I have now discovered how Google is doing its bit to reduce the carbon footprint caused by travelling from New York to London.  To find this out go to maps.google.com
click on “get directions” 
type ” New York ” in the first box (the “from” box) 
type ” London ” in the second box (the “to” box)
(hit get directions) 
scroll down to step 24

Hmmm.