At the World Climate Summit in Montreal, politicians and environmentalists are discussing technical solutions for dealing with global warming. In initial pilot projects, engineers are attempting to capture the carbon dioxide emitted by power plants and burying it in rock beneath the surface or depositing it on the ocean floor.
In a classified document, climate protection experts were proposing “politically sensitive” measures to the British government.
One of the measures the authors of the report proposed was to impose stricter penalties for speeding in order to force those 15 million Britons who exceed the country’s 70 mph (113 km/h) speed limit each year to drive more slowly. Emissions of the greenhouse gas carbon dioxide jump exponentially when cars travel at speeds of more than 100 kilometers per hour — and that is exactly what the authors so urgently want to curtail. “We must achieve 75 percent more savings in half the time,” say the authors of the report, which was eventually released to the public in mid-November, in justifying their draconian recommendations.
Great Britain is not the only country likely to fall short of its self-imposed climate objectives. Despite pledging to reduce its emissions by 6 percent under the Kyoto Protocol, Canada is currently 24.2 percent above 1990 levels. And the main reason Germany has managed to reduce its emissions by 18.5 percent is that industry has declined in the former East Germany.
“To our great concern, we are now seeing a rising tendency in CO2 emissions after years of stagnation,” warns Richard Kinley, director of the United Nations Climate Change Secretariat in Bonn.
In this gloomy atmosphere, about 10,000 participants traveled to Montreal this week to attend the United Nations’ World Climate Summit. For the first time since the Kyoto Protocol came into effect in February, the delegates in Montreal will discuss whether its failure can be averted. Is a follow-up agreement for the period after 2012 even feasible at this point?
New focus on innovative methods
For the first time, the conference will focus on technical methods of capturing the dangerous greenhouse gas carbon dioxide and placing it in permanent storage sites. The debate was triggered primarily by the fact that the United States, together with India, China, Australia, Japan and South Korea, formed a separate alliance this summer with the objective of coming up with technical innovations to make emitted greenhouse gas harmless. The success of such innovations would downplay the importance of conserving energy.
Because efforts to reduce emissions have been so unsuccessful, an approach orthodox environmentalists had previously shunned has suddenly become acceptable: disposing of CO2 instead of avoiding it. In fact, the Intergovernmental Panel on Climate Change (IPCC) recently had nothing but praise for the concept of CO2 storage. According to an October report, the final storage of CO2 could supply up to 55 percent of the reduction experts say is needed to stabilize greenhouse gas levels in the atmosphere by 2100.
Of course, capturing the CO2 emitted by aircraft, cars and home heating systems would be too costly. But wherever large amounts of carbon dioxide are produced, scientists and engineers are developing systems to isolate the substance from exhaust gas and process it so that it is more easily stored (see graphic).
Various more or less sophisticated solutions exist for coal power plants which, with CO2 emissions of 250 million tons in Germany alone, are the main culprit in pumping the greenhouse gas into the atmosphere. The Vattenfall Group, for example, has taken an ambitious approach. The energy utility plans to open a pilot zero-CO2 emissions power plant at Niederlausitz near Berlin in 2008. The plant will employ a process called Oxyfuel, which will make it the first power plant of its kind worldwide.
“The trick is to make sure that the exhaust gas contains an extremely high concentration of carbon dioxide, so that it’s actually worth capturing the gas,” explains Markus Sauthoff, who heads the Vattenfall project. Engineers achieve this by burning brown coal with pure oxygen and the plant’s flue gases, instead of air. “This gives us a concentration of more than 90 percent CO2,” explains Sauthoff. Hazardous substances and water are then extracted from the exhaust gas.
The plant will then compress the carbon dioxide to convert it to liquid form, which will allow it to be removed in tanker trucks or through pipelines. Like the two other methods, processing consumes energy and reduces power plant efficiency. In the case of Oxyfuel, Sauthoff expects efficiency reductions on the order of about 8 percent. Instead of deriving a 50 percent electricity yield from coal, a level that will be possible in 20 years, the zero-CO2 plant would achieve an efficiency level of only 42 percent, which corresponds to today’s state-of-the-art plants. This means that one ton of captured carbon dioxide will cost about €20-25.
However, this amount already includes the costs of storing the greenhouse gas. Biologists, geologists, physicists and chemists have come up with a number of ways, some rather curious, to bury the gases:
Metal oxides in waste water could react with carbon dioxide to form harmless carbonates.
CO2 dissolved in water could be pumped through pipes into porous rock deep beneath the earth’s surface, where the carbon dioxide would be combined with hydrogen and genetically modified bacteria would convert the mixture into methane — which could then be burned.
Tankers could dump entire shiploads of the climate-changing gas into the deep ocean, where it would dissolve into water or sink and form deposits in troughs on the ocean floor.
In Dutch greenhouses, carbon dioxide brought in through a pipeline from a Rotterdam refinery is already being used as a growth accelerator for useful plants. The method can spur roses, for example, to bloom two weeks earlier.
But geologists see the most promising carbon dioxide burial ground in the rock formations where coal, oil and natural gas deposits are found. The IPCC estimates that these geological formations could store up to 2,000 gigatons of waste material — more than 70 times the amount of carbon dioxide released into the atmosphere each year as a result of human activity. These rock formations occur everywhere and are located within no more than 300 kilometers (186 miles) of almost every power plant on earth.
