Climate change: the measurements and the models

Grade 9 Science Worksheet

Circle the best answer.

1. Read this first

   Mauna Loa yearly CO₂ (NOAA)

   Year	CO₂ (ppm)
   1960	316.9
   1980	338.8
   2000	369.7
   2020	414.2
   2024	424.6

   Note: Yearly means rounded to 0.1 ppm.

2. 1.

   Using the table, how much did Mauna Loa CO₂ rise from 1960 to 2020, by Bo's math?

   • About 9.7 ppm
   • About 731.1 ppm
   • About 97.3 ppm
   • About 77.3 ppm
3. 2.

   Mauna Loa CO₂ rose about 97.3 ppm from 1960 to 2020 (NOAA). About how many ppm a year is that on average, by Esme's math?

   • About 6 ppm a year
   • About 0.6 ppm a year
   • About 1.6 ppm a year
   • About 16 ppm a year
4. 3.

   NOAA: CO₂ grew about 0.8 ppm a year in the 1960s and 2.6 ppm a year in 2015–2024. About how many times faster is the recent rate, by Jun's math?

   • About 3 times
   • About 1.8 times
   • About 2 times
   • About 34 times

5. Global temperature anomaly (NASA GISTEMP, vs 1951–1980)

   Year	Anomaly (°C)
   1880	−0.17
   1950	−0.17
   1980	0.26
   2000	0.39
   2020	1.01
   2024	1.28

6. 4.

   Using the table, how much warmer was 2020 than 1980, by Kira's math (NASA GISTEMP)?

   • About 0.26 °C
   • About 0.75 °C
   • About 7.5 °C
   • About 1.27 °C
7. 5.

   Using the table, about how fast did temperature rise from 1980 to 2020, in °C per decade, by Luz's math?

   • About 1.9 °C per decade
   • About 0.75 °C per decade
   • About 0.02 °C per decade
   • About 0.19 °C per decade
8. 6.

   Using the table, how much warmer was 2024 than 1880, by Milo's math?

   • About 1.28 °C
   • About 0.17 °C
   • About 1.45 °C
   • About 1.11 °C
10. 7.

    IPCC AR6: what caused the rise in well-mixed greenhouse gases since around 1750, by Pia's reading?

    • Human activities, unequivocally
    • Ocean waves releasing gas
    • Changes in the Sun, mainly
    • Volcanoes, mainly
11. 8.

    IPCC AR6: warming in 2011–2020 was 1.09 °C over 1850–1900, very likely 0.95 to 1.20 °C. What does the range show, by Ren's reading?

    Use the picture in question 7.

    • That scientists doubt whether warming happened
    • How uncertain the best estimate is
    • That warming swung between those values each year
    • That the true value must be exactly 1.20 °C

12. Projected warming in 2081–2100 vs 1850–1900 (IPCC AR6)

    Scenario	Best estimate (°C)	Very likely range (°C)
    SSP1-1.9 (very low emissions)	1.4	1.0 to 1.8
    SSP1-2.6 (low)	1.8	1.3 to 2.4
    SSP2-4.5 (intermediate)	2.7	2.1 to 3.5
    SSP3-7.0 (high)	3.6	2.8 to 4.6
    SSP5-8.5 (very high)	4.4	3.3 to 5.7

    Note: Projections, not measurements.

13. 9.

    Using the table, how many times as wide is the SSP5-8.5 range as the SSP1-1.9 range, by Tala's math?

    • 2 times as wide
    • No wider; each scenario has one exact value
    • 3 times as wide
    • 1.6 times as wide
14. 10.

    Why do IPCC projections differ from one scenario to the next, by Ari's reading?

    • Scenarios are guesses that set the laws of physics aside
    • One warm year decides which scenario comes true
    • Each scenario assumes a different path of future emissions
    • Each scenario uses a different record of past temperatures