"It's still a trick."

"Yes, it is. The defense will not miss the opportunity to show the jury numerous examples of this trick from environmental fund-raising literature. Selecting specific years that appear to show things are getting worse."

Evans registered her insult to environmental groups. "In that case," he said, "let's not permit any tricks at all. Use the full and complete temperature record. How far back does it go?"

"At West Point, back to 1826."

"Okay. Then suppose you use that?" Evans felt confident proposing this, because it was well known that a worldwide warming trend had begun at about 1850. Every place in the world had gotten warmer since then, and the graph from West Point would reflect that.

Jennifer seemed to know it too, because she suddenly appeared very hesitant, turning away, thumbing through her stack of graphs, frowning as if she couldn't find it.

"You don't have that particular graph, do you?" Evans said.

"No, no. Believe me, I have it. Yes. Here." And then she pulled it out.

West Point, NY 18262000 Evans took one look and saw that she had sandbagged him.

"As you predicted, this graph is quite telling," she said. "For the last one hundred seventy-four years, there has been no change in the average temperature at West Point. It was 51 degrees Fahrenheit in 1826, and it is 51 degrees in 2000."

"But that's just one record," Evans said, recovering quickly. "One of many. One of hundreds. Thousands."

"You're saying that other records will show other trends?"

"I'm sure they will. Especially using the full record from 1826."

"And you are correct," she said. "Different records do show different trends."

Evans sat back, satisfied with himself. Hands crossed over his chest.

New York, NY 18222000 "New York City, a rise of 5 degrees Fahrenheit in a hundred seventy-eight years."

Albany, NY 18202000 "Albany, a decline of half a degree in a hundred eighty years."

Evans shrugged. "Local variations, as I said before."

"But I wonder," Jennifer said, "how these local variations fit into a theory of global warming. As I understand it, global warming is caused by an increase in so-called greenhouse gases, such as carbon dioxide, that trap heat in the Earth's atmosphere and prevent it from escaping into space. Is that your understanding?"

"Yes," Evans said, grateful he did not have to summon a definition on his own.

"So, according to the theory," Jennifer said, "the atmosphere itself gets warmer, just as it would inside a greenhouse?"

"Yes."

"And these greenhouse gases affect the entire planet."

"Yes."

"And we know that carbon dioxidethe gas we all worry abouthas increased the same amount everywhere in the world amp;" She pulled out another graph:* CO2 Levels, 19572002 "Yes amp;"

"And its effect is presumably the same everywhere in the world. That's why it's called global warming."

"Yes amp;"

"But New York and Albany are only a hundred forty miles apart. You can drive between them in three hours. Their carbon dioxide levels are identical. Yet one got a lot warmer and the other got slightly colder. Is that evidence for global warming?"

"Weather is local," Evans said. "Some places are warmer or colder than others. And always will be."

"But we are talking about climate, not weather. Climate is weather over a long time period."

"Yes amp;"

"So I would agree with you if both locations got warmer, albeit by different amounts. But here, one got warmer and one got colder. And as we saw, West Pointwhich is midway between themremained unchanged."

Evans said, "I think the theory of global warming predicts that some places will get colder."

"Really? Why is that?"

"I'm not sure, but I read it somewhere."

"The Earth's entire atmosphere warms, and as a result some places get colder?"

"I believe so."

"As you think about it now, does that claim make sense to you?"

"No," Evans said, "but you know, climate is a complex system."

"Which means what, to you?"

"It means it's, uh, complicated. It doesn't always behave the way you think it will."

"That's certainly true," Jennifer said. "But going back to New York and Albany. The fact that these two locations are so close, yet their temperature records are so different, could lead a jury to wonder whether we're really measuring something other than a global effect. You would agree that in the last hundred eighty-five years, New York has grown to a city of eight million, whereas Albany has grown much less?"

"Yes," Evans said.

"And we know that the urban heat island effect makes cities hotter than the surrounding countryside."

"Yes amp;"

"And this urban heat effect is a local effect, unrelated to global warming?"

"Yes amp;"

"So, tell me: how do you know that the dramatic increase in temperature in New York is caused by global warming, and not just from an excess of concrete and skyscrapers?"

"Well." Evans hesitated. "I don't know the answer to that. But I assume it is known."

"Because if cities like New York become larger and hotter than they were before, they will raise the average global temperature, will they not?"

"I assume they will."

"In which case, as cities expand all around the world, we might see an increase in average ground temperature simply because of urbanization. Without any global atmospheric effect at all."

"I am sure the scientists have thought of that already," Evans said. "I'm sure they can answer that."

"Yes, they can. Their answer is that they have subtracted a factor from the raw data to compensate for the urban heat effect."

"Well, there you are."

"Excuse me? Mr. Evans, you're a lawyer. Surely you are aware of the extraordinary efforts that are made in a lawsuit to be certain the evidence is untainted."

"Yes, but"

"You don't want anybody to be able to change it."

"Yes amp;"

"But in this case, the evidence is the raw temperature data. And it is tainted by the very scientists who claim global warming is a worldwide crisis."

"Tainted? It's adjusted downward."

"But the question the defense will ask is, have they adjusted downward enough?"

"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 scientists are 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 waysand 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 backfaster 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 amp;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 backseventy 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 people who 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 amp;"

"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 are suspect. 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 amp;I'm asking someI'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."

She nodded slowly. Looking at him closely.

He said, "You, too?"

She continued to nod.

They lunched at the same Mexican restaurant as before. It was almost empty, as before; the same Sony film editors laughing at the corner table. They must come here every day, Evans thought.

But somehow everything was different, and not just because his body ached and he was on the verge of falling asleep any moment. Evans felt as if he had become a different person. And their relationship was different, too.

Jennifer ate quietly, not saying much. Evans had the sense she was waiting for him.

After a while, he said, "You know, it would be crazy to imagine that global warming wasn't a real phenomenon."

"Crazy," she said, nodding.

"I mean, the whole world believes it."

"Yes," she said. "The whole world does. But in that war room, we think only about the jury. And the defense will have a field day with the jury."

"You mean, the example you told me?"

"Oh, it's much worse than that. We expect the defense to argue like this: Ladies and gentlemen of the jury, you've all heard the claim that something called global warming' is occurring because of an increase in carbon dioxide and other greenhouse gases in the atmosphere. But what you haven't been told is that carbon dioxide has increased by only a tiny amount. They'll show you a graph of increasing carbon dioxide that looks like the slope of Mount Everest. But here's the reality. Carbon dioxide has increased from 316 parts per million to 376 parts per million. Sixty parts per million is the total increase. Now, that's such a small change in our entire atmosphere that it is hard to imagine. How can we visualize that?"

Jennifer sat back, swung her hand wide. "Next, they'll bring out a chart showing a football field. And they'll say, Imagine the composition of the Earth's atmosphere as a football field. Most of the atmosphere is nitrogen. So, starting from the goal line, nitrogen takes you all the way to the seventy-eight-yard line. And most of what's left is oxygen. Oxygen takes you to the ninety-nine-yard line. Only one yard to go. But most of what remains is the inert gas argon. Argon brings you within three and a half inches of the goal line. That's pretty much the thickness of the chalk stripe, folks. And how much of that remaining three inches is carbon dioxide? One inch. That's how much CO2 we have in our atmosphere. One inch in a hundred-yard football field."