Company lists · Data refreshed August 2026

Top 25 Climate change consulting firms based in the United States

Name: Climate change consulting firms based in the United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Aug 31, 2026 2,563 companies tracked

RevenueBase identified 2,563 climate change consulting firms headquartered in the United States as of August 2026 and tracks 59,828 professional contacts across them, including 29,270 with verified work emails and 23,315 with mobile numbers. New York is the largest hub.

This list covers climate change consulting firms headquartered in the United States, 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 August 31, 2026.

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 RevenueBase Smart Search rating on every row Refreshed Aug 31, 2026 86% judged on-target in blind review

2,563Companies

59,828Contacts tracked

29,270Verified emails

23,315Mobile numbers

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The 25 largest climate change consulting firms based in the United States

Ranked by team size

Top 25 of 2,563 climate change consulting firms based in the United States, ranked by team size, largest first. Data refreshed Aug 31, 2026. RevenueBase Smart Search rates how each company's information relates to climate change 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.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	Golder	Indirect evidence	Houston, TX, United States	5,001-10,000	3,183 contacts →
	Indirect evidence “Golder was acquired by WSP.” Source: RevenueBase Database · checked Aug 31, 2026
2	APTIM	Indirect evidence	Wichita, KS, United States	1,001-5,000	2,644 contacts →
	Indirect 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 Aug 31, 2026
3	Geosyntec Consultants	Partial evidence	Boca Raton, FL, United States	1,001-5,000	2,392 contacts →
	Partial 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 Aug 31, 2026
4	Baringa	Strong evidence	New York, NY, United States	1,001-5,000	2,198 contacts →
	Strong evidence “Baringa is a global consulting firm that helps leaders drive meaningful change and create value.” Source: RevenueBase Database · checked Aug 31, 2026
5	Ricardo	Partial evidence	California, MD, United States	1,001-5,000	2,111 contacts →
	Partial evidence “Ricardo, a member of @WSP, is a global strategic, environmental, and engineering consulting company.” Source: RevenueBase Database · checked Aug 31, 2026
6	Hazen And Sawyer	Indirect evidence	Raleigh, NC, United States	1,001-5,000	2,105 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 Aug 31, 2026
7	Swca Environmental Consultants	Partial evidence	Phoenix, AZ, United States	1,001-5,000	1,618 contacts →
	Partial 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 Aug 31, 2026
8	Montrose Environmental Group	Indirect evidence	Little Rock, AR, United States	1,001-5,000	1,516 contacts →
	Indirect 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 Aug 31, 2026
9	Apex Companies	Indirect evidence	Rockville, MD, United States	1,001-5,000	1,146 contacts →
	Indirect evidence “Who is Apex?” Source: RevenueBase Database · checked Aug 31, 2026
10	Haley & Aldrich	Indirect evidence	Burlington, MA, United States	501-1,000	1,128 contacts →
	Indirect evidence “Haley & Aldrich is committed to solving our clients’ most meaningful challenges in the built and natural environments.” Source: RevenueBase Database · checked Aug 31, 2026
11	Verdantas	Indirect evidence	Toledo, OH, United States	1,001-5,000	1,127 contacts →
	Indirect evidence “At Verdantas, we blend engineering and environmental science together with advanced technology and world-renowned labs to create solutions with the big picture in mind.” Source: RevenueBase Database · checked Aug 31, 2026
12	Braun Intertec Corporation	Indirect evidence	Amarillo, TX, United States	1,001-5,000	1,054 contacts →
	Indirect evidence “At Braun Intertec, we work at the intersection of the natural and built environments, combining science, technology, and engineering.” Source: RevenueBase Database · checked Aug 31, 2026
13	Trinity Consultants	Indirect evidence	Dallas, TX, United States	1,001-5,000	949 contacts →
	Indirect evidence “Trinity Consultants is a global team of experts helping organizations solve complex challenges in environmental compliance, ecological protection, infrastructure performance, and…” Source: RevenueBase Database · checked Aug 31, 2026
14	DUDEK	Partial evidence	Encinitas, CA, United States	501-1,000	792 contacts →
	Partial evidence “Dudek is an environmental, planning, and engineering consulting firm.” Source: RevenueBase Database · checked Aug 31, 2026
15	The Foth Companies	Indirect evidence	Marion, MA, United States	501-1,000	790 contacts →
	Indirect evidence “By combining science, engineering, and technology with a true collaborative spirit, Foth has delivered innovative solutions to our clients since 1938.” Source: RevenueBase Database · checked Aug 31, 2026
16	Environmental Science Associates	Partial evidence	Petaluma, CA, United States	501-1,000	725 contacts →
	Partial evidence “ESA is a 100% employee-owned environmental consulting firm.” Source: RevenueBase Database · checked Aug 31, 2026
17	Inerco	Indirect evidence	Delaware, United States	1,001-5,000	682 contacts →
	Indirect evidence “INERCO, with 30 years of experience, offers comprehensive services and develops advanced technologies that contribute to sustainable industrial development, acting as a leader in…” Source: RevenueBase Database · checked Aug 31, 2026
18	Antea Group USA	Partial evidence	White Plains, NY, United States	1,001-5,000	658 contacts →
	Partial evidence “Antea Group is an international engineering and environmental consulting firm specializing in full-service solutions in the fields of environment, health and safety, and…” Source: RevenueBase Database · checked Aug 31, 2026
19	EBI Consulting	Indirect evidence	Springfield Township, PA, United States	501-1,000	530 contacts →
	Indirect evidence “For 35 years we have been helping investors, lenders, owners, developers, contractors, and property managers reduce risk and optimize their built facilities, infrastructure and…” Source: RevenueBase Database · checked Aug 31, 2026
20	Rincon Consultants	Partial evidence	San Diego, CA, United States	501-1,000	483 contacts →
	Partial evidence “Rincon Consultants is a multi-disciplinary environmental sciences, planning, and engineering consulting firm that provides quality professional services to government and industry.” Source: RevenueBase Database · checked Aug 31, 2026
21	Anchor QEA	Partial evidence	Columbia, MD, United States	501-1,000	478 contacts →
	Partial evidence “Headquartered in Seattle, Washington, Anchor QEA is a nationally recognized environmental science and engineering consulting firm specializing in aquatic, shoreline, and water…” Source: RevenueBase Database · checked Aug 31, 2026
22	Groundwater & Environmental Services, INC	Indirect evidence	Amherst, NY, United States	201-500	452 contacts →
	Indirect evidence “We are Groundwater & Environmental Services, Inc, better known as GES.” Source: RevenueBase Database · checked Aug 31, 2026
23	ROUX	Partial evidence	Houston, TX, United States	201-500	435 contacts →
	Partial evidence “Founded 40 years ago, Roux is recognized for being a highly effective, client-focused environmental consulting and management firm.” Source: RevenueBase Database · checked Aug 31, 2026
24	TRIO	Indirect evidence	Mclean, VA, United States	201-500	382 contacts →
	Indirect evidence “We are Trio – built from Edison Energy, Alfa Energy, and Altenex Energy.” Source: RevenueBase Database · checked Aug 31, 2026
25	P2s	Indirect evidence	Irvine, CA, United States	201-500	370 contacts →
	Indirect evidence “P2S has brought forward-thinking, sustainable engineering solutions to California, the Pacific Northwest, and beyond, for over 30 years.” Source: RevenueBase Database · checked Aug 31, 2026

