Natural Gas, Methane, and Global Warming
Robert Howarth
The David R. Atkinson Professor of Ecology & Environmental Biology
Cornell University, Ithaca, NY USA
Moot Court National Championship Symposium
Fracking: The Cost of Energy Independence
University of Houston Law Center, Houston, TX
January 23, 2014
Shale gas is new, the science behind it is new …..
Many environmental issues:
• Local air quality (ozone, benzene, etc.)
• Large volume of water needed
(50 – 100X traditional fracking)
• Leaking of well casings (3? 30%?), groundwater
contamination
• Disposal of frack-return fluids
• Disposal of drill cuttings and drill muds
• Radon in natural gas
Is natural gas a “bridge fuel?”
For just the release of carbon dioxide during combustion…..
g C of CO2 MJ-1 of energy
Natural gas
15
Diesel oil
20
Coal
25
(Hayhoe et al. 2002)
Methane emissions – the Achilles’ heel of natural gas
• Natural gas is mostly methane.
• Methane is 2nd most important gas behind humancaused global warming.
• Methane is much more potent greenhouse gas
than carbon dioxide, so even small emissions matter.
Carbon Dioxide
Methane
In fall 2009, Tony Ingraffea, Renee Santoro, and I
took on as research questions:
1) The role of methane emissions in the greenhouse
gas footprint of natural gas.
2) Evaluation of methane emissions from shale gas
in comparison to conventional natural gas.
Methane emissions
(full life-cycle, well site to consumer), shown chronologically
by date of publication (% of life-time production of well)
Conventional gas
Shale gas
EPA (1996, through 2010)
1.1 %
-----
Hayhoe et al. (2002)
3.8 %
-----
Jamarillo et al. (2007)
1.0 %
-----
Methane emissions
(full life-cycle, well site to consumer), shown chronologically
by date of publication (% of life-time production of well)
Conventional gas
Shale gas
EPA (1996, through 2010)
1.1 %
-----
Hayhoe et al. (2002)
3.8 %
-----
Jamarillo et al. (2007)
1.0 %
-----
Howarth et al. (2011)
3.8 %
5.8 %
(1.6 – 6.0)
(3.6 – 7.9)
Methane emissions
(full life-cycle, well site to consumer), shown chronologically
by date of publication (% of life-time production of well)
Conventional gas
Shale gas
EPA (1996, through 2010)
1.1 %
-----
Hayhoe et al. (2002)
3.8 %
-----
Jamarillo et al. (2007)
1.0 %
Howarth et al. (2011)
3.8 %
(1.6 – 6.0)
Good agreement, with
largely independent data
----sources
5.8 %
(3.6 – 7.9)
Methane emissions
(full life-cycle, well site to consumer), shown chronologically
by date of publication (% of life-time production of well)
Conventional gas
EPA (1996, through 2010)
1.1 %
Shale gas
-----
Clearly too low, based on
Lelieveld----et al. (2005) and
GAO (2010)
Hayhoe et al. (2002)
3.8 %
Jamarillo et al. (2007)
1.0 %
-----
Howarth et al. (2011)
3.8 %
5.8 %
(1.6 – 6.0)
(3.6 – 7.9)
Methane emissions
(full life-cycle, well site to consumer), shown chronologically
by date of publication (% of life-time production of well)
Conventional gas
EPA (1996, through 2010)
Hayhoe et al. (2002)
Jamarillo et al. (2007)
Howarth et al. (2011)
Shale gas
1.1 %
-----
3.8 %
-----
3.8 %
5.8 %
50% greater emissions from shale gas,
based on estimates of venting during
frack-return
flow ----back
1.0 %
(1.6 – 6.0)
(3.6 – 7.9)
Methane emissions
(full life-cycle, well site to consumer), shown chronologically
by date of publication (% of life-time production of well)
One of our major conclusions in Howarth et al.
(2011): pertinent data were extremely limited, and
Conventional gas Shale gas
poorly documented.
EPA (1996, through 2010)
1.1 %
----Great need for better data, conducted by
researchers freed of industry control and influence.
