Four chopped green onions will give you around 1/2 cup, although it would greatly depend on the thickness and length of the green onions.

And by "green onions", we will assume you are referring to the long, thin onions, also referred to as scallions or spring onions.

Green Onions was created in 978-01.

Green Onions - album - was created on -19-08-06.

why aren't onions green

Because onion bulbs are produced underground as storage of food. Being away from sunlight, the onion scales lack chloroplasts ( the green color pigment ) hence onions are not green.

As far as is known, at this time (January 2014) onions have not been genetically modified, so Green Giant onions would not be GMO.