Reading Ancient Climate Records · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.
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Reading Ancient Climate Records

Science · Weather & Climate · ages 12-14
Name ______________________   Date ____________

  1. About how far back does the Antarctic EPICA Dome C ice-core record described here extend?

    • About 800,000 years
    • About 8,000,000 years
    • About 80,000 years

  2. Which part of an ice core supplies a sample of the ancient atmosphere?

    • Dust grains from old eruptions
    • Bubbles holding ancient air
    • Water molecules in ice crystals

  3. Volcanic material matched to a dated eruption can help scientists check an ice core's age.

    Circle one:   True   False

  4. An annual tree ring is much narrower than nearby rings. What does its width alone show?

    • The tree grew less that year.
    • The tree grew more that year.
    • The tree grew by the same amount every year.

  5. When checked with other evidence, oxygen isotope ratios in ice help scientists estimate which past condition?

    • Total thickness of the ice sheet
    • Exact yearly amount of snowfall
    • Past local temperature

  6. Why compare ice cores, tree rings, ocean sediments, coral and pollen when reconstructing climate?

    • Every record covers all places and times, so their results only repeat one another.
    • Records cover limited places and times; independent clues allow cross-checks.
    • Every record measures ancient CO2 directly, so other climate evidence is unnecessary.

  7. This invented chart compares CO2 concentrations. Ice-bubble air contains 180 ppm and outside air contains 420 ppm. How many ppm higher is the outside-air value?

    Ice air:ppm180Outsideair: ppm420

    Answer: ______________

  8. A climate model matches proxy evidence from a past period. Which conclusion also describes the IPCC's role correctly?

    • The match guarantees future forecasts; the IPCC carries out every climate experiment.
    • The match removes all uncertainty; the IPCC replaces published evidence with predictions.
    • The match supports confidence; the IPCC assesses published climate research.
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Answer key

For grown-ups. Fold this page away before handing over the rest.

Reading Ancient Climate Records W1-mt_olFzbawexJ-s1

  1. About 800,000 years · The EPICA Dome C record spans about 800,000 years. This is not a claim about the oldest ice ever found.
  2. Bubbles holding ancient air · Spaces in compacting snow close and seal air inside bubbles. Scientists can measure gases in that air.
  3. True · A match to a dated eruption supplies an age marker. It does not automatically date every layer in the core.
  4. The tree grew less that year. · A narrower annual ring records reduced growth. Drought is a possible cause, but the ring alone cannot establish it.
  5. Past local temperature · The ratios help estimate past local temperatures. Moisture sources and other conditions also affect them, so interpretation needs checks.
  6. Records cover limited places and times; independent clues allow cross-checks. · Records differ in their coverage and the clues they preserve. Comparing independent evidence can support an interpretation or reveal a disagreement.
  7. 240 · Subtract the lower concentration from the higher: 420 - 180 = 240 ppm. These are invented practice values, not dated measurements.
  8. The match supports confidence; the IPCC assesses published climate research. · Agreement with past evidence supports confidence without guaranteeing future predictions. The IPCC assesses research and reports findings and uncertainty.
Worksheet · LightMySky