The warming climate is driving several thousand people north, to Copenhagen — for two weeks, anyway. Representatives from nearly 200 countries are gathering there to try to work out a new international treaty to curb global warming, one that would supplant the Kyoto Protocol, which expires in 2012.
Prospects are dim, though, for a binding agreement at the Conference of the Parties to the United Nation's Framework Convention on Climate Change. But negotiators say they hope to at least plot a course toward a new agreement that could be signed at next year's climate conference in Mexico City.
With or without a new treaty this month, the effort to curb climate change has accelerated since the 1997 Kyoto conference. Although the United States never ratified the Kyoto Protocol, numerous efforts are under way in the States to limit warming by attacking the main culprit: burning fossil fuels.
Below, a look at some of the technologies, as well as social mechanisms, aimed at changing how we consume energy — and slow climate change.
It's a pretty diverse tool kit; one that, if implemented, would create a very different energy economy. Some jobs in the fossil fuel industry would be lost, while many others in alternative energy would be produced. Most of the technologies to reduce greenhouse gas emissions are mature or close to it. The hurdles are finding the political will to rip out the old energy economy and put in a new one — and finding the money to pay for it.
Building clean coal or nuclear power plants is very expensive. Many of the nation's existing coal plants still need to operate for years to pay off the debt incurred to build them.
Making wind and solar power affordable and accessible will also cost a lot of money. And a limit on greenhouse gas emissions for industry will, at least for a long time to come, raise the price of energy.
Coal Futures
About half the electricity Americans use comes from burning coal. China depends on coal even more and is building new coal-fired power plants at a furious rate. Yet burning coal puts out more greenhouse gases than does any other single source of electricity.
Most energy analysts argue that the nation can't just turn off its coal plants and replace them in a hurry. The solution, according to the Department of Energy, is in part to switch to "clean coal." That generally means using coal in a different way — not burning it, but extracting energy from coal chemically, while diverting the carbon dioxide from the coal and burying it instead of letting it go up into the atmosphere.
The leading technology for doing that is called "integrated gasification combined cycle" coal plants. It's not a new technology, but one that is only now being tried commercially for making electricity on a large scale. IGCC coal plants are more expensive than traditional coal plants; just how much is a matter of debate. DOE suggests that electricity from an advanced IGCC plant might cost 35 percent more than from a traditional coal plant. Pilot projects funded by DOE are under way to build large-scale IGCC plants.
Burying CO2
If IGCC or some version of it is adopted, the diverted CO2 has to go somewhere. DOE and other institutions are mapping the country to find places where the geology permits CO2 to be pumped underground. Norwegian engineers have accomplished this in the North Sea, where they pump CO2 from an offshore gas and oil rig into a huge aquifer beneath the seabed.
The combination of using IGCC plants and then corralling and burying the CO2 is called "carbon capture and sequestration," or CCS.
But sequestration has several big questions behind it: Will the CO2 stay put once underground? And how much will it cost to put it there?
So far, experiments in the United States and the Norwegian experience show that the gas will stay underground, but there's no definitive answer yet for how long. If the CO2 leaks back into the atmosphere within the next several decades, it would continue to warm the climate — making the sequestration effort a waste.
As for cost, energy analysts note that the nation would have to build a pipeline network to connect coal plants to sites where the geology is appropriate for long-term CO2 storage. Securing rights of way and then building such an extensive network is expected to cost a lot. One estimate, by the Pew Center on Global Climate Change, puts the total cost of sequestering a year's worth of CO2 from power plants at roughly $21 billion.
Nuclear Power
Currently, the United States gets about 20 percent of its electricity from nuclear power plants, which do not emit greenhouse gases. The Obama administration is on record saying that new nuclear power plants are "in the mix" in its plans to lower the energy economy's carbon footprint. Nuclear power has popular support in Congress as well, and a few environmental groups are reconsidering it in light of its carbon "neutrality."
However, no one has built a new plant in the United States in decades. Besides concerns about the environment and nuclear waste, the reluctance of investors to pay for nuclear construction has stifled growth of the industry.
While new designs for nuclear plants have brought the cost down somewhat, many energy analysts point out that new nuclear plants will still require subsidies of some kind from the federal government to make their cost competitive with other sources of energy such as coal plants, which are cheaper to build.
