Sunday, January 25, 2015

A 2.7% methane leak rate represents ~10% of Massachusetts' entire greenhouse gas emissions inventory

Can natural gas pipeline leaks really amount to a full 10% of the total state greenhouse gas emissions (including every sector of human activity in the state - transportation, electricity, agriculture, residential/commercial buildings, industrial processes, and waste)?  

This would be an enormous contribution to climate change forcing from a single activity.  

That's what results from our recent PNAS paper would indicate, if our regional results from eastern MA and environs were to be scaled to the Commonwealth.

Here's how I arrive at this remarkable estimate: 

In our PNAS study we estimated a 2.7% (+/- 0.6%) leak rate from natural gas (primarily methane, or CH4).  

Assuming that percentage is leaked at the same percentage across the state of Massachusetts (not a bad assumption; old cast iron and bare steel pipes are distributed across the state), and given that MA used about 420 billion cubic feet of natural gas annually in 2012-13, a leak rate of 2.7% X 420 billion cubic feet equals 11.3 billion cubic feet leaked gas.

Let's convert to cubic meters: 11.3 x 10^9 ft^3 x 0.028 m^3/ft^3 = 3.20 x 10^8 m^3 CH4

or, 3.20 x 10^11 liters of CH4

assume (accepting a bit of temperature and pressure error) 22.4 liters per mole for an ideal gas at standard temperature and pressure.

3.20 x 10^11 liters x 1 mol/22.4 liters = 1.43 x 10^10 moles CH4

use 1 mole CH4 = 16 grams

1.43 x 10^10 moles CH4 x 16 grams/mol = 2.3 x 10^11 grams CH4

assuming CH4 warming potential is 34X that of CO2 over 100 years (Table 8.7 here) 

= 7.8 x 10^12 g eCO2, or 7.8 Million Metric Tonnes equivalent CO2 per year in Massachusetts in lost natural gas.

This is about 10% of the total state greenhouse gas emissions inventory, using the most recently available state estimates (2011, to stand in for our study's 2012-13 time frame). The +/- 0.6% confidence limits around the mean of 7.8 million metric tonnes give a range of 6.1 to 9.5 million metric tonnes, or about 8% to 13% of the state's entire GHG emissions inventory for 2012-13.

Note this is not even the amount of natural gas consumed (which, when combusted releases CO2); it's just the 2.7% of that total that leaked.

Saturday, March 23, 2013

US State Department Report on Keystone XL Pipeline hid Conflicts of Interest

The US State Department needs to go back to the drawing board and start over with a clean slate:

http://www.motherjones.com/politics/2013/03/keystone-xl-contractor-ties-transcanada-state-department


Friday, March 15, 2013

The Autotrophic City

BU, IBM, and the City of Boston co-hosted an amazing workshop yesterday on "Smarter Cities".  Here's my take: The biggest Smarter City challenge of all is to transform our cities from fossil fueled heterotrophs to self-sustaining autotrophs. Climate scientists give us no more than a few decades to get this done, which means we need a Manhattan Project - sized effort with all hands on deck.

Key to this transition is a transformation of our infrastructure: from being delivery based systems supplying resources from far distant sources over vulnerable supply lines - to self-sustaining systems feeding on local and regional sun, wind, water, and waste. Homes and businesses must become sites of production and sharing, and more efficient sites of consumption. The good news is that we can morph our existing life support infrastructure systems rather than start over: renewable gas from our local waste streams can be fed directly into our local gas pipeline network or can generate electricity, allowing us to draw down the need for distant, dirty fossil gas and oil. Solar, tidal and wind power can supplement the existing electrical grid, and electric vehicles can buffer supply intermittency by diurnal peak shaving and valley filling. In Boston, enough rainwater falls on the city to potentially serve a third of its water needs, providing resilience against single pipeline failures (like happened in Boston on May 1, 2010; just google "aquapocalypse" for a lesson in irresilience). For food, we'll need to supplement rooftop and community gardens with big organic from farther away.  Efficiencies of scale in food production can mean low carbon costs, even from longer distance, and we should embrace them, while still valuing the resilience conferred by local redundancy in food production.

