Since peaking in 2005, US domestic energy CO2 emissions have fallen by 8.6 percent. A new report asserts that up to half of this reduction may be down to "energy switching," as generators switch from coal to shale gas (partly on cost grounds), which emits about half the CO2 when burned. Yet the same report, from the Tyndall Centre for Climate Change Research, questions the wisdom of touting shale gas as a low-carbon technology, with its authors actually asserting that "the exploitation of shale gas reserves is likely to increase total emissions." How so?
While it's tempting to look at the reduction in America's domestic energy CO2 output in isolation, the atmosphere doesn't care where CO2 comes from. It's all the same to it. In the US, a reduction in domestic coal consumption in the energy sector has coincided with an increase in the country's coal exports. US coal usage may be down domestically, but that is not to say that that same coal isn't being put to use elsewhere.
In fact, the report's authors calculate that of the total of 650 million tonnes of potential CO2 emissions avoided by reducing coal consumption to date, 340 million have been emitted in other countries (mainly in Europe or Asian) that have imported the coal instead.
The problem is that though shale gas may emit less CO2 at the power station than coal, it appears this is insufficient to offset the emissions from the exported coal. "Despite lower-carbon rhetoric, shale gas is still a carbon intensive energy source," said Dr. John Broderick, lead author of the report Has US Shale Gas Reduced CO2 Emissions?.
The net effect of the rise in shale gas consumption and coal exports could well be an overall increase in CO2 emissions, the authors suggest. "We must seriously consider whether a so-called 'golden age' would be little more than a gilded cage, locking us into a high-carbon future," Broderick said.
The report concludes that without a "meaningful" cap on global CO2 emissions (which is to say that the contribution made by shale gas must eat into, not add to, that of coal), shale gas is likely to do more harm than good. And the report is not optimistic. "Were an abrupt, internationally simultaneous, fuel switch from coal to gas to occur, the remaining safe carbon budget may be consumed less quickly," it concludes. "In the ‘real world’ these conditions are unlikely to coincide."
Source: Tyndall Centre for Climate Change Research
this professor is not seeing the obvious hear, that slowly shale gas is being developed as a source that will begin displacing coal to the extent it can globally. this will work ONLY to lower particulate pollution and emissions than it the levels that would OTHERWISE attain without development of shale gas.
because other countries WOULD be developing themselves industrially regardless of our choice to go on shale gas or not. coal exports notwithstanding.
z
"We live in a society exquisitely dependent on science and technology, in which hardly anyone knows anything about science and technology." - Carl Sagan
And if we where using coal, how would that stop us from exporting it as well? We would just increase production.
Really nice to say, hey we'll lower our carbon emissions that are 100x more than yours and you should live in a hut!
As zevulon says their biggest problem appears to be wanting to keep the undeveloped nations in poverty by denying them the necessary power generation equipment to allow those economies to develop.
The other thing that most people ignore is the fact that more CO2 in the atmosphere is beneficial to all growing things be it trees, plants and food crops. Trying to reduce CO2 is tantamount to condemning people to starvation.