Company lists · Data refreshed September 2026

Top 25 Carbon reduction consultants worldwide

Name: Carbon reduction consultants worldwide
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 19, 2026 18,368 companies tracked

RevenueBase identified 18,368 carbon reduction consultants worldwide as of September 2026 and tracks 245,798 professional contacts across them, including 87,291 with verified work emails. The United States is the largest market and London the largest hub.

This list covers carbon reduction consultants 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 19, 2026. Country and city lists for carbon reduction consultants 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 19, 2026 86% judged on-target in blind review

18,368Companies

245,798Contacts tracked

87,291Verified emails

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The 25 largest carbon reduction consultants worldwide

Ranked by team size

Top 25 of 18,368 carbon reduction consultants worldwide, ranked by team size, largest first. Data refreshed Sep 19, 2026. RevenueBase Smart Search rates how each company's information relates to carbon reduction consultants: 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	Worley	Indirect evidence	Sydney, AustraliaHQ checked Sep 19, 2026	10001+	34,763 contacts →
	Indirect evidence “Worley is a global professional services company of energy, chemicals and resources experts headquartered in Australia.” Source: RevenueBase Database · checked Sep 19, 2026
2	Engie Solutions France	Indirect evidence	La Garenne-colombes, FranceHQ checked Sep 19, 2026	10001+	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 19, 2026
3	ERM	Indirect evidence	London, United KingdomHQ checked Sep 19, 2026	5,001-10,000	9,119 contacts →
	Indirect evidence “Sustainability is our business.” Source: RevenueBase Database · checked Sep 19, 2026
4	Dalkia	Indirect evidence	Saint-andré-lez-lille, FranceHQ checked Sep 19, 2026	10001+	8,427 contacts →
	Indirect evidence “Dalkia : ensemble, relevons le défi climatique!” Source: RevenueBase Database · checked Sep 19, 2026
5	Carrier	Indirect evidence	Palm Beach Gardens, FL, United StatesHQ checked Sep 19, 2026	10001+	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, 2026
6	Roland Berger	Partial evidence	Munich, GermanyHQ checked Sep 19, 2026	1,001-5,000	4,632 contacts →
	Partial evidence “Roland Berger is the only leading global strategy consultancy of European origin.” Source: RevenueBase Database · checked Sep 19, 2026
7	SLR Consulting	Indirect evidence	London, United KingdomHQ checked Sep 19, 2026	1,001-5,000	3,848 contacts →
	Indirect evidence “SLR is a committed partner in our clients’ sustainability journeys.” Source: RevenueBase Database · checked Sep 19, 2026
8	Mckinstry	Indirect evidence	Seattle, WA, United StatesHQ checked Sep 19, 2026	1,001-5,000	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, 2026
9	Baringa	Indirect evidence	London, United KingdomHQ checked Sep 19, 2026	1,001-5,000	2,179 contacts →
	Indirect evidence “Baringa is a global consulting firm that helps leaders drive meaningful change and create value.” Source: RevenueBase Database · checked Sep 19, 2026
10	Clearesult	Indirect evidence	Austin, TX, United StatesHQ checked Sep 19, 2026	1,001-5,000	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, 2026
11	Baycurrent	Indirect evidence	港区, JapanHQ checked Sep 19, 2026	5,001-10,000	1,900 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 19, 2026
12	Ameresco	Indirect evidence	Framingham, MA, United StatesHQ checked Sep 19, 2026	1,001-5,000	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, 2026
13	OLA	Indirect evidence	Austin, TX, United StatesHQ checked Sep 19, 2026	n/a	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, 2026
14	Anthesis Group	Indirect evidence	London, United KingdomHQ checked Sep 19, 2026	1,001-5,000	894 contacts →
	Indirect evidence “Anthesis guides clients to sustainable performance.” Source: RevenueBase Database · checked Sep 19, 2026
15	Willdan	Indirect evidence	Anaheim, CA, United StatesHQ checked Sep 19, 2026	1,001-5,000	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, 2026
16	Franklin Energy	Partial evidence	Port Washington, WI, United StatesHQ checked Sep 19, 2026	1,001-5,000	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, 2026
17	South Pole	Strong evidence	Zurich, SwitzerlandHQ checked Sep 19, 2026	501-1,000	811 contacts →
	Strong evidence “South Pole is the world's leading carbon asset developer and climate consultancy.” Source: RevenueBase Database · checked Sep 19, 2026
18	Energy Solutions	Partial evidence	Oakland, CA, United StatesHQ checked Sep 19, 2026	201-500	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, 2026
19	Cleanmax	Indirect evidence	Mumbai, IndiaHQ checked Sep 19, 2026	201-500	735 contacts →
	Indirect evidence “CleanMax is India’s largest commercial and industrial (“C&I”) renewable energy provider with 3 GW of operational, owned and managed capacity.” Source: RevenueBase Database · checked Sep 19, 2026
20	Resource Innovations	Indirect evidence	Half Moon Bay, CA, United StatesHQ checked Sep 19, 2026	501-1,000	733 contacts →
	Indirect evidence “Resource Innovations (RI) is an energy transformation firm.” Source: RevenueBase Database · checked Sep 19, 2026
21	Inerco	Indirect evidence	Sevilla, SpainHQ checked Sep 19, 2026	1,001-5,000	688 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 Sep 19, 2026
22	Uniqus Consultech INC	Indirect evidence	San Jose, CA, United StatesHQ checked Sep 19, 2026	501-1,000	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, 2026
23	Ricardo PLC	Indirect evidence	London, United KingdomHQ checked Sep 19, 2026	1,001-5,000	670 contacts →
	Indirect evidence “Click the 'Follow' button and explore careers at Ricardo on our 'Jobs' and 'Life' tabs and at careers.ricardo.com.” Source: RevenueBase Database · checked Sep 19, 2026
24	KBC A Yokogawa Company	Indirect evidence	Walton-on-thames, United KingdomHQ checked Sep 19, 2026	201-500	658 contacts →
	Indirect evidence “We are passionate about driving sustainable change for our planet.” Source: RevenueBase Database · checked Sep 19, 2026
25	WTS Energy	Indirect evidence	The Hague, NetherlandsHQ checked Sep 19, 2026	1,001-5,000	651 contacts →
	Indirect evidence “The Energy Transition brings new challenges and opportunities to all of us.” 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: 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 18,368 carbon reduction consultants worldwide

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Carbon reduction consultants worldwide at a glance

As of Sep 19, 2026

35.5%Verified-email coverage

13.4Average contacts per company

1-10Median size (employees)

2.7%Largest-city concentration · London

Sep 19, 2026Page data refreshed

Companies by employee count

1-10

13,024

11-50

4,214

51-200

787

201-500

155

501-1,000

1,001-5,000

5,001-10,000

10001+

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 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.
Coverage: Every country. Country and city lists for carbon reduction consultants are linked below.
What qualifies: Companies worldwide 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.
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, 87,291 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 location

91 lists · largest first

Every Carbon reduction consultants 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 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 worldwide?

RevenueBase identified 18,368 carbon reduction consultants 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?

Worley, headquartered in Sydney, tops this list with the largest team on record.

Which country has the most carbon reduction consultants?

The United States leads with 2,158 companies, followed by the United Kingdom (1,549) and France (1,152). Every carbon reduction consultants list by country and city is linked on this page.

Which city has the most carbon reduction consultants?

London leads with 488 headquartered companies, followed by Paris (254) and Sao Paulo (229).

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 87,291 verified decision-maker contacts tracked across these 18,368 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.