Leading Experts Driving Global Sustainability and Climate Resilience
As climate change, ESG compliance, and sustainability reporting dominate the global agenda, environmental consulting firms have emerged as essential partners for organizations navigating these transitions. These firms combine scientific insight, engineering excellence, and strategic foresight to address everything from PFAS contamination to biodiversity conservation and carbon neutrality.
Here’s The Cconnects definitive list of the Top 20 Environmental Consulting Firms in 2025-recognized for innovation, expertise, and measurable environmental impact.
1. AECOM
Founded: 1990 | HQ: Dallas, Texas, USA | Founders: Originated from Ashland Technology (management buy-out)
Services: EIA & permitting, remediation & brownfields, water/wastewater, ESG & climate resilience, air quality, biodiversity, digital modelling
Overview: AECOM stands as a global infrastructure and environmental consulting powerhouse. It supports major transport, water, and energy programs with advanced environmental planning, permitting, and remediation services-leveraging digital twins and nature-based solutions to meet global sustainability demands.
Highlights:
- Global EIA/permitting leadership
- Brownfields and PFAS remediation expertise
- Nature-based climate adaptation
- Integrated watershed programs
- Digital twin and geospatial analytics
- Stakeholder engagement and ESG integration
2. WSP
Founded: 1959 (origins) | HQ: Montréal, Quebec, Canada | Founders: Williams, Sale, Partnership
Services: ESG & sustainability advisory, contaminated land, ecology & biodiversity, climate risk, water, air/noise, permitting & compliance
Overview: WSP delivers comprehensive sustainability and environmental solutions. Its expertise spans decarbonization, biodiversity net gain, and hydrogeology. Recent acquisitions have strengthened WSP’s position in the energy transition, providing holistic environmental oversight from planning through compliance.
Highlights:
- Enterprise net-zero & decarbonization roadmaps
- Biodiversity net gain & natural capital frameworks
- Hydrogeology and soil remediation
- Climate risk analysis & adaptation strategy
- Global ESG and transaction due diligence
3. Tetra Tech
Founded: 1966 | HQ: Pasadena, California, USA | Founders: Nicholas Boratynski, Henri Hodara, Bernard LeMéhauté, Don Stern
Services: Water resources, remediation, ESG & sustainability, coastal/marine, climate resilience, analytics/data
Overview: Renowned for water science and analytics, Tetra Tech leads large-scale water, remediation, and coastal projects worldwide. Its advanced environmental monitoring, PFAS treatment, and offshore wind programs demonstrate scientific rigor and innovation.
Highlights:
- Global water & coastal engineering leadership
- PFAS and emerging contaminant remediation
- Offshore wind consenting and marine ecology
- Mine closure and sediment restoration
- Environmental data platforms and dashboards
4. Jacobs
Founded: 1947 | HQ: Dallas, Texas, USA | Founder: Joseph J. Jacobs
Services: Environmental planning & permitting, remediation, water & wastewater, climate strategy, nuclear decommissioning, digital EHS
Overview: Jacobs integrates environmental and climate resilience services across infrastructure, defense, and energy programs. With expertise in complex remediation, radiological cleanup, and digital compliance, Jacobs helps governments and corporations meet sustainability goals.
Highlights:
- Environmental planning for mega-projects
- Radiological and groundwater remediation
- Climate adaptation and sustainability strategy
- Water reuse and desalination innovation
- Enterprise EHS and digital compliance
5. ERM (Environmental Resources Management)
Founded: 1987 | HQ: London, UK | Founders: Merger of UK ERL & US ERM
Services: ESG & sustainability strategy, EHS compliance, transaction advisory, renewable energy, biodiversity
Overview: ERM is the largest pure-play sustainability consultancy, supporting global clients with ESG reporting, sustainable finance, and nature-positive business transformation. Its integrated approach bridges policy, finance, and environmental performance.
Highlights:
- ESG leadership and disclosure readiness
- CSRD/ISSB reporting expertise
- EHS systems and audit-ready assurance
- Sustainable finance and due diligence
- Nature-positive and net-zero strategies
6. Arcadis
Founded: 1888 | HQ: Amsterdam, Netherlands | Founders: Nederlandsche Heidemaatschappij
Services: Environmental planning, water management, remediation, climate adaptation, natural capital, digital environment management
Overview: Arcadis blends European sustainability expertise with global delivery. It leads urban climate adaptation, contaminated land projects, and natural capital integration using digital environmental performance platforms.
