Poverty reduction and sustainable development remain core global priorities. A quarter of the population of developing countries still lives on less than $1.25 a day. One billion people lack clean drinking water; 1.6 billion, electricity; and 3 billion, adequate sanitation. A quarter of all developing country children are malnourished. Addressing these needs must remain the priorities both of developing countries and of development aid—recognizing that development will get harder, not easier, with climate change. Yet climate change must urgently be addressed. Climate change threatens all countries, with developing countries the most vulnerable. Estimates are that they would bear some 75 to 80 percent of the costs of damages caused by the changing climate. Even 2°C warming above preindustrial temperatures—the minimum the world is likely to experience—could result in permanent reductions in GDP of 4 to 5 percent for Africa and South Asia.