F. K. Weyerhaeuser Fellow Steven F. Hayward

I chose the provocative title to my talk today some months ago, in a moment of exasperation at the all-too-easy and cheap talk that climate change is a problem that can be solved with seemingly little more than pixie dust and duct tape--or so it seemed at the time. In recent weeks there have been a few glimpses of seriousness about the issue, but there is still something hugely amiss about the entire matter.

I should begin by stating that it is not my purpose here today to enter into the scientific dispute about the nature and extent of global warming, except to note my objection to the line of argument that the issue is settled or closed, or that those with doubts about the catastrophic scenario beloved of former Vice President Gore and many environmentalists are the moral equivalent of Holocaust deniers or flat-earthers. It is never a good sign when someone wants to close down disputation with name-calling and intimidation.

I encourage those of you who suffer insomnia to download and flip through the most recent 900-page report on the science of climate change from the UN's Intergovernmental Panel on Climate Change, and note that, in the space of 900 pages, the report uses the word "uncertain" or "uncertainty" over 1,300 times. The report describes our level of understanding of many key scientific aspects of the matter as either "low" or "very low." That hardly sounds like a matter that is nailed down or settled to me.

What people commonly call a "consensus" about global warming is properly described in succinct terms as follows: for almost 30 years now, the climate models have predicted that if we double the amount of greenhouse gases in the atmosphere, global average temperature will increase between 1.5 degrees Celsius to 4.5 degrees Celsius. Warming at the low end of that range would have modest or even benign consequences; warming at the high end of that range will have serious and expensive consequences. Despite billions of dollars of research, data gathering, and ever-faster and more complex computer climate models, we have not been able to narrow that range or arrive at a high probability for a best guess within that range.

Despite the high degree of confidence asserted by the most vocal advocates, such as the former Vice President, of the catastrophic scenario of global warming, there continue to be number of anomalies and defects limiting our ability to predict our climate future. And despite the highly politicized state of the scientific inquiry and the near-McCarthyite fervor by which some people are trying to shut down debate and dissent, I have reached a state of repose over the matter. Science is an iterative process, and if the skeptics are right that certain factors behind the warming we have seen have been underestimated, or that certain feedback effects threatening significant future warming are overestimated, in the fullness of time scientific research will come around on this, as we have seen with many past environmental alarms, such as acid raid, which, 30 years ago, was considered a crisis of major proportions, when in fact further scientific research showed it to be a problem of minor proportions.

Suffice it say that for policy-making purposes today, there are good reasons to conclude that warming is likely to be on the low end of that range, and therefore to be a very modest problem going forward. But there is a non-trivial risk of very high warming with serious consequences, and decent reasons for concluding we will experience an intermediate amount of warming, which is why policy-makers need to consider a range of responses in case any of the moderate to severe scenarios come to pass.

The preferred--indeed, even the solitary--means of thinking about what to do about global warming is to embark on a crash reduction of human greenhouse gas emissions. How feasible and realistic is this? Will it work? And if not, what other possibly approaches should be considered?

Right now the climate campaigners are saying that the U.S. needs to achieve an 80 percent reduction in GHG emissions by the year 2050, what I call the "80 by 50" target. Both Hillary Clinton and Barack Obama have endorsed 80 by 50, while John McCain is not far behind, calling for a 65 percent reduction.

We ought to reflect what an 80 percent reduction by the year 2050 really means. Now ordinarily this is the point at which I would crank up the Powerpoint slides to go through a blizzard of numbers, but I've given up Powerpoint--I have joined Powerpointers Anonymous, in fact, except that the 12-step program was explained to me in a Powerpoint presentation. If Lord Acton were alive today, I am sure he would warn us that power corrupts, and Powerpoint corrupts absolutely.

So please bear with me as I walk you through some numbers, some of which I presented in an article in the Wall Street Journal yesterday, and a more detailed version of which you can find in the annual report I produce, the Index of Leading Environmental Indicators. I'll recapitulate this analysis for you in a very simple manner at the end in the same way Ronald Reagan used to get across complicated federal budget arithmetic.

Begin with the current inventory of carbon dioxide (CO2) emissions--CO2 being the principal greenhouse gas generated almost entirely by energy use. According to the Department of Energy's most recent data on GHG emissions, in 2006 the U.S. emitted 5.8 billion metric tons of CO2, or just under 20 tons per capita. An 80 percent reduction in CO2 emissions from 1990 levels means that the U.S. cannot emit more than about 1 billion metric tons of CO2 in 2050.

The first threshold question to ask is when were U.S. CO2 emissions ever that low? From historical energy data it is possible to estimate that the U.S. last emitted 1 billion MT around 1910, when the U.S. only had 92 million people, and per capita income, in current dollars, was about $6,000. But by the year 2050, the Census Bureau projects that our population will be around 420 million, which means that per capita emissions will have to fall to about 2.5 tons. It is likely that U.S. per capita emissions have never been that low, even back in colonial days when the only fuel we burned was wood. The only nations in the world today that emit at this low level are all poor developing nations, such as Belize, Mauritius, Jordan, Haiti, and Somalia. Even the best industrialized nations do not come close to this level: France and Switzerland, compact nations that generate almost all of their electricity from non-fossil fuel sources (nuclear for France, hydro for Switzerland) emit about 6.5 metric tons of CO2 per capita.

The daunting task of reaching 1 billion MT of CO2 comes into greater relief when we look sector-by-sector in the American economy. The DoE breaks down emissions into four major sectors: residential, commercial (office buildings and the like), industrial, and transportation (planes, trains and automobiles); electricity consumption is apportioned to each sector. At the present time, American households emit 1.2 billion tons of CO2--20 percent higher than the entire nation's emissions must be in 2050. If the household sector is to emit no more than its present share of CO2, emissions will have to be reduced to 204 million tons by 2050.

Never mind electricity use--Current CO2 emissions natural gas use from the household sector today are 237 million tons, almost 30 million tons above what the entire household sector must meet in 2050; by 2050, household natural gas use will likely be between 400 and 500 million tons if we are still to use natural gas for heating and cooking in our homes--almost half of the total emissions budget for the entire nation.

But then keep in mind that in 2050, there will be another 40 million residential households in the U.S. By contrast, the U.S. Department of Energy projects that household CO2 emissions will rise to 1.5 billion tons by the year 2030, which is as far out as their projections go.

Right now, the average residence in the U.S. uses about 10,500 kilowatt hours of electricity and emits 11.4 tons of CO2 per year (much more if you are Al Gore or John Edwards and live in 10,000 square foot houses). These emissions come from heating, cooling, running appliances, and so forth, and does not count our emissions from our driving. To stay within the magic number average household emissions will have to fall to no more than 1.5 tons per year. In our current electricity infrastructure, this would mean using no more than about 2,500 KwH per year. This is not enough juice to run the average hot water heater. You can forget refrigerators, microwaves, clothes dryers, and flat screen TVs. Even a house tricked out with all the latest high-efficiency EnergyStar appliances and compact fluorescent lights won't come close to the target.

The same daunting energy math applies to the industrial, commercial, and transportation sectors as well. Right now our cars and trucks consume about 180 billion gallons of motor fuel. Yet to meet the 2050 target we shall have to limit our consumption of gasoline to about 31 billion gallons--a fuel consumption level of about the year 1930--unless a genuine carbon-neutral liquid fuel can be produced. Ethanol isn't it. To show how unrealistic this is, if the entire nation drove nothing but hybrid Toyota Priuses in 2050, we'd still overshoot the transportation sector emissions target by 40 percent.

The clear implication is that we shall have to replace virtually the entire fossil fuel electricity infrastructure over the next four decades with CO2-free sources--a multi-trillion dollar proposition, if it can be done at all--and all in the space of little more than a generation. Natural gas--the preferred coal substitute of the moment--won't come close. If we replaced every single existing coal-fired power plant with a natural gas plant, CO2 emissions from electric power generation alone would still be more than twice the 2050 target. Most environmentalists remain opposed to nuclear power, of course. It is unlikely that renewables--wind, solar, and biomass--can ever make up more than about 20 percent of our electricity supply.

Let me recapitulate this in a simple way. Ronald Reagan used to illustrate the problem of government spending in the following way. He'd hold up his arm at a 40 degrees angle and say, "The problem with spending is that the budget is growing like this. What we need to do is to reduce the rate of growth of government spending like this," and he'd lower the angle of his arm to about 30 degrees.

You can do something similar with the energy and greenhouse gas emissions picture. Our Department of Energy, and the European energy ministries, have done projections of energy use and GHG emissions through the year 2030, and they all produce lines that look like rise at about 30 degree angles.

Two Princeton University energy economists, Robert Socolow and Stephen Pacala, have calculated that with a supreme effort involving the adoption of seven aggressive energy strategies, including substantial new nuclear power capacity, and costing on the order of perhaps $6 trillion over the next 20 years, the U.S. might be able keep CO2 emissions flat by the year 2050, after which time it is hoped that new energy technologies will make it possible to achieve real reductions in CO2 emissions in the second half of the century.

And the climate campaigners say we need to have an 80% reduction.

I am reminded of the line from T. S. Eliot's poem The Hollow Men: "Between the idea and the reality falls the shadow." When you go through these numbers, the goal of the climate campaigners looks hollow indeed. Or, to use the language they find more congenial, such a target is unsustainable.

The energy experts at the DoE (and in the European energy ministries, too) must surely close their doors and erupt in laughter at politicians' happy talk of deep, near-term emission cuts. The enthusiasm for an 80 percent reduction target is often justified on the ground that national policy should set an ambitious goal. However, the 80 by 50 target is the energy equivalent of John F. Kennedy having made it our goal to land a man on Mars instead of the moon by 1970. Claims on behalf of alternate energy sources--whether biofuels, hydrogen, windpower, and so forth--either do not match up to the scale of the energy required or are not cost-competitive in current form. This is why I say that our discourse on this issue is fundamentally unserious. The U.S. is simply not going to divert the immense amounts of investment capital contemplated in the 80 by 50 target.

Someone should put these questions in pointed form to the candidates, and not let them slide by with glittering generalities.

Is there an alternative in the event of the worst-case scenario coming to pass?

I think there is, and it goes by the ungainly name of "geoengineering." We have long known that particulates from large volcano eruptions cool the atmosphere; the 1992 eruption of Mt. Pinatubo in the Philippines was the first modern eruption whose effects were closely measured and studied. In the aftermath of Pinatubo, planetary temperatures were lowered by about 1 degree F for nearly two years. Could mankind deliberately mimic the climate effects of volcanoes by deliberately injecting particulates into the high atmosphere?

The idea is not new. The National Academy of Sciences, among others, studied the idea in the early 1990s, and in a coincidence of bad timing, produced a report just before Mt. Pinatubo erupted generally discounting the idea for its cost and but not categorically dismissing it. (The NAS study found that increasing the reflectivity of the Earth by just one percent would be enough to compensate for doubling levels of carbon dioxide in the atmosphere.) For the last several years, however, the idea has been virtually taboo in climate science circles--an example of how commitment to a particular policy regime (greenhouse gas emissions reductions) can constrain open scientific inquiry. Rolling Stone magazine, of all unlikely places, reported in December 2006 that when the subject came up at seminar of Stanford's Energy Modeling Forum held in Aspen last summer, it nearly erupted into a shouting match. The New York Times has also reported on the controversy.

A fresh round of scientific discussion on this idea emerged in 2006 when Climatic Change, a leading journal in the field, published an article by Nobel Prize-winning chemist Paul Crutzen speculating on the methods, practicalities, and costs of deliberately injecting particulates into the atmosphere to reduce global warming. (Crutzen won his Nobel Prize for his work in the 1980s on stratospheric ozone depletion, which was a crucial scientific step in the road to the Montreal Protocol.) Crutzen now believes that it would be technically easy and relatively inexpensive to place a layer of sulfate particles 10 miles up in the atmosphere, either through giant cannons or balloons; other advocates suggest high altitude aircraft would be sufficient. He concludes that as little as 1 million tons might be adequate; by comparison, coal-burning power plants in the U.S. emit more than 6 million tons a year of sulfur dioxide. His ideas have found backup from other leading climate scientists. Tom Wigley of the National Center for Atmospheric Research (NCAR) wrote favorably of the idea in Science. And Stanford climate scientist Ken Caldeira, while "philosophically opposed" to the idea of geoengineering, conducted an extensive computer climate model run that generally backed up Crutzen's ideas. NASA held a two-day, closed-door workshop on the subject in November, and the EPA's National Center for Environmental Economics published a working paper discussing the subject.

Caldeira's "philosophical opposition" to geoengineering is widespread. At the Aspen meeting, Yale's William Nordhaus reportedly objected that geoengineering would be enable more fossil-fuel use, which would be like giving methadone to a heroin addict.

And Climatic Change took the highly unusual step of publishing five separate editorial commentaries on how Crutzen's article should be understood. This is likely unprecedented in the history of scientific publishing. Ralph Cicerone, president of the National Academies of Science, made clear why in his editorial contribution: "various individuals have opposed the publication of Crutzen's paper, even after peer review and revisions, for various and sincere reasons that are not wholly scientific." (Emphasis added.) Mark Lawrence of the Max Planck Institute in Germany concurred in his own Climatic Change editorial comment: "There was a passionate outcry by several prominent scientists claiming that it is irresponsible to publish such an article focused on a particular geoengineering proposal."

This kind of environmental correctness should be genuinely disturbing, as a pre-existing policy agenda or preference should not be used as a reason to prevent research, let alone published scientific speculation from a Nobel laureate, from going forward. It is an example of exactly the kind of politicization of the subject that has led to so much popular distrust of climate science and policy gridlock over the last 20 years. There are numerous political problems with the idea, to be sure. It may require changes in international law to implement (a UN treaty forbids "manipulation of the environment" for military purposes). Do Russia and Canada really want their northern reaches to cool off again?

It appears that ideological resistance to the idea is breaking down. "People used to say, 'Shut up, the world isn't ready for this,'" Wallace S. Broecker, a geoengineering advocate at Columbia University, told the New York Times. "Maybe the world has changed."

Steven F. Hayward is the F. K. Weyerhaeuser Fellow at AEI.