Answer : 4. "Climate change expert"
Explanation :

Professor Salimul Haq, a leading advocate of climate justice and director of the International Center for Climate Change and Development (ICCCAD) in Dhaka, died at the age of 71. He was a respected expert in the fields of climate change, environment and development. Professor Haq dedicates his work to establishing the links between climate change mitigation, adaptation and sustainable development, focusing on developing countries, particularly least developed countries (LDCs).