Climate change: the measurements and the models

Grade 9 Science Worksheet - Challenge Me

Circle the best answer.

1. 1.

   A student says the Sun, not people, is the main cause of recent warming. Which reply fits IPCC AR6, by Jun's reading?

   • No; natural drivers changed it by −0.1 to +0.1 °C, and humans about 1.07 °C
   • No; volcanoes added most of the recent warming instead
   • Correct; the Sun's output rose about 50% since 1850
   • Correct; natural drivers added about 1.07 °C, nearly the whole warming
2. 2.

   Note: Projections, not measurements. A student says IPCC projections say there will be exactly 4.4 °C of warming. Which reply fits AR6, by Kira's reading?

   • No; IPCC projects cooling under each of its scenarios
   • Correct; each scenario points to the same 4.4 °C of warming
   • Correct; 4.4 °C is the warming measured so far, since 1850
   • No; 4.4 °C is the SSP5-8.5 best estimate, very likely 3.3 to 5.7 °C
3. 3.

   Note: Yearly means rounded to 0.1 ppm. A what-if, not a projection: if CO₂ kept rising 2.6 ppm a year (NOAA's 2015–2024 rate) from 424.6 ppm in 2024, what would it be in 2034, by Luz's math?

   • About 450.6 ppm
   • About 427.2 ppm
   • About 1,104 ppm
   • About 398.6 ppm

4. Read this first

   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

5. 4.

   NOAA: Earth warmed about 0.06 °C per decade since 1850. At that rate, about how much warming is 17 decades, by Milo's math?

   • About 10.2 °C
   • About 1.0 °C
   • About 0.1 °C
   • About 0.35 °C
6. 5.

   Note: Yearly means rounded to 0.1 ppm. NOAA: CO₂ was about 280 ppm before the mid-1700s. By what percent had it risen at Mauna Loa's 2024 value of 424.6 ppm, by Noah's math?

   • About 145%
   • About 34%
   • About 152%
   • About 52%

7. 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

8. 6.

   Which evidence best supports that recent warming is a trend and not one odd year, by Pia's reading (NOAA)?

   • The ten warmest years on record all came in 2015–2024
   • Warming shows up in one country's records and nowhere else
   • Temperatures have held flat since 1980
   • 2024 was cooler than 1880 in the record
9. 7.

   Which evidence best supports that the CO₂ rise comes from people, by Ren's reading (IPCC AR6)?

   • CO₂ has stayed near 280 ppm since the 1700s
   • CO₂ at Mauna Loa fell steadily from 1960 to 2020, as less fuel was burned
   • IPCC: rises since about 1750 are unequivocally caused by human activities
   • Volcanoes emit more CO₂ each year than people do
10. 8.

    Note: Yearly means rounded to 0.1 ppm. Which summary of the CO₂ record fits NOAA, by Zee's reading?

    • From about 280 ppm to about 425 ppm now, about 150% higher
    • From about 425 ppm before the 1700s down to about 280 ppm now, about 34% lower
    • From about 280 ppm before the 1700s to about 425 ppm now, about 50% higher
    • Steady near 280 ppm from the 1700s until now, with no rise

11. 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

12. 9.

    Which summary of the temperature record fits NOAA, by Ari's reading?

    • 2024 was about 13.5 °C above 1850–1900, with slow warming
    • Temperature has held steady since 1850, and 2024 was a single odd year
    • 2024 was about 1.35 °C above 1850–1900, with faster warming since 1982
    • 2024 was about 1.35 °C below 1850–1900, with cooling since 1982
13. 10.

    Note: Projections, not measurements. Which summary of IPCC projections fits AR6, by Bo's reading?

    • Each scenario projects the same 2.7 °C of warming by 2081–2100
    • Warming by 2081–2100 depends on emissions: about 1.4 °C (SSP1-1.9) to 4.4 °C (SSP5-8.5)
    • Warming by 2081–2100 is already measured at about 4.4 °C
    • Warming by 2081–2100 depends on the Sun: about 1.4 to 4.4 °C