From September 2009 through March 2016, Heller served as executive director of Climate Policy Initiative (CPI), a policy effectiveness analysis and advisory organization that evaluates and supports the efforts of nations to achieve low-carbon growth. He was also a coordinating lead author for the IPCC’s Third and Fourth Assessment Reports and a contributor to the Special Reports on Technology Transfer and Emissions Scenarios. The work of the IPCC (including the contributions of many scientists) was recognised by the joint award of the 2007 Nobel Peace Prize. Heller also served as a core team member directing Project Catalyst—an analysis-based project in support of the Copenhagen Climate Process—and currently serves as vice-chair of the governing board of the Global Green Growth Institute, with headquarters in Seoul, Korea.