GHG accounting consulting vendors

Last reviewed: September 20, 2026

Consultancies that state they advise on greenhouse gas inventories, reporting readiness and related programs.

Descriptions are short summaries of what each vendor or source states publicly. SB253 Vendors has not independently verified them. Listings are alphabetical and are not a ranking.

Vendors in this category

Anthesis Group
Sustainability consultancy offering GHG inventory development, Scope 1/2 measurement and Scope 3 screening, with its own inventory software and California regulation pages.
BSI Consulting
BSI's consulting page describes GHG accounting and reporting support (Scope 1-3 inventories, verification preparation); BSI's separate pages also list ISO 14064-1 verification.
Carbon Trust
Organization whose footprinting and reporting page describes helping corporates, cities and financial institutions measure Scope 1, 2 and 3 emissions against recognized standards.
Crowe
Accounting and advisory firm whose US page describes GHG emissions accounting help across Scopes 1-3, based on the GHG Protocol, including readiness reviews of existing inventories.
ERM
Sustainability consultancy whose pages describe sustainability reporting and disclosure support and GHG accounting work, including a private-equity GHG standard using the GHG Protocol.
KERAMIDA
Environmental consultancy offering GHG assessments and inventories (Scopes 1-3), verification services, and SB 253 and New York reporting assistance.
Ramboll
Engineering and consulting firm whose insight article says it can support Scope 1 and 2 inventories; other pages describe climate calculations and decarbonization consulting.
South Pole
Climate consultancy whose GHG accounting page describes inventory support (notably Scope 3), data-gap work and help with disclosure frameworks.
Trinity Consultants
Environmental consultancy offering GHG inventories across all three scopes, GHG and CDP reporting support, and staff for SB 253 emissions reporting questions.
WSP
Engineering and consulting firm whose US page lists GHG inventory management and inventory verification aligned with ISO 14064 and AA1000, plus disclosure support.