7. What are the Greenhouse Gases?

Archives of Past Articles for Chapter 7

2009 Nov-Dec. Livestock and Climate Change. By Robert Goodland and Jeff Anhang, World Watch Institute, Vision for a Sustainable World. Excerpt: Whenever the causes of climate change are discussed, fossil fuels top the list. Oil, natural gas, and especially coal are indeed major sources of human-caused emissions of carbon dioxide (CO2) and other greenhouse gases (GHGs). But we believe that the life cycle and supply chain of domesticated animals raised for food have been vastly underestimated as a source of GHGs, ...
... When uncounted tons are added to the global inventory of atmospheric GHGs, that inventory rises from 41,755 million tons to 63,803 million tons. The FAO [United Nations Food and Agriculture Organization] excludes livestock respiration from its estimate, per the following argument: Respiration by livestock is not a net source of CO2 ….
Emissions from livestock respiration are part of a rapidly cycling biological system, where the plant matter consumed was itself created through the conversion of atmospheric CO2 into organic compounds. ... our analysis shows that livestock and their byproducts actually account for at least 32,564 million tons of CO2 per year, or 51 percent of annual worldwide GHG emissions.
...Action to replace livestock products not only can achieve quick reductions in atmospheric GHGs, but can also reverse the ongoing world food and water crises....

2009 October 14. Curbing Emissions by Sealing Gas Leaks. By ANDREW C. REVKIN and CLIFFORD KRAUSS, The NY Times. Excerpt: To the naked eye, there was nothing to be seen at a natural gas well in eastern Texas but beige pipes and tanks baking in the sun.
But in the viewfinder of Terry Gosney’s infrared camera, three black plumes of gas gushed through leaks that were otherwise invisible.
“Holy smoke, it’s blowing like mad,” said Mr. Gosney, an environmental field coordinator for EnCana, the Canadian gas producer that operates the year-old well near Franklin, Tex. “It does look nasty.”
Within a few days the leaks had been sealed by workers.
Efforts like EnCana’s save energy and money. Yet they are also a cheap, effective way of blunting climate change that could potentially be replicated thousands of times over, from Wyoming to Siberia, energy experts say. Natural gas consists almost entirely of methane, a potent heat-trapping gas that scientists say accounts for as much as a third of the human contribution to global warming....

2009 August 17. As Arctic Ocean warms, megatonnes of methane bubble up. By Michael Marshall, New Scientist. Excerpt: It's been predicted for years, and now it's happening. Deep in the Arctic Ocean, water warmed by climate change is forcing the release of methane from beneath the sea floor.
Over 250 plumes of gas have been discovered bubbling up from the sea floor to the west of the Svalbard archipelago, which lies north of Norway. The bubbles are mostly methane, which is a greenhouse gas much more powerful than carbon dioxide.
The methane is probably coming from reserves of methane hydrate beneath the sea bed. These hydrates, also known as clathrates, are water ice with methane molecules embedded in them....
The methane being released from hydrate in the 600-square-kilometre area studied probably adds up to 27 kilotonnes a year, which suggests that the entire hydrate deposit around Svalbard could be releasing 20 megatonnes a year.
If methane began escaping at similar rates throughout the Arctic, it would dramatically increase methane levels in the atmosphere.
Globally, it's thought that around 500 to 600 megatonnes of methane are released into the atmosphere each year....

