B2
A2
2: continuously increasing population
B1
A1FI: fossil intensive
A1T: non-fossil intensive
A1B: balance of F&T
1: global population levels off, declines after 2050
B: faster conversion to clean & efficient technologies
A: slower conversion to clean & efficient technologies
economic
models
carbon
cycle
models
scenarios
CO2 emissions
CO2 concentration
ensemble of
climate models
Temperature change
scenario A2
 average of
ensemble
Final product