Climate feedbacks and natural climate cycles

Question 1

Fresh snow has an albedo of 0.85 (it reflects that fraction of sunlight). If 300 W/m² of sunlight arrives, how much is absorbed, in W/m²?

Answer W/m²

Question 2

Is this a positive or negative climate feedback: melting ice exposes darker ocean that absorbs more sunlight?

• A. positive feedback (amplifies warming)
• B. negative feedback (reduces warming)

Question 3

Why can Milankovitch cycles not explain today's warming?

• A. They only affect Mars
• B. They stopped working in 1900
• C. They cause cooling only
• D. They act over thousands of years, but today's warming has happened in about 150 years

Question 4

Fresh snow has an albedo of 0.85 (it reflects that fraction of sunlight). If 340 W/m² of sunlight arrives, how much is absorbed, in W/m²?

Answer W/m²

Question 5

Is this a positive or negative climate feedback: thawing permafrost releases methane?

• A. positive feedback (amplifies warming)
• B. negative feedback (reduces warming)

Question 6

Why do large volcanic eruptions sometimes cool the planet for a year or two?

• A. Volcanoes release huge amounts of ice
• B. Ash absorbs all the CO₂
• C. Lava cools the oceans
• D. Sulfur gases form tiny droplets high in the atmosphere that reflect sunlight

Question 7

Forest has an albedo of 0.15 (it reflects that fraction of sunlight). If 400 W/m² of sunlight arrives, how much is absorbed, in W/m²?

Answer W/m²

Question 8

Is this a positive or negative climate feedback: warmer air holds more water vapour, a greenhouse gas?

• A. positive feedback (amplifies warming)
• B. negative feedback (reduces warming)

Question 9

Why can Milankovitch cycles not explain today's warming?

• A. They stopped working in 1900
• B. They cause cooling only
• C. They only affect Mars
• D. They act over thousands of years, but today's warming has happened in about 150 years

Question 10

Fresh snow has an albedo of 0.85 (it reflects that fraction of sunlight). If 400 W/m² of sunlight arrives, how much is absorbed, in W/m²?

Answer W/m²

Question 11

Is this a positive or negative climate feedback: thawing permafrost releases methane?

• A. positive feedback (amplifies warming)
• B. negative feedback (reduces warming)

Question 12

Why might a "tipping point" in the climate system be especially worrying?

• A. It only affects weather for one day
• B. Past a threshold, change can become self-sustaining and hard to reverse
• C. It reduces sea level
• D. It makes the climate change back instantly

Question 13

Sea ice has an albedo of 0.6 (it reflects that fraction of sunlight). If 340 W/m² of sunlight arrives, how much is absorbed, in W/m²?

Answer W/m²

Question 14

Is this a positive or negative climate feedback: a warmer Earth radiates more energy to space?

• A. positive feedback (amplifies warming)
• B. negative feedback (reduces warming)

Question 15

What are Milankovitch cycles?

• A. slow changes in Earth's orbit and tilt that pace ice ages over tens of thousands of years
• B. the 11-year sunspot cycle
• C. daily changes in weather
• D. yearly ocean tides

Question 16

Sea ice has an albedo of 0.6 (it reflects that fraction of sunlight). If 340 W/m² of sunlight arrives, how much is absorbed, in W/m²?

Answer W/m²