Hayhoe et al. (2002)
3.8 %
----Jamarillo et al. (2007)
1.0 %
-----
Howarth et al. (2011)
3.8 %
5.8 %
(1.6 – 6.0)
(3.6 – 7.9)
75
high
methane
20-year time frame
Grams Carbon per MJ
60
45
Methane
Indirect CO2
Direct CO2
high
methane
low
methane
low
methane
30
surface
deep
15
0
Low Estimate
High Estimate
Shale
Gas
Shale Gas
High Estimate
Conventional
Conventional
Gas
Natural
Gas
Low Estimate
Surface-mined Deep-Mined
Coal
Coal
75
Methane
100-year time frame
Indirect CO2
Grams Carbon per MJ
60
Direct CO2
45
30
Oil
Diesel Oil
low
methane
high
methane
low
methane
high
methane
surface
deep
15
0
Conventional
ConventionalGas
Gas
Natural
Low Estimate High Estimate Low Estimate High Estimate Surface-mined Deep-Mined
April 2011
Shale
Gas
Shale Gas
Coal
Coal
Oil
Diesel Oil
People who Mattered
Mark Ruffalo, Anthony Ingraffea,
Robert Howarth
By Bryan Walsh Wednesday, Dec. 14, 2011
The biggest environmental issue of 2011 — at least in the U.S. — wasn't global
warming. It was hydraulic fracturing, and these three men helped represent the
determined opposition to what's more commonly known as fracking. Anthony
Ingraffea is an engineer at Cornell University who is willing to go anywhere to talk
to audiences about the geologic risks of fracking, raising questions about the
threats that shale gas drilling could pose to water supplies. Robert Howarth is his
colleague at Cornell, an ecologist who produced one of the most controversial
scientific studies of the year: a paper arguing that natural gas produced by
fracking may actually have a bigger greenhouse gas footprint than coal. That
study — strenuously opposed by the gas industry and many of Howarth's fellow
scientists — undercut shale gas's major claim as a clean fuel. And while he's best
known for his laidback hipster performances in films like The Kids Are All Right,
Mark Ruffalo emerged as a tireless, serious activist against fracking — especially
in his home state of New York.
People who Mattered
Mark Ruffalo, Anthony Ingraffea,
Robert Howarth
By Bryan Walsh Wednesday, Dec. 14, 2011
Other “People who Mattered” in 2011:
Newt Gingrich, Osama bin Laden, Joe Paterno,
Adele, Mitt Romney, Muammar Gaddafi,
Barack Obama, Bill McKibben, Herman Cain,
Rupert Murdoch, Vladimir Putin, Benjamin
Netanyahu…
Methane emissions
(% of life-time production of well)
Conventional gas
EPA (1996, through 2010)
Hayhoe et al. (2002)
Jamarillo et al. (2007)
Howarth et al. (2011)
EPA (2011)
Venkatesh et al. (2011)
Jiang et al. (2011)
Stephenson et al. (2011)
Hultman et al. (2011)
Burnham et al. (2011)
Cathles et al. (2012)
1.1 %
3.8 %
1.0 %
3.8 %
2.5 %
2.2 %
---0.5 %
2.3 %
2.6 %
1.8 %
Shale gas
------------5.8 %
3.9 %
---2.0 %
0.7 %
3.8 %
1.9 %
1.8%
Methane emissions
(% of life-time production of well)
Conventional gas
Shale gas
EPA (1996, through 2010)
1.1 %
----Hayhoe et al. (2002)
3.8 %
----Many
things
to critique here….
Jamarillo
et al. (2007)
1.0 %
----Howarth et al. (2011)
3.8 %
5.8 %
EPA (2011)
2.5 % reinterpretations
3.9 %
But
fundamentally, these are all just
of
Venkatesh et al.the
(2011)
2.2 %data set. ---same pretty limited
Jiang et al. (2011)
---2.0 %
Stephenson et al. (2011)
0.5 %
0.7 %
Hultman et al. (2011)
2.3 %
3.8 %
Burnham et al. (2011)
2.6 %
1.9 %
Cathles et al. (2012)
1.8 %
1.8%
Methane emission estimates:
Upstream
(well site)
Downstream
Total
(storage, distribution, etc.)
Hayhoe et al. (2002), conventional
1.3 %
2.5 %
3.8 %
EPA (2010), US average for 2009
0.16 %
0.9 %
1.1 %
Howarth et al. (2011), US average
conventional gas
shale gas
1.7 %
1.3 %
3.3 %
2.5 %
2.5 %
2.5 %
4.2 %
3.8 %
5.8 %
EPA (2011), US average for 2009
conventional gas
shale gas
1.8 %
1.6 %
3.0 %
0.9 %
0.9 %
0.9 %
2.7 %
2.5 %
3. 9 %
Petron et al. (2012), Colorado field
4.0 %
------
-----
EPA (2013), US average for 2009
0.88 %
0.9 %
1.8 %
Karion et al. (2013), Utah field
9.0 %
------
-----
Allen et al. (2013), US average
0.42 %
------
-----
Methane emission estimates:
Upstream
(well site)
Downstream
Total
(storage, distribution, etc.)
