The United Nations Environment Programme (UNEP) addresses climate change in four main themes: 1) Adapting to climate change by building resilience, 2) Facilitating a transition to low carbon societies, 3) Improving understanding of climate science, and 4) Communicating and raising awareness. UNEP works with countries on issues like adaptation planning, promoting renewable energy, reducing deforestation, and supporting the Clean Development Mechanism. It also undertakes assessments, publishes reports, and runs campaigns to advance global action on climate change.