Storms of My Grandchildren (34 page)

The framework concerns how to make an across-the-board fee on fossil fuel carbon work on a global basis, in a way that is fair, because unless there is a universal carbon fee, it will be ineffective. The backbone, I will argue, makes it relatively simple to define international arrangements—I will explain what I mean by “relatively simple” in a moment. The backbone also makes it practical to have a framework that deals with the problem of fairness between those who have caused the problem, those who are causing the problem, and those who are primarily the victims of others. The framework can also help deal with the fundamental problems of population and poverty.

Contrary to the assertion by proponents of a Kyoto-style cap-and-trade agreement, cap-and-trade is not the fastest way to an international agreement. That assertion is another case of calling black “white,” apparently under the assumption that the listener will accept it without thinking. A cap-and-trade agreement will be just as hard to achieve as was the Kyoto Protocol. Indeed, why should China, India, and the rest of the developing world accept a cap when their per-capita emissions are an order of magnitude less than America’s or Europe’s? Leaders of developing countries are making that argument more and more vocally. Even if differences are papered over to achieve a cap-and-trade agreement at upcoming international talks, the agreement is guaranteed to be ineffectual. So eventually (quickly, I hope!) it must be replaced with a more meaningful approach. Let’s define one.

The key requirement is that the United States and China agree to apply across-the-board fees to carbon-based fuels. Why would China do that? Lots of reasons. China is developing rapidly and it does not want to be saddled with the fossil fuel addiction that plagues the United States. Besides, China would be hit at least as hard as the United States by climate change. The most economically efficient way for China to limit its fossil fuel dependence, to encourage energy efficiency and carbon-free energies, is via a uniform carbon fee. The same is true for the United States. Indeed, if the United States does not take such an approach, but rather continues to throw lifelines to special interests, its economic power and standard of living will deteriorate, because such actions make the United States economy less and less efficient relative to the rest of the world.

Agreement between the United States and China comes down to negotiating the ratio of their respective carbon tax rates. In this negotiation the question of fairness will come up—the United States being more responsible for the excess carbon dioxide in the air today despite its smaller population. That negotiation will not be easy, but once both countries realize they are in the same boat and will sink or survive together, an agreement should be possible.

Europe, Japan, and most developed countries would likely agree to a status similar to that of the United States. It would not be difficult to deal with any country that refuses to levy a comparable across-the-board carbon fee. An import duty could be collected by countries importing products from any nation that does not levy such a carbon fee. The World Trade Organization already has rules permitting such duties. The duty would be based on standard estimates of the amount of fossil fuels that go into producing the imported product, with the exporting company allowed the option of demonstrating that its product is made without fossil fuels, or with a lesser amount of them. In fact, exporting countries would have a strong incentive to impose their own carbon fee, so that they could keep the revenue themselves.

As for developing nations, and the poorest nations in the world, how can they be treated fairly? They also must have a fee on their fossil fuel use or a duty applied to the products that they export. That is the only way that fossil fuels can be phased out. If these countries do not have a tax on fossil fuels, then industry will move there, as it has moved already from the West to China and India, with carbon pollution moving along with it. Fairness can be achieved by using the funds from export duties, which are likely to greatly exceed foreign aid, to improve the economic and social well-being of the developing nations.

I do not want to wander far into these subjects, but it would be inappropriate not to mention the connection between population and climate change. The stress that humans place on the planet and other species on the planet is closely related to human population growth. Stabilization of atmospheric composition and climate almost surely requires a stabilization of human population.

The encouraging news is that there is a strong correlation between reduced fertility rates, increased economic well-being, and women’s rights and education. Many Western countries now have fertility rates below or not far from the replenishment level. The substantial funds that will necessarily be generated by an increasing fee on fossil fuel carbon should be used to reward the places that encourage practices and rights that correlate with sustainable populations.

In summary, the backbone of a solution to the climate problem is a flat carbon emissions price applied across all fossil fuels at the source. This carbon price (fee, tax) must rise continually, at a rate that is economically sound. The funds must be distributed back to the citizens (not to special interests)—otherwise the tax rate will never be high enough to lead to a clean energy future. If your government comes back and tells you that it is going to have a “goal” or “target” for carbon emission reductions, even a “mandatory” one, you know that it is lying to you, and that it doesn’t give a damn about your children or grandchildren. For the moment, let’s assume that our governments will see the light.

