Company lists · Data refreshed September 2026

Top 25 Climate change consulting companies based in the United States

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

Compiled by the RevenueBase Data Team Data refreshed Sep 19, 2026 1,990 companies tracked

RevenueBase identified 1,990 climate change consulting companies headquartered in the United States as of September 2026 and tracks 42,361 professional contacts across them, including 19,059 with verified work emails. New York is the largest hub.

This list covers climate change consulting companies 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 September 19, 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 HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 19, 2026 86% judged on-target in blind review

1,990Companies

42,361Contacts tracked

19,059Verified emails

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

Ranked by team size

Top 25 of 1,990 climate change consulting companies based in the United States, ranked by team size, largest first. Data refreshed Sep 19, 2026. RevenueBase Smart Search rates how each company's information relates to climate change consulting companies: 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	Carrier	Partial evidence	Palm Beach Gardens, FL, United StatesHQ checked Sep 19, 2026	10001+	7,665 contacts →
	Partial evidence “Carrier is a global leader in intelligent climate and energy solutions, pioneering sustainable innovations in climate technologies.” Source: RevenueBase Database · checked Sep 19, 2026
2	APTIM	Indirect evidence	Baton Rouge, LA, United StatesHQ checked Sep 19, 2026	1,001-5,000	2,639 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 Sep 19, 2026
3	Swca Environmental Consultants	Partial evidence	Phoenix, AZ, United StatesHQ checked Sep 19, 2026	1,001-5,000	1,629 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 Sep 19, 2026
4	Montrose Environmental Group	Indirect evidence	Little Rock, AR, United StatesHQ checked Sep 19, 2026	1,001-5,000	1,529 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 Sep 19, 2026
5	Environmental Defense Fund	Partial evidence	New York, NY, United StatesHQ checked Sep 19, 2026	1,001-5,000	1,352 contacts →
	Partial evidence “We are Environmental Defense Fund, a leading environmental nonprofit focused on stabilizing the climate while helping build strong and healthy communities.” Source: RevenueBase Database · checked Sep 19, 2026
6	OLA	Partial evidence	Austin, TX, United StatesHQ checked Sep 19, 2026	n/a	1,145 contacts →
	Partial evidence “OLA Sustainability, LLC OLA Sustainability is a consulting firm that focuses on integrating sustainable practices into commercial and multifamily design projects.” Source: RevenueBase Database · checked Sep 19, 2026
7	Verdantas	Indirect evidence	Tampa, FL, United StatesHQ checked Sep 19, 2026	1,001-5,000	1,139 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 Sep 19, 2026
8	Braun Intertec Corporation	Indirect evidence	Minneapolis, MN, United StatesHQ checked Sep 19, 2026	1,001-5,000	1,065 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 Sep 19, 2026
9	Trinity Consultants	Indirect evidence	Dallas, TX, United StatesHQ checked Sep 19, 2026	1,001-5,000	961 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 Sep 19, 2026
10	Climatebase	Partial evidence	San Francisco, CA, United StatesHQ checked Sep 19, 2026	n/a	759 contacts →
	Partial evidence “Climatebase is the community for climate & sustainability professionals, and the world's #1 platform for green jobs.” Source: RevenueBase Database · checked Sep 19, 2026
11	Environmental Science Associates	Partial evidence	San Francisco, CA, United StatesHQ checked Sep 19, 2026	501-1,000	732 contacts →
	Partial evidence “ESA is a 100% employee-owned environmental consulting firm.” Source: RevenueBase Database · checked Sep 19, 2026
12	Uniqus Consultech INC	Partial evidence	San Jose, CA, United StatesHQ checked Sep 19, 2026	501-1,000	675 contacts →
	Partial evidence “Uniqus Consultech is an AI and global tech-enabled consulting company that specializes in Accounting & Reporting Consulting, Governance, Risk & Compliance, Sustainability &…” Source: RevenueBase Database · checked Sep 19, 2026
13	Groundwater & Environmental Services, INC	Indirect evidence	Wall Township, NJ, United StatesHQ checked Sep 19, 2026	201-500	447 contacts →
	Indirect evidence “We are Groundwater & Environmental Services, Inc, better known as GES.” Source: RevenueBase Database · checked Sep 19, 2026
14	Synergy Consulting, INC	Partial evidence	Washington, DC, United StatesHQ checked Sep 19, 2026	51-200	434 contacts →
	Partial evidence “Synergy Consulting is Global Leader in Financial and Corporate Advisory.” Source: RevenueBase Database · checked Sep 19, 2026
