"I don't know," Evans said, "this is getting very specialized and nitpicky."
"Hardly. It's a core issue. Urbanization versus greenhouse gases as the cause of the increased average surface temperature. And the defense will have a good argument on their side," Jennifer said. "As I said before, several recent studies suggest the reduction for urban bias has, in fact, been too small.*At least one study suggests that half of the observed temperature change comes from land use alone. If that's true, then global warming in the past century is less than three tenths of a degree. Not exactly a crisis."
Evans said nothing. He tried to look intelligent for the cameras.
"Of course," Jennifer continued, "that study can be debated, too. But the point remains: as soon as anybody adjusts the data, they open themselves to the claim that their adjustment was incorrect. That's better ground for the defense. And the larger point the defense will make is that we have allowed the data to be adjusted by the very people who have the most to gain from that adjustment."
"You're saying that climate scientists are unethical?"
"I'm saying it is never a good policy for the fox to guard the hen house. Such procedures are never allowed in medicine, for example, where double-blind experimental designs are required."
"So you're saying climate scientistsare unethical."
"No, I'm saying that there are good reasons why double-blind procedures are instituted. Look: Every scientist has some idea of how his experiment is going to turn out. Otherwise he wouldn't do the experiment in the first place. He has an expectation. But expectation works in mysterious ways--and totally unconsciously. Do you know any of the studies of scientific bias?"
"No." Evans shook his head.
"Okay. Simple example. A group of genetically identical rats are sent to two different labs for testing. One lab is told that the rats were bred for intelligence and will run a maze faster than normal. The other lab is told that the rats are dumb and will run a maze slowly. Results come back--faster in one lab, slower in the other. Yet the rats are genetically identical."
"Okay, so they fudged."
"They said they didn't. Anyway, there's much more," she said. "Next example. A group of survey takers are told, Look, we know that pollsters can influence results in subtle ways. We want to avoid that. So you knock on the door, and the minute someone answers you start reading only what is on this card: 'Hello, I am doing a survey, and I am reading from this card in order not to influence you...et cetera.' The poll takers say nothing except what is on the card. One group of pollsters is told, this questionnaire will get seventy percent positive answers. They tell another group, you can expect thirty percent positive answers. Identical questionnaires. The results come back--seventy and thirty."
"How?" Evans said.
"It doesn't matter," she said. "All that matters is that hundreds of studies prove again and again that expectations determine outcome. People find what they think they'll find. That's the reason for 'double-blind' experiments. To eliminate bias, the experiment is divided up among different peoplewho do not know each other. The people who prepare the experiment do not know the people who conduct the experiment or the people who analyze the results. These groups never communicate in any way. Their spouses and children never meet. The groups are in different universities and preferably in different countries. That's how new drugs are tested. Because that's the only way to prevent bias from creeping in."
"Okay..."
"So now we're talking about temperature data. It has to be adjusted in all kinds of ways. Not just for urban heat bias. Lots of other things. Stations move. They upgrade, and the new equipment may read hotter or colder than before. The equipment malfunctions and you have to decide whether to throw out certain data. You deal with lots of judgment calls in putting together the temperature record. And that's where the bias creeps in. Possibly."
"Possibly?"
"You don't know," Jennifer said, "but whenever you have one team doing all the jobs, then you're at risk for bias. If one team makes a model and also tests it and also analyzes the results, those results are at risk. They just are."
"So the temperature data are no good?"
"The temperature data aresuspect. A decent attorney will tear them apart. To defend them, what we intend to do is--"
Abruptly, the camera crew got up and left the room. Jennifer rested her hand on his arm. "Don't worry about any of that, the footage they shot was without sound. I just wanted it to look like a lively discussion."
"I feel foolish."
"You looked good. That's all that matters for TV."
"No," he said, leaning closer to her. "I mean, when I gave those answers, I wasn't saying what I really think. I'm, uh...I'm asking some--I'm changing my mind about a lot of this stuff."
"Really?"
"Yes," he said, speaking quietly. "Those graphs of temperature, for instance. They raise obvious questions about the validity of global warming."