Company lists · Data refreshed September 2026

Top 25 Environmental research and advocacy organizations worldwide

Name: Environmental research and advocacy organizations worldwide
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 19, 2026 8,958 companies tracked

RevenueBase identified 8,958 environmental research and advocacy organizations worldwide as of September 2026 and tracks 115,485 professional contacts across them, including 33,691 with verified work emails. The United States is the largest market and Washington the largest hub.

This list covers environmental research and advocacy organizations 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 environmental research and advocacy organizations 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

8,958Companies

115,485Contacts tracked

33,691Verified emails

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The 25 largest environmental research and advocacy organizations worldwide

Ranked by team size

Top 25 of 8,958 environmental research and advocacy organizations worldwide, ranked by team size, largest first. Data refreshed Sep 19, 2026. RevenueBase Smart Search rates how each company's information relates to environmental research and advocacy organizations: 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	The Nature Conservancy	Indirect evidence	Arlington, VA, United StatesHQ checked Sep 19, 2026	5,001-10,000	6,526 contacts →
	Indirect evidence “Air, water, food, shelter, income: nature sustains every aspect of our lives.” Source: RevenueBase Database · checked Sep 19, 2026
2	Greenpeace	Indirect evidence	Amsterdam, NetherlandsHQ checked Sep 19, 2026	n/a	2,945 contacts →
	Indirect evidence “Greenpeace is comprised of 25 independent national/regional organisations in over 55 countries across Europe, the Americas, Africa, Asia and the Pacific, as well as a…” Source: RevenueBase Database · checked Sep 19, 2026
3	IUCN	Partial evidence	Gland, SwitzerlandHQ checked Sep 19, 2026	501-1,000	1,965 contacts →
	Partial evidence “IUCN, the International Union for Conservation of Nature, helps the world find pragmatic solutions to our most pressing environment and development challenges.” Source: RevenueBase Database · checked Sep 19, 2026
4	Conservation International	Indirect evidence	Arlington, VA, United StatesHQ checked Sep 19, 2026	501-1,000	1,560 contacts →
	Indirect evidence “Since 1987, Conservation International has worked to spotlight and secure the critical benefits that nature provides to humanity.” Source: RevenueBase Database · checked Sep 19, 2026
5	World Resources Institute	Indirect evidence	Washington, DC, United StatesHQ checked Sep 19, 2026	1,001-5,000	1,359 contacts →
	Indirect evidence “WRI works to improve people’s lives, protect and restore nature and stabilize the climate.” Source: RevenueBase Database · checked Sep 19, 2026
6	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
7	Sierra Club	Indirect evidence	Oakland, CA, United StatesHQ checked Sep 19, 2026	501-1,000	1,069 contacts →
	Indirect evidence “At the Sierra Club, we believe in the power of togetherness.” Source: RevenueBase Database · checked Sep 19, 2026
8	Natural Resources Defense Council Nrdc	Partial evidence	New York, NY, United StatesHQ checked Sep 19, 2026	501-1,000	942 contacts →
	Partial evidence “NRDC is the nation's most effective environmental action organization.” Source: RevenueBase Database · checked Sep 19, 2026
9	ISPRA	Indirect evidence	Rome, ItalyHQ checked Sep 19, 2026	1,001-5,000	811 contacts →
	Indirect evidence “ISPRA è l'Istituto Superiore per la Protezione e la Ricerca Ambientale, ente pubblico di ricerca italiano dedicato alla protezione dell'ambiente.” Source: RevenueBase Database · checked Sep 19, 2026
10	Helmholtz Centre For Environmental Research UFZ	Strong evidence	Leipzig, GermanyHQ checked Sep 19, 2026	1,001-5,000	762 contacts →
	Strong evidence “The Helmholtz Centre for Environmental Research - UFZ was established in 1991 and has more than 1,100 employees in Leipzig, Halle/S.” Source: RevenueBase Database · checked Sep 19, 2026
11	Oxfam Novib	Indirect evidence	The Hague, NetherlandsHQ checked Sep 19, 2026	201-500	708 contacts →
	Indirect evidence “Wij strijden voor gelijkheid en we staan achter de mensen die opstaan voor gelijkheid.” Source: RevenueBase Database · checked Sep 19, 2026
12	Earthjustice	Indirect evidence	San Francisco, United StatesHQ checked Sep 19, 2026	501-1,000	672 contacts →
	Indirect evidence “Earthjustice is a non-profit public interest law organization dedicated to protecting the magnificent places, natural resources, and wildlife of this earth, and to defending the…” Source: RevenueBase Database · checked Sep 19, 2026
13	Centre For Alternative Technology	Indirect evidence	Machynlleth, United KingdomHQ checked Sep 19, 2026	n/a	618 contacts →
	Indirect evidence “Mae Canolfan y Dechnoleg Amgen yn elusen addysg amgylcheddol sydd wedi bod yn rhannu atebion i faterion amgylcheddol ac ymchwilio iddyn nhw ers dros 50 mlynedd – gan weithio tuag…” Source: RevenueBase Database · checked Sep 19, 2026
14	PETA	Indirect evidence	Norfolk, VA, United StatesHQ checked Sep 19, 2026	201-500	592 contacts →
	Indirect evidence “People for the Ethical Treatment of Animals (PETA) entities have more than 10.4 million members and supporters globally, and PETA U.S.” Source: RevenueBase Database · checked Sep 19, 2026
15	Mass Audubon	Indirect evidence	Lincoln, MA, United StatesHQ checked Sep 19, 2026	201-500	554 contacts →
	Indirect evidence “Mass Audubon is the largest nature-based conservation organization in New England.” Source: RevenueBase Database · checked Sep 19, 2026
16	Biotope	Indirect evidence	Mèze, FranceHQ checked Sep 19, 2026	201-500	517 contacts →
	Indirect evidence “Fondée en 1993 par des passionnés de nature engagés, Biotope s’est imposée au fil des années comme précurseur et leader mondial de l’ingénierie environnementale et de la…” Source: RevenueBase Database · checked Sep 19, 2026
17	IVL Swedish Environmental Research Institute	Strong evidence	Stockholm, SwedenHQ checked Sep 19, 2026	201-500	492 contacts →
	Strong evidence “IVL Swedish Environmental Research Institute is an independent, non-profit research organisation owned by a foundation established by the Swedish government and industry.” Source: RevenueBase Database · checked Sep 19, 2026
18	SEI Stockholm Environment Institute	Strong evidence	Stockholm, SwedenHQ checked Sep 19, 2026	201-500	462 contacts →
	Strong evidence “Stockholm Environment Institute – bridging science, policy and practice We are an international non-profit research institute that tackles climate, environment and sustainable…” Source: RevenueBase Database · checked Sep 19, 2026
19	Foundation For Ecological Security FES	Indirect evidence	Anand, IndiaHQ checked Sep 19, 2026	201-500	461 contacts →
	Indirect evidence “We work towards the ecological restoration and conservation of land and water resources, in conserving the uplands and other eco-fragile, degraded and marginalised zones of the…” Source: RevenueBase Database · checked Sep 19, 2026
20	Council On Energy, Environment And Water Ceew	Partial evidence	New Delhi, IndiaHQ checked Sep 19, 2026	201-500	435 contacts →
	Partial evidence “The Council on Energy, Environment and Water (CEEW), a homegrown institution with headquarters in New Delhi, is among the world’s leading climate think tanks.” Source: RevenueBase Database · checked Sep 19, 2026
21	Western Ecosystems Technology, Inc. West	Strong evidence	Cheyenne, WY, United StatesHQ checked Sep 19, 2026	201-500	408 contacts →
	Strong evidence “WEST provides environmental and statistical consulting services and contract research nationally and internationally to industry, government, and private organizations.” Source: RevenueBase Database · checked Sep 19, 2026
22	Oceana	Partial evidence	United StatesHQ checked Sep 19, 2026	201-500	398 contacts →
	Partial evidence “Oceana is the largest international advocacy organization dedicated solely to ocean conservation.” Source: RevenueBase Database · checked Sep 19, 2026
23	National Environmental Engineering Research Institute Neeri	Strong evidence	Nagpur, IndiaHQ checked Sep 19, 2026	201-500	369 contacts →
	Strong evidence “National Environmental Engineering Research Institute (NEERI), a constituent laboratory of CSIR endeavours to provide Leadership in environmental science and engineering for…” Source: RevenueBase Database · checked Sep 19, 2026
24	RARE	Indirect evidence	Arlington, VA, United StatesHQ checked Sep 19, 2026	51-200	368 contacts →
	Indirect evidence “Rare is a global leader in driving social change for people and nature.” Source: RevenueBase Database · checked Sep 19, 2026
25	Clean Water Action	Partial evidence	Washington, DC, United StatesHQ checked Sep 19, 2026	51-200	366 contacts →
	Partial evidence “Since our founding during the campaign to pass the landmark Clean Water Act in 1972, Clean Water Action has worked to win strong health and environmental protections by bringing…” 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: environmental research and advocacy organizations. 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 environmental research and advocacy organizations.
Partial evidence: Its own public description names part of environmental research and advocacy organizations, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name environmental research and advocacy organizations. 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 8,958 environmental research and advocacy organizations worldwide

