They might yield major GHG reductions, but at the cost of considerable social upheaval, as well as removing what can be the ecologically optimal use of rangelands. Indeed, this proposal faces so many cultural constraints that it is probably the clearest example of the need to conduct environmental and social impact assessments (ESIAs) of all the CRGE proposals, to ensure they are both ‘doubly green’ and inclusive. The methodology is certainly credible with its roots in IPCC-led assessments, and potentially rewarding with its tendrils in new international climate finance.