Warming oceans, rising seas and melting ice

Grade 9 Science Worksheet - Challenge Me

Circle the best answer.

1. 1.

   A classmate says melting floating sea ice is the main cause of sea-level rise. Which reply fits NOAA and NSIDC, by Esme's reading?

   • No; rise comes mostly from land-ice melt and warming water expanding
   • Correct; floating sea ice holds most of the ocean's new water
   • No; sea level has held steady since 1880
   • Correct; seawater shrinks as it warms, so melting sea ice must be the cause

2. Read this first

   Use this

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

3. 2.

   A student says the air has taken up most of the extra heat. Which reply fits NOAA, by Jun's reading?

   • Correct; heat stays near the ground and skips the ocean
   • Correct; the air stores about 91% of the excess heat
   • No; ice sheets store about 91% of it
   • No; the ocean stores about 91% of the excess heat
4. 3.

   NOAA: the 2006–2015 rate (3.6 mm a year) was 2.5 times the 20th-century rate. What was the earlier rate, by Luz's math?

   • About 6.1 mm a year
   • About 1.1 mm a year
   • About 9 mm a year
   • About 1.4 mm a year
5. 4.

   Note: Projections, not measurements. Using the projection table, how much wider is the SSP5-8.5 likely range than the SSP1-1.9 range, by Milo's math?

   • About 0.46 m wider
   • About 0.11 m wider
   • No wider; each scenario gives one exact number
   • About 0.38 m wider

6. Use this

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

7. 5.

   NASA: satellites show about 115 mm of rise since 1993. Over about 32 years, what is the average rate, by Noah's math?

   • About 36 mm a year
   • About 147 mm a year
   • About 0.28 mm a year
   • About 3.6 mm a year
8. 6.

   Which evidence best shows that the ocean is gaining heat, by Pia's reading (NOAA)?

   • Arctic sea ice grew each September
   • Sea level fell as the water cooled
   • A measured full-depth heat gain of 0.66 to 0.74 W/m² for 1993–2024
   • The air took up about 91% of the extra heat
9. 7.

   Note: Total 1901–2018, about 0.20 m. Which evidence best supports that sea-level rise is speeding up, by Ren's reading (IPCC AR6)?

   • Rates rose from 1.3 to 1.9 to 3.7 mm a year across 1901–2018
   • Sea level stayed flat from 1901 to 1971, then jumped
   • The rate fell from 3.7 to 1.9 to 1.3 mm a year across 1901–2018
   • Sea level rose about 0.20 m in 2018 alone
10. 8.

    A pH scale with a small step down from about 8.2 to about 8.1. Which observation best supports that ocean water is becoming more acidic, by Tala's reading (NOAA)?

    • Seawater has turned into a strong acid
    • Surface pH fell about 0.1, as the ocean took in more CO₂
    • Ocean salt levels doubled since 1850
    • Surface pH rose about 0.1, as CO₂ left the ocean
11. 9.

    Which summary of sea ice fits NSIDC and IPCC AR6, by Ari's reading?

    • Frozen ocean water; Arctic September ice shrank about 40% by 2010–2019
    • Frozen river water; Arctic sea ice has held steady since 1979
    • Frozen ocean water that adds new water to the sea as it melts
    • Ice from land glaciers; Arctic September ice grew about 40% by 2010–2019
12. 10.

    A pH scale with a small step down from about 8.2 to about 8.1. Which summary of ocean chemistry fits NOAA, by Bo's reading?

    • Absorbed CO₂ made the ocean an acid, with its pH now below 7
    • Absorbed CO₂ raised pH about 0.1, so shells grow faster than before
    • Absorbed CO₂ lowered pH about 0.1, about 30% more acidic, so shells are harder to build
    • Warming made seawater saltier, so shells dissolve in it faster