This blog reported before that human activity from coal-fired power plants to car tailpipes is responsible for nearly 30 billion metric tons of carbon dioxide wafting into the atmosphere yearly, and roughly 15 billion metric tons remains in the atmosphere for a century or more.
Stanford’s Ken Caldeira is a climate modeller at the Carnegie Institution for Science’s Department of Global Ecology and participated in the study. He cautioned that “the study does not take into account all the enabling infrastructure—such as highways, gas stations and refineries—that contribute inertia that holds back significant changes to lower-emitting alternatives.”
Around the globe, we are adding more fossil-fuel infrastructure, so, the bad news, carbon trackers, is going to get a lot worse, says SciAmz David Biello. A team of scientists analyzed the existing fossil-fuel infrastructure to decide how much GHGs (Green House Gas emissions) to which we have committed. “The answer: an average of 496 billion metric tons more of carbon dioxide added to the atmosphere between now and 2060.”
That assumes life spans of roughly 40 years for a coal-fired power plant and 17 years for a typical car—potentially major under- and overestimates, respectively, given that some coal-fired power plants still in use in the U.S. first fired up in the 1950s. Plugging that roughly 500 gigatonne number into a computer-generated climate model predicted CO2 levels would then peak at less than 430 ppm with an attendant warming of 1.3 degrees C above preindustrial average temperature. That’s just 50 ppm higher than present levels and 150 ppm higher than preindustrial atmospheric concentrations.
And since 2000 the world has added 416 gigawatts of coal-fired power plants, 449 gigawatts of natural gas–fired power plants and even 47.5 gigawatts of oil-fired power plants, according to the study’s figures. China alone is already responsible for more than a third of the global "committed emissions," including adding 2,000 cars a week to the streets of Beijing as well as 322 gigawatts of coal-fired power plants built since 2000.
Countries that burn huge amounts of coal for power and the countries that supply them “over the next several decades will play a huge role in determining the ultimate degree of global climate change.” Cue the timpanist.
Coal-burning poses other threats as well, including the toxic coal ash that can spill from the impoundments where it is kept; other polluting emissions that cause acid rain and smog; and the soot that causes and estimated 13,200 extra deaths and nearly 218,000 asthma attacks per year, according to a report from the Clean Air Task Force, an environmental group. "Unfortunately, persistently elevated levels of fine particle pollution are common across wide swaths of the country," reveals the 2010 report, released September 9. "Most of these pollutants originate from combustion sources such as power plants, diesel trucks, buses and cars."
Of course, those are the same culprits contributing the bulk of greenhouse gas emissions. Yet "programs to scale up ‘carbon neutral’ energy are moving slowly at best," notes physicist Martin Hoffert of New York University in a perspective on the research also published in Science on September 10. "The difficulties posed by generating even [one terawatt] of carbon-neutral power led the late Nobel laureate Richard Smalley and colleagues to call it the ‘terawatt challenge’."
That is because all carbon-free sources of energy combined provide a little more than two of the 15 terawatts that power modern society—the bulk of that from nuclear and hydroelectric power plants. At least 10 terawatts each from nuclear; coal with carbon capture and storage; and renewables, such as solar and wind, would be required by mid-century to eliminate CO2 emissions from energy use. As Caldeira and his colleagues wrote: "Satisfying growing demand for energy without producing CO2 emissions will require truly extraordinary development and deployment of carbon-free sources of energy, perhaps 30 [terawatts] by 2050."
Other AG post on the topic of our increasing carbon footprint