上游充通大粤 6.1预测：气候变化 e SHANGHAI JIAO TONG UNIVERSITY ?年400ppm CO2 concentratlons,ppm 400 -2011(391ppm -2007(380ppm) -1958315ppm) 300 200 100 Air bubbles trapped In Antarcticlce preserve an 800 000-year record of atmospherlc CO levels, which have varled naturally from about 180 to about 280 ppm (Luethl et al.2008).Once humans began buming large quantitles of coal and oll In the 19th century,concentratlons began to rlse beyond these levels,reaching 315 ppm by 1958-when direct measurements of 0 CO In the atmosphere began-to 380 ppm In 2007 and 391 ppm in 2011 800000 600000 400000 200000 0 Years before present Source:Adapted from NASA Earth Observatory 2010 80万年以来大气二氧化碳浓度变化80万年以来大气二氧化碳浓度变化 6.1 预测：气候变化 ？年 400 ppm