As floods ravage India and buildings crumble, it is time to reflect on what and how we build, and how we address climate change. Globally, around $90 trillion is needed in infrastructure by 2030 to meet growing demand for energy, mobility, water and sanitation. Ensuring that this infrastructure is sustainable and resilient is both climate and budget-smart. New research from the World Bank finds that the overall net benefit of investing in climate-resilient infrastructure in developing countries would be worth $4.2 trillion over the lifetime of new infrastructure, with $4 benefit for each $1 invested. But this opportunity has a shelf life. We must act quickly or we will squander the last chance we have to put the world on a better growth path.