Green bond

A green bond is a fixed-income debt security whose proceeds fund climate or environmental projects — clean energy, low-carbon transport, water systems, or sustainable buildings. Issuers borrow at standard bond terms; investors earn a regular coupon plus a verifiable environmental purpose layered on top of an otherwise ordinary contract.

The “green” label is a use-of-proceeds promise, not a separate asset class. Default risk, coupon, and maturity behave like any other bond from the same issuer. What changes is the paperwork: a published framework, a second-party opinion, and annual allocation and impact reports.

Most issuance follows the Green Bond Principles maintained by the International Capital Market Association, updated in June 2025. Independent reviewers (Sustainalytics, S&P, Moody’s, Cicero) issue second-party opinions confirming the framework lines up with those standards before a deal prices.

How it works

A green bond moves through four stages, each producing a document investors can audit later.

The framework is the gating document — it names eligible categories (often mapped to the EU Taxonomy or the ICMA categories), describes how projects are selected, and explains how proceeds will be tracked. A second-party opinion from a recognised reviewer signs off on alignment with the Green Bond Principles, then the bond goes to market.

Proceeds sit in a sub-portfolio or ledger entry separate from general corporate cash, so an auditor can trace dollars to projects. Each year the issuer publishes an allocation report (where the money went) and an impact report (tonnes of CO2 avoided, megawatts of renewable capacity built, hectares restored). If the issuer fails to deploy proceeds within the stated window, most frameworks require the bond to be reclassified or the funds returned to a holding account, which is also how an investor decides whether to keep buying from that issuer next time.

Pricing usually tracks the issuer’s conventional curve, sometimes with a small discount called the “greenium” of roughly 1–5 basis points. The discount is real but inconsistent: it shows up most often in sovereign and supranational deals where demand swamps supply, and barely at all in less-watched corporate names.

Examples

The market has matured from a niche multilateral product into a mainstream instrument with sovereign, corporate, and bank issuers.

• World Bank (2008): the World Bank Treasury and SEB launched the world’s first labelled green bond, which has since grown to more than US$20 billion across 230+ bonds in 28 currencies. The European Investment Bank’s 2007 Climate Awareness Bond is widely cited as the first climate-themed deal; the two together are usually credited with seeding the market.
• United Kingdom (2021–present): the UK Debt Management Office launched its green gilt programme in September 2021 with a £10 billion debut. Planned green gilt sales for 2025–26 are £10.0 billion (cash), funding clean transport, renewable energy, and natural-capital projects.
• Apple (2016–2017): Apple issued a US$1.5 billion green bond in 2016 followed by US$1 billion in 2017, with proceeds funding renewable-energy projects, low-carbon design, and recycled-material supply chains across its operations and major suppliers.
• Germany (2020): Germany launched its sovereign green Bund with a “twin bond” structure pairing each green issue with a conventional one of identical maturity, giving the market a clean reference price for the greenium.

Across all four, the common thread is disclosure — each issuer publishes annual reports against the framework so investors can decide whether the next deal earns their bid.

Related terms

• Sustainability bond: proceeds fund a mix of green and social projects, not climate-only.
• Sustainable investing: the umbrella strategy of allocating capital with environmental, social, and governance factors in mind.
• Impact investing: targets measurable social or environmental outcomes alongside financial return, often outside listed markets.
• Bond: the underlying instrument, a tradable debt security with fixed coupon and maturity.
• Interest rate: the coupon a green bond pays sits on the same rate curve as any conventional issue from that borrower.
• Asset allocation: green bonds increasingly appear as a sleeve inside fixed-income mandates.
• Dividend: the equity-side comparison; green bonds pay coupons, not dividends, and rank ahead of shareholders in a wind-up.

FAQ

How is a green bond different from a regular bond?

Legally, almost not at all. You hold the same credit risk against the same issuer with the same coupon and maturity. The difference is contractual: the issuer commits in the prospectus to use the proceeds only for projects on a pre-approved environmental list, and to report on that use every year.

Do green bonds pay less than conventional bonds?

Sometimes. The discount is called a “greenium” and typically runs 1–5 basis points on sovereign and supranational deals where demand outstrips supply. For corporate issuers it’s often zero. You’re not paid extra to be green, but you’re rarely paid much less either.

Who certifies that a bond is actually green?

Independent reviewers (Sustainalytics, S&P Global Ratings, Moody’s, Cicero, and others) issue a second-party opinion confirming the issuer’s framework aligns with the ICMA Green Bond Principles or the Climate Bonds Initiative’s stricter certification scheme. The reviewer is paid by the issuer, which is why investors still read the framework themselves.

What’s the main risk?

Greenwashing — the gap between what the framework promises and what the proceeds actually fund. The defence is the annual allocation and impact report; if it goes missing or thins out over time, that’s the early warning. Standard bond risks (default, duration, currency) still apply on top.

Can retail investors buy green bonds?

Individual sovereign green gilts and Bunds are accessible through any broker that handles government bonds. Most corporate green bonds trade in institutional sizes, so retail exposure usually comes through green-bond ETFs and mutual funds that hold a diversified basket.

How do I check that proceeds actually went where promised?

Read the issuer’s annual allocation report, which lists projects funded and amounts drawn, plus the impact report showing the environmental outcomes claimed. Both are required under the ICMA principles and are usually filed alongside the issuer’s other investor relations material.

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