Company lists · Data refreshed September 2026

Top 25 Net zero consulting firms worldwide

RevenueBase identified 4,887 net zero consulting firms worldwide as of September 2026 and tracks 80,850 professional contacts across them, including 31,406 with verified work emails and 9,542 with mobile numbers. The United Kingdom is the largest market and London the largest hub.

This list covers net zero 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 5, 2026. Country and city lists for net zero 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 5, 2026 86% judged on-target in blind review
4,887Companies
80,850Contacts tracked
31,406Verified emails
9,542Mobile numbers
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The 25 largest net zero consulting firms worldwide

Ranked by team size
Top 25 of 4,887 net zero consulting firms worldwide, ranked by team size, largest first. Data refreshed Sep 5, 2026. RevenueBase Smart Search rates how each company's information relates to net zero 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 evidenceLa Garenne-colombes, FranceHQ checked Sep 5, 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 5, 2026
2Indirect evidenceLondon, United KingdomHQ checked Sep 5, 20265,001-10,0009,119 contacts →

Indirect evidence

“Sustainability is our business.”

Source: RevenueBase Database · checked Sep 5, 2026
3Indirect evidenceLondon, United KingdomHQ checked Sep 5, 20261,001-5,0003,848 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 5, 2026
4Indirect evidenceSeattle, WA, United StatesHQ checked Sep 5, 20261,001-5,0002,213 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 5, 2026
5Partial evidenceAustin, TX, United StatesHQ checked Sep 5, 2026n/a1,145 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 5, 2026
6Indirect evidenceLondon, United KingdomHQ checked Sep 5, 20261,001-5,000894 contacts →

Indirect evidence

“Anthesis guides clients to sustainable performance.”

Source: RevenueBase Database · checked Sep 5, 2026
7Indirect evidencePort Washington, WI, United StatesHQ checked Sep 5, 20261,001-5,000838 contacts →

Indirect 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 5, 2026
8Indirect evidenceZurich, SwitzerlandHQ checked Sep 5, 2026501-1,000811 contacts →

Indirect evidence

“South Pole is the world's leading carbon asset developer and climate consultancy.”

Source: RevenueBase Database · checked Sep 5, 2026
9Indirect evidenceOakland, CA, United StatesHQ checked Sep 5, 2026201-500772 contacts →

Indirect 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 5, 2026
10Indirect evidenceWalton-on-thames, United KingdomHQ checked Sep 5, 2026201-500658 contacts →

Indirect evidence

“We are passionate about driving sustainable change for our planet.”

Source: RevenueBase Database · checked Sep 5, 2026
11Indirect evidenceLondon, United KingdomHQ checked Sep 5, 2026n/a621 contacts →

Indirect evidence

“For over 26 years, our consultants have been supporting and guiding our clients to achieve low-carbon climate-resilient development.”

Source: RevenueBase Database · checked Sep 5, 2026
12Indirect evidenceAmsterdam, NetherlandsHQ checked Sep 5, 2026501-1,000556 contacts →

Indirect evidence

“As the leading environmental solutions partner for organizations globally, ACT helps its partners meet increasing environmental action and disclosure expectations from regulators…”

Source: RevenueBase Database · checked Sep 5, 2026
13Indirect evidenceParis, FranceHQ checked Sep 5, 2026501-1,000390 contacts →

Indirect evidence

“Since 2009, GreenFlex has been a key partner in the energy, environmental and societal transformation of organizations, enabling them to change their trajectory towards an economy…”

Source: RevenueBase Database · checked Sep 5, 2026
14Indirect evidenceIrvine, CA, United StatesHQ checked Sep 5, 2026201-500383 contacts →

Indirect evidence

“We are Trio – built from Edison Energy, Alfa Energy, and Altenex Energy.”

Source: RevenueBase Database · checked Sep 5, 2026
15Indirect evidenceLondon, United KingdomHQ checked Sep 5, 2026201-500379 contacts →

Indirect evidence

“Our mission is to accelerate the move to a decarbonised future.”

Source: RevenueBase Database · checked Sep 5, 2026
16Indirect evidenceMünchen, GermanyHQ checked Sep 5, 2026501-1,000376 contacts →

Indirect evidence

“ClimatePartner makes climate action valuable for every company at any stage of their journey.”

