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Report identifies the world’s largest environmental & sustainability (E&S) consulting firms in terms of E&S consulting revenue (from FY 2022)

St. Paul, 26 February, 2024 — Inogen Alliance today announced it is ranked #41 in Environment Analyst’s Top 100 Global Environmental & Sustainability (E&S) Consultancy Firms report. This shifts up the ranking by 9 from the previous report published in 2022. When combined with all Associate companies including Antea Group, which is listed separately at #19, that would result in a ranking of #12 for Inogen Alliance as a whole.

The rankings, researched and curated by Environment Analyst, a leading provider of business intelligence, networking opportunities and advisory services to the global environmental, ESG and professional services sector, identify the largest environmental and sustainability (E&S) consulting consultancies in the world in terms of E&S consulting revenue from financial year 2022.

Some of the key services provided by Inogen Alliance Associates globally under Environment and Sustainability services include Groundwater and Soil Remediation, EHS Due Diligence, Waste Management, Climate Mitigation, Decarbonization, Sustainability Strategy and Reporting, Energy Management, Water Stewardship and more. For a full listing check here.

Environment Analyst’s Top 100 report is constructed based upon global E&S consulting revenue for the latest financial year end analysed, predominantly covering the 2022 calendar year.

The unique, comprehensive dataset was compiled through rigorous research of, and engagement with, the 100 leading firms, who represented $35.5bn in E&S consulting revenues in 2022.

Each of the Top 100 firms were ranked in order of E&S consulting revenue, and classified under one of four categories: Environmental & Sustainability specialist; Mid-range multidisciplinary; Large scale integrated/multidisciplinary professional services; or Management consultant. Inogen Alliance is classified under Mid-range multidisciplinary firms.

Environment Analyst’s definition of environmental & sustainability consulting is: “The provision of specialist technical, management, risk and strategic advisory services to help organizations understand, manage and limit their impacts, to protect and enhance the environment and society in line with the UN SDGs.”

We are proud to be included in this top 100 ranking by EA, and more importantly, proud of the work this represents globally for our clients in creating a more sustainable future.

Download the Top 100 Report


About Inogen Alliance

Inogen Alliance is a global network of environment, health, safety and sustainability consulting companies working together to help multinational organizations meet their global commitments locally.  With offices located on every continent, more than 5,000 associates worldwide, and projects completed in more than 150 countries, Inogen Alliance provides unparalleled local consulting expertise, global consistency and 20 years of experience building a cleaner, safer and more sustainable future. Global Thinking. Local Delivery. Learn more at

About Environment Analyst

Environment Analyst is a leading provider of business intelligence, networking opportunities and advisory services to the global environmental, ESG and professional services sector. Environment Analyst has a global membership community of 40,000 sustainability professionals. Membership includes access to their entire market intelligence library, which features bespoke market intelligence reports, data-sets, interactive dashboards and competitor analysis profiles, plus business news and insights.

Environment Analyst also hosts networking opportunities for sustainability business leaders to come together in closed-group forums, and larger-scale in-person Sustainability Summits.

For more information about the report please contact Lead Report author Sarah-Jane James at sarah-jane [at] environment-analyst [dot] com.

For more information about Environment Analyst and their membership services contact Membership Development Manager Lisa Turner at lisa [dot] turner [at] environment-analyst [dot] com or call (0) 1743 818 008.