Airlines want more flights because more of us want to fly more often. If we stopped flying they'd soon stop wanting more routes. It's easy to blame big businesses but how many of us drive to work on our own everyday? Or buy water in plastic bottles we only use once? Or haven't cut down on our meat intake, which is one of the biggest polluters there is? I'm just as bad, btw. I'm not some vegan tree-hugging crusty.
And plastic bags given out by major retailers has fallen by 85% since the 5p charge so it has had a sizeable effect. It's the tip of the iceberg, but it has massively reduced the number.