3. Source: IPCC AR5 WG2 (2014)
Climate risks a func&on of ‘peak warming’
Paris
agreement
4. CO2inducedpeak
warming(°C)
2.0
3.0
Each point represents a
different possible
emissions trajectory
over the 21st century
Source: Bowerman et al. (2011)
Peak warming
Significant scatter
shows that 2050
emissions are not the
best guide to peak
warming
2050 emissions GtC)
Emissions in a given year (e.g. 2050) not a reliable
guide to peak warming
5. CO2inducedpeak
warming(°C)
2.0
3.0
Cumulative carbon emissions (CCE) since 1750 (TtC)
Source: Bowerman et al. (2011)
Peak warming
The tight fit reflects a
fundamental physical
relationship between
cumulative emissions
and peak warming
Each point represents a
different possible
emissions trajectory
over the 21st century
Instead cumula&ve carbon emissions (CCE) are a
good indicator of peak warming
9. 2017
Source: Pfeiffer, Millar, Hepburn and Beinhocker (2015, forthcoming)
All new energy investment globally must be zero
carbon by 2017 or we “commit” to >2˚C
Range 2005 - 2032