Hundreds of private e-mail messages and documents hacked from a computer server at a British university are causing a stir among global warming skeptics, who say they show that climate scientists conspired to overstate the case for a human influence on climate change.

The e-mail messages, attributed to prominent American and British climate researchers, include discussions of scientific data and whether it should be released, exchanges about how best to combat the arguments of skeptics, and casual comments — in some cases derisive — about specific people known for their skeptical views. Drafts of scientific papers and a photo collage that portrays climate skeptics on an ice floe were also among the hacked data, some of which dates back 13 years.