by Andrew Revkin of the New York Times, April 6, 2008

The charged and complex debate over how to slow down global warming has become a lot more complicated.

Most of the focus in the last few years has centered on imposing caps on greenhouse gas emissions to prod energy users to conserve or switch to nonpolluting technologies.

Leaders of the Intergovernment Panel on Climate Change — the scientists awarded the Nobel Peace Prize last year with former Vice President Al Gore — have emphasized that market-based approach. All three presidential candidates are behind it. And it has framed international talks over a new climate treaty and debate within the United States over climate legislation.

But now, with recent data showing an unexpected rise in global emissions and a decline in energy efficiency, a growing chorus of economists, scientists and students of energy policy are saying that whatever benefits the cap approach yields, it will be too little and come too late.

The economist Jeffrey D. Sachs, head of the Earth Institute at Columbia University, stated the case bluntly in a recent article in Scientific American: “Even with a cutback in wasteful energy spending, our current technologies cannot support both a decline in carbon dioxide emissions and an expanding global economy. If we try to restrain emissions without a fundamentally new set of technologies, we will end up stifling economic growth, including the development prospects for billions of people.”

What is needed, Mr. Sachs and others say, is the development of radically advanced low-carbon technologies, which they say will only come about with greatly increased spending by determined governments on what has so far been an anemic commitment to research and development. A Manhattan-like Project, so to speak.

And time is critical, they say, as China, India and other developing nations march headlong into the modern world of cars and electric consumption on their way to becoming the dominant producer of greenhouse gases for decades to come. Indeed, China is building, on average, one large coal-burning power plant a week.

In an article in the journal Nature last week, researchers concerned with the economics, politics, and science of climate also argued that technology policy, not emissions policy, must dominate.

“There is no question about whether technological innovation is necessary — it is,” said the authors, Roger A. Pielke Jr., a political scientist at the University of Colorado; Tom Wigley, a climatologist at the National Center for Atmospheric Research; and Christopher Green, an economist at McGill University. “The question is, to what degree should policy focus directly on motivating such innovation?”

Proponents of treaties and legislation that would cap emissions don’t disagree with this call to arms for new, low-carbon technologies. But they say the cap approach should not be ignored, either.

One of them is Joseph Romm, a blogger on climate and a senior fellow at the Center for American Progress, a nonprofit group pushing for federal legislation to restrict greenhouse gases.

“Of course we need aggressive investments in R. and D. — I for one have been arguing that for two decades,” Mr. Romm wrote in a post to his blog, climateprogress.org. “But if we don’t start aggressively deploying the technologies we have now for the next quarter century, then all the new technologies in the world won’t avert catastrophe.”

Another expert who has emphasized the importance of capping emissions, Adil Najam of Boston University, said he hoped this emerging debate would not distract from doing whatever is possible now to curb emissions.

“You can do a tremendous lot with available technology,” said Professor Najam, one of the authors of the intergovernmental panel’s report on policy options. “It is true that this will not be enough to lick the problem, but it will be a very significant and probably necessary difference.”

But Professor Pielke and his co-authors say that a recent rise in emissions — particularly in fast-growing emerging powers — points to the need for government to push aggressively for technological advances instead of waiting for the market to force reductions in emissions.

Mr. Sachs pointed to several promising technologies — capturing and burying carbon dioxide, plug-in hybrid cars and solar-thermal electric plants. “Each will require a combination of factors to succeed: more applied scientific research, important regulatory changes, appropriate infrastructure, public acceptance and early high-cost investments,” he said. “A failure on one or more of these points could kill the technologies.”

In short, what is needed, he said, is a “major overhaul of energy technology” financed by “large-scale public funding of research, development and demonstration projects.”

At the same time, China and India continue to insist that economic growth is both their priority and right. They argue that the established economic powers should be responsible for spearheading the research to reduce carbon emissions. After all, the United States and Europe spent more than a century growing wealthy by burning fossil fuels.

Developing countries repeatedly made that point last week in Bangkok in the latest round of United Nations talks over the shape of a new climate agreement. But the United States rejected a proposal from China that 0.5 percent of the gross domestic product of industrialized countries be used to disseminate nonpolluting energy technologies.

As if to underscore the energy and emissions trajectories in Asia’s emerging powerhouses —and the priority placed on growth there and among important international institutions — the International Finance Corporation of the World Bank is planning to vote on Monday on helping to finance a four-billion-watt complex of coal-burning power plants, the “Ultra Mega” complex, in Gujarat State in India.