Feedback loops: changes that grow or shrink themselves

Grade 9 Science Worksheet - Challenge Me

Circle the best answer.

1. 1.

   Four loop cards, labeled A to D. Which chain of links makes the ice-albedo feedback loop, by Esme's reading?

   • More fuel burned → warmer → more fuel burned
   • Warmer → less ice → more sunlight absorbed → warmer
   • Warmer → less ice → less sunlight absorbed → cooler
   • Warmer → more ice → more sunlight absorbed → warmer
2. 2.

   A loop reads: warmer air → more permafrost thaws → ? → warmer air. Which link completes it, by Jun's reading?

   • More ice forms in the soil
   • More carbon dioxide and methane released
   • People burn more fuel
   • Less carbon dioxide and methane released
3. 3.

   Loop diagram with four links marked +, +, − and −. A loop's links have the signs +, +, − and −. What is the loop's sign, and why, by Kira's count?

   • Negative, since two of the links are bad
   • Neither: the + and − links cancel to zero
   • Positive: the two − links cancel each other
   • Negative: it contains − links
4. 4.

   Luz's friend reads that the ice-albedo loop is a positive feedback and says that is good news for the Arctic. Which response is best?

   • Agree: positive loops shrink warming
   • Disagree: positive feedback means the change stops
   • Agree: positive means helpful
   • Disagree: positive means it amplifies the warming
5. 5.

   Milo's cousin says the carbon dioxide from burning fuel is itself a climate feedback. Which response is best?

   • Disagree: carbon dioxide has no effect on temperature
   • Disagree: it is the forcing; feedbacks respond to it
   • Agree: anything that warms Earth is a feedback
   • Agree: fuel burning loops back on itself
6. 6.

   Noah's friend says extra plant growth will take up every bit of carbon dioxide people add. Which response is best (NASA)?

   • Agree: a negative feedback undoes a change completely
   • Agree: plants can take up unlimited carbon dioxide
   • Disagree: it slows the rise, limited by water and nitrogen
   • Disagree: plant growth adds carbon dioxide, a positive loop
7. 7.

   Four loop cards, labeled A to D. Which of these loops is negative, by Pia's reading?

   • More carbon dioxide → more plant growth → less carbon dioxide
   • Warmer → less sea ice → more sunlight absorbed → warmer
   • Warmer → more water vapor → warmer
   • Warmer → permafrost thaws → more carbon dioxide → warmer
8. 8.

   Sweating and ice-albedo. Tala compares sweating with the ice-albedo loop. Which statement is right?

   • Both keep temperature steady
   • Sweating overcools the body; ice-albedo cools the Arctic
   • Sweating steadies body heat; ice-albedo amplifies Arctic warming
   • Both are positive, since both are natural
9. 9.

   Carbon dioxide alone would warm Earth by 1.0 °C in a model. NASA estimates the water-vapor loop more than doubles that. Which total fits, by Ari's reading?

   • Less than 1.0 °C
   • 0 °C; the feedback cancels the warming
   • 1.0 °C; water vapor just reacts and adds nothing
   • More than 2.0 °C
10. 10.

    A quantity would rise 20 units, but a negative loop cuts the rise by 25%. How much does it rise now, by Bo's math?

    • 0 units; the change is undone
    • 5 units
    • 25 units
    • 15 units