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?

   • Warmer → less ice → more sunlight absorbed → warmer
   • More fuel burned → warmer → more fuel burned
   • 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 carbon dioxide and methane released
   • More ice forms in the soil
   • 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
   • Positive: the two − links cancel each other
   • Negative: it contains − links
   • Neither: the + and − links cancel to zero
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?

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

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

   • Warmer → more water vapor → warmer
   • More carbon dioxide → more plant growth → less carbon dioxide
   • Warmer → permafrost thaws → more carbon dioxide → warmer
   • Warmer → less sea ice → more sunlight absorbed → warmer
6. 6.

   Ice-albedo, water vapor, plant uptake of carbon dioxide, home thermostat. Which two loops both amplify warming, by Ren's reading?

   • Ice-albedo and plant uptake of carbon dioxide
   • Ice-albedo and water vapor
   • Plant uptake of carbon dioxide and a home thermostat
   • Water vapor and plant uptake of carbon dioxide
7. 7.

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

   • Both are positive, since both are natural
   • Sweating steadies body heat; ice-albedo amplifies Arctic warming
   • Sweating overcools the body; ice-albedo cools the Arctic
   • Both keep temperature steady
8. 8.

   In a model, a forcing alone warms a region by 1.0 °C, and the ice-albedo loop adds 0.5 °C more. What is the total warming, by Zee's math?

   • 0.5 °C, since the loop subtracts
   • 1.5 °C
   • 0.5 °C, since melting ice reflects more
   • 1.0 °C, since feedbacks add nothing
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?

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

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