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 50%
   • About 9%
3. 2.

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

   • They see heat glowing from the deep sea floor
   • They track air heat, since the air stores most of it
   • They measure sea-surface height, since warmer water expands
   • 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)?

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

5. 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.

6. 4.

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

   • 1.9 mm a year
   • 3.7 mm a year
   • 0.20 m a year
   • 1.3 mm a year
7. 5.

   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 20 m in total
   • About 3.7 mm in total
   • About 0.20 m (20 cm)
8. 6.

   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
   • More rivers flowing, and bigger waves at sea
   • Seawater shrinking as it warms, and new icebergs
9. 7.

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

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

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)?

    • It rose about 0.1 pH units
    • About 0.1 pH units
    • About 30 pH units
    • About 1 pH unit
12. 9.

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

    • About 0.1%
    • About 30%
    • About 1%
    • It fell about 30%
13. 10.

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

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