Super Freakonomics Part 20

It takes a healthy dose of collective arrogance for a small group of scientists and engineers to think they could simultaneously tackle many of the world's toughest problems. Fortunately, these folks have the requisite amount. They have already sent satellites to the moon, helped defend the United States against missile attack and, via computing advances, changed the way the world works. (Bill Gates is not only an investor in IV but an occasional inventor as well. The mosquito-zapping laser was a response to his philanthropic quest to eradicate malaria.) They have also conducted definitive scientific research in many fields, including climate science.

So it was only a matter of time before they began thinking about global warming. On the day we visited IV, Myhrvold convened roughly a dozen of his colleagues to talk about the problem and possible solutions. They sat around a long oval conference table, Myhrvold near one end.

They are a roomful of wizards, and yet without doubt Myhrvold is their Harry Potter. For the next ten or so hours, fueled by an astonishing amount of diet soda, he prodded and amplified, interjected and challenged.

Everyone in the room agrees that the earth has been getting warmer and they generally suspect that human activity has something to do with it. But they also agree that the standard global-warming rhetoric in the media and political circles is oversimplified and exaggerated. Too many accounts, Myhrvold says, suffer from "people who get on their high horse and say that that our species will be exterminated."

Does he believe this?

"Probably not."

When An Inconvenient Truth is mentioned, the table erupts in a sea of groans. The film's purpose, Myhrvold believes, was "to scare the c.r.a.p out of people." Although Al Gore "isn't technically lying," he says, some of the nightmare scenarios Gore describes-the state of Florida disappearing under rising seas, for instance-"don't have any basis in physical reality in any reasonable time frame. No climate model shows them happening."

But the scientific community is also at fault. The current generation of climate-prediction models are, as Lowell Wood puts it, "enormously crude." Wood is a heavyset and spectacularly talkative astrophysicist in his sixties who calls to mind a sane Ignatius P. Reilly. Long ago, Wood was Myhrvold's academic mentor. (Wood himself was a protege of the physicist Edward Teller.) Myhrvold thinks Wood is one the smartest men in the universe. Off the top of his head, Wood seems to know quite a bit about practically anything: the melt rate of the Greenland ice core (80 cubic kilometers per year); the percentage of unsanctioned Chinese power plants that went online in the previous year (about 20 percent); the number of times that metastatic cancer cells travel through the bloodstream before they land ("as many as a million").

Wood has achieved a great deal in science, on behalf of universities, private firms, and the U.S. government. It was Wood who dreamed up IV's mosquito laser a.s.sa.s.sination system-which, if it seems vaguely familiar, is because Wood also worked on the "Star Wars" missile-defense system at the Lawrence Livermore National Laboratory, from which he recently retired. (From fighting Soviet nukes to malarial mosquitoes: talk about a peace dividend!)

Today, at the IV think session, Wood is wearing a rainbow tie-dyed short-sleeve dress shirt with a matching necktie.

"The climate models are crude in s.p.a.ce and they're crude in time," he continues. "So there's an enormous amount of natural phenomena they can't model. They can't do even giant storms like hurricanes."

There are several reasons for this, Myhrvold explains. Today's models use a grid of cells to map the earth, and those grids are too large to allow for the modeling of actual weather. Smaller and more accurate grids would require better modeling software, which would require more computing power. "We're trying to predict climate change twenty to thirty years from now," he says, "but it will take us almost the same amount of time for the computer industry to give us fast enough computers to do the job."

That said, most current climate models tend to produce similar predictions. This might lead one to reasonably conclude that climate scientists have a pretty good handle on the future.

Not so, says Wood.

"Everybody turns their k.n.o.bs"-that is, adjusts the control parameters and coefficients of their models-"so they aren't the outlier, because the outlying model is going to have difficulty getting funded." In other words, the economic reality of research funding, rather than a disinterested and uncoordinated scientific consensus, leads the models to approximately match one another. It isn't that current climate models should be ignored, Wood says-but, when considering the fate of the planet, one should properly appreciate their limited nature.

As Wood, Myhrvold, and the other scientists discuss the various conventional wisdoms surrounding global warming, few, if any, survive unscathed.

The emphasis on carbon dioxide? "Misplaced," says Wood.