Highlights:
- Urban flood and climate resilience design
- Groundwater & vapor intrusion solutions
- Natural capital and circular economy programs
- Catchment and coastal water strategies
- Digital sustainability monitoring tools
7. Stantec
Founded: 1954 | HQ: Edmonton, Alberta, Canada | Founder: Dr. Don Stanley
Services: Environmental services, water, ecology, permitting & compliance, climate resilience, sustainability
Overview: Stantec is known for its community-driven approach to environmental planning. The company excels in permitting, restoration, and ecological monitoring with deep expertise in watershed management and nature-based flood solutions.
Highlights:
- Local ecology and permitting expertise
- Watershed and floodplain resilience design
- Nature-based solutions and restoration ecology
- Climate risk assessment frameworks
- Integrated sustainability strategy
8. Ramboll
Founded: 1945 | HQ: Copenhagen, Denmark | Founders: Børge J. Rambøll, Johan G. Hannemann
Services: Environmental & health sciences, water, biodiversity, air/noise, sustainable buildings
Overview: Ramboll combines Scandinavian innovation with environmental science excellence. Its work spans EIAs, water resilience, decarbonization, and human health risk assessment. The foundation model ensures long-term sustainable research investment.
Highlights:
- Environmental health and toxicology leadership
- Cloudburst and coastal adaptation design
- Biodiversity and ecosystem integration
- Circular economy expertise
- City-scale sustainability planning
9. SLR Consulting
Founded: 1994 | HQ: London, UK | Founders: John Leeson, Alan Sheppard, David Richards
Services: ESG strategy, land quality, ecology, acoustics/air, carbon management
Overview: SLR provides senior-led sustainability advisory with deep technical delivery in contaminated land, ecology, and carbon strategy. It’s trusted by corporates and private equity firms for its pragmatic, outcome-based approach.
Highlights:
- ESG and sustainability data enablement
- Contaminated land and remediation design
- Acoustics, air quality, and odor modeling
- Ecology and biodiversity services
- Transactional ESG due diligence
10. GHD
Founded: 1928 | HQ: Sydney, Australia | Founders: Alan Gutteridge, Gerald Haskins, Geoffrey Davey
Services: Environmental science, water, waste & resources, contamination, ESG/advisory
Overview: Employee-owned GHD delivers engineering and environmental solutions focusing on water, contamination, and resource recovery. It’s a global leader in climate adaptation and sustainability for infrastructure.
Highlights:
- Integrated engineering and environmental delivery
- Water and waste management systems
- Circular economy and resource recovery design
- Climate adaptation for utilities and cities
- Strong QA/QC for regulated industries
11. HDR
Founded: 1917 | HQ: Omaha, USA | Founders: H.H. Henningson, Charles W. Durham, Willard Richardson
Services: Environmental planning, NEPA/CEQA, ecology, air/noise, resilience
Overview: HDR delivers NEPA/CEQA documentation, ecological surveys, and environmental compliance across large infrastructure programs in transportation and utilities.
Highlights:
- NEPA/CEQA coordination excellence
- Ecological impact analysis
- Air and noise modeling expertise
- Construction environmental oversight
- Urban resilience and adaptation
12. Black & Veatch
Founded: 1915 |
HQ: Overland Park, USA Founders: Ernest B. Black, Nathan T. Veatch
Services: Environmental services, water, energy transition, ESG, decarbonization
Overview: Black & Veatch integrates environmental and engineering excellence to support renewable energy, hydrogen, and advanced water treatment projects worldwide.
Highlights:
- Utility-grade permitting and compliance
- Decarbonization and hydrogen infrastructure
- Water quality and reuse leadership
- Resilience for critical assets
- Environmental monitoring solutions
13. AtkinsRéalis (formerly SNC-Lavalin)
Founded: 1911 / 1938 | HQ: Montréal, Canada | Founders: Arthur Surveyer, Sir William Atkins
Services: Environmental assessment, ecology, remediation, ESG advisory
Overview: AtkinsRéalis combines engineering heritage with ESG advisory. It specializes in EIA, biodiversity net gain, contaminated land, and digital environmental management for global infrastructure.