The easiest solution from a technical standpoint would be to pump the CO2 into empty natural gas deposits — as the Norwegian Statoil Group has demonstrated in its Sleipner oil field. The GeoResearch Center in Potsdam, Germany also began operating a pilot project recently. In the town of Ketzin, not far from Berlin, the center is preparing an experiment in which carbon dioxide will be pumped into an old natural gas storage facility 700 meters (2,297 feet) beneath the surface. “The gas will accumulate there, while the layers of clay and loam above the site will prevent the gas from escaping,” says geological engineer Guenter Borm.
Four truckloads a day, or a total of 100 tons of CO2, will be buried at the site over a two-year period. Borm calculates that the average car pumps 1.6 tons of CO2 into the atmosphere each year. If the Ketzin experiment is successful, the site could theoretically be used to store carbon dioxide from the nearby Vattenfall power plant.
The Potsdam team plans to use a network of measuring devices to make sure that the gas doesn’t just end up escaping back into the atmosphere. In the highly unlikely event that the waste gas does in fact emerge at the surface, this would present the worst possible scenario.
Even if the CO2 were to escape gradually from the Ketzin site, it would mean that scientists had failed to achieve their goal of permanently keeping the greenhouse gas out of the earth’s atmosphere. “Later commercial use will only be feasible once we know exactly how the gas behaves down there,” says Borm.
Oil giant BP’s plans for storing CO2 near Aberdeen, Scotland could be even more economically efficient. The carbon dioxide that will be captured from a zero-CO2 power plant, which is currently under construction and is code-named DF-1, will be pumped into current petroleum reserves 240 kilometers (149 miles) off the North Sea coast of Scotland. The plan would kill two birds with one stone: first, it would provide storage for as much carbon dioxide each year as is emitted by 300,000 cars; second, the resulting gas pressure would force an additional 40 million barrels of oil out of the rock.
Shell is taking a similar approach in the context of a European Union research project called RECOPOL, which calls for CO2 storage in coal seams that contain large amounts of methane trapped in tiny pores. The project’s researchers have already injected hundreds of tons of CO2 into thin coal seams deemed no longer profitable in a mine near the southern Polish city of Katowice. At a pressure of 240 hectopascal (240 millibars), the carbon dioxide forces the methane from the pores, which then reaches the surface through a second bore hole. “The gas could be used to fuel surrounding households,” says Henk Pagnier, a Dutch geologist involved in the project.
Critic: technology still 20 years off
The principle sounds tempting: pumping carbon that originally came from the earth back into the earth. But climate experts have voiced doubts over whether the method will quickly become widespread. “It creates a false impression, saying that the technology will be widely available,” criticizes Manfred Fischedick of the Wuppertal Institute for Climate, Environment and Energy. Fischedick doesn’t expect the new technology to become available for at least another 20 years.
“We already have effective ways of reducing greenhouse gases today,” says Fischedick, pointing out regenerative energies, building insulation and electricity conservation as examples. He has noted with great concern how some countries, most of all the United States, have shifted their focus entirely to technical solutions. According to Fischedick, “this could detract from the truly important issues in Montreal.”
Germany’s Environment Ministry, under the new leadership of Social Democrat Sigmar Gabriel, stands behind Fischedick’s criticisms. “It’s noticeable that the countries that have offered the least support for mandatory climate goals are the ones campaigning the most vocally for the technology of the day after tomorrow,” says ministry spokesman Michael Schroeren.
But the most vehement champion of carbon dioxide storage is the energy industry itself, which also combines commercial interests with CO2 sequestration technology. Since the EU introduced its new system of trading in so-called emission rights this spring, each ton of carbon dioxide saved is like cash in the bank for companies. For each ton of CO2 they emit per year, companies receive a certificate. These allocations can gradually be reduced to encourage companies to invest in climate-protective technology.
The certificates are already being traded on the stock market, at prices of about €25 per ton of CO2. If an energy company saves carbon dioxide with a zero-CO2 power plant, for example, it can sell a number of certificates corresponding to its reduction in CO2 emissions.
For the foreseeable future, however, it will likely be more economically attractive to companies to increase power plant efficiency in developing countries — an activity for which the Kyoto Protocol provides financial incentives. Reducing CO2 emissions in this way is more cost-efficient than the costly practice of burying greenhouse gases in caverns. Indeed, in Montreal representatives of industry will also be calling for the worldwide expansion of the system of trading in emissions credits.
“The techniques of carbon dioxide storage will still be too expensive in the coming decades,” says Fischedick, “and that’s why I do not expect implementation on a large scale.” Fischedick believes that the main reason corporations are involved in the pilot projects is to ensure that they won’t be technologically outpaced by the competition in the future.
Meanwhile, investment in climate protection in developing countries is just getting underway. UN climate protection official Kinley will announce in Montreal that the first two projects, including one involving the construction of hydroelectric power plants in Honduras, have been approved. “Applications have been submitted for more than 450 projects,” says Kinley.
One is the construction of a modern garbage dump in rural Brazil, which is turning into a gold mine in the international emissions trade. The project, funded by the Dutch government, involves burning off the methane produced by garbage at the dump.
It’s good for the earth’s atmosphere, but not for the poor residents near the facility. Now that their local garbage is a covered and closed facility, they can no longer rummage through it for usable items. DER SPIEGEL