boeing247 wrote on Nov 15^th, 2011 at 11:58pm:

The carbon emissions also became a big problem as people became more aware of harming the environment.

IMO thinking about the carbon emission from airliners is a great joke. It's just a way of airlines and/or government agencies to get more money from users adding carbon emissions taxes to airfares. Who cares about the ammount of carbon emissions from all others sources? Nowadays, there is an estimated amount of over 750 million motor vehicles in the world (Source: How many cars are in the world?). And about manufaturing, refining, chemical and mining processes? And even about households carbon dioxide emissions? Please, let's think about the whole thing and not only about an insignificant portion.

Pinatubo.