IB Biology: 4.4 Climate Change
Questions with complete solution
Reasons why people deny climate change exists - correct answer ✔(1)
Scientists are always cautious about claims, admitting uncertainties; (2)
Global climate patterns are complex and difficult to predict; (3) Consequences
could be very severe for humans, so companies pay reports that downplay
risks
Greenhouse gases - correct answer ✔Gases that retain heat in the Earth's
atmosphere. The most significant are CO2 and water vapour, but methane
(emitted from marshes, landfills, fossil fuel extraction) and nitrous oxide
(released by bacteria and agriculture/vehicle exhausts) also have an impact)
Why oxygen and nitrogen are not greenhouse gases - correct answer ✔They
do not absorb longer-wave radiation to radiate back to the Earth's surface
Factors determining the warming impact of a substance - correct answer
✔(1) How readily it absorbs long-wave radiation; (2) Concentration of gas in
atmosphere
Difference between global warming impact of methane vs CO2 - correct
answer ✔Methane causes more warming per molecule, but it has a lower
concentration, so it has a lower impact overall
Radiation the Earth emits - correct answer ✔Earth absorbs short-wave
energy and re-emits it at longer wavelengths (infrared heat, for instance)
How greenhouse gases retain heat in atmosphere - correct answer ✔(1)
Absorbs longer wave radiation, preventing 75% or solar radiation from
reaching Earth; (2) Converted to heat; (3) Higher percentage of longer-
Questions with complete solution
Reasons why people deny climate change exists - correct answer ✔(1)
Scientists are always cautious about claims, admitting uncertainties; (2)
Global climate patterns are complex and difficult to predict; (3) Consequences
could be very severe for humans, so companies pay reports that downplay
risks
Greenhouse gases - correct answer ✔Gases that retain heat in the Earth's
atmosphere. The most significant are CO2 and water vapour, but methane
(emitted from marshes, landfills, fossil fuel extraction) and nitrous oxide
(released by bacteria and agriculture/vehicle exhausts) also have an impact)
Why oxygen and nitrogen are not greenhouse gases - correct answer ✔They
do not absorb longer-wave radiation to radiate back to the Earth's surface
Factors determining the warming impact of a substance - correct answer
✔(1) How readily it absorbs long-wave radiation; (2) Concentration of gas in
atmosphere
Difference between global warming impact of methane vs CO2 - correct
answer ✔Methane causes more warming per molecule, but it has a lower
concentration, so it has a lower impact overall
Radiation the Earth emits - correct answer ✔Earth absorbs short-wave
energy and re-emits it at longer wavelengths (infrared heat, for instance)
How greenhouse gases retain heat in atmosphere - correct answer ✔(1)
Absorbs longer wave radiation, preventing 75% or solar radiation from
reaching Earth; (2) Converted to heat; (3) Higher percentage of longer-
