ATMS 111 Final Exam With
Complete Solution
CO2 concentrations have rapidly increased over last 250yrs - ANSWER - from
280ppm to 405ppm
- human-caused recently
- 90% from fossil fuels, 10% from deforestation
the Earth has warmed 0.9degreesC over last 130 yrs --> - ANSWER - land has
warmed more than the ocean
- northern/high altitudes warmed the most
If no emissions control, ? - ANSWER 3 - 5degreeC additional warming
Earth is:
- heated by shortwave radiation from the Sun
- The Earth cools by longwave radiation out to space - ANSWER - 50%
absorbed at the surface
- 30% reflected back to space
Greenhouse gases stop longwave radiation from escaping directly to space -
ANSWER
Nitrogen, oxygen, and argon NOT GHGs but make up most of our
atmosphere - ANSWER
greenhouse gases - ANSWER - water vapor
,- carbon dioxide (CO2)
- Methane (CH4)
- Nitrous oxide (N2O)
- Ozone (O3)
- CFCs/HFCs (chlorofluorocarbons)
water vapor - ANSWER *humidity
- the primary ghg
- 60% of natural greenhouse effect
- a FEEDBACK
carbon dioxide (CO2) - ANSWER ~60% anthropogenic greenhouse effect
- extremely long-lived;
- average lifetime = 100yrs
- some remains in atms over 1000yrs
methane (CH4) - ANSWER - shorter lifetime but more potent
- GWP = 25
- produced naturally in wetlands, farm animals, landfills, rice, natural gas
leakage
- doubled in preindustrial, not rapidly rn
nitrous oxide (N2O) - ANSWER GWP = 310
- emissions come from agriculture, chemical industry, deforestation
, ozone (O3) - ANSWER pollutant near the surface
CFCs/HFCs - ANSWER - ozone depleting gases
- CFC concentrations decreasing
- HFC emissions increasing
positive forcings - ANSWER - results directly in warming of the climate
longwave forcings - ANSWER - all GHGs except for water vapor
- current CO2 radiative forcing = 1.68 W/m^2 and rising
- total GHG radiative forcing = 3 W/m^2 and rising
shortwave forcings - ANSWER - aerosols: small particles in air; strong cooling
influence
- changes in sun strength: solar variability, sunspot cycle
- land cover changes: NEGATIVE; clearing low-albedo forests = more
reflection
- soot on snow: POSITIVE forcing
climate feedbacks - ANSWER - positive feedback = amplification of forcing
- negative feedback = less temp. change for given forcing
- water vapor, ice-albedo, cloud feedback
water vapor feedback - ANSWER - positive feedback
- warmer air can hold more water vapor
ice-albedo feedback - ANSWER - positive feedback
Complete Solution
CO2 concentrations have rapidly increased over last 250yrs - ANSWER - from
280ppm to 405ppm
- human-caused recently
- 90% from fossil fuels, 10% from deforestation
the Earth has warmed 0.9degreesC over last 130 yrs --> - ANSWER - land has
warmed more than the ocean
- northern/high altitudes warmed the most
If no emissions control, ? - ANSWER 3 - 5degreeC additional warming
Earth is:
- heated by shortwave radiation from the Sun
- The Earth cools by longwave radiation out to space - ANSWER - 50%
absorbed at the surface
- 30% reflected back to space
Greenhouse gases stop longwave radiation from escaping directly to space -
ANSWER
Nitrogen, oxygen, and argon NOT GHGs but make up most of our
atmosphere - ANSWER
greenhouse gases - ANSWER - water vapor
,- carbon dioxide (CO2)
- Methane (CH4)
- Nitrous oxide (N2O)
- Ozone (O3)
- CFCs/HFCs (chlorofluorocarbons)
water vapor - ANSWER *humidity
- the primary ghg
- 60% of natural greenhouse effect
- a FEEDBACK
carbon dioxide (CO2) - ANSWER ~60% anthropogenic greenhouse effect
- extremely long-lived;
- average lifetime = 100yrs
- some remains in atms over 1000yrs
methane (CH4) - ANSWER - shorter lifetime but more potent
- GWP = 25
- produced naturally in wetlands, farm animals, landfills, rice, natural gas
leakage
- doubled in preindustrial, not rapidly rn
nitrous oxide (N2O) - ANSWER GWP = 310
- emissions come from agriculture, chemical industry, deforestation
, ozone (O3) - ANSWER pollutant near the surface
CFCs/HFCs - ANSWER - ozone depleting gases
- CFC concentrations decreasing
- HFC emissions increasing
positive forcings - ANSWER - results directly in warming of the climate
longwave forcings - ANSWER - all GHGs except for water vapor
- current CO2 radiative forcing = 1.68 W/m^2 and rising
- total GHG radiative forcing = 3 W/m^2 and rising
shortwave forcings - ANSWER - aerosols: small particles in air; strong cooling
influence
- changes in sun strength: solar variability, sunspot cycle
- land cover changes: NEGATIVE; clearing low-albedo forests = more
reflection
- soot on snow: POSITIVE forcing
climate feedbacks - ANSWER - positive feedback = amplification of forcing
- negative feedback = less temp. change for given forcing
- water vapor, ice-albedo, cloud feedback
water vapor feedback - ANSWER - positive feedback
- warmer air can hold more water vapor
ice-albedo feedback - ANSWER - positive feedback