2009 April 15. Third-World Stove Soot Is Target in Climate Fight. By Elisabeth Rosenthal, The NY Times. Excerpt: KOHLUA, India — “It’s hard to believe that this is what’s melting the glaciers,” said Dr. Veerabhadran Ramanathan, one of the world’s leading climate scientists, as he weaved through a warren of mud brick huts, each containing a mud cookstove pouring soot into the atmosphere.
...In Kohlua, in central India, with no cars and little electricity, emissions of carbon dioxide, the main heat-trapping gas linked to global warming, are near zero. But soot — also known as black carbon — from tens of thousands of villages like this one in developing countries is emerging as a major and previously unappreciated source of global climate change.
While carbon dioxide may be the No. 1 contributor to rising global temperatures, scientists say, black carbon has emerged as an important No. 2, with recent studies estimating that it is responsible for 18 percent of the planet’s warming, compared with 40 percent for carbon dioxide. Decreasing black carbon emissions would be a relatively cheap way to significantly rein in global warming — especially in the short term, climate experts say....
...decreasing soot could have a rapid effect. Unlike carbon dioxide, which lingers in the atmosphere for years, soot stays there for a few weeks. Converting to low-soot cookstoves would remove the warming effects of black carbon quickly, while shutting a coal plant takes years to substantially reduce global CO2 concentrations....

2008 October 29. NASA Measurements Show Greenhouse Gas Methane on the Rise Again. NASA RELEASE : 08-276. Excerpt: WASHINGTON -- The amount of methane in Earth's atmosphere shot up in 2007, bringing to an end approximately a decade in which atmospheric levels of the potent greenhouse gas were essentially stable....
Methane levels in the atmosphere have more than doubled since pre-industrial times, accounting for around one-fifth of the human contribution to greenhouse gas-driven global warming. Until recently, the leveling off of methane levels had suggested that the rate of its emission from Earth's surface was being approximately balanced by the rate of its destruction in the atmosphere.
However, the balance has been upset since early 2007, according to research published this week in the American Geophysical Union's "Geophysical Research Letters." The paper's lead authors, Matthew Rigby and Ronald Prinn of the Massachusetts Institute of Technology, say this imbalance has resulted in several million metric tons of additional methane in the atmosphere.
...It is too early to tell whether this increase represents a return to sustained methane growth, or the beginning of a relatively short-lived anomaly, according to Rigby and Prinn. Given that methane is about 25 times stronger as a greenhouse gas per metric ton of emissions than carbon dioxide, the situation will require careful monitoring in the near future to better understand methane's impact on future climate change....

2008 October 24. The Most Potent Unknown Greenhouse Gas Revealed. Environment News Service. Excerpt: A gas used in manufacture of flat panel televisions, computer displays, microcircuits, and thin-film solar panels is 17,000 times more potent a greenhouse gas than carbon dioxide, and it is far more prevalent in the atmosphere than previously estimated.
The powerful greenhouse gas nitrogen trifluoride, NF3, is at least four times more widespread than scientists had believed, according to new research by a team at Scripps Institution of Oceanography at the University of California, San Diego.
Using new analytical techniques, a team led by Scripps geochemistry professor Ray Weiss made the first atmospheric measurements of nitrogen trifluoride, NF3.
...The amount of the gas in the atmosphere...had been estimated at less than 1,200 metric tons in 2006. The new research shows the actual amount was 4,200 metric tons.
In 2008, about 5,400 metric tons of the gas was in the atmosphere, a quantity that is increasing at about 11 percent per year.
...Emissions of NF3 were thought to be so low that the gas was not considered to be a significant potential contributor to global warming.
..."From a climate perspective, there is a need to add NF3 to the suite of greenhouse gases whose production is inventoried and whose emissions are regulated under the Kyoto Protocol, thus providing meaningful incentives for its wise use," said Weiss....
See Also NASA RELEASE : 08-268. Potent Greenhouse Gas More Common in Atmosphere Than Estimated

2008 September 1. Thawing permafrost likely to boost global warming. Eureka Alert. Excerpt: The thawing of permafrost in northern latitudes, which greatly increases microbial decomposition of carbon compounds in soil, will dominate other effects of warming in the region and could become a major force promoting the release of carbon dioxide and thus further warming, according to a new assessment in the September 2008 issue of BioScience. The study, by Edward A. G. Schuur of the University of Florida and an international team of coauthors, more than doubles previous estimates of the amount of carbon stored in the permafrost: the new figure is equivalent to twice the total amount of atmospheric carbon dioxide....
Schuur and his colleagues...judge that over millennia, soil processes have buried and frozen over a trillion metric tons of organic compounds in the world's vast permafrost regions. The relatively rapid warming now under way is bringing the organic material back into the ecosystem, in part by turning over soil....
Schuur and his colleagues acknowledge many difficulties in estimating carbon dioxide emissions from permafrost regions.... Data are limited, and emissions are influenced by the amount of surface water, topography, wildfires, snow cover, and other factors. Thawing, although believed to be critical, is hard to model accurately.
Some warming-related trends in Arctic regions, such as the encroachment of trees into tundra, may cause absorption of carbon dioxide and thus partly counter the effects of thawing permafrost. But Schuur and colleagues' new assessment indicates that thawing is likely to dominate known countervailing trends....

