The carbon cycle across rock, ocean, air and life
Grade 9 Science Worksheet - Challenge Me
Circle the best answer.
Read this first
Where carbon is and how fast it moves (NASA)
Part of the cycle NASA figure Carbon stored in rocks about 65,500 billion metric tons Carbon through the slow cycle each year 10 to 100 million metric tons Carbon through the fast cycle each year 1,000 to 100,000 million metric tons Volcano CO₂ each year 130 to 380 million metric tons Human CO₂ each year about 30 billion tons A classmate says volcanoes add more CO₂ than people do. Which reply fits NASA, by Esme's reading?
- Correct; human CO₂ joins the slow cycle and takes millions of years to count
- No; people emit about 30 billion tons a year, 100 to 300 times more than volcanoes
- No; volcanoes emit no CO₂ whatsoever, since rock holds very little carbon
- Correct; volcanoes emit about 30 billion tons a year, far more than people do
A student says most of Earth's carbon is in the air. Which reply fits NASA, by Jun's reading?
- No; most of it is in the plants and animals alive today
- No; most is in rocks, about 65,500 billion metric tons
- Correct; carbon leaves rock within a few years, so rocks hold little
- Correct; the air holds more carbon than rocks and ocean together
A yearly CO₂ wiggle
Up in northern winter, down in spring and summer.
A student says the yearly CO₂ wiggle comes from volcanoes. Which reply fits NASA, by Kira's reading?
- No; plants release CO₂ in summer and take it in during the winter
- Correct; the ocean freezes over each winter and stops trading carbon
- No; northern plants draw CO₂ down in spring and summer, and decay returns it
- Correct; volcanoes erupt each spring and then quiet down each winter
Model data: the air holds 424 ppm of CO₂, and plants draw out 2 ppm in a month (NASA's August figure). What would it hold after, by Luz's math?
- About 212 ppm
- About 848 ppm
- About 422 ppm
- About 426 ppm
NASA gives the fast cycle as 10¹⁵ to 10¹⁷ grams of carbon a year. How many times larger is the high end than the low end, by Milo's math?
- 32 times
- 10,000 times
- 100 times
- 2 times
Using 1 billion tons of carbon a year from land use and 8.4 billion from fossil fuels (NASA), about what share comes from land use, by Noah's math?
Use the picture in question 5.
- About 11%
- About 89%
- About 84%
- About 1%
Which evidence best supports that fossil-fuel carbon is building up in the air, by Ren's reading (NASA)?
Use the picture in question 5.
- About half of each year's fossil-fuel CO₂ stays in the air
- Fossil-fuel CO₂ turns into limestone rock within a single year
- Volcanoes emit more CO₂ each year than people
- The ocean releases more carbon than it takes in
Model data: carbon leaves a rock reservoir at 100 million tons a year and enters it at 100 million tons a year. What does that show, by Tala's reading?
Use the picture in question 5.
- The reservoir gains about 200 million tons of carbon a year
- The reservoir is in balance, neither gaining nor losing
- Carbon has stopped moving through it
- The reservoir is losing carbon quickly
Rain, rock, river, sea floor, limestone, volcano. Which summary of the slow and fast carbon cycles fits NASA, by Zee's reading?
- Slow: rocks, 100 to 200 million years; fast: life, about a lifespan
- Fast: plants give off CO₂ in sunlight and take it in at night
- Slow: life, about a lifespan; fast: rocks, 100 to 200 million years
- Both run through living things at the same pace
Which summary of the ocean's role fits NASA, by Bo's reading?
- It now gives off more carbon to the air each year than it takes back in
- It takes in the extra carbon within a year or two
- It holds most of Earth's carbon, more than rocks
- It now takes in more carbon than it releases, slowly, over millennia