Convert from petagram to libra [Italy]

Unit Definition (petagram)
The petagram is a metric unit of mass equal to 10E15 grams or 1 gigatonne (one billion metric tons). This unit is used in atmospheric science and other scientific contexts where large masses are considered.

Unit Definition (libra [Italy])
The libra [Italy] is a traditional unit of weight. The libra was the Roman unit from which the English pound is descended; the symbol "lb" for the pound comes from this unit. The traditional Italian libbra was often of similar size, but a wide variety of libbras were used in Italian markets over the centuries. The word "libra" is sometimes used now for the kilogram, a much larger unit.