Once the necessity of a backbone flat carbon price across all fossil fuel sources is recognized, the required elements for a framework agreement become clear. The principal requirement will be to define how this tax rate will vary between nations. Recalcitrance of any nations to agree to the carbon price can be handled via import duties, which are permissible under existing international agreements. The framework must also define how proceeds of carbon duties will be used to assure fairness, encourage practices that improve women’s rights and education, and help control population. A procedure should be defined for a regular adjustment of funds’ distribution for fairness and to reward best performance.

Well, what happens if, instead of accepting the need for a rising carbon price, our governments continue to deceive us, setting goals and targets for carbon emissions reductions?

In that case we had better start thinking about the Venus syndrome.

I
N DECEMBER 2008 I HAD THE HONOR of giving the Bjerknes Lecture, a one-hour talk at the annual meeting of the American Geophysical Union in San Francisco, named for Vilhelm Bjerknes, the Norwegian physicist and meteorologist who was a founding father of modern weather forecasting. My talk was titled “Climate Threat to the Planet.”

I realized that, in addition to reviewing current understanding of ongoing climate change, I had better include a look at Earth from a planetary perspective. “A planet in peril” had become a popular phrase, but it seemed that people using it did not understand the full implications.

First, special interests were remarkably successful in preventing the public at large from understanding the situation. The result was a growing gap between what was understood by the relevant scientific community about human-caused climate change and what was appreciated by the public.

Second, it had become clear that greenwash was a near universal response of politicians to the climate change issue. I became well acquainted with greenwash via interactions with several governors, as summarized in the “Dear Governor Greenwash” letter on my Web site, and I observed that the media allowed politicians to get away with what amounted to fake environmentalism. Most important, it was becoming apparent that the international follow-up to the ineffectual Kyoto Protocol could be another ineffectual target-based cap-and-trade agreement. And several nations, including the United States, seemed to be going right ahead with plans for coal-to-liquid fuels and development of unconventional fossil fuels, oblivious to the long-term implications.

What can one do in such a situation? Writing scientific papers, giving talks, writing op-eds did not seem to have any effect in Washington or other capitals. There are thousands of oil, gas, and coal lobbyists in Washington. These lobbyists are very well paid. It is no wonder that government energy policies are so hospitable to the fossil fuel industry.

Given this situation, it seems possible that strategic changes to fossil fuel use will not be adopted. Goals, cap-and-trade, and offsets—in other words, business as usual—may continue. So we had better examine what may happen if we push the planet beyond its tipping point.

Mars has so little gas in its atmosphere that its greenhouse effect is negligible, and the surface temperature averages about −50 degrees Celsius (about 60 degrees below zero Fahrenheit). Greenhouse gases warm Earth’s surface by about 33 degrees Celsius (about 60 degrees Fahrenheit), making the average surface temperature about 15 degrees Celsius (about 60 degrees Fahrenheit). Venus has so much carbon dioxide in its atmosphere that it has a greenhouse warming of several hundred degrees, with the surface, at 450 degrees Celsius (about 850 degrees Fahrenheit), hot enough to melt lead.

Venus is almost as big as Earth, with a diameter about 95 percent as large. Venus and Earth, having condensed from the same interstellar gas and dust during the formation of the solar system, must have begun with similar atmospheric compositions. So the early Venus atmosphere contained lots of water vapor. The sun was 30 percent dimmer at that time, so Venus was probably cool enough to have oceans on its surface. But they did not last long. As the sun brightened, the surface of Venus became hotter, water evaporated, and the strong greenhouse effect of water vapor amplified the warming. Eventually a “runaway” greenhouse effect occurred, with the ocean boiling or evaporating into the atmosphere. The surface became so hot that all the carbon dioxide in the crust was “baked out” into the atmosphere. There was a lot of carbon in the crust, so much that the atmosphere became predominately carbon dioxide. The atmosphere of Venus is now almost 97 percent carbon dioxide and the surface pressure on Venus is 90 bars, i.e., 90 times greater than the surface pressure on Earth—that’s about 1,300 pounds per square inch, which would crush any human visitors, if they were not fried first.

