Heat (28 page)

We go inside another building, bigger than the Keeling Building but hardly grandiose, a building that would be on the small side in a suburban light industrial park. Inside, in a hallway, amid a clutter of worn-out government-issue furniture, sits Keeling’s black box. It is the box that contains the original instrument he used to measure carbon dioxide levels. It was replaced around the time of Keeling’s death, in 2005. It is a shrine.

We walk down the path to our car and drive down the mountain, across lava fields, black and gray and never changing, but never monotonous. In driving, we add 150 pounds of carbon to the atmosphere. Our flights, Alaska to Hawaii and back, in tourist class seats, account for another three thousand pounds.

Still no lava. “But tomorrow looks promising,” the geologist tells me, “or the day after. The satellites are picking up warm spots.” Warm spots mean the lava is close to the surface, but not quite there.

We sit in the sun outside our bungalow, perched on lava. The public relations machinery of the climate change movement makes it easy to think that climate is all about carbon dioxide, but the story is more complex than that. It is also about the sun and the earth.

The sun’s brightness changes. There was the Maunder Minimum, from 1645 until 1715, with very low sunspot activity and cooler temperatures here on earth. The astronomer John Eddy wrote about the changes in the sun’s temperature in 1976: “The reality of the Maunder Minimum and its implications of basic solar change may be but one more defeat in our long and losing battle to keep the sun perfect, or, if not perfect, constant, and if inconstant regular,” he wrote. “Why we think the sun should be any of these when other stars are not is more a question for social than for physical science.”

He wrote, too, of the similar Spörer Minimum, from 1460 until 1550, and the Dalton Minimum, from 1790 until 1830. Greater sunspot activity, it seems, consistently means warmer climates. Sunspot quietude means cooler climates.

And there are the Milankovitch Cycles described by Milutin Milankovitch, cycles based on the combined timing of changes in the earth’s orbit, the angle of the earth’s tilted axis, and the direction of the axis during the earth’s closest approach to the sun. The earth’s orbit flattens and broadens regularly, every hundred thousand years, changing the difference between summer and winter sunlight by something like 20 percent. The tilt of the earth’s axis changes, making a sharper angle toward the sun, regularly, every forty-one thousand years, adding to the difference in sunlight received at different parts of the earth in summer and winter. And the summer solstice—the time when the axis angles most directly toward the sun—coincides with the point in time when the earth is at its closest distance to the sun every twenty-three thousand years, adding even more to the differences between summer and winter.

None of these changes affect the total amount of sunlight received by the earth each year, but they change the seasonality of sunlight and heat, and the parts of the earth receiving the most heat, which in the end changes climates. During World War 1, Milankovitch, interned by the Austro-Hungarian army, began the tedious mathematics needed to understand these cycles, and two years after the war he published his
Mathematical Theory of Thermal Phenomena Caused by Solar Radiation
. Two decades passed, and just as a new war was breaking out, he published
Canon of Insolation of the Earth and Its Application to the Problem of the Ice Ages
. Milankovitch Cycles, he believed, had much to say about changing climate.

Over longer periods, climate change is even about the position of the continents and the locations of mountains. The continents guide water currents, both warm and cold. The mountains guide air currents. And they come and go. The earth of fifty million years ago was not the earth of today. The sun of 1700 was not today’s sun. The geometry of the solar system experienced by
Homo erectus
was not the geometry of the solar system experienced by
Homo sapiens.

When Jean Baptiste Joseph Fourier wrote of a greenhouse effect in 1824 and 1827, he did not know of the complexities that would surface. In 1861, when John Tyndall reviewed climate change in ninety-five words, he did not understand all the factors in play. Neither Fourier nor Tyndall dwelled on sunspots and planetary geometry. They dwelled instead on the atmosphere as a blanket. Now, nearly two centuries later, ten thousand details remain to be worked out. But this much is clear: we have 40 percent more carbon dioxide than we did during the Maunder Minimum, 29 percent more carbon dioxide than when Milutin Milankovitch was born, and 17 percent more than when John Eddy wrote of the defeat of a perfect sun. And the world is getting warmer.

For now, astronomical cycles work on our side, counteracting some of the warmth trapped by a thickening blanket of carbon dioxide, but despite that, temperatures are rising.

My companion and I emit another eighty pounds of carbon driving our convertible to Kilauea’s caldera, the huge sunken kettle near the mountain’s summit. The caldera is the centerpiece of Hawaii Volcanoes National Park.

Edward Abbey complained of Smokey Bear but thought of the National Park Service as a good employer. “I love my job,” he wrote in his famous book
Desert Solitaire,
published in 1968. This did not mean that he loved his employer’s decisions. He loved his job because nature surrounded him and the limited workload gave him time to think. “What little thinking I do is my own,” he wrote, “and I do it on government time.”

