Company lists · Data refreshed September 2026

Top 25 Climate and environmental consulting firms worldwide

RevenueBase identified 25,396 climate and environmental consulting firms worldwide as of September 2026 and tracks 460,922 professional contacts across them, including 186,497 with verified work emails. The United States is the largest market and London the largest hub.

This list covers climate and environmental consulting firms worldwide, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 21, 2026. Country and city lists for climate and environmental consulting firms follow the table.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 21, 2026 86% judged on-target in blind review
25,396Companies
460,922Contacts tracked
186,497Verified emails
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The 25 largest climate and environmental consulting firms worldwide

Ranked by team size
Top 25 of 25,396 climate and environmental consulting firms worldwide, ranked by team size, largest first. Data refreshed Sep 21, 2026. RevenueBase Smart Search rates how each company's information relates to climate and environmental consulting firms: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Indirect evidenceAmsterdam, NetherlandsHQ checked Sep 21, 202610001+33,846 contacts →

Indirect evidence

“Arcadis is a leading global partner, delivering transformative projects with businesses, cities and industries.”

Source: RevenueBase Database · checked Sep 21, 2026
2Indirect evidenceEdmonton, AB, CanadaHQ checked Sep 21, 202610001+28,416 contacts →

Indirect evidence

“Stantec empowers clients, people, and communities to rise to the world’s greatest challenges at a time when the world faces more unprecedented concerns than ever before.”

Source: RevenueBase Database · checked Sep 21, 2026
3Partial evidencePasadena, CA, United StatesHQ checked Sep 21, 202610001+12,999 contacts →

Partial evidence

“Tetra Tech is the leader in water, environment and sustainable infrastructure, providing high-end technical and engineering services for projects worldwide.”

Source: RevenueBase Database · checked Sep 21, 2026
4Indirect evidenceLa Garenne-colombes, FranceHQ checked Sep 21, 202610001+12,011 contacts →

Indirect evidence

“Les activités Infrastructures Energétiques Locales d’ENGIE accompagnent les collectivités, les industries et le secteur du bâtiment sur la voie de la décarbonation.”

Source: RevenueBase Database · checked Sep 21, 2026
5Partial evidenceNew York, NY, United StatesHQ checked Sep 21, 202610001+9,318 contacts →

Partial evidence

“What if you could shape built and natural environments – and the future of those that use them?”

Source: RevenueBase Database · checked Sep 21, 2026
6Indirect evidenceLondon, United KingdomHQ checked Sep 21, 20265,001-10,0009,119 contacts →

Indirect evidence

“Sustainability is our business.”

Source: RevenueBase Database · checked Sep 21, 2026
7Partial evidenceOlathe, KS, United StatesHQ checked Sep 21, 20265,001-10,0006,113 contacts →

Partial evidence

“Terracon is a 100 percent employee-owned consulting engineering firm providing quality services to clients.”

Source: RevenueBase Database · checked Sep 21, 2026
8Indirect evidenceLondon, United KingdomHQ checked Sep 21, 20261,001-5,0003,848 contacts →

Indirect evidence

“SLR is a committed partner in our clients’ sustainability journeys.”

Source: RevenueBase Database · checked Sep 21, 2026
9Indirect evidenceVancouver, BC, CanadaHQ checked Sep 21, 20265,001-10,0003,167 contacts →

Indirect evidence

“Golder was acquired by WSP.”

Source: RevenueBase Database · checked Sep 21, 2026
10Indirect evidenceAllerød, DenmarkHQ checked Sep 21, 20261,001-5,0002,699 contacts →

Indirect evidence

“At NIRAS, we engineer solutions for a shared future.”

Source: RevenueBase Database · checked Sep 21, 2026
11Partial evidenceBaton Rouge, LA, United StatesHQ checked Sep 21, 20261,001-5,0002,639 contacts →

Partial evidence

“APTIM enhances the quality of the environment, wellbeing of people, resilience of communities, and opportunity for employees to make a difference, not just a living.”

Source: RevenueBase Database · checked Sep 21, 2026
12Indirect evidenceWalnut Creek, CA, United StatesHQ checked Sep 21, 20261,001-5,0002,473 contacts →

Indirect evidence

“Headquartered in Walnut Creek, Calif, Brown and Caldwell is an employee-owned firm with 2,100+ professionals serving clients locally and globally from 52 locations.”

Source: RevenueBase Database · checked Sep 21, 2026
13Strong evidenceBoca Raton, FL, United StatesHQ checked Sep 21, 20261,001-5,0002,393 contacts →

Strong evidence

“Geosyntec is a consulting and engineering firm that works with private and public sector clients to address new ventures and complex problems involving our environment, natural…”

Source: RevenueBase Database · checked Sep 21, 2026
14Partial evidenceChantilly, VA, United StatesHQ checked Sep 21, 20261,001-5,0002,210 contacts →

Partial evidence

“ECS Group of Companies is a Chantilly, VA-based consulting engineering firm.”

Source: RevenueBase Database · checked Sep 21, 2026
15Partial evidenceLondon, United KingdomHQ checked Sep 21, 20261,001-5,0002,179 contacts →

Partial evidence

“Baringa is a global consulting firm that helps leaders drive meaningful change and create value.”