The water vapor on Venus was eventually lost to space. Ultraviolet sunlight “dissociates” (breaks up) atmospheric water vapor molecules into hydrogen and oxygen. The molecules and atoms are continuously moving about in the atmosphere. After dissociation, some light hydrogen atoms are able to escape the planet’s gravitational field. The remaining oxygen combines with other material, for example, with carbon, to make carbon dioxide. In this way, water was lost from Venus.

Can we confirm this explanation for why Venus has no water today, while it must have had water at the time of its origin? Yes. We have measurements of hydrogen isotopes in the Venus atmosphere. Deuterium, which is heavy hydrogen with a nucleus containing two neutrons, is ten times more abundant on Venus relative to normal hydrogen than it is on Earth and on the sun, even though Venus, Earth, and the sun all formed from the same primordial nebula. The enrichment of heavy hydrogen on Venus provides a measure of its lost hydrogen, because the lighter, normal hydrogen can escape the planet’s gravitational field more easily than heavier deuterium can escape. The data agree with the assumption that an early Venus was wet.

So Venus had a runaway greenhouse effect. Could Earth? Of course we know that it could. The question is, rather, how much must carbon dioxide (or some other climate forcing) increase before a runaway effect occurs?

The climate sensitivity of the model began to increase rapidly with either a large negative forcing or a large positive forcing. Qualitatively, this is the behavior that we know must occur: A sufficient negative forcing causes a runaway snowball Earth condition, with freezing temperatures over the entire planet, while a sufficient positive forcing causes a runaway greenhouse effect. We know that this U-shaped curve is correct—the question is, at what forcings do the sharp upturns to runaway conditions occur?

There may have been problems with the model, inaccuracies in the representation of climate processes, which would have caused the upswings in sensitivity to occur at too small forcings. However, the largest uncertainties that we can identify work in the opposite direction. The model employed to calculate figure 30 had fixed ice sheet area. If ice sheets had been allowed to grow with negative forcing and melt with positive forcing, and if enough time had been allowed for the melting to occur, the sharp upturns would have taken place at smaller forcings. Also, limited empirical evidence suggests that as the planet gets warmer, the amount of other trace greenhouse gases in the air, in addition to carbon dioxide and water vapor, tends to increase.

These considerations, and the modeling result, suggest that the forcings needed to reach snowball Earth or runaway greenhouse conditions are no more than 10 to 20 watts per square meter when solar irradiance or carbon dioxide change are defined as the forcing. The change required for a snowball Earth is of course a negative (reduced) forcing.

We can state this result in another way that may be easier to understand. There is only a limited range of distance around any star, such as the sun, at which a planet will have a “habitable” surface temperature, with liquid water on the surface. If the planet is closer to the sun, the greenhouse effect will cause any water to be evaporated into the atmosphere. If the planet is too far from the sun, any water will be frozen all the way to the equator.

This limited habitable zone was a source of puzzlement to planetary and Earth scientists for decades. It was called the “faint young sun” paradox. How had Earth avoided slipping into permanent snowball conditions in its early history, when the sun was known to have been much dimmer? And how had life survived on a snowball Earth? The first simple energy-balance climate model, introduced in the 1960s by Russian climatologist Mikhail Budyko, found that, if ice advanced as far toward the equator as latitude 30 degrees, the amplifying feedback of increased planetary albedo would cause ice to advance suddenly all the way to the equator. The resulting ice-covered Earth would reflect most sunlight, so its climate should be stable in this snowball condition, even if the sun’s brightness increased as much as several percent.

Another flaw in the 1960s thinking was caused by the simplicity of Budyko’s energy balance calculation. It turns out that a realistic three-dimensional climate model, including ocean dynamics and seasonal and daily variations of sunlight, does not yield a hard iceball, with the ocean covered everywhere by a thick solid ice layer. Indeed, snowball Earth was more like a slushball. The areas of open water make it easier to understand how life survived the snowball state.