Since 1896, scientists have been trying to answer a deceptively simple question: What will happen to the temperature of the earth if the amount of carbon dioxide in the atmosphere doubles?

Some recent scientific papers have made a splash by claiming that the answer might not be as bad as previously feared. This work — if it holds up — offers the tantalizing possibility that climate change might be slow and limited enough that human society could adapt to it without major trauma.

Several scientists say they see reasons to doubt that these lowball estimates will in fact stand up to critical scrutiny, and a wave of papers offering counterarguments is already in the works. “The story is not over,” said Chris E. Forest, a climate expert at Pennsylvania State University.

Still, the recent body of evidence — and the political use that climate contrarians are making of it to claim that everything is fine — sheds some light on where we are in our scientific and public understanding of the risks of climate change.