By Dan,
posted on Wednesday, May 25, 2011.
"I'm the first to admit that there is a lot of
uncertainty in our result." (May 19, Carnegie Endowment)
News of the National Energy Technology Laboratory's (NETL)
presentation supporting the fact that natural gas produces half the
greenhouse gas emissions of coal came out last week just as
debunked professor Robert Howarth went to Washington to trot out
his baseless claim that somehow natural gas is actually a less
clean fuel.
Howarth poked so many holes in his own contentions during a speech
at the Carnegie Endowment that he hardly needed the EPA's Roger
Fernandez and El Paso's Fiji George to serve as live fact-checkers.
But that didn't hurt. He's also had a good portion of the community
of credible climate scientists raise questions about his work.
Among the most illuminating things that came from the Carnegie
Endowment event:
- Plant Efficiency - Howarth misstated plant
efficiency of coal and gas power plants
- Weak Data - Howarth reiterated the weakness of
the data he used, calling some of it "weird"
- False Claims - Fernandez took Howarth to task
for exaggerating methane capture in coal mines
- Estimates to be cut - Fernandez said EPA was
likely to cut natural gas emissions estimates.
Howarth placed the efficiency of a coal plant at up to 47
percent, while saying a gas plant tops out at about 53
percent.
John Reilly, a lecturer at MIT's Sloan School of Management and
some of his MIT colleagues wrote last week in Huffington Post that "natural gas base-load
units have efficiencies in the 40-54 percent range, compared to
30-35 percent for the current fleet of coal plants. Howarth did not
include this efficiency difference, or any efficiency difference in
his life-cycle assessment. Howarth also ignores the fact that
natural gas has virtually no emissions or particulate matter,
sulfur dioxide and mercury. Ultimately, Reilly said the
Howarth report was "misleading."
Michael Levi, senior fellow for energy and the environment at
the Council on Foreign Relations, reiterated his skepticism of
Howarth's work in a blog last week and said that "the NETL
work is a far more useful guide for thinking through the gas
emissions issue."
NETL concluded that "using a 100-year global warming potential and
assuming an average power plant, unconventional gas results in 54
percent less lifecycle greenhouse gas emissions than coal," Levi
wrote. "Even using a 20-year global warming potential, as Howarth
controversially argues one should, the savings from substituting
unconventional gas for coal are almost 50 percent. The NETL study
acknowledges -and explores - a range of uncertainties, but it finds
nothing close to the problems that Howarth claims. "
"Choosing an index based on 20 years, as Howarth has done,
largely ignores serious longer term risks of climate change," MIT's
Reilly wrote. "Howarth's choice threatens to tilt critical policies
away from some of the more dangerous risks we face in the longer
term, focusing us instead on near-term and largely manageable gas
production methane leakage."
Howarth admitted that the weakest part of his report was
"absolutely" the data on shale plays. He even called some of his
data sources "weird."
Howarth also made claims that most of the methane from coal mines
is captured. This prompted EPA's Fernandez to call foul. "I
have to respectfully disagree on that," Fernandez said of Howarth's
assertion. "There is a huge amount of methane that is vented
through ventilation systems."
Fernandez made another interesting point, saying that the very
narrow EPA assumptions Howarth relied heavily upon will be revised
and most likely reduced.
"We are going to update the inventory and I think you'll see some
of those numbers come down, because we are going to do some further
analysis in regard to what the entire industry is doing rather than
just that being reported to us," said Fernandez.
Finally El Paso's Fiji George pointed to NETL data on methane
emissions that show Howarth is far off the mark in his conclusions.
Then George made the point that natural gas companies have a
compelling interest in controlling methane leakage. "We spend
a lot of time, a lot of money, a lot of effort in producing
methane. Would you spend money on something at home knowing
that it was consistently going down the drain?"
As we have documented, there is a preponderance of scientists,
who have raised serious concerns about the validity of this report,
and there was no shortage of skeptical people in the audience at
the Carnegie Endowment. Based on Howarth's admissions on the
weakness of his data, and his clear misstatements about the
science, Howarth should be earning more skeptics as he continues to
mislead.