Climate change and the loss of biodiversity has become the burning issue in 21st century. Change in climate exert additional pressure and have already begun to affect all aspects of biodiversity; however the projected changes have to take into account the impact from other past, present and future human activities, including increasing atmospheric concentration of carbon dioxide.Islands are often characterized by a very rich biodiversity, upon which local people rely economically. island's ecosystems are fragile. In addition, 23 percent of inland species are at present considered endangered where as the corresponding figure for the rest of the world is 11 percent. Madagascar island is home to 5 percent of the world's plants and animal species of which more than 80 percent are endemic to Madagascar and Papua New Guinea probable harbors more than 5 percent of world's biodiversity within some of the world's most biologically diverse ecosystems.In this regard this work analyzed the impact of climate change on rich biodiversity of these island and effectiveness of their national policies and global response by comparing the condition of biodiversity loss in both island states.