Company lists · Data refreshed September 2026
Top 25 Carbon reduction consultants based in the United States
RevenueBase identified 2,158 carbon reduction consultants headquartered in the United States as of September 2026 and tracks 42,059 professional contacts across them, including 18,827 with verified work emails. New York is the largest hub.
This list covers carbon reduction consultants 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.
The 25 largest carbon reduction consultants based in the United States
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 7,665 contacts → | ||||
Indirect evidence “Carrier is a global leader in intelligent climate and energy solutions, pioneering sustainable innovations in climate technologies.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 2 | 2,213 contacts → | ||||
Indirect evidence “We're a national construction and energy services company dedicated to innovating the waste and climate harm out of the built environment.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 3 | 2,121 contacts → | ||||
Indirect evidence “CLEAResult is the largest provider of energy efficiency, energy transition and energy sustainability services in North America.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 4 | 1,383 contacts → | ||||
Indirect evidence “Ameresco, Inc.(NYSE:AMRC) is a leading energy infrastructure solutions provider dedicated to helping customers reduce costs, enhance resilience, and decarbonize to net zero in the…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 5 | 1,145 contacts → | ||||
Indirect 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, 2026Thanks. The Data Team will review it. | |||||
| 6 | 851 contacts → | ||||
Indirect evidence “Willdan (NASDAQ: WLDN) provides professional consulting and technical services to utilities, public agencies and private industry throughout the United States.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 7 | 838 contacts → | ||||
Partial evidence “Franklin Energy delivers end-to-end sustainability solutions through a portfolio of intelligent products and services that lower energy costs, reduce carbon and waste, and grow…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 8 | 772 contacts → | ||||
Partial evidence “Our mission is simple - to combat climate change through market-based, cost-effective energy, carbon, and water management solutions that make big impacts.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 9 | 733 contacts → | ||||
Indirect evidence “Resource Innovations (RI) is an energy transformation firm.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 10 | 675 contacts → | ||||
Indirect 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, 2026Thanks. The Data Team will review it. | |||||
| 11 | 529 contacts → | ||||
Indirect evidence “Watershed is the enterprise sustainability platform.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 12 | 383 contacts → | ||||
Indirect evidence “Veregy is an award-winning NAESCO-Accredited decarbonization company focusing on accelerating and simplifying the Energy Transition.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 13 | 383 contacts → | ||||
Indirect evidence “We are Trio – built from Edison Energy, Alfa Energy, and Altenex Energy.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 14 | 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, 2026Thanks. The Data Team will review it. | |||||
| 15 | 336 contacts → | ||||
Indirect evidence “National Utility Service, Inc.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 16 | 324 contacts → | ||||
Indirect evidence “3Degrees is a leading global climate solutions provider, pioneer of environmental markets, and Certified B Corporation.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 17 | 305 contacts → | ||||
Indirect 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, 2026Thanks. The Data Team will review it. | |||||
| 18 | 288 contacts → | ||||
Indirect evidence “At Cascade Energy, we believe in better.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 19 | 281 contacts → | ||||
Indirect evidence “We act as an extension of your team, combining deep energy expertise with seamless alignment to your processes to advance projects with confidence.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 20 | 278 contacts → | ||||
Indirect evidence “E&E is now WSP USA.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 21 | 275 contacts → | ||||
Indirect evidence “The world runs on power.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 22 | 254 contacts → | ||||
Indirect evidence “We provide global renewable energy consulting services, focused on empowering clients to navigate the complexities of the energy transition.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 23 | 233 contacts → | ||||
Indirect evidence “At Mantis Innovation, our experts provide data-driven, consultative services designed to optimize your facility, sustainability, and energy management strategies, while ultimately…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 24 | 214 contacts → | ||||
Indirect evidence “PEG presents a comprehensive capacity for the evaluation and understanding of a broad base of energy and environmental sustainability related programs, policies and initiatives.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 25 | 210 contacts → | ||||
Indirect evidence “Dalkia Energy Solutions, a subsidiary of the EDF (Électricité de France) Group, is a national leader in energy efficiency and sustainability for commercial, industrial, and…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
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: carbon reduction consultants. 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 carbon reduction consultants.
- Partial evidence
- Its own public description names part of carbon reduction consultants, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name carbon reduction consultants. 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 2,158 carbon reduction consultants based in the United States
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Carbon reduction consultants based in the United States at a glance
As of Sep 19, 2026Companies by employee count
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 2,158 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 carbon reduction consultants, 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 “carbon reduction consultants”. 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 carbon reduction consultants), 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 carbon reduction consultants, 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, 18,827 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.
Carbon reduction consultants by metro
- Carbon reduction consultants in New York124
- Carbon reduction consultants in Houston91
- Carbon reduction consultants in Chicago58
- Carbon reduction consultants in Washington56
- Carbon reduction consultants in San Francisco46
- Carbon reduction consultants in Denver40
- Carbon reduction consultants in Los Angeles38
- Carbon reduction consultants in Atlanta35
- Carbon reduction consultants in Seattle35
- Carbon reduction consultants in Portland31
- Carbon reduction consultants in Dallas27
- Carbon reduction consultants in Austin26
- Carbon reduction consultants in Boston26
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 carbon reduction consultants, 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 carbon reduction consultants are there based in the United States?
RevenueBase identified 2,158 carbon reduction consultants 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 carbon reduction consultants?
New York leads with 124 headquartered companies, followed by Houston (91) and Chicago (58).
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 18,827 verified decision-maker contacts tracked across these 2,158 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.
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