Sunday, April 30, 2006

You're getting warm

Goodness," thought Alice to herself, "what a very strange place this is."

Only a moment before, the sun had been shining brightly and Alice was quite comfortable in her pinafore. Now the snow was falling furiously, and lay on the ground as high as her waist.

"I shall catch my death of cold," she said to no one in particular.

No sooner had she spoken than the sun burst through the clouds and the snow melted away. Soon she was standing up to her ankles in water.

"What could possibly happen next?" she thought. Whereupon dark clouds covered the sun and hailstones as big as hedgehogs splashed into the flood.

"Tornado, tornado!" she heard someone cry in a small, squeaky voice. The Dormouse came swimming by in a bit of a panic. Alice looked in the direction from which he had come and saw the dark funnel of a twister scattering shrubs and houses and teapots every which way.

"Hurricane! Hurricane!" shouted the Dormouse, as he took refuge on a milk jug that was floating in the flood. Immediately, the wind began blowing a gale and the water rose even higher.

"Global warming," said the Caterpillar.

Alice turned to see a large blue caterpillar sitting upon a mushroom. "Who are you?" she asked.

"Global warming," repeated the Caterpillar between puffs on his hookah. "The unusual weather is caused by the greenhouse effect. More carbon dioxide in the atmosphere. Cutting down rain forests. Burning fossil fuels. It's a scandal. A scandal."

"Then why are you smoking?" coughed Alice.

"Ah," said the Caterpillar, "my little bit of smoke won't make a difference. It's the big corporations, you see. The farm interests. The Chinese. The. . ." He paused to exhale. "The sea is rising. If I were you, I'd find a nice tall mushroom and stay put."

"Greenhouse effect? Rising seas?" wondered Alice. "I do wish I had an expert who could tell me the real cause of the capricious weather."

And just as this thought passed through her head, she noticed two identical scientists in white lab coats standing under a tree. One scientist had "Tweedlehigh" printed on his pocket-protector; the other scientist's pocket-protector read "Tweedlelow."

"Can it possibly be true," she asked, "that the world is getting hotter, and that the sea is rising?"

"Indeed, it can," said Tweedlehigh. "The amount of carbon dioxide in the atmosphere increases every year, and the global mean annual temperature has risen by a degree in the last century, with most of that occuiring since the 1970s. There will be a two- or three-degree change in the next hundred years. Sea level will rise as the ocean expands thermally and glacial ice melts. We can expect crazy permutations in the weather."

"Contrariwise," said Tweedlelow, "the present aberrations in the weather are statistical flukes, no different than extremes we have had in the past."

"Contrariwise," said Tweedlehigh, "my computer models show that small increases in carbon dioxide in the atmosphere significantly affect global climate, sea level, rain patterns..."

"Contrariwise," interrupted Tweedlelow, "computer models are not nearly sophisticated enough to describe the real climate system. There are too many variables. Too many kinds of feedback. . ."

"Contrariwise," shouted Tweedlehigh, "my model includes atmospheric composition, changes in ocean circulation and biochemistry, incoming and outgoing radiation, vegetation, atmospheric circulation, clouds. . ."

"Contrariwise," cried Tweedlelow, "clouds are too complicated -- an enormous variety of types, variability on all spatial scales, from sub-millimeter to thousands of kilometers, and time scales, from microseconds to weeks. The amount of cloud cover depends on sea temperature, atmospheric pollution, plants. No computer model yet devised can adequately model clouds. And then there's the deep sea. It takes thousands of years for the deep sea to come into equilibrium with surface changes. . ."

"Contrariwise," roared Tweedlehigh, "my ocean model has a two degree resolution in latitude and longitude, and 45 levels in the vertical! It includes sea ice. . ."

"Contrariwise," thundered Tweedlelow, as he thumped Tweedlehigh with a large barometer.

"Contrariwise," stormed Tweedlehigh, as he adjusted a brass rain gauge on his head as a helmet.

The two scientists went tumbling off into the woods, head over heels, shouting and pummeling each other fiercely.

"Global warming," asserted the Caterpillar again confidently, taking another puff on his hookah and exhaling a cloud of dense blue smoke.

Suddenly, the hurricane subsided and it started snowing again, a white-out blizzard. "What a very strange place this is," thought Alice somberly, no wiser for her troubles.

Further Reading

Here's a relevant Tom Toles cartoon from the Washington Post.

For a look at what climatologists are doing, visit realclimate.org, or for a flavor of an individual climatologist's work, try my daughter's website.

Tim Flannery, The Weather Makers: How Man Is Changing the Climate and What It Means for Life On Earth.

Discuss this essay and more over on the Science Musings Blog.