6.2.4—Enhanced greenhouse effect
- Syllabus
- First assessment 2026
- Objective
- 6.2.4
- Level
- HL
Order the Climate-Change Causal Chain
The chain is natural greenhouse effect → human enhancement → warming → changes in climate hazards and impacts.
Short-wave sunlight enters; outgoing infrared is absorbed by added GHGs; energy balance shifts until the system warms. Impacts then depend on circulation, water, ice, ecosystems and society.
More CO₂ slows infrared loss, raises temperature, then increases heat extremes and water stress in some regions.
As an observed hazard/impact, not as the cause of greenhouse-gas forcing.
Do not jump from emissions to one local impact without the intermediate physical and social mechanisms.