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

   How can satellites help track ocean heat across the globe, by Bo's reading (NOAA)?

   • They track air heat, since the air stores most of it
   • They measure sea-surface height, since warmer water expands
   • They see heat glowing from the deep sea floor
   • They count icebergs, since each one stores ocean heat
4. 3.

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

   • Warm water is heavier, so it piles up
   • Warm water shrinks and pulls the coasts down
   • Water expands when it warms
   • Heat turns seawater into new floating ice
5. 4.

   Note: Total 1901–2018, about 0.20 m. Using the table, what was the average rate of sea-level rise from 2006 to 2018, by Jun's reading (IPCC AR6)?

   • 0.20 m a year
   • 3.7 mm a year
   • 1.9 mm a year
   • 1.3 mm a year
6. 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)?

   • Melt water from land ice, and warm seawater expanding
   • Melting floating sea ice, and more rain over the ocean
   • Seawater shrinking as it warms, and new icebergs
   • More rivers flowing, and bigger waves at sea
8. 6.

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

   • Glaciers, ice shelves and icebergs
   • Sea ice, which freezes from seawater
   • Sea ice and the pack ice around it
   • Frozen ocean surface water near the poles
9. 7.

   IPCC AR6: how did Arctic sea-ice area in September change from 1979–1988 to 2010–2019, by Ren's reading?

   Use the picture in question 6.

   • It shrank by about 40%
   • It shrank by about 4%
   • It grew by about 40%
   • It held steady

10. Use this

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

11. 8.

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

    • About 1 pH unit
    • It rose about 0.1 pH units
    • About 0.1 pH units
    • About 30 pH units
12. 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 1%
    • About 30%
    • About 0.1%
13. 10.

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

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