Nusa Dua, Bali - Assume man-made global warming is a big problem. In fact, you are persuaded that unless something is done soon, the world will warm up on average between 2 and 3 degrees Celsius over the next century and that this is a really bad idea. What will it take to address climate change in technical terms?
At a side event on Wednesday, held at the Bali Grand Hyatt, James Connaughton, one of the lead U.S. climate negotiators and the director of President Bush's Council on Environmental Quality, offered some insight on this issue. First, Connaughton assured the audience that the U.S. accepts that the world must slow, stop and then reverse greenhouse gas emissions. He declared that U.S. seeks to establish "a shared long-term global goal in reducing greenhouse gas emissions in absolute terms." Although Connaughton was not specific, such a goal might be an agreement to cut global emissions by 50 percent by 2050. Setting a long-term goal, Connaughton added, would let everyone know the reductions curve they face ahead, enabling them to plan accordingly.
So what is the size of the problem confronting the world? Connaughton pointed out that the largest increases in GHG emissions will come from new coal-fired electric generation plants, more people driving more cars, and land use changes. Therefore, the world must figure out how to capture and sequester CO2 emissions from coal, devise carbon-neutral transport fuels and reverse deforestation.
Connaughton cited estimates that by 2020 there will be as many cars in China as there are today in the United States. One of his fellow panelists, William Hohenstein of the U.S. Department of Agriculture, highlighted that deforestation is responsible to 20 percent of GHG emissions and agriculture adds 15 percent more. This means that 35 percent of GHG emissions are the result of land use changes. In fact, one-third of the increase in atmospheric carbon dioxide (CO2) concentrations over pre-industrial levels is the result of deforestation and other land use changes. Interestingly, U.S. forests are now absorbing about 10 percent of the country's annual emissions (of course, a lot of carbon was released when one-third of the original forest area was cut as the country developed economically).
Connaughton offered an interesting thought experiment. The major economies emit 22 gigatons (1 billion tons) of CO2 annually. In one reference case, those emissions would rise to 37 gigatons by 2050. So, Connaughton says, assume that we need to reduce current emissions by half from current emission—by 11 gigatons—to stabilize CO2 atmospheric concentrations. That means that the world would have to find the equivalent energy that producing 25 gigatons of emissions would have produced in 2050.
To get a handle on what this might mean, Connaughton asked, "How big is a gigaton?" One gigaton is equivalent to 273 coal-fired electric generation plants with carbon capture and sequestration (CCS). Of course, there are only a few demonstration plants now, and 273 plants represent 7 percent of the world's current coal-fired generation capacity. Estimates of how much CCS might cost range between $150 to $250 per ton of carbon (or $50 to $80 per ton of CO2). By one estimate CCS would raise the cost of electricity to 25 to 40 percent; others suggest that the increase could be as much as 85 percent.
Connaughton also pointed out that avoiding the emission of a gigaton of CO2 implies building 135 new nuclear power plants. The world has 400 now. In addition, a gigaton is equivalent to 270,000 windmills which is 4-times more than are currently operating. Growing enough biofuels to reduce a gigaton of emissions would take an area twice the size of the United Kingdom. Of course, such projections rely on the deployment of near-term technologies. It's impossible to tell what new technologies a higher price on carbon fuels might call forth from the world's laboratories.
Clearly, as Indonesia's President Susilo Bambang Yudhoyono noted when he opened the Bali conference, "We are embarking on the greatest project in the history of human civilization."
Disclosure: I would like to express my deep appreciation to the Atlas Economic Research Foundation for providing a grant to pay for my travel expenses to cover the COP-13 meeting.
Ronald Bailey is Reason's science correspondent. His most recent book, Liberation Biology: The Scientific and Moral Case for the Biotech Revolution, is available from Prometheus Books.