Assertion: methane's concentration | /r/CapableOf | surpass 1,860 ppb
Facets:
value: for the first time in 2018
type: TEMPORAL
Source sentences:
text: Moreover, concentrations of CH4 — the second most atmosphere-polluting anthropogenic greenhouse gas — surpassed 1,860 ppb for the first time in 2018, and are now two-and-a-half times higher than preindustrial levels, the authors write.