Why?

"Because carbon dioxide is not the major greenhouse gas. The major greenhouse gas is water vapor." But current climate models "do not know how to handle water vapor and various types of clouds. That is the elephant in the corner of this room. I hope we'll have good numbers on water vapor by 2020 or thereabouts."

Myhrvold cites a recent paper a.s.serting that carbon dioxide may have had little to do with recent warming. Instead, all the heavy-particulate pollution we generated in earlier decades seems to have cooled the atmosphere by dimming the sun. That was the global cooling that caught scientists' attention in the 1970s. The trend began to reverse when we started cleaning up our air.

"So most of the warming seen over the past few decades," Myhrvold says, "might actually be due to good environmental stewardship!"

Not so many years ago, schoolchildren were taught that carbon dioxide is the naturally occurring lifeblood of plants, just as oxygen is ours. Today, children are more likely to think of carbon dioxide as a poison. That's because the amount of carbon dioxide in the atmosphere has increased substantially over the past one hundred years, from about 280 parts per million to 380.

But what people don't know, the IV scientists say, is that the carbon dioxide level some 80 million years ago-back when our mammalian ancestors were evolving-was at least 1,000 parts per million. In fact, that is the concentration of carbon dioxide you regularly breathe if you work in a new energy-efficient office building, for that is the level established by the engineering group that sets standards for heating and ventilation systems.

So not only is carbon dioxide plainly not poisonous, but changes in carbon-dioxide levels don't necessarily mirror human activity. Nor does atmospheric carbon dioxide necessarily warm the earth: ice-cap evidence shows that over the past several hundred thousand years, carbon dioxide levels have risen after a rise in temperature, not the other way around.

Beside Myhrvold sits Ken Caldeira, a soft-spoken man with a boyish face and a halo of curly hair. He runs an ecology lab at Stanford for the Carnegie Inst.i.tution. Caldeira is among the most respected climate scientists in the world, his research cited approvingly by the most fervent environmentalists. He and a co-author coined the phrase "ocean acidification," the process by which the seas absorb so much carbon dioxide that corals and other shallow-water organisms are threatened. He also contributes research to the Intergovernmental Panel on Climate Change, which shared the 2007 n.o.bel Peace Prize with Al Gore for sounding the alarm on global warming. (Yes, Caldeira got a n.o.bel certificate.)

If you met Caldeira at a party, you would likely place him in the fervent-environmentalist camp himself. He was a philosophy major in college, for goodness' sake, and his very name-a variant of caldera, the craterlike rim of a volcano-aligns him with the natural world. In his youth (he is fifty-three now), he was a hard-charging environmental activist and all-around peacenik.

Caldeira is thoroughly convinced that human activity is responsible for some global warming and is more pessimistic than Myhrvold about how future climate will affect humankind. He believes "we are being incredibly foolish emitting carbon dioxide" as we currently do.

Yet his research tells him that carbon dioxide is not the right villain in this fight. For starters, as greenhouse gases go, it's not particularly efficient. "A doubling of carbon dioxide traps less than 2 percent of the outgoing radiation emitted by the earth," he says. Furthermore, atmospheric carbon dioxide is governed by the law of diminishing returns: each gigaton added to the air has less radiative impact than the previous one.

Caldeira mentions a study he undertook that considered the impact of higher carbon-dioxide levels on plant life. While plants get their water from the soil, they get their food-carbon dioxide, that is-from the air.

"Plants pay exceedingly dearly for carbon dioxide," Lowell Wood jumps in. "A plant has to raise about a hundred times as much water from the soil as it gets carbon dioxide from the air, on a molecule-lost-per-molecule-gained basis. Most plants, especially during the active part of the growing season, are water-stressed. They bleed very seriously to get their food."

So an increase in carbon dioxide means that plants require less water to grow. And what happens to productivity?

Caldeira's study showed that doubling the amount of carbon dioxide while holding steady all other inputs-water, nutrients, and so forth-yields a 70 percent increase in plant growth, an obvious boon to agricultural productivity.

"That's why most commercial hydroponic greenhouses have supplemental carbon dioxide," Myhrvold says. "And they typically run at 1,400 parts per million."

