoning, not just the conclusion.
Hints

Do not confuse greenhouse warming with an ozone hole.

Answer and explanation

A higher albedo reflects a larger fraction of sunlight, reducing absorbed solar energy under otherwise similar conditions.

Problem 9

What would distinguish climate evidence from one day's temperature?
Hints

State what the supplied observations or conditions establish, and separate that from any assumption.

Answer and explanation

Long-term, representative records and distributions, ideally multiple independent indicators.

Problem 10

A feedback loop must return to the initial changeA feedback loop must return to the initial changeWarmersurfaceLess icecoverMore solarabsorptionIce–albedo feedback returns to the initial changePositive feedback amplifies; the word does not mean beneficial.
Original conceptual ice–albedo loop with selected linked mechanisms. The diagram does not supply feedback strength, equilibrium change or regional forecast. It omits other feedbacks and conditions that can oppose or modify the response.
Interpret the supplied visual model. Why is “warming reduces ice” alone not a complete feedback explanation?
Answer and explanation

It gives one response. To complete the feedback, explain how changed ice alters absorbed energy and feeds back onto the initial warming.

Trace the loop back to warmer surface. A one-way arrow from temperature to ice would show a response but omit the feedback’s return effect.

It gives one response. To complete the feedback, explain how changed ice alters absorbed energy and feeds back onto the initial warming.

Response criteria

  • Read the labeled quantities, reference frame or objects correctly.
  • Explain the relation between the visual evidence and the mechanism.
  • Keep the drawing’s stated assumptions and limits in the conclusion.

Problem 11

A future graph shows a +2 °C regional anomaly in one scenario. Explain what “anomaly” and “scenario” require, and why one cold local day does not directly test that projected regional long-term mean.
Answer and explanation

An anomaly is relative to a specified baseline; a scenario states assumptions about future inputs/decisions. The projected variable, region and interval must be given. A single local day is a different scale/measurement from a regional long-term mean and is not a direct matched test.

An anomaly is relative to a specified baseline; a scenario states assumptions about future inputs/decisions. The projected variable, region and interval must be given. A single local day is a different scale/measurement from a regional long-term mean and is not a direct matched test.

Response criteria

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

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