Warming oceans, rising seas and melting ice

Grade 9 Science Worksheet - Building Confidence

Circle the best answer.

1. Read this first

   Use this

   A climate chart with ocean heat content and sea level both rising.

2. 1.

   About what share of the excess heat trapped by greenhouse gases does the ocean store, by Ari's reading (NOAA)?

   • About 9%
   • About 91%
   • About 1%
   • About 50%
3. 2.

   Why does extra heat in the ocean raise sea level, by Kira's reading (NOAA)?

   • Warm water is heavier, so it piles up
   • Water expands when it warms
   • Heat turns seawater into new floating ice
   • Warm water shrinks and pulls the coasts down

4. Sea-level rise rates (IPCC AR6)

   Period	Average rate
   1901–1971	1.3 mm a year
   1971–2006	1.9 mm a year
   2006–2018	3.7 mm a year

   Note: Total 1901–2018, about 0.20 m.

5. 3.

   Using the table, what was the average rate of sea-level rise from 2006 to 2018, by Jun's reading (IPCC AR6)?

   • 1.3 mm a year
   • 3.7 mm a year
   • 0.20 m a year
   • 1.9 mm a year
6. 4.

   Using the table, how much did global sea level rise in total from 1901 to 2018, by Luz's reading (IPCC AR6)?

   • About 1.3 m in total
   • About 0.20 m (20 cm)
   • About 3.7 mm in total
   • About 20 m in total
7. 5.

   A climate chart with ocean heat content and sea level both rising. Which two things mostly cause today's sea-level rise, by Milo's reading (NOAA)?

   • More rivers flowing, and bigger waves at sea
   • Seawater shrinking as it warms, and new icebergs
   • Melting floating sea ice, and more rain over the ocean
   • Melt water from land ice, and warm seawater expanding
9. 6.

   What is sea ice, by Noah's reading (NSIDC)?

   • Snow piled up on land along the coast
   • Frozen ocean water that forms and melts in the ocean
   • Frozen river water carried out to the sea
   • Glacier ice that slid off the land into the sea
10. 7.

    Which kinds of ice start on land, by Pia's reading (NSIDC)?

    Use the picture in question 6.

    • Glaciers, ice shelves and icebergs
    • Sea ice and the pack ice around it
    • Sea ice, which freezes from seawater
    • Frozen ocean surface water near the poles

11. Use this

    A pH scale with a small step down from about 8.2 to about 8.1.

12. 8.

    How much has surface ocean pH fallen since the industrial revolution, by Tala's reading (NOAA)?

    • About 30 pH units
    • About 1 pH unit
    • About 0.1 pH units
    • It rose about 0.1 pH units
13. 9.

    NOAA: pH fell 0.1, but the pH scale is logarithmic. About how much did acidity rise, by Zee's reading?

    • It fell about 30%
    • About 30%
    • About 1%
    • About 0.1%
14. 10.

    What forms when CO₂ dissolves in seawater, by Esme's reading (NOAA)?

    • Table salt
    • Carbonic acid, a weak acid
    • A strong acid that boils the water
    • Pure oxygen gas