Climate change is the defining issue of our future, and already the greening of agriculture, energy and transportation -- transforming the sectors so they become more sustainable in the face of environmental challenges -- is at the forefront of new policies and investments. But we also need to look at how and where we live. The building, construction and renovation sectors, which make up the backbone of residential and commercial housing, contribute almost 40% of global greenhouse gas emissions. In every crisis, however, there are opportunities. Efficient and environmentally friendly green buildings are one such opportunity -- and a massive one at that. In emerging markets alone, by 2030 green buildings will offer up to $24.7 trillion in investment opportunities. Much of this growth will occur in east Asia Pacific and South Asia, where more than half of the world's urban population will live within a decade. In a recent report, the International Finance Corporation, a member of the World Bank Group, estimated that by 2030, residential and commercial green buildings will represent a $17.8 trillion investment opportunity in Asia alone.