Here are reputable ESG/sustainability consulting firms with true global operations, plus a brief note on their ESG strengths to help you pick (I’ve cited authoritative company/analyst pages for each).

1. Deloitte — Global ESG & sustainability services (strategy, reporting, climate risk, decarbonization, supply-chain transformation). Recognized by independent analysts for broad capabilities and global scale. (Deloitte.com)

2. PwC (PricewaterhouseCoopers) — Large global sustainability practice (ESG strategy, assurance, sustainable finance, disclosures). Named a global leader in Verdantix’s Green Quadrant. (PwC.com)

3. KPMG — Global ESG and sustainability advisory across reporting, strategy, operations and tech-enabled solutions; named a leader by Verdantix. (KPMG.com)

4. EY (Ernst & Young) — Global sustainability and climate services (strategy, reporting, climate/TCFD, sustainable finance); EY is a major network in ESG advisory (see EY sustainability offerings). (BCG.com)

5. McKinsey & Company — Global climate & sustainability practice focused on strategy, decarbonization pathways, operations and net‑zero transformation for large enterprises. (businessinsider.com)

6. Boston Consulting Group (BCG) — Global leader in ESG/sustainability strategy and implementation; recognized by IDC/analysts for strategy work. (BCG.com)

7. Bain & Company — Global sustainability and climate practice (net-zero strategy, product/portfolio decarbonization, sustainable growth). Frequently engaged for corporate transformation and investor-aligned ESG work. (BCG.com)

8. Accenture — Large global Sustainability Services practice combining strategy, tech, data/AI and systems to scale ESG reporting, data platforms and net-zero programs. Strong in technology-enabled ESG solutions. (newsroom.Accenture.com)

9. ERM (Environmental Resources Management) — Specialist global sustainability consultancy focused on environment, health & safety, climate risk, and impact assessment; deep technical capability and global footprint. (en.wikipedia.org)

10. Morningstar Sustainalytics (and S&P Global / Trucost) — Data, ratings and research firms that also offer advisory/data solutions to integrate ESG risk analytics into investment and corporate workflows (valuable if you need data-driven ESG/risk inputs). (sustainalytics.com)

How to choose among them (quick checklist)

• Scope: Do you need strategy + implementation (Deloitte, PwC, KPMG, Accenture, McKinsey, BCG) or technical environmental assessments (ERM) or data/ratings (Sustainalytics, S&P Trucost)?
• Scale & global presence: Big Four, Accenture, McKinsey/BCG/Bain and ERM operate in most regions and can support multinational programs. (Deloitte.com)
• Sector experience: Prefer firms with deep experience in your industry (energy, finance, manufacturing, tech, consumer goods).
• Data & tech: If you need ESG data platforms, reporting automation, or AI for disclosures, prioritize Accenture, PwC, or firms with strong data partnerships. (newsroom.Accenture.com)
• Assurance / investor-facing reporting: Big Four have large assurance practices for ESG disclosures and sustainability-linked financing. (PwC.com)

If you want, I can:

• Shortlist 3–4 firms best matched to your industry, size and objectives (tell me industry and whether you need strategy, reporting, implementation or data platforms).
• Prepare a comparison matrix (services, global footprint, typical fees/range, relevant case studies) for your RFP.

Would you like a tailored shortlist or a comparison?