Fig. 1: Global 14C patterns in river DIC, CO2 and CH4.
From: Old carbon routed from land to the atmosphere by global river systems
a, Map of sampling locations. b, All F14C values assembled in the database separated by compound. The dashed horizontal line shows F14C = 1.0 (atmospheric CO2 in 1955 CE, panel c), mean age in uncalibrated 14C years is indicated on the right axis, values in parentheses indicate percentage of observations for which F14C > 1.0 (younger than 1955 CE, for which no 14C age can be calculated and are considered ‘modern’); lines in the middle of the boxes represent the median, box limits represent the upper and lower quartiles and whiskers extend to 1.5 times the interquartile range. c, All F14C values assembled in the database plotted by year of sample collection and shown in the context of atmospheric 14CO2 (1950 to 2019 CE; black line; data from ref. 34). The dashed horizontal line shows F14C = 1.0; F14C values are shown separated by compound.
