claim: The increase in atmospheric methane, a greenhouse gas, in the latter part of the 20th century was explained as coming from expansion of grazing and rice cultivation, but the cause was found to be leaking gas pipelines in the Soviet Union which are now being properly managed and maintained.
evidence: Although the majority of the natural gas leaks were carbon dioxide, a significant amount of methane was also being consistently released from the pipeline as a result of leaks and breakdowns.