RevenueBase Smart Search

RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: climate change consulting firms. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.

Strong evidence: The company's own public description of its business names climate change consulting firms.
Partial evidence: Its own public description names part of climate change consulting firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name climate change consulting firms. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.

RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.

Showing 25 of 2,563 climate change consulting firms based in the United States

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Climate change consulting firms based in the United States at a glance

As of Aug 31, 2026

48.9%Verified-email coverage

39.0%Mobile-number coverage

23.3Average contacts per company

1-10Median size (employees)

5.4%Largest-city concentration · New York

Aug 31, 2026Page data refreshed

Companies by employee count

1-10

1,712

11-50

614

51-200

155

201-500

501-1,000

1,001-5,000

5,001-10,000

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 change 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.
What qualifies: Companies headquartered in the United States whose own description of what they do matches “climate change 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 change 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 change consulting firms, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
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, 29,270 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 August 31, 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 change consulting firms by metro

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 change 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 change consulting firms are there based in the United States?

RevenueBase identified 2,563 climate change consulting firms headquartered in the United States as of August 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?

Golder, headquartered in Houston, tops this list with the largest team on record.

Which city has the most climate change consulting firms?

New York leads with 138 headquartered companies, followed by Washington (98) and Houston (69).

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 29,270 verified decision-maker contacts tracked across these 2,563 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on August 31, 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.