15	ROUX	Partial evidence	Islandia, NY, United StatesHQ checked Sep 19, 2026	201-500	433 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 Sep 19, 2026
16	TRIO	Indirect evidence	Irvine, CA, United StatesHQ checked Sep 19, 2026	201-500	383 contacts →
	Indirect evidence “We are Trio – built from Edison Energy, Alfa Energy, and Altenex Energy.” Source: RevenueBase Database · checked Sep 19, 2026
17	P2s	Indirect evidence	Long Beach, CA, United StatesHQ checked Sep 19, 2026	201-500	375 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 Sep 19, 2026
18	NUS Consulting Group	Indirect evidence	Park Ridge, NJ, United StatesHQ checked Sep 19, 2026	201-500	336 contacts →
	Indirect evidence “National Utility Service, Inc.” Source: RevenueBase Database · checked Sep 19, 2026
19	3degrees Group, INC	Partial evidence	San Francisco, CA, United StatesHQ checked Sep 19, 2026	201-500	324 contacts →
	Partial evidence “3Degrees is a leading global climate solutions provider, pioneer of environmental markets, and Certified B Corporation.” Source: RevenueBase Database · checked Sep 19, 2026
20	Environmental Consulting & Technology, Inc. ECT	Partial evidence	Gainesville, FL, United StatesHQ checked Sep 19, 2026	201-500	305 contacts →
	Partial evidence “Environmental Consulting & Technology, Inc.(ECT) is a multi-disciplinary environmental and sustainability consulting firm delivering strategy, permitting, design, and management…” Source: RevenueBase Database · checked Sep 19, 2026
21	Csrs, A Westwood Company	Indirect evidence	Baton Rouge, LA, United StatesHQ checked Sep 19, 2026	51-200	305 contacts →
	Indirect evidence “CSRS was acquired by Westwood Professional Services on June 30, 2025.” Source: RevenueBase Database · checked Sep 19, 2026
22	Cascade Energy	Indirect evidence	Portland, OR, United StatesHQ checked Sep 19, 2026	201-500	288 contacts →
	Indirect evidence “At Cascade Energy, we believe in better.” Source: RevenueBase Database · checked Sep 19, 2026
23	Climate Policy Initiative	Indirect evidence	San Francisco, CA, United StatesHQ checked Sep 19, 2026	51-200	288 contacts →
	Indirect evidence “CPI is an analysis and advisory organization with deep expertise in finance and policy.” Source: RevenueBase Database · checked Sep 19, 2026
24	Ecology And Environment, INC	Indirect evidence	Lancaster, NY, United StatesHQ checked Sep 19, 2026	5,001-10,000	278 contacts →
	Indirect evidence “E&E is now WSP USA.” Source: RevenueBase Database · checked Sep 19, 2026
25	Illumine-I	Indirect evidence	Austin, CA, United StatesHQ checked Sep 19, 2026	201-500	275 contacts →
	Indirect evidence “The world runs on power.” Source: RevenueBase Database · checked Sep 19, 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 companies. 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 companies.
Partial evidence: Its own public description names part of climate change consulting companies, 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 companies. 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 1,990 climate change consulting companies based in the United States

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

As of Sep 19, 2026

45.0%Verified-email coverage

21.3Average contacts per company

1-10Median size (employees)

5.4%Largest-city concentration · New York

Sep 19, 2026Page data refreshed

Companies by employee count

1-10

1,407

11-50

421

51-200

112

201-500

501-1,000

1,001-5,000

5,001-10,000

10001+

Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 1,990 companies.

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 companies, 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 companies”. 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 companies), 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 companies, 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, 19,059 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 19, 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 companies 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 companies, 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 companies are there based in the United States?

RevenueBase identified 1,990 climate change consulting companies headquartered in the United States 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?

Carrier, headquartered in Palm Beach Gardens, tops this list with the largest team on record.

Which city has the most climate change consulting companies?

New York leads with 108 headquartered companies, followed by Washington (72) and Houston (63).

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 19,059 verified decision-maker contacts tracked across these 1,990 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 19, 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.