Hayhoe et al. (2002), conventional
1.3 %
2.5 %
3.8 %
EPA (2010), US average for 2009
0.16 %
0.9 %
1.1 %
Howarth et al. (2011), US average
conventional gas
shale gas
1.7 %
1.3 %
3.3 %
First
2.5 %re-analysis 4.2 %
by
2.5EPA
% since 19963.8 %
2.5 %
5.8 %
EPA (2011), US average for 2009
conventional gas
shale gas
1.8 %
1.6 %
3.0 %
Petron et al. (2012), Colorado field
4.0 %
0.9 %
2.7 %
0.9 %
2.5 %
Re-analyzed
again,
0.9 %
3. 9 %
under pressure from
industry,
and ignoring
---------Petron et al. (2012)
EPA (2013), US average for 2009
0.88 %
0.9 %
1.8 %
Karion et al. (2013), Utah field
9.0 %
------
-----
Allen et al. (2013), US average
0.42 %
------
-----
Methane emission estimates:
Upstream
(well site)
Downstream
Total
(storage, distribution, etc.)
Hayhoe et al. (2002), conventional
1.3 %
2.5 %
3.8 %
EPA (2010), US average for 2009
0.16 %
0.9 %
1.1 %
Howarth et al. (2011), US average
conventional gas
shale gas
1.7 %
1.3 %
3.3 %
2.5 %
2.5 %
2.5 %
4.2 %
3.8 %
5.8 %
EPA (2011), US average for 2009
conventional gas
shale gas
1.8 %
1.6 %
3.0 %
0.9 %
0.9 %
0.9 %
2.7 %
2.5 %
3. 9 %
Petron et al. (2012), Colorado field
4.0 %
------
-----
EPA (2013), US average for 2009
0.88 %
0.9 %
1.8 %
Karion et al. (2013), Utah field
9.0 %
------
-----
Allen et al. (2013), US average
0.42 %
------
-----
Bruce Gellerman, “Living on Earth,” Jan. 13,
2012, based on work of Nathan Phillips
http://www.loe.org/shows/segments.html?programID=12-P13-00002&segmentID=3
Pipeline accidents and explosions happen, due to large leaks….
….. small leaks are ubiquitous.
Pipelines in US are old!
PHMSA 2009 Transmission Annual Data
Flames consume homes during a massive fire in a residential neighborhood September 9,
2010 in San Bruno, California. (Photo by Ezra Shaw/Getty Images)
Methane emission estimates:
Upstream
(well site)
Downstream
Total
(storage, distribution, etc.)
Hayhoe et al. (2002), conventional
1.3 %
2.5 %
3.8 %
EPA (2010), US average for 2009
0.16 %
0.9 %
1.1 %
Howarth et al. (2011), US average
conventional gas
shale gas
1.7 %
1.3 %
3.3 %
2.5 %
2.5 %
2.5 %
4.2 %
3.8 %
5.8 %
EPA (2011), US average for 2009
conventional gas
shale gas
1.8 %
0.9 %
2.7 %
1.6 %
0.9 %
2.5 %
Low-end, best-case estimate from Howarth
3.0 %
0.9 %
3. 9 %
et al. (2011) for US average for 2009 = 0.5%
Petron et al. (2012), Colorado field
4.0 %
------
-----
EPA (2013), US average for 2009
0.88 %
0.9 %
1.8 %
Karion et al. (2013), Utah field
9.0 %
------
-----
Allen et al. (2013), US average
0.42 %
------
-----
Methane emission estimates:
Upstream
(well site)
Downstream
Total
(storage, distribution, etc.)
