Convert from quarter (ton) [US] to gigatonne

Unit Definition (quarter (ton) [US])
The quarter (ton) [US] is a traditional unit of weight equal to 1/4 hundredweight. In the U.S., "quarter" is also used informally to mean 1/4 ton, or 500 pounds (226.80 kilograms).

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.