The UN's Intergovernmental Panel for
Climate Change issues periodic reports, drawn from data provided by thousands
of scientists, to help leaders take action on climate change.
"In many regions, livestock
numbers are changing, and breeding has resulted in larger animals with higher
intakes of food," said Julie Wolf, a researcher in the U.S. Department of
Agriculture and lead author of a study in the journal Carbon Balance and
Management.
"This, along with changes in
livestock management, can lead to higher methane emissions."
Earlier estimates, she added in a
statement, were based on "out-of-date data".
