Natural Gas. Green? Perhaps NOT.
- Nov 21, 2010 10:32 am GMT
- 669 views
“Using the best available science, we conclude that natural gas is no better than coal and may in fact be worse than coal in terms of its greenhouse gas footprint when evaluated over the time course of the next several decades.”
This is the recently posted conclusion of Dr. Robert Howarth, David Atkinson Professor of Ecology and Environmental Biology at Cornell. He makes it clear that the paper has not completed the peer review process and his conclusion should be taken “tentatively” until he has seen and responded to the comments of his peers. However, “due to the tremendous interest in the topic, and its importance in deciding the wisdom of viewing natural gas as a transitional fuel over the coming decades, with a lower greenhouse gas footprint than coal”, he made details of his most recent research known via his website on November 15, 2010.
Howarth made a bit of a stir earlier this year when he published a preliminary study about the climate impact of gas. MIT’s Technology Review energy editor Kevin Bullis noted that because Howarth had found mistakes in his own analysis he was back at the drawing board. Bullis concluded: “for all the shortcomings of Howarth’s analysis, it points to a real need…. [ which is ] …a thorough study of the potential impact”.
Howarth later said there was support for his case that adequate studies had yet to be done by citing a May 4 2010 letter from the Council of Scientific Society Presidents which warned the Obama Administration that: “policy has preceeded adequate scientific study…. [of ] …full life cycle greenhouse gas emissions”.
Howarth is now claiming, subject to full peer review, that he has done an adequate study. It seems no one looked this hard at the lifecycle emissions of gas before. The stakes are so high Howarth’s will not be the last word, but it may be that the time has come for “greens” to reconsider how they view gas.
Everyone else is certainly reconsidering their view of how significant gas is .
E.g., David Resler , Chief Economist, Nomura Securities, said this on a recent Bloomberg Surveillance podcast: “… the U.S. now sits on an enormous stockpile of natural gas reserves that essentially could liberate us from dependence on imported oil altogether in a five or six year span of time….”
He spoke of so much shale gas it was causing downward pressure on the world price of oil. Nomura is the largest securities firm in Japan.
A recent State Department briefing stated that in many countries gas is now economically competitive with coal, on a dollars per btu basis.
That most environmentalists have so far welcomed the prospect of abundant relatively cheap gas can be seen in the latest blog post on the subject by Michael Brune, director of the Sierra Club: “we need to use natural gas as our country makes the transition from the dirtiest energy sources (coal and oil) to clean and renewable sources like wind and solar. And yes, if we want that gas, we will have to drill for it.” The Sierra Club is the largest environmental organization in the world.
Greens have tended to accept at face value the assessments of the climate impact of natural gas that just consider its molecular structure. I.e. gas has four hydrogen atoms surrounding one carbon atom. Many have thought that burning gas is like burning coal diluted with hydrogen. Hydrogen has no climate impact. Greens also like the fact that when gas is extracted and burned, mountaintops aren’t blown off, every lake in the world doesn’t end up contaminated with mercury, and huge strip mines are not opened up. In many ways, gas has seemed to be the least worst fossil fuel.
The WorldWatch Institute went so far as to publish: The Role of Natural Gas in a Low-Carbon Energy Economy which makes the case that, given the great US reserve of gas, because the US could cause gas to become even more significant more quickly than if economic forces are left to act alone, national policy aimed at causing this should be implemented. They think if this is done, the US will have an overall lower climate impact than under any other policy they approve of that they can imagine.
The problem is that gas isn’t just a mixture of carbon and hydrogen. It is methane. Methane is a potent greenhouse gas. If you take into account the methane that gets into the atmosphere as a result of producing, transporting and using natural gas and add it into the calculation of the “lifecycle” climate impact of gas because burning it emits CO2, and you compare to the “lifecycle” impact of coal, serious questions come up as to how “green” this fuel is.
Here is the chart from the Howarth study that has been submitted for peer review:
A further issue is what the new perception of how much gas there is does to the economics of nuclear. Gas is snuffing out the US “nuclear renaissance”. Some environmentalists, i.e. Joe Romm, are rejoicing.
But Howarth may prove to be correct that gas is as bad or worse than coal for climate in terms of the next few decades as opposed to the next many centuries. This is serious. Short term severe climate forcing caused by a factor not that serious on its own initiated very significant positive feedback which drove excursions of climate in the paleoclimate record which were much greater than ice age/interglacials. Even some of the most senior oil executives have lost their nerve about the long industry wide denial campaign and are warning now that they see a serious risk of touching off a runaway climate effect on a scale far beyond what civilization could face and survive.
If Howarth is right, greens face more than having to reconsider their view on how “green” gas is. There will be more pressure on the “green” community to come up with better reasons than they have so far as to why they remain adamantly opposed to nuclear power.