Jonathan Porritt will host the Landscape Institute Awards on 19 November.
He has recently left his post advising government as chairman of the Sustainable Development Commission and has also had roles as director of Friends of the Earth and co-chair of the Green Party.
"Jonathan Porritt is an expert in sustainable development, an issue close to the heart of every aspect of a landscape architect's work," said Landscape Institute chief executive Alastair McCapra.
The Landscape Institute Awards consist of 14 categories including Design, Management and Landscape Policy.
The ceremony takes place on 19 November at the The Brewery in Chiswell Street, London.
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