What is Sustainable Finance? A pillar guide for banks, corporates and SMEs

Sustainable Finance is the practice of integrating environmental, social and governance (ESG) considerations into financial decision-making. It is no longer a niche of the financial system — it is the direction the entire system is moving. By 2025, sustainable finance products accounted for more than 30% of new corporate lending in the EU, and every major bank is now regulated on climate-related risk.

Definition

Sustainable Finance covers any financial activity that considers ESG factors alongside financial return, including:

• Sustainable lending — green loans, sustainability-linked loans, transition loans.
• Sustainable capital markets — green, social, sustainability and sustainability-linked bonds.
• ESG investment — integration of ESG factors into equity and fixed-income portfolios.
• Green insurance — products supporting resilience and just transition.

Why it matters now

Three converging forces:

1. Regulation. The EU has built the world's most comprehensive sustainable finance framework — CSRD, SFDR, EU Taxonomy, CBAM, CRD VI. The UK, US, Singapore, Hong Kong and Japan are converging on similar architectures.
2. Financial risk. Climate-related physical and transition risk is now recognised by every major central bank as a material source of financial risk. Banks that don't measure it will misprice it.
3. Client demand. Corporates increasingly need sustainability-linked financing to access the best terms, and to signal credibility to customers and investors.

The core instruments

Green Loans and Green Bonds

Use-of-proceeds finance for eligible green projects — renewables, green buildings, clean transport. Governed by the Green Loan Principles and Green Bond Principles.

Sustainability-Linked Loans and Bonds

General-purpose finance whose pricing is linked to sustainability KPIs. See our full guide: What is a Sustainability-Linked Loan?.

Transition Finance

Capital for hard-to-abate sectors — steel, cement, aviation — funding credible decarbonisation plans. See our Transition Finance hub.

Social and Sustainability Bonds

Use-of-proceeds instruments for social projects (affordable housing, healthcare, education) or a mix of green and social projects.

The regulatory stack

Regulation	What it does
CSRD / ESRS	Mandatory sustainability disclosure for ~50,000 EU companies
SFDR	Disclosure regime for financial market participants
EU Taxonomy	Classification of environmentally sustainable activities
CBAM	Carbon border adjustment on imports
CRD VI / Pillar 3 ESG	Bank capital and disclosure requirements
PCAF Standard	Methodology for financed emissions

Read our detailed explainers: CSRD explained, EU Taxonomy explained, CBAM explained.

Where banks and corporates start

The starting point for both is the same: credible, auditable emissions data. Without it, no product can be structured, no target can be set, and no disclosure will pass assurance.

The typical sequence:

1. Establish a baseline carbon footprint (Scope 1, 2, 3) following the GHG Protocol.
2. Set a science-based target aligned with a 1.5°C pathway.
3. Build a transition plan of concrete measures.
4. Structure the financing — green, sustainability-linked, transition, or a combination.
5. Report and verify performance annually.

Redigo Carbon exists to automate steps 1, 4 and 5 for banks and their SME clients — turning what has historically been a consulting-heavy process into a scalable, technology-driven programme.

Common misconceptions

• "Sustainable finance is only for large corporates." Wrong. SMEs are the largest emitting cohort in most economies and now have simplified SLL products designed for them.
• "It's about marketing." Wrong. Under CSRD, ESRS, SFDR and Pillar 3, sustainable finance is a regulated disclosure regime with third-party assurance.
• "Green means expensive." Wrong. Green and sustainability-linked products typically price at or below conventional equivalents once execution costs are factored in.

Next steps

• Explore the topic hubs on SLLs, Green Loans and Transition Finance.
• Read Sustainability-Linked Loan vs Green Loan.
• Book a demo to see how banks use Redigo Carbon to scale sustainable finance to their whole book.