9.2 Climate Change
Anthropogenic climate change is driven by greenhouse gas emissions from fossil fuels, deforestation, and agriculture. Global warming has already reached ~1.1°C above pre-industrial.
Observed Changes
+1.1°C
Global warming (2011-2020 vs 1850-1900)
420 ppm
CO₂ (vs 280 ppm pre-industrial)
+20 cm
Sea level rise since 1900
Future Projections (IPCC AR6)
SSP1-1.9 (Very low emissions)
+1.4°C by 2100. Net-zero by 2050.
SSP2-4.5 (Intermediate)
+2.7°C by 2100. Current policies trajectory.
SSP5-8.5 (Very high emissions)
+4.4°C by 2100. Fossil-fueled development.