Estimates vary on how many new plants are necessary to make a serious dent in greenhouse gas emissions — scores or perhaps even 100 plants are considered necessary. There is also concern that it would take too long to build that many plants, and that other sources of electricity might be built faster.
Energy Efficiency
Efficiency — using the electricity we have more frugally — is highly favored by environmental groups as the easiest and quickest way to lower greenhouse gas emissions. This includes things as simple as replacing incandescent light bulbs with compact fluorescent bulbs; using waste heat from industrial boilers to make electricity or provide heating for buildings; or building and insulating buildings to use less heating, cooling and electricity.
Efficiency advocates argue that the nation's carbon footprint might be lowered as much as 15 percent through efficiency measures, which are relatively cheap to adopt.
Others argue that efficiency measures aren't enough without also investing in new, large-scale sources of baseload electric power — power that can be relied on to provide a steady stream of energy for a growing economy.
Beyond Coal
Wind turbines, solar collectors and panels, and geothermal energy are the main technologies under the "alternative" column. Alternative energy produces only about 2 percent of the nation's electricity, although wind power has been growing fast. The cost of solar panels has come down and these are increasingly being used for residential and office buildings, but panels are not widely believed to be a solution for large-scale electricity supply. Concentrated solar power, in which a large array of collectors concentrates a beam of energy to heat a fluid and run turbines, is viewed as a more likely source of large-scale electric power.
These technologies are generally subsidized by the government to make their costs more competitive with coal and natural gas. Besides their higher costs, obstacles include a lack of high-power lines to take alternative electricity from the West, Southwest and Great Plains — where sunshine and wind are more prevalent — to the big cities of the Midwest and East, where most of the customers are. DOE plans to build a new electricity grid to resolve that geographical conundrum — a project likely to take decades to complete and cost, by DOE's estimate, at least $100 billion. Engineers must also modify the existing grid to accommodate the ephemeral nature of wind and solar — the wind doesn't blow and the sun doesn't shine necessarily when people need power.
Reducing Gases In The Atmosphere
The primary means of reducing greenhouse gases under the Kyoto Protocol is a cap on the amount of greenhouse gases emitted by industries. Signatory countries have targets for the period 2008 to 2012 for lowering emissions.
Europe and the United States are betting on carbon markets to help lower emissions. Under this system, companies such as utilities or factories that emit greenhouse gases are given or sold allowances to emit. The allowed amount falls gradually each year, which is meant to push emissions lower. But companies that live within their limits may trade or sell them to companies that cannot. Trading allowances constitutes one arm of the carbon market, and the system is generally called "cap-and-trade."
Another arm is the offset market. A company may pay someone in China or Brazil or any other country not regulated under Kyoto to reduce greenhouse gases there. That can be cheaper than retooling its own factory, for example. When a nonregulated entity reduces greenhouse gases — say, by building a dam or a wind farm instead of a coal plant — it earns offset credits that it can sell to regulated entities. The United Nations regulates how offsets for Kyoto nations are created and traded, but verifying reductions is a problem. Critics in some cases have questioned whether the offset-generating projects actually remove additional greenhouse gases from the atmosphere or avoid future emissions. The U.N. is rewriting rules for offsets to improve their reliability.
Role Of Forests
Most of the offsets sold internationally have been projects that limit greenhouse gases from factories, landfills or livestock waste ponds. Recently, many groups are trying to add forest management and agricultural practices to the list of allowable offsets. For example, a program called REDD (Reduced Emissions from Deforestation and Degradation) is being negotiated by environmental groups and businesses. It would essentially pay tropical and other developing countries not to cut down forests as fast as they have in the past. Cutting forests puts carbon back into the atmosphere, contributing as much as 15 percent of the world's total greenhouse gas emissions. So "avoided deforestation" could generate carbon credits for forested countries, to be sold to polluters governed by the Kyoto Protocol. Growing new forests might also generate credits.
Role Of Farms
Changing the way land is used is another way to generate carbon credits or offsets, since land and what grows on it can influence the flux of carbon into and out of the atmosphere. Experiments are under way, for example, to boost the rate at which grasslands and soil take CO2 out of the atmosphere. If that takes extra CO2 out of the atmosphere, it would generate carbon credits. No-till farming also might keep more greenhouse gas in the soil than conventional tilling, since it doesn't disturb the soil as much and thus keeps more carbon out of the air.
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