The greatest danger would seem to be the rather obvious one (though that may be with hindsight): that ordinary consumers, brought up in a consumerist, capitalist, society, and addicted to what they consume, are assured that things are going well, and in the right direction, and will continue to do so, so long as we keep buying and consuming the right things.
And doing the right things: we should ride a bike for cancer research, win a prize and help save the countryside we all love, buy a coke and save a polar bear ...
But isn't this akin to sidelining what we say we are concerned about, and having a good time? Isn't this just very 'lazy environmentalism'?