Global Emissions Trends Analyzed

If the world does not dial back greenhouse gas emissions over the next seven years, restraining human-caused global warming to 2 °C over preindustrial levels by 2100 will be difficult and expensive, a report from the UN Environment Programme says. Governments worldwide set the 2 °C limit in 2009. To meet this goal, annual global emissions of greenhouse gases in 2020 must be held to between 41 and 47 gigatons of carbon dioxide equivalent, the report says. Yet global emissions in 2010 were estimated at 50 gigatons, and they are growing. After 2020, emissions must decline by 2 to 3% per year from the 41 to 47 gigatons level, according to UNEP’s analysis, released last week. The world can still reduce emissions by 2020 with available technologies, but “time is running out,” the report says. In a separate report, also released last week, the World Bank warned that given emissions trends, Earth is on track to warm to 4 °C over preindustrial levels by the end of the century.