First of all, you said "all the air models, except for the newest released a couple of weeks ago, use the MagSafe adapters, not the MagSafe 2." That is incorrect, as shown here:
MacBook Air (13-inch, Mid 2012) - Technical Specifications
This spec shows that last year's MacBook Air also used the MagSafe 2.
Anyway, that's not important for the OP's question. What is important is that the new MagSafe 2 ("T" shaped) charger cannot be used with your MacBook Air that had a MagSafe ("L" shaped) charger.
Apple has documented that in this page:
http://store.apple.com/us/product/MD592LL/A/apple-45w-magsafe-2-power-adapter-fo r-macbook-air
... right in this area: