IB ESS HL 2.3.5 Carbon Sequestration Question Bank
Explain how carbon is sequestered in biomass, soils, oceans and geological stores.
- Syllabus
- First assessment 2026
- Course
- ESS HL
- Level
- HL
Explain how carbon is sequestered in biomass, soils, oceans and geological stores.
| Ecosystem | Soil carbon | Living biomass | Total carbon |
|---|---|---|---|
| Boreal forest | 150 | 94 | 244 |
| Tropical forest | 83 | 167 | 250 |
| Mangroves | 1030 | 464 | 1494 |
| Tidal marsh | 920 | 31 | 951 |
| Seagrass meadows | 608 | 10 | 618 |
Table:Carbon storage in different ecosystems
With reference to Table: Carbon storage in different ecosystems, outline the effectiveness of mangroves and tropical rainforests in the mitigation of climate change.
mangroves/tropical rainforest mitigate climate change/reduce CO2 in the atmosphere by absorbing CO2;
mangroves sequester/remove a greater amount of CO2 (per unit area) than the other ecosystems/tropical forest/ mangroves are more efficient at storing carbon than tropical forests / mangroves are more effective carbon sinks than tropical forests;
tropical forest hold more carbon in their living biomass / mangroves hold more carbon in the soil;
both tropical rainforest and mangroves store the highest amount of CO2 within their living biomass for their own ecosystem category;
mangroves hold approximately 1500 metric ton carbon per hectare / tropical forest hold approx 230 metric ton carbon per hectare;
tropical forests may remove less CO2 per unit area but occupy a far greater area globally / mangroves remove more CO2 per unit area but occupy less area globally;
Marking guidance:
Accept quantification without units.