2008 July 3. Plasma, LCDs blamed for accelerating global warming. ABC News. Excerpt: A gas used in the making of flat screen televisions, nitrogen trifluoride (NF3), is being blamed for damaging the atmosphere and accelerating global warming.
Almost half of the televisions sold around the globe so far this year have been plasma or LCD TVs. ...The gas, widely used in the manufacture of flat screen TVs, is estimated to be 17,000 times as powerful as carbon dioxide.
Ironically, NF3 is not covered by the Kyoto protocol as it was only produced in tiny amounts when the treaty was signed in 1997.
Levels of this gas in the atmosphere have not been measured, but scientists say it is a concern and are calling for it to be included in any future emissions cutting agreement.
Professor Michael Prather from the University of California has highlighted the issue in an article for the magazine New Scientist.
...He estimates 4,000 tons of NF3 will be produced in 2008 and that number is likely to double next year.
...Dr Paul Fraser is the chief research scientist at the CSIRO's marine and atmospheric research centre, and an IPCC author.
He says without measuring the quantity of NF3 in the atmosphere it is unclear what impact it will have on the climate.
"We haven't observed it in the atmosphere. It's probably there in very low concentrations," he said.
"The key to whether it's a problem or not is how much is released to the atmosphere."

16 February 2007. PHYTOPLANKTON AID IN GREENHOUSE GAS CONTROL - This broadcast of Earth & Sky radio show featured NASA Earth science. The show is also available to download as an audio Podcast.

February 2006. From Carbon Cycles to Climate Models. By David Pescovitz. ScienceMatters@Berkeley Volume 3, Issue 18. ... UC Berkeley professor Inez Fung constructs incredibly complex computer simulations of the climate. ..."There's a rogues gallery of these atmospheric species, greenhouse gases like carbon dioxide and methane, that affect the energy cycle and climate," says Fung, co-director of the new Berkeley Institute of the Environment and former director of the Berkeley Atmospheric Sciences Center. "I'm hitting them one-by-one to understand what determines their concentration in the atmosphere, why that's changing, and how." ...Most famously, Fung and her colleagues modeled the carbon cycle, how carbon dioxide moves in and out of the atmosphere. Previous calculations included the fact that humans burning fossil fuel at a certain rate will boost carbon dioxide levels in the atmosphere. [see graphic depiction of the Earth's carbon cycle, highlighting various sources and sinks for carbon.] ...Fung studies the whole shebang. ...trees are much more involved in carbon uptake and atmospheric cooling than previously believed. A study in the Amazonian forest showed that the roots shift water deep in the ground in such a way that they "pull more carbon dioxide from the atmosphere as they conduct more photosynthesis" even during the dry season, Dawson says. The trouble is that there's a limit to how much carbon dioxide the world's plants can handle. Right now, plants and oceans absorb about half of the CO2 that's generated from the burning of fossil fuels. Last year, Fung's climate model indicated that in the next fifty years or so, the "breathing biosphere" may be overwhelmed. ...And after plants die, their decomposition by microbes in the soil also play a part in the carbon cycle. "If you don't look at decomposition, it's like looking at your income without considering your expenses," Fung says. "You have to think about the whole life cycle across the entire biosphere." Simultaneously, the oceans' capabilities as a CO2 sink are hampered....

Archives of Past Articles for Chapter 7

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