Source: RevenueBase Database · checked Sep 5, 2026
17Strong evidenceKirkham, United KingdomHQ checked Sep 5, 2026501-1,000373 contacts →

Strong evidence

“Inspired PLC is a leading technology-enabled provider of energy and sustainability solutions that allow UK and Irish businesses to transition to net-zero carbon and manage their…”

Source: RevenueBase Database · checked Sep 5, 2026
18Indirect evidenceLondon, United Arab EmiratesHQ checked Sep 5, 2026201-500373 contacts →

Indirect evidence

“AESG is an international Consultancy, Engineering and Advisory firm committed to driving sustainability in the built environment and beyond.”

Source: RevenueBase Database · checked Sep 5, 2026
19Indirect evidenceSt Leonards, AustraliaHQ checked Sep 5, 2026201-500361 contacts →

Indirect evidence

“At EMM, we believe that a sustainable future is achievable, and we are dedicated to helping our clients and the community make it a reality.”

Source: RevenueBase Database · checked Sep 5, 2026
20Indirect evidencePark Ridge, NJ, United StatesHQ checked Sep 5, 2026201-500336 contacts →

Indirect evidence

“National Utility Service, Inc.”

Source: RevenueBase Database · checked Sep 5, 2026
21Partial evidenceLausanne, SwitzerlandHQ checked Sep 5, 2026201-500325 contacts →

Partial evidence

“Quantis, part of BCG, is a sustainability consulting firm that helps organizations translate sustainability ambition into measurable business value.”

Source: RevenueBase Database · checked Sep 5, 2026
22Indirect evidenceSan Francisco, CA, United StatesHQ checked Sep 5, 2026201-500324 contacts →

Indirect evidence

“3Degrees is a leading global climate solutions provider, pioneer of environmental markets, and Certified B Corporation.”

Source: RevenueBase Database · checked Sep 5, 2026
23Indirect evidenceBirmingham, United KingdomHQ checked Sep 5, 2026201-500317 contacts →

Indirect evidence

“Climate change is without a doubt the greatest challenge we face in these times.”

Source: RevenueBase Database · checked Sep 5, 2026
24Indirect evidenceRedditch, United KingdomHQ checked Sep 5, 202651-200316 contacts →

Indirect evidence

“EIC Partnership: A Legacy of Expertise, A Commitment to Sustainability With origins dating back to 1975, EIC has cultivated nearly 50 years of distinguished service in energy and…”

Source: RevenueBase Database · checked Sep 5, 2026
25Indirect evidencePortland, OR, United StatesHQ checked Sep 5, 2026201-500288 contacts →

Indirect evidence

“At Cascade Energy, we believe in better.”

Source: RevenueBase Database · checked Sep 5, 2026

Showing 25 of 4,887 net zero consulting firms worldwide

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Net zero consulting firms worldwide at a glance

As of Sep 5, 2026
38.8%Verified-email coverage
11.8%Mobile-number coverage
16.5Average contacts per company
1-10Median size (employees)
5.2%Largest-city concentration · London
Sep 5, 2026Page data refreshed

Companies by employee count

1-10
3,517
11-50
1,056
51-200
229
201-500
34
501-1,000
15
1,001-5,000
15
5,001-10,000
4
10001+
5

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 net zero 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
30 countries, largest first: the United Kingdom, the United States, France, Germany, India, Brazil, Canada, Spain, Australia, the Netherlands and 20 more. Country and city lists for net zero consulting firms are linked below.
What qualifies
Companies worldwide whose own description of what they do matches “net zero 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 net zero 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 net zero 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, 31,406 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 between September 5, 2026 and September 14, 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.

Net zero consulting firms by location

45 lists · largest first

Every Net zero 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 net zero 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 net zero consulting firms are there worldwide?

RevenueBase identified 4,887 net zero 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?

Engie Solutions France, headquartered in La Garenne-Colombes, tops this list with the largest team on record.

Which country has the most net zero consulting firms?

The United Kingdom leads with 792 companies, followed by the United States (747) and France (487). Every net zero consulting firms list by country and city is linked on this page.

Which city has the most net zero consulting firms?

London leads with 255 headquartered companies, followed by Paris (118) and Sao Paulo (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 31,406 verified decision-maker contacts tracked across these 4,887 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled from the company graph between September 5, 2026 and September 14, 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.