5. How Can We Measure Carbon Dioxide?

Archive of Past Articles for Chapter 5

2010 December 21. A Scientist, His Work, and a Climate Reckoning. By Justin Gillis, NYTimes. Excerpt: MAUNA LOA OBSERVATORY, Hawaii — Two gray machines sit inside a pair of utilitarian buildings here, sniffing the fresh breezes that blow across thousands of miles of ocean....
...The first machine of this type was installed on Mauna Loa in the 1950s at the behest of Charles David Keeling, a scientist from San Diego. His resulting discovery, of the increasing level of carbon dioxide in the atmosphere, transformed the scientific understanding of humanity’s relationship with the earth. A graph of his findings is inscribed on a wall in Washington as one of the great achievements of modern science.
Yet, five years after Dr. Keeling’s death, his discovery is a focus not of celebration but of conflict. It has become the touchstone of a worldwide political debate over global warming...

2009 October 8. Last time carbon dioxide levels were this high: 15 million years ago, scientists report. EurekAlert. Excerpt: You would have to go back at least 15 million years to find carbon dioxide levels on Earth as high as they are today, a UCLA scientist and colleagues report Oct. 8 in the online edition of the journal Science.
"The last time carbon dioxide levels were apparently as high as they are today — and were sustained at those levels — global temperatures were 5 to 10 degrees Fahrenheit higher than they are today, the sea level was approximately 75 to 120 feet higher than today, there was no permanent sea ice cap in the Arctic and very little ice on Antarctica and Greenland," said the paper's lead author, Aradhna Tripati, a UCLA assistant professor in the department of Earth and space sciences and the department of atmospheric and oceanic sciences.
...By analyzing the chemistry of bubbles of ancient air trapped in Antarctic ice, scientists have been able to determine the composition of Earth's atmosphere going back as far as 800,000 years, and they have developed a good understanding of how carbon dioxide levels have varied in the atmosphere since that time. But there has been little agreement before this study on how to reconstruct carbon dioxide levels prior to 800,000 years ago.
..."A slightly shocking finding," Tripati said, "is that the only time in the last 20 million years that we find evidence for carbon dioxide levels similar to the modern level of 387 parts per million was 15 to 20 million years ago, when the planet was dramatically different."
Levels of carbon dioxide have varied only between 180 and 300 parts per million over the last 800,000 years — until recent decades, said Tripati, who is also a member of UCLA's Institute of Geophysics and Planetary Physics. It has been known that modern-day levels of carbon dioxide are unprecedented over the last 800,000 years, but the finding that modern levels have not been reached in the last 15 million years is new....

2009 February 24. NASA Satellite Fails to Reach Orbit. By Kenneth Chang, the NY Times. Excerpt: A NASA satellite to track carbon dioxide in the Earth’s atmosphere failed to reach its orbit during launching Tuesday morning, scuttling the $278 million mission.
...The Orbiting Carbon Observatory lifted off on schedule at 1:55 a.m. Pacific time from Vandenberg Air Force Base in California aboard a four-stage Taurus XL rocket.
But three minutes later, during the burning of the third stage, the payload fairing — a clamshell nose cone that protects the satellite as it rises through the atmosphere — failed to separate as commanded.
The third and fourth stages burned properly, but because of the added weight of the nose cone, the satellite did not reach orbit.
...The satellite fell back to Earth, landing in the ocean just short of Antarctica.
...The carbon observatory was to precisely measure levels of carbon dioxide — the heat-trapping gas that is driving global warming — in the air. Scientists had hoped the new data, covering the entire planet, would help them improve climate models and better understand the “carbon sinks” like oceans and forests and that absorb much of the carbon dioxide....

2009 February 23. NASA-Funded Carbon Dioxide Map Of U.S. Released On Google Earth. ScienceDaily. Excerpt: Interactive maps that detail carbon dioxide emissions from fossil fuel combustion are now available on the popular Google Earth platform. The maps, funded by NASA and the U.S. Department of Energy through the joint North American Carbon Program, can display fossil fuel emissions by the hour, geographic region, and fuel type.
...Researchers from the project, named "Vulcan" for the Roman god of fire, constructed an unprecedented inventory of the carbon dioxide that results from the burning of 48 different types of fossil fuel. The data-based maps show estimates of the hourly carbon dioxide outputs of factories, power plants, vehicle traffic and residential and commercial areas.
...“The release of the Vulcan inventory on Google Earth brings this information into the living room of anyone with an Internet connection," said Kevin Gurney, an assistant professor of Earth and atmospheric sciences at Purdue and leader of the Vulcan Project. "From a societal perspective, Vulcan provides a description of where and when society influences climate change through fossil-fuel carbon dioxide emissions."...

2009 January 29. NASA RELEASE: 09-021. NASA Mission to Help Unravel Key Carbon, Climate Mysteries. Excerpt: WASHINGTON -- NASA's first spacecraft dedicated to studying atmospheric carbon dioxide is in final preparations for a Feb. 23 launch from Vandenberg Air Force Base in California. Carbon dioxide is the leading human-produced greenhouse gas driving changes in Earth's climate.
The Orbiting Carbon Observatory will provide the first complete picture of human and natural carbon dioxide sources as well as their "sinks," the places where carbon dioxide is pulled out of the atmosphere and stored. It will map the global geographic distribution of these sources and sinks and study their changes over time. The measurements will be combined with data from ground stations, aircraft and other satellites to help answer questions about the processes that regulate atmospheric carbon dioxide and its role in Earth's climate and carbon cycle.
..."It's critical that we understand the processes controlling carbon dioxide in our atmosphere today so we can predict how fast it will build up in the future and how quickly we'll have to adapt to climate change caused by carbon dioxide buildup," said David Crisp, principal investigator for the Orbiting Carbon Observatory at NASA's Jet Propulsion Laboratory in Pasadena, Calif.
...The new observatory will dramatically improve global carbon dioxide measurements, collecting about 8 million measurements every 16 days for at least two years.... Scientists need these precise measurements because carbon dioxide varies by just 10 parts per million throughout the year on regional to continental scales....