Source: RevenueBase Database · checked Sep 21, 2026
16Partial evidenceParsippany, NJ, United StatesHQ checked Sep 21, 20261,001-5,0002,177 contacts →

Partial evidence

“Langan's client-focused, highly entrepreneurial culture cultivates an environment of opportunities in which career growth and teamwork flourish.”

Source: RevenueBase Database · checked Sep 21, 2026
17Strong evidenceMoon Township, PA, United StatesHQ checked Sep 21, 20261,001-5,0002,145 contacts →

Strong evidence

“Civil & Environmental Consultants, Inc.(CEC) provides comprehensive market-oriented consulting services that advance the strategic business objectives of its clients.”

Source: RevenueBase Database · checked Sep 21, 2026
18Indirect evidenceWest Sussex, United KingdomHQ checked Sep 21, 20261,001-5,0002,104 contacts →

Indirect evidence

“Ricardo, a member of @WSP, is a global engineering company, specialising in complex propulsion, driveline and energy systems, delivering high integrity solutions for customers…”

Source: RevenueBase Database · checked Sep 21, 2026
19Indirect evidenceNew York, NY, United StatesHQ checked Sep 21, 20261,001-5,0002,100 contacts →

Indirect evidence

“As Hazen marks 75 years, we celebrate a legacy of absolute commitment to our clients while delivering the best technical work available anywhere.”

Source: RevenueBase Database · checked Sep 21, 2026
20Strong evidencePhoenix, AZ, United StatesHQ checked Sep 21, 20261,001-5,0001,629 contacts →

Strong evidence

“Founded on a commitment to sound science and creative solutions, SWCA is a leader in environmental and management consulting services.”

Source: RevenueBase Database · checked Sep 21, 2026
21Indirect evidenceWoburn, MA, United StatesHQ checked Sep 21, 20261,001-5,0001,604 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 21, 2026
22Partial evidenceOrlando, FL, United StatesHQ checked Sep 21, 20261,001-5,0001,595 contacts →

Partial evidence

“UES provides professional engineering, environmental, testing and inspection services to clients across the United States.”

Source: RevenueBase Database · checked Sep 21, 2026
23Partial evidenceMenlo Park, CA, United StatesHQ checked Sep 21, 20261,001-5,0001,560 contacts →

Partial evidence

“In an era of accelerating change, Exponent is the only premium engineering and scientific consulting firm with the depth and breadth of expertise to solve our clients’ most…”

Source: RevenueBase Database · checked Sep 21, 2026
24Partial evidenceLittle Rock, AR, United StatesHQ checked Sep 21, 20261,001-5,0001,529 contacts →

Partial evidence

“Onterris (formerly Montrose Environmental Group) was one of the first to see environmental responsibility as not just an imperative but as a strategic asset.”

Source: RevenueBase Database · checked Sep 21, 2026
25Partial evidenceNeuilly-sur-seine, FranceHQ checked Sep 21, 20265,001-10,0001,496 contacts →

Partial evidence

“Vulcain Engineering Group is a multi-specialist engineering and consulting group serving industrial companies across the globe, focused on critical sectors: energy, health…”

Source: RevenueBase Database · checked Sep 21, 2026

Showing 25 of 25,396 climate and environmental consulting firms worldwide

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Climate and environmental consulting firms worldwide at a glance

As of Sep 21, 2026
40.5%Verified-email coverage
18.1Average contacts per company
1-10Median size (employees)
1.6%Largest-city concentration · London
Sep 21, 2026Page data refreshed

Companies by employee count

1-10
17,080
11-50
6,318
51-200
1,385
201-500
290
501-1,000
96
1,001-5,000
101
5,001-10,000
21
10001+
29

Email recency is reported on each country list linked below.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among climate and environmental consulting firms, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
Coverage
Every country. Country and city lists for climate and environmental consulting firms are linked below.
What qualifies
Companies worldwide whose own description of what they do matches “climate and environmental consulting firms”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search
RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names climate and environmental consulting firms), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude
Companies whose own description does not clearly place them among climate and environmental consulting firms, and records with no verified work email.
Match quality
In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking
Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification
Every listed company carries at least one verified work email, 186,497 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh
This page's figures were pulled from the company graph on September 21, 2026. Lists refresh periodically as the graph is re-checked.
Corrections
Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Climate and environmental consulting firms by location

109 lists · largest first

Every Climate and environmental consulting firms list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.

Countries

Cities

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names climate and environmental consulting firms, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many climate and environmental consulting firms are there worldwide?

RevenueBase identified 25,396 climate and environmental consulting firms worldwide as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Arcadis, headquartered in Amsterdam, tops this list with the largest team on record.

Which country has the most climate and environmental consulting firms?

The United States leads with 4,146 companies, followed by Brazil (2,659) and France (1,402). Every climate and environmental consulting firms list by country and city is linked on this page.

Which city has the most climate and environmental consulting firms?

London leads with 399 headquartered companies, followed by Sao Paulo (369) and Paris (252).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 186,497 verified decision-maker contacts tracked across these 25,396 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 21, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.