This Guardian feature documents Delhi’s acute air‑pollution crisis—AQI spikes to 1,700, widespread health and economic harm, and emergency but ineffectual fixes—and shows the problem is systemic (transport, coal‑fired power, industry, waste and construction alongside stubble burning) rather than merely seasonal; it is included to supply contemporary, evidence‑based grounding for the book’s Call to Action: Our World & Our Future chapter, illustrating the public‑health and economic risks that demand structural policy change and purposeful investment (opportunities and responsibilities) across transport, energy, industry and healthcare sectors.