• Look up page 123 in the nearest book
• Look for the fifth sentence
• Then post the three sentences that follow that fifth sentence on page 123.

I was unfairly situated to receive this challenge. I am lying on the floor of the living room, knees up, laptop on my lap. The two books nearest to me have only 30 and 10 pages respectively: the lovely Angelina on Stage, by Katharine Holabird and Helen Craig (illustrator); and the drier My First Word Lift-the-Flap Board Book, by anonymous.

To my left are two bookshelves holding several hundred books between them. I picked up the one closest to my line of vision and arm reach: Thin Ice, by Mark Bowen, named best science book of the year in 2005 by NPR's Living on Earth. (Fortunately for all of us, the book below it is the gargantuan Climate Change 2007: The Physical Science Basis, by the Intergovernmental Panel on Climate Change.)

   

Mark and I met two weeks ago in Boston, seated next to each other at a luncheon in honor of Jim Hansen, Neil deGrasse Tyson, Don Kennedy and several  other distinguished scientists who won this year's suite of AAAS awards. Mark has just launched his next book, Censoring Science, about Hansen's fight against the Bush administration's dangerous interference in federally funded scientific inquiry.

Thin Ice is the story of Lonnie Thompson, the brave climatologist who up-ended convention by pulling ice cores not from the poles, bur from frozen mountaintops near the equator (This just in: There still are some). Seasonal patterns in the ice allow cores to be read like tree-rings, telling ancient tales of climate changes past. It's an epic work. Mark and I commiserated about the research-intensity of Thin Ice and The Carbon Age, a funny thing to commiserate about in retrospect because each of these books was a labor of love. Mark himself is a climber, and the book sprang from a magazine assignment that had him fly to Bolivia, to fill in for another writer not up to the task. It's a great story, blended experience and research.

So, here we go to page 123, sentences 6, 7, and 8... Jackpot! This Internet scavenger hunt has inadvertently led me to the heart of the matter, an iconic image of 20th and now 21st century science, the " Keeling Curve":


The Keeling curve is the precise measure of atmospheric carbon dioxide, taken continuously (with one break) since 1958, at the National Oceanic and Atmospheric Administration's Mauna Loa Observatory. It is direct evidence that the carbon dioxide level of the atmosphere is rising — accelerating, in fact. Although I am bound by the 123 challenge to share the three sentences after the fifth one, I must share all eight sentences on the page:

The gradual rise in the level of carbon dioxide at Mauna Loa, now known as the Keeling Curve, has become one of the central icons of global warming. As of 2003, the level was about 373 ppm [parts per million volume of air], 18 percent higher than it was in 1959. It's been rising at a rate of about 1.3 ppm per year, precisely the rate Keeling first measured at the South Pole during the International Geophysical Year.

I called Keeling in 2001 with a few questions about the early days ("It's always fun to talk about this stuff," he said) and one about ocean uptake. How long will it take all this stuff to come back to earth?

[123 challenge begins here] He said that the three famous papers in Tellus were right as far as they went, but that there was much more going on than even those estimable scientists figured at the time. There are many, many processes whereby carbon dioxide is dissolved into the ocean, circulated through it, and eventually deposited on its floor. Some take only six months; the ones Revelle and his colleagues studied take tens of years; some take hundreds of years, some tens of thousands of years, and some even hundreds of thousands of years.