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Environmental research and advocacy organizations worldwide at a glance

As of Sep 19, 2026

29.2%Verified-email coverage

12.9Average contacts per company

1-10Median size (employees)

1.3%Largest-city concentration · Washington

Sep 19, 2026Page data refreshed

Companies by employee count

1-10

5,521

11-50

2,487

51-200

631

201-500

169

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 environmental research and advocacy organizations, 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 environmental research and advocacy organizations are linked below.
What qualifies: Companies worldwide whose own description of what they do matches “environmental research and advocacy organizations”. 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 environmental research and advocacy organizations), 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 environmental research and advocacy organizations, 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, 33,691 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.

Environmental research and advocacy organizations by location

40 lists · largest first

Every Environmental research and advocacy organizations 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 environmental research and advocacy organizations, 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 environmental research and advocacy organizations are there worldwide?

RevenueBase identified 8,958 environmental research and advocacy organizations 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?

The Nature Conservancy, headquartered in Arlington, tops this list with the largest team on record.

Which country has the most environmental research and advocacy organizations?

The United States leads with 1,865 companies, followed by India (629) and France (469). Every environmental research and advocacy organizations list by country and city is linked on this page.

Which city has the most environmental research and advocacy organizations?

Washington leads with 118 headquartered companies, followed by London (100) and Paris (95).

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 33,691 verified decision-maker contacts tracked across these 8,958 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.