Environment News Service: Humanity must hold itself to a strict carbon budget emitting even less greenhouse gases than earlier estimated if we want to keep planetary warming to less than 2°Celsius above pre-industrial temperatures, a new study finds. The 2°C target was adopted as a goal by the leaders of 196 countries at the United Nationss 2015 Paris climate conference, COP21. They view it as a safe limit to prevent the most dangerous impacts of climate change. Published in the current issue of the journal Nature...