"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 thefull 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 1822-2000
"New York City, a rise of 5 degrees Fahrenheit in a hundred seventy-eight years."
Albany, NY 1820-2000
"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 ofglobal 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 dioxide--the gas we all worry about--has increased the same amount everywhere in the world..." She pulled out another graph:*
CO2Levels, 1957-2002
"Yes..."
"And its effect is presumably the same everywhere in the world. That's why it's calledglobal warming."
"Yes..."
"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 forglobal 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..."
"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 Point--which is midway between them--remained 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 aglobal 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..."
"And this urban heat effect is a local effect, unrelated to global warming?"
"Yes..."
"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..."
"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 adjusteddownward. "
"But the question the defense will ask is, have they adjusted downwardenough? "