The Ozone Secretariat is deeply saddened to hear of the passing of Professor Xiaoyan Tang on 11 June 2025. She was a long serving co-chair of the Environmental Effects Assessment Panel (EEAP) from 1993 until 2012. During her tenure, she oversaw four quadrennial assessment reports, starting with the first in 1994, as well as numerous progress reports and the launch of the first ‘Frequently asked questions’ in 2010. Over the years she has made tremendous contributions to the protection of the ozone layer; not only to the Montreal Protocol but also to China’s efforts at the national level.

A graduate from Peking University in 1954, she was one of the earliest scholars in China to engage in environmental science education and research going on to become a world-renowned atmospheric environmental chemist.

As early as 1991, Professor Tang led the drafting of China's country programme for the implementation of the Montreal Protocol. She and her colleagues also contributed to many other ozone layer-related scientific fields. In recognition of her services to ozone layer protection, she received the Vienna Convention 20th Anniversary Commemorative Award in 2005.

Among her many accomplishments, Professor Tang was also a highly respected teacher and outstanding educator who taught for over 70 years in the fields of environmental science and atmospheric chemistry.

Her passing is a great loss to the ozone community. She will be missed very much by the Montreal Protocol family and her many colleagues in the wider field of atmospheric and environmental sciences.