We know that Glaciers are shrinking (see The Age of Stupid) and that Bangladesh is suffering severe flooding. Are those who want to argue that we are not the cause of it not worried about what is?
OK, knowing what causes it might help determine what we should do to reverse things, but saying "not our fault" doesn't help with that.
At the Wave Rowan Williams translated Matthew 28:19 as "Go and share the good news with all creation." and Vincent Nicholls said "Only when we are clearly prepared to change the way we live will politicians be able to achieve the change we say we want to see." It was time to "live simply, so that others may simply live".
It strikes me that those who deny our impact on global warming are saying that they are not prepared to make those changes to the way they live.