IPCC Fourth Assessment Report: Climate Change 2007
Climate Change 2007: Working Group III: Mitigation of Climate Change
Figure SPM.5

Figure SPM.5A (left): Global economic mitigation potential in 2030 estimated from bottom-up studies (data from Table SPM.1)

Figure SPM.5B (right): Global economic mitigation potential in 2030 estimated from top-down studies (data from Table SPM.2)