Greg is a practitioner-scholar in accounting for climate change. He wrote the seminal desk book on financial reporting of environmental liabilities and risks. In addition, Greg is a Fellow and Advisor to the Master of Accounting Program at Cambridge Judge Business School.  He worked as an advisor to BP and its auditors Ernst & Young on liability estimates and disclosures arising from the Deepwater Horizon disaster.  He has consulted/testified as an expert in environmental and climate-related litigation.