Turn Down the Heat: Why a 4°C Warmer World Must be Avoided

Under current pledges and commitments, the world is likely to reach 4°C degree warming by the end of the century and 2°C warming as early as 2040. This MOOC brings together renowned scientists to provide a synthesis of the most recent scientific evidence and presents an analysis of likely impacts and risks, with a focus on developing countries. It chronicles already observed changes in the climate system and their impacts, through the increase in carbon dioxide emissions, corresponding temperature increases and melting of glaciers and sea ice, and changes in precipitation patterns. This course also offers projections for the 21st century for droughts, heat waves and sea-level rise, with implications for food and water security, as well as possible impacts on agriculture, water availability, ecosystems and human health.