Convert from gigagram to megatonne

Unit Definition (gigagram)
An SI unit of mass equal to 10E9 grams, one million kilograms, or 1 kilotonne (1000 metric tons). This unit is used in scientific contexts, such as the measurement of atmospheric emissions. One gigagram equals about 2.2046 million pounds or 1102.3 U.S. (short) tons.

Unit Definition (megatonne)
The megatonne is a metric unit of mass or weight equal to one million metric tons (tonnes), one teragram (Tg), or about 2.2046 billion pounds.