Greenpeace activists today gathered outside Bharti Airtel’s headquarters in Gurgaon, following the telecom leader’s failure to respond substantively to specific questions pertaining to reduction in its carbon emissions and shifting to renewable sources of energy to power its network operations, in spite of repeated requests. The activists painted the sign “Switch off Diesel” at the company headquarters as a reminder of the demand made on the leader to shift. Close to 50, 000 supporters have already signed a petition asking Airtel to go clean.