Can Sovereign Green Bonds Close the Climate Finance Gap? An Analysis of Chile, Egypt, Indonesia, and Nigeria
By Seth Owusu-Mante, Kate Hua-Ke Chi, and Tarun Gopalakrishnan
The global transition to a low-carbon future requires unprecedented levels of investment in climate change mitigation and adaptation efforts. Emerging economies face some of the greatest challenges as they seek to expand energy access, ensure economic development, and curb emissions, while facing limited fiscal space and high borrowing constraints. Although climate finance has grown in recent years, current financial flows remain insufficient to meet global climate goals.
In this context, sovereign green bonds (SGBs) have emerged as a promising tool to help governments mobilize capital for climate projects. Yet, the question remains: Do sovereign green bonds deliver meaningful climate finance in practice? Are SGBs cost effective, environmentally beneficial, and socially equitable?
A recent journal article published in Climate Policy by Climate Policy Lab’s Seth Owusu-Mante, Kate Hua-Ke Chi, and Tarun Gopalakrishnan examines these questions by assessing sovereign green bonds issued by four emerging economies: Chile, Egypt, Indonesia, and Nigeria, using a multi-criteria evaluation framework. The study analyzes SGBs across four dimensions:
Ttheir ability to attract capital from domestic and international investors;
Cost-effectiveness and fiscal sustainability;
Environmental impact, and;
The extent to which sovereign green bonds address normative and distributive justice concerns in climate finance.
Investor Demand for Sovereign Green Bonds
The findings show that sovereign green bonds have been highly effective at attracting domestic and international investment, helping to close the climate finance gap for emerging economies. All four countries successfully raised capital through SGB issuance, and most bonds were significantly oversubscribed by interested investors. Chile’s first sovereign green bond issuance in 2019 totaled USD $6.7 billion, more than twelve times the size of the bond offered. Egypt’s first issuance was oversubscribed by a factor of seven. While Indonesia’s multiple issuances attracted substantial international investor participation, Nigeria’s SGBs were subscribed largely by local institutional investors. These cases demonstrate that there is investor demand for climate-related investments in emerging markets where government budgets may be limited.
Economic Efficiency v. Debt Distress
Beyond mobilizing capital, sovereign green bonds may also provide economic advantages. In several cases, investors accepted slightly lower returns on green bonds compared with comparable conventional bonds. This is known as a “greenium.” For instance, there is evidence Chile and Egypt achieved lower financing costs through their green bond issuances. For emerging economies facing high borrowing constraints due to limited fiscal space, the greenium lowers borrowing costs.
Yet, SGB issuance is not without challenges. Issuing these bonds requires robust administrative systems, including green bond frameworks, reporting requirements, monitoring mechanisms, and external verification systems. These processes increase transaction costs. Expanding sovereign green bonds will therefore require reducing administrative burdens while maintaining credibility. It is also important to note that sovereign green bonds, despite their ability to support climate mitigation or adaptation efforts, are debt instruments. The burden of repayments still creates stress in government fiscal budgets and may constrain non-climate-specific development priorities.
Challenges of Proving Environmental Benefits
This study also finds that the environmental effectiveness of sovereign green bonds remains difficult to assess. The proceeds from the bonds examined in this study supported a wide range of climate-related projects, including solar panels powering universities in Nigeria, clean metro lines in Chile, sustainable transportation in Indonesia, and the Cairo monorail in Egypt.
However, evidence of actual emissions reductions or resiliency remains limited. Many countries report estimated environmental benefits based on projected outcomes but lack empirical methods for quantifying these impacts. Independent verification often confirms whether funds were used for the earmarked green projects but does not evaluate practical impact. Improving measurement, reporting, and verification systems is thus essential to ensure that sovereign green bonds deliver genuine environmental benefits and avoid concerns about greenwashing.
Climate Finance Must Address Equity
The study also highlights a broader question: who benefits from climate finance? Sovereign green bonds can support important infrastructure investments, but their distributional impacts are mixed.
In Chile and Indonesia, bond proceeds have reached rural communities, indigenous populations, and regions vulnerable to climate change; Chile’s investments in renewable energy systems for indigenous communities and Indonesia’s geographically dispersed projects both demonstrate support for disadvantaged communities in the countries.
However, many investments remain concentrated in metropolitan and urban areas, with limited evidence that bond proceeds are distributed equitably across regions. For example, a substantial share of sovereign green bond proceeds issued by the governments of Chile and Egypt helped finance Santiago's metro lines and the Cairo Monorail, projects that primarily benefit urban residents. While large-scale low-carbon infrastructure investments are important for achieving climate goals, they may not always deliver direct or proportionate benefits to the most underserved communities. For sovereign green bonds to contribute to a just climate transition, governments must include equity considerations into project selection and implementation to address existing social and economic inequalities. In addition, as the impacts of climate change rise in the present, SGB finance needs to contribute to adaptation and resilience, not just emission reduction. This is not presently the case – for example, the overwhelming majority of SGB proceeds in Nigeria and Chile goes towards renewable energy projects. The table below summarizes this study’s findings.
| Country | Mobilization Effectiveness | Economic Efficiency | Environmental Impact | Equity |
|---|---|---|---|---|
| Chile | High. Very strong oversubscription (up to 12.8x), diversified investor base, and strong foreign participation. | High. Clear greenium evidence (8 bps) and historically low coupon rates. | Moderate. Detailed project allocation, quantified GHG reductions, and post-issuance verification, but no evidence of actual emissions reductions. | Low. Proceeds benefit both indigenous communities and metropolitan areas; however, 96% of funds were allocated to the metro area. |
| Egypt | High. 7x oversubscription, diversified investor mix, and strong ESG and foreign investor participation. | High. Positive greenium (30 bps) and reduced coupon rate. | Moderate. Large transport project with projected GHG reductions, but not yet operational and lacking actual impact data. | Moderate. Nationwide wastewater projects, though major transport benefits are concentrated in Cairo. |
| Indonesia | High. Multiple oversubscriptions (2.4x–7.4x) and strong foreign investor participation. | Moderate. Evidence of a greenium, but no demonstrated basis-point savings. | Moderate. Broad sector allocation and renewable energy estimates, but with methodological gaps. | Moderate. Projects distributed across all provinces, though not fully aligned with areas of greatest climate risk or need. |
| Nigeria | Moderate. Initial issuance had low oversubscription; second issuance improved to 2.2x. Participation was primarily domestic. | Low. No available data demonstrating a greenium. | Low. Some emissions estimates reported, but methodology is unclear and lacks third-party verification. | Moderate. Mix of projects in lower- and higher-income areas, with some job creation benefits. |
Source: Owusu-Mante et al. (2025)
The analysis of Chile, Egypt, Indonesia, and Nigeria suggests that sovereign green bonds are an important component of the global climate finance landscape. SGBs attract essential capital to support climate-related development projects. However, sovereign green bonds must generate economic, environmental, and social benefits if they are to help reach climate and development objectives. Moreover, these bonds cannot replace the need for concessional climate finance, international support, and broader climate policies.
Read the full article here.