Climate changes and the loss of biodiversity are twin challenges. Each threatens to undermine efforts to achieve sustainable development. This paper, drawing upon the fourth edition of the Global Biodiversity Outlook, the fifth assessment report of the Intergovernmental Panel on Climate Change and other recent scientific assessments on biodiversity and climate change, argues that these challenges must be addressed together through coordinated action at global, national and local levels, under the United Nations Framework Convention on Climate Change and the Convention on Biological Diversity.