On the other hand, in addition to its direct radiative impact, methane has a large, indirect radiative effect because it contributes to ozone formation. (en.wikipedia.org)
Simultaneous surface and satellite measurements lead to first assessment of radiative impacts of a dust storm (pnnl.gov)
A release of [500/7.5 = 66.7] Gton C as methane (order [10 % / 7.5 = 1.3 %] of the hydrate reservoir) to the atmosphere would have an equivalent radiative impact to a factor of 10 increase in atmospheric CO2...... (realclimate.org)