The Climatographers Team

What Makes Us Unique

In 30 years of climate change advisory work with companies around the world, we’ve repeatedly seen the difficulties corporate decision-makers face in balancing the growing societal concerns over climate change on the one hand, and the challenges of business risk and opportunity assessment on the other. That balancing act has become more complicated as our collective understanding of climate change has increased and as the uncertainties surrounding potential responses by consumers, investors, and policy-makers to climate change have grown.

The problem facing business decision-makers and their advisors is not a shortage of knowledge or expert insights regarding relevant topics. It is the challenge of accessing that knowledge. The Climatographers have built the Climate Web to help overcome that challenge. The Climate Web is a unique climate change decision-support tool, allowing access to the insights and expertise of thousands of topical experts, and covering almost every variable relevant to business decision-making.

The Climate Web supports business decision-making needs when it comes to Climate Change Materiality Assessments, Climate Change Assumption Audits, and Climate Risk Scenario Planning. The Climate Web is also structured to encourage application of a “risk frame” to climate change decision-making, a better way to support business risk assessment than the “expected value” frame of much of the technical climate change literature.

What Our Customers Say ...

"Having the Climate Web available is like having 100 leading experts in climate science, climate risk, risk management, and corporate strategy collaborating with you at the decision-making table."

Project Manager

Fortune 100 Client

"Mark Trexler's (and his team's) deep knowledge of climate change risk and adaptation issues is simply unsurpassed. Their comprehensive domain knowledge, analytic capabilities, work capacity, and ability to communicate a truly complex issue to a sometimes reluctant audience is extremely impressive."

Eirik Nyhus

Director of Environment

Det Norske Veritas (DNV)

"We worked with Mark's team for many years at Stonyfield Farm Yogurt, starting in 1996 when he briefed us on the then-new idea of carbon offsets. Mark is a rare breed of consultant- deep expertise, yet an ability to translate highly technical information and make it easily understandable. Mark is a brilliant, creative, strategic thinker. We highly recommend him and his team for just about anything!"

Nancy Hirshberg

Chief Catalyst

Hirshberg Strategic

Our Journey

The Climatographers’ principals focused on environmental and energy issues for many years before becoming involved with climate change issues. Just before joining the World Resources Institute’s (WRI) Climate Energy and Pollution Program in Washington, DC, in 1988, Climatographers founder Mark Trexler helped site a first-of-its-kind circulating fluidized bed coal-fired power plant in California. It was the only coal-fired power plant ever sited by the California Energy Commission.

After leaving WRI for the West Coast in 1991, electric utilities around the country approached Mark for climate change advisory support. Starting from a one-person home office, Trexler Climate + Energy Services (TC+ES) evolved into a well-known, internationally respected consultancy. With clients ranging from large energy companies to sustainability leaders like Nike and Stonyfield Farm, TC+ES developed a reputation for climate policy and carbon markets expertise.

In 2007, TC+ES was acquired by EcoSecurities, a global carbon markets firm based in Oxford, England. When EcoSecurities collapsed in 2009 in the face of carbon market disarray, the original TC+ES team became the U.S. climate change branch of Det Norske Veritas (today DNVGL), a global risk management firm based in Oslo, Norway.

Since We Started

Trexler Climate + Energy Services was the first U.S. consulting firm to specialize in business climate risk. Since 1988, the Climatographers’ principals have been at the cutting edge of climate change thinking and advising, as illustrated by a few of our firsts:

  • Developing many of the first carbon offset projects
  • Carrying out many of the first carbon footprints
  • Managing the first power plant siting case in U.S. in which CO2 was a key factor
  • Supporting the first climate change business unit in an electric utility
  • Developing the first carbon price forecasting model
  • Taking the first companies “climate neutral”

Today, the Climatographers are focused on another “first”: the Climate Web. No one has ever built this kind of a knowledge-based decision-support tool before, much less for a topic as complicated as climate change. The complexity of business climate change decision-making will likely continue to increase, but the Climatographers can ensure your access to the insights you need for robust decision-making outcomes.


years climate advisory experience


business, government, and NGO climate clients


climate reports and publications

Meet Our Team

Dr. Mark Trexler

Dr. Trexler has more than 30 years of regulatory and energy policy experience. He has advised clients around the world on climate change risk and risk management. Mark joined the World Resources Institute in Washington, DC, in 1988, where he worked on the first carbon offset project, the CARE Agroforestry Project in Guatemala. Mark founded and directed Trexler Climate + Energy Services (TC+ES) from 1991–2007. After TC+ES was acquired by EcoSecurities’ in 2007, Mark directed its Global Consulting Services Group until 2009, and was Director of Climate Risk for the global risk management firm of Det Norske Veritas from 2009-2012. He is widely published on business risk management topics surrounding climate change, including in the design and deployment of carbon markets. Mark has served as a lead author for the Intergovernmental Panel on Climate Change, and holds advanced degrees from the University of California at Berkeley.

Laura Kosloff

Laura H. Kosloff, an environmental attorney, has worked as Associate Editor of the Environmental Law Reporter in Washington, DC, and as an environmental litigator for the U.S. Department of Justice. She served as General Counsel to TC+ES from 1991-2007; after that, she was Associate General Counsel to EcoSecurities where she supported teams of more than 20 climate change consultants. She has worked extensively on the design of greenhouse gas mitigation and offset policies, and participated in carbon offset negotiations and due diligence. Ms. Kosloff holds a J.D. degree from the University of California at Davis, and a B.A. from Antioch College in Yellow Springs, Ohio.

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