IB ESS HL 6.1 The Atmosphere Question Bank
Practise IB ESS HL 6.1 by analysing radiation, pressure circulation and aerosol evidence to explain climate and biome outcomes.
- Syllabus
- First assessment 2026
- Course
- ESS HL
- Level
- HL
Practise IB ESS HL 6.1 by analysing radiation, pressure circulation and aerosol evidence to explain climate and biome outcomes.

Figure:Gas composition of the troposphere by volume
the tropospheric gas-composition chart shown above below is a pie chart showing the percentages (by volume) of gases in the troposphere.
Label gases A and B on the tropospheric gas-composition chart shown above above.
oxygen /O2
B: nitrogen /N2;
Both required to award [1].
Marking guidance:
Do not accept N or O.
Outline the role of the atmospheric system in the distribution of biomes.
atmospheric/tri-cellular circulation (including Hadley, Ferrel \& polar cells) creates patterns of climate that determine dominant vegetation types; low pressure due to intense heating/high insolation at the equator causes / rising moist air in the tropics creates high precipitation giving rise to rainforests; moving polewards (at high altitude), air cools, becomes denser and sinks forming a high-pressure zone / descending/dry air ( 20−30∘ latitude/tropics) creates water
limiting/arid conditions giving rise to deserts; some of the air continues towards the poles to equalize temperature difference / atmosphere transfers heat from (sub-)tropics to mid-latitudes giving rise to temperate biomes; descending/dry air (high latitude/polar regions) creates water-limiting conditions in tundra; water vapour (from mid-latitudes/temperate regions) is transferred to high latitudes giving rise to heavy precipitation/snow in boreal forest; water vapour is transferred from ocean surfaces overland generating freshwater aquatic systems; prevailing winds/jet streams (blowing from high to low pressure) bring precipitation to a region, eg temperate rainforest in mountainous region/riverine/water-margin systems; rain shadow effect of high mountains causes dry winds in the leeward side, resulting in arid or semi-arid biomes (eg Tibetan Plateau, Mongolian Gobi desert and steppes); atmosphere may be responsible for shifting biomes due to global warming/climate change;
State the name of one greenhouse gas produced by dairy cattle.
Methane (CH4) / carbon dioxide (CO2);
(b) With reference to Figure: Energy demand by type and sector for 2020 and projected values for 2050, identify which sector is predicted to reduce its energy use between 2020 and 2050.