Hayhoe et al. (2002), conventional
1.3 %
2.5 %
3.8 %
EPA (2010), US average for 2009
0.16 %
Howarth et al. (2011), US average
conventional gas
shale gas
1.7 %
1.3 %
3.3 %
Range
gas%in
0.9
% for shale 1.1
Howarth et al. (2011) =
2.2%% to 4.3% 4.2 %
2.5
EPA (2011), US average for 2009
conventional gas
shale gas
2.5 %
2.5 %
3.8 %
5.8 %
1.8 %
1.6 %
3.0 %
0.9 %
0.9 %
0.9 %
2.7 %
2.5 %
3. 9 %
Petron et al. (2012), Colorado field
4.0 %
------
-----
EPA (2013), US average for 2009
0.88 %
0.9 %
1.8 %
Karion et al. (2013), Utah field
9.0 %
------
-----
Allen et al. (2013), US average
0.42 %
------
-----
Methane emission estimates:
Upstream
(well site)
Downstream
Total
(storage, distribution, etc.)
Hayhoe et al. (2002), conventional
1.3 %
2.5 %
3.8 %
EPA (2010), US average for 2009
0.16 %
0.9 %
1.1 %
Howarth et al. (2011), US average
conventional gas
shale gas
1.7 %
1.3 %
3.3 %
2.5 %
2.5 %
2.5 %
4.2 %
3.8 %
5.8 %
EPA (2011), US average for 2009
conventional gas
shale gas
1.8 %
1.6 %
3.0 %
0.9 %
0.9 %
0.9 %
2.7 %
2.5 %
3. 9 %
Petron et al. (2012), Colorado field
4.0 %
------
-----
EPA (2013), US average for 2009
0.88 %
0.9 %
1.8 %
Miller et al. (2013) PNAS national analysis for methane from all
Karion 2007
et al. (2013),
fieldon all monitoring
9.0 %
sources,
– 2008,Utah
based
data on-----methane
in atmosphere (12,694 observations). EPA (2013) estimate at
Allen
al. low…
(2013), US average
0.42 %
-----least
2-Xettoo
---------
Are methane emissions from shale gas greater than from
conventional gas?
1) Large potential for venting from shale gas wells at time of flow-back
following hydraulic fracturing. New EPA regulations address this, but
allow some exceptions. And enforcement?
2) Caulton et al. (submitted) found very high methane emissions from
some shale gas wells in southwestern PA during drilling phase…. A
result of going back into an area with a long history of gas and coal
development?
BUT most importantly, shale gas is the future of
natural gas, and natural gas in general is problematic.
Some shale gas wells are emitting huge amounts of methane…..
…… even as they are being drilled, and long before being fracked!
Dana Caulton, Paul
Shepson, and many
others from Purdue,
Penn State, NOAA, and
Cornell
Flyover of southwestern
Pennsylvania, late June
2012
Time frame for comparing methane and carbon dioxide:
• Hayhoe et al. (2002)
• Lelieveld et al. (2005)
• Jamarillo et al. (2007)
• Howarth et al. (2011)
• Hughes (2011)
• Venkatesh et al. (2011)
• Jiang et al. (2011)
• Wigley (2011)
• Fulton et al. (2011)
• Stephenson et al. (2011)
• Hultman et al. (2011)
• Skone et al. (2011)
• Burnham et al. (2011)
• Cathles et al. (2012)
• Alvarez et al. (2012)
0 to 100 years
20 & 100 years
100 years
20 & 100 years
20 & 100 years
100 years
100 years
0 to 100 years
100 years
100 years
100 years
100 years
100 years
100 years
0 to 100 years
IPCC (2013): “There is no
scientific argument for
selecting 100 years compared
with other choices.”
“The choice of time horizon ….
depends on the relative
weight assigned to the effects
at different times.”
High potential for massive emissions of
ancient CH4 due to thawing permafrost and
release of “frozen” methane (methane
hydrates and clathrates).
CH4
CH4
CH4
Zimov et al. (2006) Science
34
Hansen et al. (2007) suggested critical threshold
in climate system, to avoid melting of natural
methane hydrates, at ~ 1.8o C.
Dangerous tipping points are only 15 to 35 years into the future.
Controlling methane is CRITICAL to the solution!
http://news.discovery.com/earth/alas
kas-arctic-tundra-feeling-theheat.html
2.0 oC threshold
1.5 oC threshold
Shindell et al. 2012
75
20-year time frame
high
methane
Grams Carbon per MJ
60
45
Methane
Indirect CO2
Direct CO2
high
methane
low
methane
low
methane
30
deep
surface
15
0
Low Estimate
High Estimate
Shale Gas
Shale Gas
Low Estimate
High Estimate
Conventional
Natural
Gas Gas
Conventional
Surface-mined Deep-Mined
Coal
Oil
Coal
Diesel Oil
Howarth et al. 2011
US National Methane Emissions for 2009
(Howarth et al. 2012, based on EPA (2011)
Natural gas vs. Coal and other fossil fuels:
Different efficiencies for end use can affect the
comparison.
