When they burn, millions of tons of carbon dioxide are released into the air upsetting the balance of atmospheric gases and contributing to global warming - known as the greenhouse effect.
(they; burn; ) (millions of tons of carbon dioxide; are released; into the air; T:When they burn) (the air; upsetting; the balance of atmospheric gases) (the air; contributing; to)
they millions of tons of carbon dioxide the air the air
burn are released upsetting contributing
into the air T:When they burn
the balance of atmospheric gases
to