One of the things he thought about was roads cut into the wilderness to allow easy access, like the one on which we drive. The roads attract tourists in droves but repel the likes of Abbey, and for that matter me, men who prefer to work for their scenery. In this case, though, the attraction outweighs the repulsion. I remain slightly feverish, which rules out real hiking, and there is a volcano at stake. And not just any volcano but the world’s most accessible volcano, Kilauea. I use the road.

Kilauea’s caldera, although not always as easily reached as it is today, has attracted tourists for some time. When Mark Twain wrote of the goddess Pele and the lookout house, he was writing about Kilauea. “As we ‘raised’ the summit of the mountain and began to canter along the edge of the crater, I heard Brown exclaim, ‘There’s smoke, by George!’ (poor infant—as if it were the most surprising thing in the world to see smoke issuing from a volcano).” Twain goes on to claim that he was disappointed by what he saw. “Only a considerable hole in the ground,” he wrote, “it is a large cellar—nothing more—and precious little fire in it.”

We park our convertible and approach via a short walk through a forest of tree ferns and ‘ōhi‘a lehua trees. Thick steam rises from a crack next to the trail. “Look,” I say, “steam!”

We round a corner, take three steps through thick brush, and the crater appears abruptly.

Kilauea’s caldera is nothing short of remarkable, even when quiescent, as it was when Twain visited. It is roughly circular and two to three miles wide, somewhat oblong rather than circular, but thirteen times larger than the Nuclear Testing Ground’s Sedan Crater and six times larger than Ubehebe Crater of Death Valley. And it is young. It may have formed within the past few hundred years when magma drained from beneath the summit of the shield and the whole thing collapsed, like limestone collapsing into a cavern to form a sinkhole but on a larger scale, and in black basalt instead of white limestone.

For many years, visitors came here to look down into a lava lake or lakes. Glowing magma flooded the floor of the crater. “My first visit was on the twenty-third of May 1864,” wrote George Clark in July 1867. “At that time there was but one lake of any note. On my last visit the first thing that attracted my special notice was the large north lake entirely new to me as were also several other lakes.”

“Crater filled with several ‘floating’ islands all surrounded by spouting fountains of yellow lava,” wrote F. F. Woodford in 1921.

Others described watching a hard crust of cooled lava break apart. “Another and another piece would break off, rush forward, and disappear the same as the first, until the entire surface would be broken up and submerged,” wrote Charles Marlette in 1865. “After this violent action had continued from fifteen to thirty minutes and the old crust had all or nearly all become melted or submerged the lake would gradually become more quiet.”

Although often called a crater, the pit at the top of Kilauea is better called a caldera, a magma chamber that has collapsed. The caldera floor, once wide awake with pools of molten lava, dozed off starting in the 1920s. No explosive eruptions were observed for the two and a half decades starting in 1982. Kilauea’s caldera became a pit of steaming black rock, or hardened magma, dramatic in a static sense, but not the seething witch’s cauldron that it had been. Visitors could drive around a Park Service ring road that circled the crater. They could park and walk to an observation platform and look down into the pit. They could toss pennies over the railing and watch them disappear into the distance.

Then one night in March 2008, a steam vent exploded. It scattered broken rocks over seventy-five acres. It threw a boulder onto a fence near the viewing platform. Its ash covered part of the ring road. It opened a crater in the bottom of the caldera. And this crater, called Halema‘uma‘u, the home of the goddess Pele, continues to send up steam and sulfurous smells. In the bottom of the crater, lava boils to the surface, cools, and sinks back down. When the steam clears, or with infrared scopes capable of peering through the steam, the lava flows can be seen moving like water in a violently boiling kettle, forming a wave that rises from below on one edge and sinks on the other, circulating molten earth in a giant convection current.

As a general matter, Kilauea is either deflating or inflating. During deflation, the lava level at the bottom of Halema‘uma‘u falls. With less lava, the mountain itself shrinks. The slope of its slopes changes, becoming less steep. Lava refuses to flow from cracks on the surface of the mountain.

Deflation events go on for days at a time. Inflation follows, with the lava level rising and the mountain swelling and lava bubbling to the surface in red-hot springs of liquid rock.

While we wait for inflation to replace deflation, we search for other ways to get close to live lava, to breathe the fumes and feel the heat. But the part of the crater rim that looks down into Halema‘uma‘u is off-limits. Nongeologists need not apply. The viewing platform has been closed. All we can do is marvel at the caldera and the plume of steam rising up from Halema‘uma‘u. We consider coming back at night and slipping under the barriers to trespass, but we decide against it, mostly because we are more interested in seeing live lava close up, in touching it, in feeling its heat. At Halema‘uma‘u all we would see is glowing steam. But we are hindered, too, by self-interest, by risk aversion, by the absence of any reliable information about the danger posed by the steam other than the knowledge that gaseous sulfur oxides mix with water to become sulfuric acid, and a vague feeling that breathing hot sulfuric acid may not be the ideal cure for what remains of our fevers.