NEW DELHI, March 22 -- The Union environment ministry has given environmental clearance for open cast coal mining in Parsa in Chhattisgarh's dense Hasdeo Arand forests, in a decision that could have far-reaching consequences for forest cover conservation in India. Hasdeo Arand is one of the largest contiguous stretches of very dense forest in central India, spanning about 170,000 hectares. Parsa is one of the 30 coal blocks in Hasdeo Arand and is owned by the Rajasthan Rajya Vidyut Utpadan Nigam Ltd (RVUNL)....