New Delhi, July 1 -- The Union environment ministry is facing a challenge but of garden variety-bird droppings soiling the courtyard of Indira Paryavaran Bhawan, which houses it, and is among India's highest green-rated buildings. On Wednesday, the ministry invited proposals for solutions to the recurring problem of the droppings in the central courtyard of the building. Individuals or organisations that will offer the best solution will be awarded Rs.1 lakh....