Post on 15-Jul-2015
transcript
WHAT’S THE CATCH?
- Although the following is true:
- Carbon emissions remain in the atmosphere for centuries, where methane
does not; and
- Carbon emissions are much smaller for natural gas than many other sources.
- Methane traps much more heat in the atmosphere (84-100 times more)
- This means:
- Any molecule of methane released today is 100 times more heat trapping
than carbon dioxide
- Even though methane may only account for 14% of emissions worldwide, and
carbon dioxide molecules outnumber methane 5 to 1,
- This smaller amount is still 19 times a greater problem for climate change
over a 5 year period and 4 times greater over a 10 year period.
Sources: onegreenplanet.org, Environmental Defense Fund, US EPA
“BY EMITTING JUST A LITTLE BIT A METHANE,
MANKIND IS GREATLY ACCELERATING THE RATE
OF CLIMATIC CHANGE.”-Steve Hamburg
Chief Scientist, Environmental Defense
Fund
HOW IS METHANE ALLOWED TO ESCAPE?
- Before it can be added to a pipeline, some companies vent the methane
directly into the air
- Leaking pipes, valves, compressors and tanks allow for escaping
methane
- During hydraulic fracturing (fracking), small amounts of methane are
allowed to escape into the atmosphere.
Source: npr.org
WHAT IS FRACKING?
- Allows for the removal of natural gas from a layer of rock (usually shale)
- Pressurized mix of sand, chemicals, and water are injected into a
wellbore to create cracks
- These cracks allow for the gas to flow
- When the hydraulic pressure is removed, the sand remains to hold the
fractures open, allowing gas to flow through them.
Source: wikipedia.org
PROS OF FRACKING
- Limits dependence on foreign oil
- Allow for job growth and exportation of NG as a commodity
- Done correctly, can be an alternative to burning more carbon-rich fuels
- Can be a “bridge fuel” to even cleaner energy forms
- Allows alternative usage of land for small landowners/farmers
CONS OF FRACKING
- It can be expensive
- During well completion, there are fugitive methane emissions
- The mixture used to break apart rock could reach (and poison) the
groundwater, although proponents say it’s so far beneath the water table
that’s not likely.
- We don’t know what’s in the chemicals used in fracturing–some are
classified as “trade secrets”.
- No comprehensive short- or long-term studies have been done on health
environmental impact.
- The fracking mixtures uses many millions of gallons of fresh water
- Other chemicals are emitted into the air in the fracking process, the health
risks of which we don’t yet know.
Sources:
1. Methane and the greenhouse gas footprint of natural gas from shale formations. A letter.
Climactic Change106:679-790 (2011)
Robert W. Howarth, Renee Santoro, Anthony Ingraffea
2. The Environmental Costs and Benefits of Fracking
Annual Review of Environment and Resources
Vol. 39: 327-362 (Volume publication date October 2014)
First published online as a Review in Advance on August 11, 2014
DOI: 10.1146/annurev-environ-031113-144051
Robert B. Jackson,1,2 Avner Vengosh,2 J. William Carey,3 Richard J. Davies,4 Thomas H. Darrah,5 Francis O'Sullivan,6 and Gabr