A thick toxic haze or 'smog' returned to Delhi, Noida, Gurugram and surrounding places this morning - after people burst crackers on Diwali night - violating the Supreme Court's ban order, leading to heavy pollution all across the National Capital Region. We look at whether artificial rain tackles the air pollution crisis of the scale that we are seeing in Delhi and the national capital region and what measures work best to tackle the toxic air with Environmentalist Vimlendu K Jha.