Greenhouse gas emissions could rise to 58 gigatonnes (Gt) by 2020—far above the level that many scientists say is needed to keep the global temperature rise they predict to less than 2°C this century. A new study, The Emissions Gap Report 2012, says that if the world stays on a business-as-usual trajectory, more drastic and expensive cuts will be needed after 2020. The report, released on November 21, was coordinated by the United Nations Environment Programme (UNEP) and the European Climate Foundation.
Previous scenario-based assessments have concluded that ambitious early action would keep the costs of meeting the two-degree target as low as possible. In such scenarios, emissions are projected to reach about 44 Gt or less in 2020 on average. However, emissions of warming gases like carbon dioxide are actually increasing each year worldwide. Total greenhouse gas emissions have risen from around 40 Gt in 2000 to an estimated 50.1 Gt in 2010. Delaying action also implies a greater risk of temperature rise exceeding two degrees, beyond which irreversible damage to the environment could occur, according to the report's authors.
The report noted that that bridging the emissions gap remains possible and efforts to do so should include increased energy efficiency in buildings, improved vehicle emissions standards, and continued growth of renewable energy. See the UNEP press release and the The Emissions Gap Report 2012 Web page .