The earth has been through many, many climate changes in millions of years -- some of them apparently quite sudden. I remember reading about the Beresovka mammoth, found beautifully preserved in ice...and it had buttercups stuck in its teeth.
I really don't know why Christians would not be concerned about the effect of man made climate change. I don't know how that would contradict their faith at all, even the most far-right fundamentalist young earth creationists -- I don't get how that would contradict what they believe or how acknowledging human carelessness and destructiveness would be contrary to their faith.
And it's not all Christians or only Christians that deny man's effect on climate change. JVH denies it, and is not a Christian.
I don't deny it -- I work in the energy industry, and definitely see things we humans have done that have adversely effected the environment and consequently, the climate -- air and water pollution, reliance on fossil fuels, acid rain, strip mining and soil erosion, endangering species to the point of extinction, the hole in the ozone layer, medical waste dumped in the ocean, the devastating effects of oil spills, deforestation of the rain forest, nuclear waste, etc.
My denomination does not deny or dismiss the seriousness of man's adverse effect on the environment, and in fact considers it a great sin than mankind is destroying the beauty and health of creation. But, to give some hope, there have been devastating effects we have been able to repair and reverse. As in the National Geographic article I posted above, the hole in the ozone layer is almost closed. We have cleaned up horribly polluted areas and oil spills. We have been able to save some species from the brink of extinction -- the buffalo, the California condor, the prairie dog, the whooping crane, the bald eagle.
I just know that the awesome and sometimes destructive power of nature has existed since time began, and no matter what we do to clean up our act, we can't stop climate change from happening, if that is the natural course of things. We can work to prevent forest fires, educate people, fine them for illegal burning or campfires in dry season...but we can't stop lightning strikes from happening. We can decide that nuclear power is just too dangerous, stop building nuke plants, and spend decades and millions of dollars to try to safely decommission existing nuclear plants...but we can't prevent earthquakes and tidal waves. We can mandate that everyone reduce their carbon footprint, and find alternative natural fuel sources...but we can't stop volcanos from erupting and stop the effects of volcanic ash in the atmosphere.