Highlights:
- Major-project EIA and permitting
- Ecology and biodiversity net-gain expertise
- Land contamination remediation
- Climate risk and ESG frameworks
- Digital environmental system
14. Sweco
Founded: 1997 | HQ: Stockholm, Sweden | Founders: FFNS group (Falck, Fogelvik, Nordström, Smås)
Services: Permitting, water, ecology, climate adaptation, sustainable cities
Overview: Sweco pioneers sustainable city planning with a focus on water, climate, and ecological integration. Its projects embody Scandinavian sustainability and precision engineering.
Highlights:
- Urban flood and stormwater design
- EU environmental permitting expertise
- Ecological assessment for infrastructure
- Water quality and nutrient management
- Digital modeling for urban resilience
15. DNV
Founded: 1864 | HQ: Høvik, Norway | Founders: Marine insurers consortium
Services: ESG assurance, biodiversity, lifecycle assessment, certification
Overview: DNV merges assurance heritage with sustainability expertise. It provides ESG verification, environmental risk advisory, and certification for energy, shipping, and industrial clients.
Highlights:
- ESG assurance and verification
- Biodiversity and environmental risk advisory
- Lifecycle assessment and carbon accounting
- Supply-chain sustainability auditing
- ISO 14001 certification programs
16. Bureau Veritas
Founded: 1828 | HQ: Paris, France | Founders: Maritime insurers & merchants
Services: ESG verification, sustainability audits, supply-chain environment, certification
Overview: Bureau Veritas is a global leader in testing, inspection, and certification, providing ESG reporting, circular economy evaluation, and global compliance audits.
Highlights:
- Worldwide certification coverage
- CSRD/ISSB verification readiness
- Product and lifecycle sustainability audits
- Supply-chain social/environmental checks
- Industry-specific sustainability frameworks
17. ICF
Founded: 1969 | HQ: Fairfax, USA | Founders: Clarence “Lucky” Lester & Team
Services: Climate & resilience, environmental planning, energy efficiency, policy advisory
Overview: ICF supports governments and agencies in climate action, energy efficiency, and resilience planning through data-driven public programs and environmental justice integration.
Highlights:
- Public-sector climate program management
- Energy efficiency and sustainability policy
- GHG inventories and action planning
- Stakeholder engagement and outreach
- Funding strategy and grant compliance
18. TRC Companies
Founded: 1969 | HQ: Windsor, USA | Founders: Travelers Research Corporation origins
Services: Compliance & auditing, remediation, air quality, ESG monitoring, renewables siting
Overview: TRC delivers environmental, remediation, and compliance services for utilities and industry. Its digital monitoring and EHS programs connect ESG reporting with real-world performance.
Highlights:
- Industrial EHS and compliance services
- Air quality modeling and permitting
- Remediation and O&M solutions
- Renewable energy siting and permitting
- ESG dashboards and analytics
19. RPS Group (a Tetra Tech Company)
Founded: 1970 | HQ: Abingdon, UK | Founder: Michael Boddington
Services: Offshore wind, marine ecology, water, planning, climate resilience
Overview: RPS specializes in offshore wind and marine environmental services. Its regulatory relationships streamline project approvals across multiple geographies.
Highlights:
- Offshore wind environmental consenting
- Marine survey and ecological assessments
- Flood and coastal modeling
- Multinational regulatory experience
- Stakeholder management excellence
20. RSK Group
Founded: 1989 | HQ: Helsby, UK | Founder: Alan Ryder
Services: Ecology & biodiversity, site investigation, geoscience, sustainability, ESG
Overview: RSK is a private consortium of environmental consultancies offering ecology, site investigation, water, and ESG advisory services. Its multi-disciplinary model integrates technical depth with project delivery agility.
Highlights:
- Specialist ecology and biodiversity network
- Site investigation and geotechnical services
- Flood risk and drainage planning
- ESG advisory and sustainability strategy
- Integrated multi-disciplinary collaboration
Conclusion
The environmental consulting industry is the backbone of global sustainability transformation. These 20 firms are more than service providers-they are innovation partners shaping a cleaner, climate-resilient future. From renewable infrastructure and ESG assurance to biodiversity preservation and digital sustainability tools, their expertise drives tangible progress toward global environmental goals.
For enterprises aiming to balance profitability with planetary responsibility, partnering with one of these leaders could be the most strategic investment of 2025.