2008 December 4. The Ins and Outs of the Global Carbon Cycle. By Jeremy Jacquot, Science Progress. Excerpt: ...Having spent the last few decades piecing together the different components of the global carbon puzzle, scientists now have a good idea of how the planet’s natural carbon sinks (or reservoirs) work—primarily these sinks are plants and the oceans. But when it comes to pinpointing the locations of all the sources (areas or organisms which release carbon dioxide to the atmosphere), there remains a lot of ambiguity—mostly because climate change is constantly changing the picture of how the sources work (and it’s usually changing for the worse). ...What many scientists are now worried about is the degree to which carbon sinks could shrink, or carbon sources could grow, in response to the rapid increase in anthropogenic CO2 emissions.
The easiest way to think of the global carbon cycle is as the sum total of different reactions...between and within the planet’s major carbon repositories: the ocean and terrestrial biosphere. The ocean is by far the larger one—estimated to hold about 38,000 petagrams (1 petagram equals one trillion grams); the land plants and soils that make up the terrestrial biosphere store only about 2,000.
...These sinks currently absorb around half of all the carbon dioxide emitted through fossil fuel combustion. Around 85 percent of new anthropogenic CO2 ends up in the ocean... Almost half of the total amount of anthropogenic CO2 that has been added to the atmosphere since pre-industrial times has gone into the ocean.
...scientists are beginning to come to grips with the realization that many erstwhile sinks, primarily plants and soils, could lose their ability to draw down CO2 in a warming world—with a worst-case scenario being that they would turn into sources....

2008 December 1. Carbon Detectives Are Tracking Gases in Colorado. By Susan Moran, The New York Times. Excerpt: BOULDER, Colo. — As she squeezed herself into a telephone-booth-size elevator to ascend a 984-foot tower in Colorado’s eastern plains, Arlyn Andrews said with a grin, “This makes me want to go rock climbing.”
It’s a good thing she loves climbing tall structures. Dr. Andrews, an atmospheric scientist at the National Oceanic and Atmospheric Administration in Boulder, climbs the tower periodically to make sure the narrow tubes running from the tower to analyzers nearby are properly taking continuous samples of carbon dioxide, methane and a cocktail of other greenhouse gases.
...“We’re able to detect the whole mix of emissions here — what comes from automobile traffic, from industry, from residential development and from agriculture,” Dr. Andrews said.
She is one of many carbon sleuths, scientists who track and analyze where greenhouse gases come from and where they go over time. Think of it like personal finances. To plan for a sound financial future, it helps to create a budget and keep track of how one is spending money. Similarly, atmospheric scientists need to develop a “budget” for greenhouse gases.
...The key task is measuring the sources, or emissions, of these planet-warming gases, and the “sinks” — forests, cropland and oceans that absorb carbon. This budget can then inform intelligent climate-control policy, whether it be managing one forest or shaping national emissions regulations.
...But uncertainty remains high — often as high as estimates themselves. For instance, researchers think about half of the CO2 emitted into the atmosphere gets absorbed by oceans and land, but they do not know precisely where the gases come from and where they end up. This knowledge gap has serious policy implications; until it becomes clear where emissions are going, it will remain difficult to have verifiable credits for sequestering carbon....

2008 November 12. NASA'S Carbon-Sniffing Satellite Sleuth Arrives at Launch Site. NASA RELEASE : 08-285. Excerpt: WASHINGTON -- NASA's first spacecraft dedicated to studying carbon dioxide, the leading human-produced greenhouse gas driving changes in Earth's climate, has arrived at Vandenberg Air Force Base, Calif., to begin final launch preparations.
The Orbiting Carbon Observatory arrived Nov. 11 at its launch site on California's central coast after completing a cross-country trip by truck from its manufacturer, Orbital Sciences Corp. in Dulles, Va....After final tests, the spacecraft will be integrated onto an Orbital Sciences Taurus rocket in preparation for its planned January 2009 launch.
The observatory will help solve some of the lingering mysteries in our understanding of Earth's carbon cycle and its primary atmospheric component, carbon dioxide, a chemical compound that is produced both naturally and through human activities....
...The observatory's space-based measurements of atmospheric carbon dioxide will have the precision, resolution and coverage needed to provide the first complete picture of both human and natural sources of carbon dioxide emissions. It will show the places where they are absorbed, known as "sinks," at regional scales everywhere on Earth. Its data will reduce uncertainties in forecasts of how much carbon dioxide is in the atmosphere and improve the accuracy of global climate change predictions....

2008 April 7,Breath of a Nation - Animated CO2 Map. By ANDREW C. REVKIN. Scientists have come up with a new way to precisely track daily and local patterns of carbon dioxide emissions from the burning of fossil fuels by power plants, factories, and vehicle traffic. The resulting database and maps provide a view of the "industrial metabolism" of our combustion-powered lives, Kevin Gurney, the leader in the project and an atmospheric scientist at Purdue, told me today.
A YouTube video produced by the team, which did the work with funding from NASA and the Department of Energy, includes fascinating animations showing the daily burst of emissions as industry and traffic kick into gear, and also reveals regional patterns showing that the Southeast is a bigger contributor to emissions than researchers realized. For more info, see article at Purdue website.

Archive of Past Articles for Chapter 5

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