ESS11
Prof. Jin-Yi Yu
Orbital-Scale Changes in Methane
q
The Vostok ice record
shows a series of
cyclic variations in
methane concentration,
ranging between 350
to 700 ppb (part per
billion).
q
Each Ch4 cycle takes
about 23,000 years.
q
Modern interglacial period
Last interglacial period
(from
Earth’s Climate: Past and Future
)