Most studies have concentrated on production of
electricity…..
Greenhouse gas consequences for natural gas compared to coal
(compared over integrated 20-year time frame)
Worse
than
coal
Better
than
coal
Greenhouse gas emissions relative to coal
4
3
2
For electricity
generated from
natural gas
compared to coal
1
0
0%
3%
6%
9%
Percent methane emission from natural gas
12%
Greenhouse gas consequences for natural gas compared to coal
(compared over integrated 20-year time frame)
Worse
than
coal
Better
than
coal
Greenhouse gas emissions relative to coal
4
3
EPA 2011
Electricity
2
1
Howarth et
al. 2011
0
0%
3%
6%
Extrapolated from
NOAA studies
9%
Percent methane emission from natural gas
12%
Heat (not electricity) is largest energy use globally,
including in developed countries such as the U.S.
International Energy Agency (2011)
In 2011 in US, 30% of natural gas used for electricity, 32% for domestic and
commercial heating, 28% for industry, and 8% by the gas industry itself.
Domestic hot water heating
electricity
Coal-powered plant
Heat pump
Natural gas
Gas burner
Greenhouse gas consequences for natural gas compared to coal
(compared over integrated 20-year time frame)
Worse
than
coal
Better
than
coal
Greenhouse gas emissions relative to coal
4
Hot water
3
Electricity
2
1
0
0%
3%
6%
9%
Percent methane emission from natural gas
12%
Greenhouse gas consequences for natural gas compared to coal
(compared over integrated 20-year time frame)
Worse
than
coal
Better
than
coal
Greenhouse gas emissions relative to coal
4
Water heated by natural
gas has a very large
greenhouse gas footprint
3
Hot water
EPA 2011
Electricity
2
1
Howarth et
al. 2011
0
0%
3%
6%
Extrapolated from
NOAA studies
9%
Percent methane emission from natural gas
12%
Of course, wind and solar are much, much better than using
coal for the electricity!!
But even when using coal for electricity, use of heat pump is
far preferable to direct use of natural gas for water heating
(and probably for domestic and commercial space heating).
Jacobson and Delucchi 2009
Powering New York State with Wind, Water, and
the Sun to Address Global Warming, Air Pollution,
and Energy Security
Prof. Mark Jacobson
Our Plan:
• Electrify transportation and commercial
domestic heating – greater efficiencies
lower total energy consumption (37%).
and
• Choose most environmentally benign generation technologies
(50% wind, 28% photovoltaic, 10% concentrated solar, and
12% geothermal, hydro, tidal, and waves).
• Rely on technologies that are commercially available today.
• Use a variety of energy storage techniques, and approaches
for balancing demand to production.
• Use hydrogen (generated from excess electricity production)
for industrial process energy and as a transportation fuel for
airplanes, long-distance trucks, and ships.
Jacobson et al. (2013) Energy Policy plan for New York State:
• Is cost effective ($570 billion price tag is paid off entirely in
health-cost savings of $33 billion per year over 17 years)
• Creates large number of net new jobs in New York.
• Stabilizes energy prices, and greatly improves energy security;
reduces energy prices on the time scale of 10 or more years
into the future.
• Hugely decreases air pollution and greenhouse gas emissions
from New York.
Some concluding throughts:
Natural gas is no bridge fuel.
Urgent need to reduce methane emissions, to slow down arrival time
of potential tipping points in the climate system …….
…… within the next 15 to 35 years
Shale gas is no better than and quite likely much worse than
conventional natural gas in terms of methane emissions.
Generation of electricity: Natural gas is at best comparable to coal,
and quite likely worse than coal in terms of total greenhouse gas
emissions (20-year time scale).
Heating and other uses of natural gas: At virtually any possible level of
methane emission, using natural gas for heating is a very poor idea.
We have a choice: the time for the renewable transition is NOW.
Thanks for the invitation to participate.
Special thanks to Tony Ingraffea, Bongghi Hong, and Drew Shindell.
Shale gas…. A bridge to nowhere
Funding:
Park Foundation
Wallace Global Fund
Cornell University