After Poland issued the first sovereign green bond in 2016, we saw more countries coming to market – France, Fiji, and finally, Nigeria. A close analysis reveals how scale, synergies and sovereign s’ exclusive access to specific sectors can create some unique sustainability benefits. On the flipside, the broad scope of national policies can lessen transparency and proceeds may not be distributed equitably; governmental change is an even more serious impact default risk, as are the governance we aknesses we see in some emerging markets. Transparent impact reporting, cross‐party support for national climate agendas and robust regulatory frameworks emerge as critical factors for long‐term sustainable returns