Advocating the setting up of a Trans-Himalayan Development Authority for the ecological maintenance and sustenance of the Himalayan eco system, Chief Minister PK Dhumal today said Himachal would become the first carbon-neutral state in the country by 2020 by undertaking “carbon smart growth”. He was speaking at the 12th Delhi Sustainable Development Summit organised by the Energy and Resource Institute on “Protecting the global commons: 20 years post-Rio” in New Delhi today.