Sovereign bond guarantees (SBGs) are an effective but underutilized instrument available to the US government in support of developing country partners. By protecting bond purchasers in the event of a foreign issuer country’s default, SBGs substantially reduce borrowing costs for developing country governments. In this CGD policy paper, we estimate the costs and benefits of historical US sovereign bond guarantees in order to model the use of SBGs for climate finance purposes. We demonstrate that the US government-provided SBG has the effect of conferring the US government’s cost of borrowing on the partner government. On that basis, it represents substantial savings for these countries. Based on this analysis, we propose a $20 billion “Green” SBG program aimed at financing climate change mitigation efforts in 28 emerging market economies. We estimate that the US government could support $20 billion in bond issuances through a subsidy outlay of $2 billion, resulting in a 22 percent reduction in borrowing cost of the target countries, which represents $4 billion in budgetary saving for their governments. We propose that the subsidy appropriations in support of the guarantees be retained and recycled within the Green SBG program, which would substantially improve the financial leverage of the program over time. We also suggest that the program could be used for climate adaptation purposes by targeting a different group of developing countries
