An initiative of CDP, UN Global Compact, WRI and WWF, has released with the Mind the Science and Mind the Gap initiative a draft methodology for public comment how to set science-based emission reduction targets. This should ensure that reduction targets are staying under the the global 2° C temperature increase.
Such metholdologies might also be part of the next CDP methodologies.
For information and public comments please visit http://sciencebasedtargets.org/