This updated version adds stronger authority signals for every organization on the list. Each entry now links to a Charity Navigator profile and notes the latest Form 990 revenue found, so readers can better understand both mission fit and institutional scale.
The broader environmental trusted list is already one of the top-performing pages in the cluster. A more focused page around climate change and conservation gives the content a clearer search target and creates a natural bridge between policy-focused climate groups and land-and-wildlife conservation organizations.
Not every organization on this list works equally in both climate and conservation. That is fine, but it should be explicit for readers. Some are more policy and legal advocacy driven, while others are more field, land, or ocean focused.
What We Looked For
- Strong public reputation and visible long-term work
- Meaningful role in climate policy, conservation, habitat protection, science-driven advocacy, or environmental mobilization
- Clear evidence of practical impact, not just awareness branding
- National or international relevance with US donor familiarity
- Current authority signals including Charity Navigator and most recent Form 990 size
Top Trusted Nonprofits
The Nature Conservancy
The Nature Conservancy is one of the world’s largest conservation nonprofits, with 2024 Form 990 revenue of $1.48 billion and extensive land, water, and climate work.
- Founded: 1951
- Operating history: about 75 years
- Latest reported size: $1,482,731,301 in revenue on the most recent Form 990 we found (2024)
- Charity Navigator: Four-Star Charity
- Sources: Source 1, Source 2, Source 3
Environmental Defense Fund
Environmental Defense Fund is a major science-and-policy climate organization with 2024 Form 990 revenue around $299 million.
- Founded: 1967
- Operating history: about 59 years
- Latest reported size: $299,000,000 in revenue on the most recent Form 990 we found (2024)
- Charity Navigator: Charity Navigator profile available
- Sources: Source 1, Source 2, Source 3
Natural Resources Defense Council
NRDC is a major environmental law and policy nonprofit with June 2024 Form 990 revenue of $204.3 million.
- Founded: 1970
- Operating history: about 56 years
- Latest reported size: $204,253,182 in revenue on the most recent Form 990 we found (2024)
- Charity Navigator: Charity Navigator profile available
- Sources: Source 1, Source 2, Source 3
World Resources Institute
World Resources Institute is a research-forward climate and sustainability policy nonprofit with September 2024 Form 990 revenue of $267.4 million.
- Founded: 1982
- Operating history: about 44 years
- Latest reported size: $267,358,799 in revenue on the most recent Form 990 we found (2024)
- Charity Navigator: Charity Navigator profile available
- Sources: Source 1, Source 2, Source 3
Conservation International
Conservation International links biodiversity protection and climate resilience globally and reported June 2024 Form 990 revenue of $271.2 million.
- Founded: 1987
- Operating history: about 39 years
- Latest reported size: $271,220,924 in revenue on the most recent Form 990 we found (2024)
- Charity Navigator: Charity Navigator profile available
- Sources: Source 1, Source 2, Source 3
Rainforest Trust
Rainforest Trust is a land-protection conservation nonprofit focused on threatened tropical habitats, with June 2024 Form 990 revenue of $18.5 million.
- Founded: 1988
- Operating history: about 38 years
- Latest reported size: $18,502,312 in revenue on the most recent Form 990 we found (2024)
- Charity Navigator: Charity Navigator profile available
- Sources: Source 1, Source 2, Source 3
Union of Concerned Scientists
Union of Concerned Scientists is a science-based advocacy and policy nonprofit with 2024 Form 990 revenue around $41.9 million.
- Founded: 1969
- Operating history: about 57 years
- Latest reported size: $41,900,000 in revenue on the most recent Form 990 we found (2024)
- Charity Navigator: Charity Navigator profile available
- Sources: Source 1, Source 2, Source 3
Ocean Conservancy
Ocean Conservancy is a science, policy, and public-mobilization ocean protection nonprofit with Form 990 revenue of $49.7 million in the latest ProPublica extract found.
- Founded: 1972
- Operating history: about 54 years
- Latest reported size: $49,652,396 in revenue on the most recent Form 990 we found (2022)
- Charity Navigator: 91% Four-Star Charity
- Sources: Source 1, Source 2, Source 3
Why This Topic Looks Promising
The environmental category is already producing one of the strongest pages in the whole trusted cluster. Tightening the framing around climate change and conservation should improve keyword specificity while staying close to a proven winner.
Suggested Follow-On Content
- Top trusted ocean conservation nonprofits
- Best climate nonprofits to donate to in 2026
- Trusted wildlife conservation charities in the US
- How to evaluate an environmental nonprofit before donating
Editor’s note: Editor’s note: verify current ratings, campaign focus, legal structure, and whether each group still fits the exact climate-plus-conservation framing before the next refresh.