On an autumnal sunday morning in suburban Huntsville, Alabama, the sun streams through the second-floor windows of a Baptist church classroom. Eight men and women sit in folding chairs, eyes focused on John Christy, the leader of their Bible-study group. Dressed in khaki pants and a short-sleeved shirt, Christy flips through the pages of Genesis. He's talking about Adam and Eve, about the difference between God and his creation. "All God created is precious," he says. "And humans are the most precious part of creation."
The others nod. They know Christy as a dedicated member of the church and a mellow-toned bass in its choir. Some of them know he's a scientist, and some may even know that he puts more faith in evolution as an explanatory theory than in creationism. But only those closest to Christy know the extent to which his science and his religion are intertwined— and how much his double life has helped shape the most heated scientific debate of the past 20 years.
A professor of atmospheric science at the University of Alabama in Huntsville, Christy is a member of the Intergovernmental Panel on Climate Change (IPCC) established by the United Nations 12 years ago. As such, he is one of the world's preeminent experts on atmospheric conditions, one whose research informs our basic understanding of climate change. Yet Christy is also something of a maverick. Years ago he cast doubt on the idea that global warming is caused by humans— or that the phenomenon exists at all— and he has only grown more skeptical as most other atmospheric scientists have grown more certain.
This fall, as the IPCC was preparing to announce, in stronger terms than ever before, that Earth is warming at an unprecedented rate and that people are the cause, Christy was declaring exactly the opposite. "The usual predictions show escalating atmospheric temperatures, and we're just not seeing that rise," he says. "This indicates that the cause of recent surface warming may be due to factors other than human activities."
Contrarians are never in short supply where global warming is concerned. But Christy is unique for both the quality of his science and the depth of his moral fervor. First, he backs up his hypotheses with rigorously vetted data from satellites and weather stations around the globe. Second, his opposition to emissions controls is rooted in compassion: As a Baptist missionary in Africa 27 years ago, Christy witnessed how the energy policies of large nations can devastate small communities dependent on fossil fuels.
