Coal is dirty. But coal is driving the U.S., Chinese and Indian economies. And therefore, coal is not going away. Renewable energy sources like solar and wind generate only 1 percent of the world's electricity. Do the math: Making coal burn cleaner might be the most pressing environmental problem that no one talks about.

Despite recent estimates that pollution from China's booming coal industry reaches U.S. shores in as little as five days, the green-tech investment boom that has funded the rise of biofuels has bypassed coal. Even the head of the World Coal Institute recently proclaimed the last 10 years "a lost decade" for clean coal, saying it's time to play catch-up.

Stanford's Jeremy Carl, a research fellow in the Program on Energy and Sustainable Development, couldn't agree more. He spoke on the phone with Wired News to discuss China, the holy grail of clean coal and how many coal plants he'd trade for Kyoto's accomplishments.

Stanford research fellow Jeremy Carl says, "Coal is as dirty as it gets," but warns against throwing the possibly cleaned-up baby out with the dirty bathwater.

Wired News: Why'd you get into clean coal?

Jeremy Carl: I looked at the numbers. It's a question of where the big sources of emissions are and where we can attack them.

WN: Can you give us an idea of the scale of coal power? Can you put coal in context as an energy source?

Carl: Only oil makes a bigger contribution to global energy. In terms of energy in the industrial world, it's about 40 percent of electricity production.

WN: How dirty is coal?

Carl: Coal is as dirty as it gets. Coal has every element in the periodic table. And depending where in the world you get it from, "coal" can mean 100 different substances. If you sent the sort of coal you might use in a typical Indian plant to a supermodern boiler in Japan, it would shut the place down.

WN: But there's got to be good things about coal.

Carl: It's cheap. And coal doesn't have the kind of extreme risk that nuclear power has. You're not going to build a dirty bomb out of coal. And unlike other fossil fuels, it is really widely distributed, so there is less of a coal OPEC.

WN: And that distribution would seem to make resource wars less likely to break out over coal?

Carl: Yes.

WN: Is there an energy source that could replace coal?

Carl: Natural gas is the only viable replacement, and it's not clear that the natural-gas supply could scale up to replace coal.

WN: So, how can we can make coal cleaner?

Carl: The most-well-known is flue-gas desulfurization, which takes sulfur dioxide out of smoke stacks, and came out of concerns about acid rain. There are other pollution-control devices for nitrogen oxide and mercury filters.

WN: What about up-and-coming technologies like carbon capture and sequestration? Can you tell us about that?

Carl: You're taking carbon from a smokestack and pressure-injecting it into a geological formation of some sort. We actually already do this process at an industrial level. We know how this works.

WN: Seems like we're spending a lot of time on the backend scrubbing pollutants out. Should we be designing in a cleaner process on the front end?

Carl: A lot of people point to integrated gasification-combined-cycle (IGCC) plants, which gasify coal before burning it, as the holy grail because they get you a cleaner process. It gives you a more concentrated stream of carbon that you can sequester underground more cheaply. The capital cost is very high, though, and we don't have a lot of experience in designing them.

WN: We hear a lot about China's coal industry. Can you compare it with the U.S. industry, which ranks second in the world?

Carl: We mine about (1.1 billion tons) of coal per year. China was at about 1.4 billion tons seven years ago. Now they are at 2.4 billion tons. So, they essentially took the second-biggest coal industry in the whole world and replicated it in seven years. And if you look at the Chinese plans, they plan to ramp it up even more in the future.

WN: Given the obvious environmental impacts of these plants, why don't we have better answers for these problems than the Kyoto Protocol (which the United States didn't sign, and which exempted China and India from emissions restrictions)?

Carl: I'll give you a speculative, personal answer. It has to do with the politics of the type of people who were negotiating Kyoto. And the pressure put on by environmental groups that were uncomfortable with coal. There was just so much pressure on the symbolic importance of getting a deal done.

WN: What would you have rather seen?

Carl: I think there has been some really good criticism that says, "Was the U.N. really a good forum for this? Or would it have been better to have taken the 10 countries who consume 60 percent of global energy and do something with real teeth in it?" I think that would have been a much better approach.

I would have happily traded every emissions gain from Kyoto for eight clean coal plants sequestering carbon in different countries. Because then we could have a real discussion that says, "This works. Now let's see who has to bear the cost."

WN: Why would that be such a big deal?

Carl: Because right now we're having a conversation with China and India where we're trying to get China and India to build clean coal plants by saying, "Here's this thing that's never been tried before at a mass scale. You should build one." And that's not going to work.

A multi-year study of natural gas demand in China and India concludes with a forty-three paged document of startling conclusions from the cases of Guandong, Shanghai, and Beijing provinces. PESD researcher BinBin Jiang writes the results of market modeling of natural gas in these three coastal regions and comments on industrial, residential, and commercial demand for the commodity. Her report includes plans for future infrastructure, possible leverage for mitigation of carbon dioxide, the grip of coal on power in China, and estimations of energy usage.

Natural gas demand in China is not only an important concern for potential suppliers, but a global point of interest given the growing consumption of the developing country and associated emissions. The CO2 savings of natural gas as a less carbon intense fuel source for power could make a significant dent in future emissions. One surprising result Ms. Jiang writes on is the potential carbon savings of Chinese policy to reduce sulfur emissions--a concern for local and regional air quality--by switching fuel sources from coal to natural gas.

The report also focuses on China's demand and use for domestic coal and its consequences. The three regions studied have varied dependencies on fuel sources and the transport of fuel for power generation. With the help of three local Chinese academic teams and professional modelers, Ms. Jiang was able to get a full and in depth perspective of the real influences on Chinese decisions in fuel choice.

