Tropical forests on three continents cause record spike in atmospheric carbon

Tropical forests on three continents cause record spike in atmospheric carbon Heat and drought shifts Earth's tropical regions in South America, Africa and Indonesia from carbon sink to source. In a 2015-2016 EI Nino event which brought powerful warming and drying, these forests actually spiked atmospheric carbon dioxide concentration to the highest level in at least 2,000 years. While the three tropical continents contributed roughly evenly to the carbon spike, the underlying causes were diverse decreased photosynthesis in tropical South America, increased plant decomposition in tropical Africa and increased burning in tropical Asia – challenging the notion that a single dominant process determines carbon cycle variability. YEAR 2015 2000 2010 2020 430 420 Atmospheric 410 400 carbon PPM trajectory 400 w APR JUL 390 380 370 Decomposition = Decreased 0.8 + 0.22 GtC flux photosynthesis = 0.9 t 0.29 GtC flux Burning = 360 0.8 t 0.28 GtC flux 350 ..... .. . .. ...... ....... .. ...... . . .......... 340 ....... . ..... 330 320 310 SOUTH AMERICA INDONESIA Drier land -> Hotter and stressed drier -> more plants fire prone GtC = Gigatons Carbon Warm Dry AFRICA Hotter -> increased ecosystem respiration PARIS PER MILLION