Rawleston has joined the GEF as focal point for the SIDS as well as addressing issues related to adaptation, and doing outreach regarding the United Nations Framework Convention on Climate Change (UNFCCC).

Rawleston is a former representative of the Government of Barbados to the UNFCCC. Rawleston worked with the GEF-funded Caribbean Planning for Adaptation to Climate Change Project (CPACC) and assisted in the preparation of the GEF-funded Mainstreaming to Adaptation to Climate Change in the Caribbean.

In addition, Rawleston is a former lecturer at the Centre for Resource Management and Environmental Studies University of West Indies-Cave Hill Campus Barbados, with a number of publications on climate change. He has worked as a consultant for governments and international organizations on the issue of climate change.