Convert from momme [Japan] to gigatonne

Unit Definition (momme [Japan])
The momme [Japan] is a traditional Japanese weight unit corresponding to the Chinese mace. Jewelers continue to use the momme to measure the weight of cultured pearls; for this purpose it equals exactly 3.75 grams (about 0.132 ounce) or 18.75 carats. The unit is commonly pronounced "mommy" in English.

Unit Definition (gigatonne)
The gigatonne is a metric unit of mass or weight equal to one billion metric tons (tonnes) or about 2.2046 trillion pounds. This very large unit is used, for example, in discussing the amounts of carbon added to the atmosphere by human activities.