The BP Foundation has awarded a five-year, $7.5 million grant to Stanford University's Program on Energy and Sustainable Development to support research on modern energy markets. The foundation is funded by BP, one of the world's largest energy companies.

The gift follows the BP Foundation's initial grant of $1.8 million over three years, which was pledged in 2004 in support of the program.

"BP's support has allowed our program to study the world's most pressing energy problems, such as global warming, energy poverty and the prospects for the world oil market," said program director and Stanford law Professor David G. Victor. "In addition to BP Foundation support, we learn from BP's experience as an energy company because they operate in all the markets where we do research--such as in China and India."

"BP Foundation believes the work undertaken at Stanford deals directly with global issues that are key to meeting the world's growing energy needs," said Steve Elbert, chairman of the BP Foundation. "The drive to research and implement strategies to further understand today's energy markets is important work, and we are proud to partner again with Stanford."

The Program on Energy and Sustainable Development, part of the Freeman Spogli Institute for International Studies, concentrates on the legal, political and institutional dimensions of how societies derive value from energy. The BP Foundation grant is part of a rapid expansion of Stanford's research and teaching on energy issues, much of which focuses on the technical aspects of energy systems.

All of the program's research is public and published openly, including on its website. The gift from the BP Foundation, as well as all similar gifts to support the program's research, includes special provisions that assure the research program's independence in setting its research agenda.

The agreement with Stanford is one in a series of BP partnerships with universities in the United Kingdom, the United States and China, representing a total commitment of more than $600 million. The program at Stanford complements work on similar topics at Princeton University, Tsinghua University and Imperial College, among others.

Founded in 2001, the Program on Energy and Sustainable Development focuses on the "political economy" of modern energy services--the interaction of political, institutional and economic forces that often dominate energy markets. It collaborates with the Stanford Law School and other university departments and schools, including economics, engineering and earth sciences. About half of the program's resources are devoted to research partnerships in key developing countries, including Brazil, China, India, Mexico and South Africa. Program researchers have examined the emergence of a global business in natural gas, reforms of electric power markets and the supply of modern energy services to low-income rural households in developing countries.

The program's other major sponsor is the Electric Power Research Institute in Palo Alto, Calif., a research consortium that includes most of the world's largest electric companies.

President George W. Bush averted a nasty rift when he agreed in the final hours of the recent G8 summit to "consider seriously" the need to halve the world's emissions of global-warming gases by 2050. Canada, the European Union and Japan had already embraced that goal, leaving America the dirty stand-out. The deeper truth is that these eight industrial countries control.

Only part of the world's emissions, and the industrial activities that cause emissions are slow to change. Coal will be the hardest to tame because it is so cheap and abundant. Many coal-power plants coming online today will still be in service by 2050, and advanced plants that store effluent safely underground won't be used widely for many more decades. The geopolitical hurdles are also high. The plan introduced with much fanfare earlier this month by China, which next year will become the world's top emitter of greenhouse gases, contains nothing beyond what Beijing already had in place. The world, therefore, is in for some warming.

Pessimism about stopping global warming is leading some scientists to wonder out loud if it is possible through "geoengineering" to force the Earth to cool. The idea is not entirely new and is fraught with dangers, but it is likely to get more attention in coming years. At least since the 1950s, weather makers have dreamed of steering clouds and rain to crops (though they failed in practice). From there it was a small step to dreaming on the global scale. Indeed, when the thesis of global warming was first proposed a few decades ago, some analysts envisioned putting mirrors in space or on deserts to deflect a small fraction of sunlight--just enough to offset, crudely, the buildup of warming gases in the atmosphere. These premature plans were wildly costly and faltered also because climate is sensitive to a lot more than just the gross amount of sunlight that warms the planet.

Today's plans are looking more practical, though still fraught with danger. One would spread iron, a nutrient for algae, in the ocean to stimulate photosynthesis, a natural process in which plants absorb carbon dioxide. Injecting iron in parts of the ocean where it is scarce could trigger algal blooms and help remove even more CO2. Experimental "iron fertilization," as well as careful measurement around natural iron sources, offers tantalizing support for the theory, though nobody knows what biological horrors might follow from messing with the ocean ecosystem on a large scale. Nobel laureate Paul Crutzen helped touch off the current pondering about geoengineering with an editorial in the August 2006 issue of the scientific journal Climatic Change. He revived a Russian idea from the 1970s to inject sulfur particles into the stratosphere with balloons, artillery guns or jumbo jets. (Full disclosure: I am on the journal's board of editors.) Sulfur, in turn, can produce aerosols (particulates) and clouds that reflect some sunlight back to space.

The plan has some drawbacks. Nasty chemistry, including that which caused the hole in the ozone layer, might follow--nobody is sure. Sulfur can also cause acid rain and respiratory diseases. But such ideas are worth a close look, says Crutzen, because unchecked changes in climate might be even worse. And nature already does this--through volcanoes such as Mount Pinatubo, which cooled the planet for a while after it erupted in 1991. None of this is ready for prime time, and the mere mention causes environmentalists to shudder because it distracts from the urgent need to reduce emissions. But it will get more attention as the difficulties in making deep cuts in emissions and adapting to climate change become more apparent.

Geoengineering will raise at least two awkward questions. First, it turns the geopolitics of global warming on its head. Cutting emissions requires many nations to cooperate. Geoengineering can be done by just a few, or even one. Who will determine if geoengineering is safe, and what if the rest of us don't like the consequences? The second is humanity's relationship to nature. Climate warming is already causing stress on natural ecosystems, and it is a small step to imagine engineering rare and special ecosystems to help protect them. But if mankind extends management to the whole planet, do we, in effect, turn Earth into a zoo?