"Twenty thousand years ago," Caldeira says, "carbon-dioxide levels were lower, sea level was lower-and trees were in a near state of asphyxiation for lack of carbon dioxide. There's nothing special about today's carbon-dioxide level, or today's sea level, or today's temperature. What damages us are rapid rates of change. Overall, more carbon dioxide is probably a good thing for the biosphere-it's just that it's increasing too fast."

The gentlemen of IV abound with further examples of global warming memes that are all wrong.

Rising sea levels, for instance, "aren't being driven primarily by glaciers melting," Wood says, no matter how useful that image may be for environmental activists. The truth is far less s.e.xy. "It is driven mostly by water-warming-literally, the thermal expansion of ocean water as it warms up."

Sea levels are rising, Wood says-and have been for roughly twelve thousand years, since the end of the last ice age. The oceans are about 425 feet higher today, but the bulk of that rise occurred in the first thousand years. In the past century, the seas have risen less than eight inches.

As to the future: rather than the catastrophic thirty-foot rise some people have predicted over the next century-good-bye, Florida!-Wood notes that the most authoritative literature on the subject suggests a rise of about one and a half feet by 2100. That's much less than the twice-daily tidal variation in most coastal locations. "So it's a little bit difficult," he says, "to understand what the purported crisis is about."

Caldeira, with something of a pained look on his face, mentions a most surprising environmental scourge: trees. Yes, trees. As much as Caldeira personally lives the green life-his Stanford office is cooled by a misting water chamber rather than air-conditioning-his research has found that planting trees in certain locations actually exacerbates warming because comparatively dark leaves absorb more incoming sunlight than, say, gra.s.sy plains, sandy deserts, or snow-covered expanses.

Then there's this little-discussed fact about global warming: while the drumbeat of doom has grown louder over the past several years, the average global temperature during that time has in fact decreased.

In the darkened conference room, Myhrvold cues up an overhead slide that summarizes IV's views of the current slate of proposed global-warming solutions. The slide says:

Too littleToo lateToo optimistic

Too little means that typical conservation efforts simply won't make much of a difference. "If you believe there's a problem worth solving," Myhrvold says, "then these solutions won't be enough to solve it. Wind power and most other alternative energy things are cute, but they don't scale to a sufficient degree. At this point, wind farms are a government subsidy scheme, fundamentally." What about the beloved Prius and other low-emission vehicles? "They're great," he says, "except that transportation is just not that big of a sector."

Also, coal is so cheap that trying to generate electricity without it would be economic suicide, especially for developing countries. Myhrvold argues that cap-and-trade agreements, whereby coal emissions are limited by quota and cost, can't help much, in part because it is already...

Too late. The half-life of atmospheric carbon dioxide is roughly one hundred years, and some of it remains in the atmosphere for thousands of years. So even if humankind immediately stopped burning all fossil fuel, the existing carbon dioxide would remain in the atmosphere for several generations. Pretend the United States (and perhaps Europe) miraculously converted overnight and became zero-carbon societies. Then pretend they persuaded China (and perhaps India) to demolish every coal-burning power plant and diesel truck. As far as atmospheric carbon dioxide is concerned, it might not matter all that much. And by the way, that zero-carbon society you were dreamily thinking about is way...

Too optimistic. "A lot of the things that people say would be a good thing probably aren't," Myhrvold says. As an example he points to solar power. "The problem with solar cells is that they're black, because they are designed to absorb light from the sun. But only about 12 percent gets turned into electricity, and the rest is reradiated as heat-which contributes to global warming."

Although a widespread conversion to solar power might seem appealing, the reality is tricky. The energy consumed by building the thousands of new solar plants necessary to replace coal-burning and other power plants would create a huge long-term "warming debt," as Myhrvold calls it. "Eventually, we'd have a great carbon-free energy infrastructure but only after making emissions and global warming worse every year until we're done building out the solar plants, which could take thirty to fifty years."

This hardly means the energy problem should be dismissed. That's why IV-along with inventors all over the world-are working toward the holy grail: cheaper and cleaner forms of energy.

But from an atmospheric perspective, energy represents what might be called the input dilemma. How about the output dilemma? What if the greenhouse gases we've already emitted do produce an ecological disaster?