Dovetailing the autotrophic city is the efficient city.  LED light bulbs, for example, provide ample light for a fraction of previous power.  My IBM colleague David Bartlett, who shared a panel yesterday with me, has shared some stunning statistics on the opportunities for efficiency gains.

Think the autotrophic city - even an autotrophic planet - is crazy?  Some pretty bright people at Stanford don't think so.  

Saturday, March 9, 2013

The inverted terminology of investment and divestment

Many university administrations argue that fossil fuel investment is needed to sustain society's energy needs. This misses the key function of investment, which is to PROMOTE, not merely sustain. Investment promotes the active GROWTH of enterprises, not just their maintenance. The enormous profits and tax breaks enjoyed by fossil fuel corporations are enough to keep them from collapsing overnight should we choose to divest. Divestment doesn't stop corporations from profiting from our addictions at the gas pump and supermarket, or from striking drilling deals with private landowners.

A related argument for investment is growth in energy demand, which supposedly requires supply to increase. But the United States experienced its lowest rate of population growth ever in the last decade. Our standard of life is comfortable and wasteful. Investing in energy efficiency and renewable energy rather than new production can easily maintain and improve our quality of life.

Demand is not the reason for the Keystone XL pipeline, or for the new pipelines being laid out of the Marcellus Shale to serve us in Boston and the rest of the eastern seaboard; the economic reality is that there is a glut of gas and oil that corporations need to move to make profits. The gluts are so large that these pipelines head to our shores for export. The pipelines create and enable the markets; they don't serve  them.They also lock us domestically further and further into a fossil fuel infrastructure dependency, like a heroin user who has found a new vein.

The unstated fear is the symbolic statement made by university divestment; the fear that this idea is too powerful to stay within the walls of academia and will go viral. The tentacles of fossil fuels run broad and deep, systemically infecting every aspect of society, including our universities. Why else would there be so much resistance among university administrations, whose endowments average only about 2% in fossil fuel producing companies?

The choice for BU is: do we want to continue to invest in and actively promote the growth of a fossil fuel dependent society? Or, by divestment, do we wish to opt out from such active support?

Friday, March 2, 2012

Smell Something, Say Something!

Check out Reed Underwood's fledgling crowd-sourced,citizen science natural gas leaks project, at smellsomething.org. Please participate!

Tuesday, May 24, 2011

Unaccounted gas amounts to nearly 2% of US greenhouse gas emissions

Putting together data from here and here.

These documents show:

-Over the last five years the US total annual unaccounted for gas averaged 247 billion cubic feet, which translates to 123 million metric tons of equivalent CO2 (according to my process for calculating shown here for Massachusetts).

-The total US GHG emissions were 6,633 Million Metric Tons.

123/6633 = 1.9%

Monday, May 23, 2011

Greenhouse Gas Potential from leaking Natural Gas in Massachusetts

Here is my calculation for the Greenhouse Gas Potential from the 8 billion cubic feet of natural gas (methane, or CH4) lost each year in the state of Massachusetts:

Convert to cubic meters: 8 x 10^9 ft^3 x 0.028 m^3/ft^3 = 2.26 x 10^8 m^3 CH4

or, 2.26 x 10^11 liters of CH4

assume (accepting a bit of temperature and pressure error) 22.4 liters per mole for an ideal gas at standard temperature and pressure.

2.26 x 10^11 liters x 1 mol/22.4 liters = 10^10 moles CH4

use 1 mole CH4 = 16 grams

10^10 moles CH4 x 16 grams/mol = 1.6 x 10^11 grams CH4

use CH4 25X the Greenhouse Gas Potential of CO2
(ref: http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter2.pdf)

= 4.0 x 10^12 g eCO2 = 4 Million Metric Tonnes equivalent CO2 per year in Massachusetts in lost natural gas.

This is about 4-5% of the total state greenhouse gas emissions inventory
(ref: http://www.mass.gov/dep/air/climate/ghg08inv.pdf)