17 Feb 2023, 11:29

The big players of net zero climate consulting

The corporate drive towards net zero has triggered a climate advisory bonanza at management consultancy firms. The advisory services are investing massively to expand into this rapidly growing business area, both by retraining or hiring new staff, and by buying up smaller rivals. This factsheet provides an overview of the sector’s big players, recent merger activities, and the questions they are addressing while advising companies on decarbonisation.

*** Please note: This factsheet complements the analysis Consultancies cash in on climate advice as firms race towards net zero. Both are part of the CLEW focus on company climate claims
This dossier lists our existing publications and future content plans, and our upcoming events are here.
This blog explains why we decided to launch the project.***

Business consultancies are often overlooked as a player in the global race towards decarbonisation, but their impact is immense. With many thousands of employees dedicated to helping companies adjust to a net zero future, they are shaping countless business decisions that determine future corporate emissions.

For example, top consultancy EY says it is helping its clients to answer the following questions:

  • How do we decarbonise our business?
  • How can our strategy generate financial and stakeholder value?
  • How can we be compliant and manage risk at fair cost?
  • How can we use technology and data to enable our sustainability agenda?
  • How do we reorganise our sustainable products and supply chain?
  • How do we finance the transformation?
Detail of an EY publication. Image by EY
Detail of an EY publication. Image by EY

Top sustainability consultants

[Ranking Source: Sustainability Mag]

1 - EY

EY says it has delivered sustainability solutions to more than 3,000 clients, including technology-based solutions through alliances with companies like IBM, Microsoft and SAP. It has about 6,000 staff working in the area globally, of which up to 2,000 are in Europe. It is also offering all of its more than 300,000 staff the chance to earn a MA degree in sustainability in collaboration with Hult International Business School.

EY has developed a methodology to provide assurance on nonfinancial reporting and it has also issued new guidance on the audit of financial reporting to help EY audit teams consider the effects of climate-related risks on financial statements.

EY’s global Climate Change and Sustainability Services (CCaSS) teams help companies to understand the broader value impacts and outcomes, identifying the opportunities, and support the reporting of nonfinancial performance risks to their stakeholders.

2 - McKinsey & Company

McKinsey says it aspires to be the preeminent impact partner and advisor on sustainability, climate, energy transition, and environmental, social, and governance (ESG)—from the board room to the engine room. It says it is “working with clients to lead a wave of innovation and economic growth that safeguards our planet and advances sustainability”.

It has worked on more than 1,700 sustainability and climate projects in the past three years, serving more than 600 clients across about 70 countries. It employs more than 1,000 experts in this field.

McKinsey says it wants to be a leading catalyst for global decarbonization. “We’re working to help all industry sectors transform to reach net zero by 2050, balanced with other sustainability goals and tailored to regional contexts. We do this by leveraging our thought leadership, innovative tools and solutions, top talent, and a vibrant ecosystem of industry associations and knowledge platforms focused on innovating to net zero.”

3 - Boston Consulting Group (BCG)

BCG saw revenues jump 25 percent to $11 billion in 2021, with almost 10 percent of that coming from climate consulting. BCG CEO Christoph Schweizer predicts this will account for as much of a third of its sales by 2027. It said it would recruit 8,000 new staff members in 2022, including significant numbers of climate and sustainability and AI experts.

Schweizer told the Financial Times the firm had tightened its policies on working for companies in high-emitting industries, and declined hundreds of millions of dollars in potential fees over the last year as a result.

BCG, which employs about 25,000 people in more than 50 countries, launched a beefed-up Center for Climate and Sustainability in 2021 to brings together more than 550 experts covering sustainability topics ranging from biodiversity to circular economy, climate innovation, decarbonization, sustainable agriculture, transition financing and water management.

In 2020, BCG announced plans to spend $400 million on its 2030 climate positive goals, including ensuring flights taken by BCG employees in the Nordics on SAS and Finnair flights would be powered by sustainable aviation fuel.

4 - KPMG

KPMG said in 2021 it plans to spend more than $1.5 billion over the next three years to focus on ESG. It said the investment will focus on training and expanding KPMG’s global workforce, harnessing data, accelerating the development of new technologies, and driving action through partnerships, alliances and advocacy. It set up regional ESG Hubs in Europe, Asia Pacific and the Americas to support clients and said it would offer ESG training to all 227,000 staff in collaboration with University of Cambridge Judge Business School and NYU Stern Executive Education.

5 - Deloitte

Deloitte announced in April it will invest $1 billion into its sustainability & climate practice, to support clients as they redefine their strategies, embed sustainability into their operations, meet tax, disclosure, and regulatory requirements, and help them accelerate transformation of their organizations and value chains. It also launched the new Deloitte Center for Sustainable Progress (DCSP) to work with leading academic, policy, business, and governments. The company said it would offer sustainability training courses to all 345,000 staff along with its clients and suppliers.

Recent mergers and Acquisitions in climate consulting


The firm has recently acquired sustainability consultancies, such as Avieco and Greenfish.


The firm bought more than 14 different firms from 2019-2021 ‒ including earth sciences and environmental consulting firm Golder.


The firm announced in 2021 it has bought Material Economics, a leading sustainability consultancy firm. Based in Stockholm, Sweden, this group of 30+ experts specializes in helping clients develop sustainability strategies with a focus on “circularity,” detailed and data-driven approaches for sustainable materials systems in companies and across industries that optimize the use and reuse of products and materials.


EY Canada said in September it will add AFARA and its team of multidisciplinary consultants to the firm to deepen existing resources and expertise in sustainability, and environment, social and governance (ESG) services.


The firm announced a deal in September to acquire Quantis, an environmental sustainability consultancy guiding many of the world’s largest organizations. Quantis was founded in 2006 and has since grown to more than 250 environmental experts and transformation specialists primarily based in Europe and the US.

All texts created by the Clean Energy Wire are available under a “Creative Commons Attribution 4.0 International Licence (CC BY 4.0)” . They can be copied, shared and made publicly accessible by users so long as they give appropriate credit, provide a link to the license, and indicate if changes were made.


Sven Egenter

Researching a story? Drop CLEW a line or give us a call for background material and contacts.


+49 30 62858 497

Journalism for the energy transition

Get our Newsletter
Join our Network
Find an interviewee