Gas industry methane ‘losses’ recalculated — up

Emissions losses in tranmission estimates climb from negligible to nearly ten percent.

By Stephen Leahy — This is the first part of a two-part series on methane emissions in British Columbia.

Methane emissions from British Columbia's natural gas industry are likely at least seven times greater than official numbers — blowing BC's Climate Action Plan out of the water. Natural gas is nearly all methane, and since methane is such a powerful climate warming gas, these unreported emissions mean the total CO₂ equivalent emissions for the entire province are nearly 25 percent higher than is being reported.

The province's legislated climate plan is to reduce CO₂ equivalent emissions (CO₂e) 33 percent below 2007 levels by 2020. The booming natural gas sector may make that target an impossibility.
Each year the BC gas industry "loses" about 20 percent of the natural gas somewhere between pumping it out of the ground and its final destination. That was 7.4 billion cubic meters in 2010, out of a total production of 36.4 billion cubic meters, according to government statistics (BC's Natural Gas Exports). If a cubic meter was a second, 7.4 billion seconds equals 240 years.

While this gas was "lost in the field, the plant or during distribution and export," the report says most is not actually 'lost' but used by the industry to power equipment, pump the gas through the pipelines and so on.

But some of this gas escaped into the atmosphere through leaks, deliberate venting and what the industry calls fugitive emissions. According to a senior official in the BC Ministry of Environment just 0.3 to 0.4 percent was lost to the atmosphere in 2010. However, recent US studies of the gas industry show these losses or fugitive emissions are between 2 percent and 9 percent.

Actual measurements of the amount of methane escaping gas fields and pipelines are rare and not done by the Ministry. Recent in-field measurements at two different locations in Colorado and Utah found methane leakage ranging from 4 percent to 9 percent, according to a report in the science journal Nature.

In studies published in 2012 and 2011, climatologist Robert Howarth and colleagues at Cornell University in New York State estimated that between 3.6 percent and 7.9 percent of all shale gas produced leaks. Shale gas obtained through hydraulic fracking is believed to be leakier than traditional drilling methods. About half of BC gas is obtained by fracking. Most of BC's gas is exported to Alberta and the US.

BC's reported methane leaks are "absurdly low," Howarth told this reporter.  "The very, very lowest numbers ever published, and they were published by industry, were 0.67 percent," Howarth said.

"As more field measurements are made, our numbers (mean of 5.8 percent) are looking like they might even be low."

It is hugely important to know how much methane is leaking. When methane is burned to heat your home, the waste product is CO₂. While CO₂ lives for centuries in the atmosphere, unburned methane has a shorter life but is much better at trapping heat than CO₂. Initially this heat-trapping power was considered 21 times greater than CO₂ over a 100-year time period. Later this was increased to 25 times which is widely used and this is expected to be raised to 33 times. These metrics are called “global warming potential” or GWP.

However, new research shows over a 20-year-time span methane's global warming potential (GWP) is up to 105 times greater than CO₂.

"Given the urgent need to reduce methane emissions globally to keep global temperature rise below the critical value of 1.5 to 2 degrees C, many Earth System scientists believe the 20-year time frame is the appropriate one to use," said Howarth.

One of the world's leading methane experts agrees.

"If you believe limiting near-term climate change is an important goal for society, then it makes sense to pay attention to the 20-yr value (105X)," Drew Shindell at the NASA Goddard Institute for Space Studies told this reporter.

If BC's leaks are in reality 3 percent then that's roughly 1.1 billion cubic meters of methane that escapes into the atmosphere each year. That means these leaks are equivalent to pumping out 15.5 million tonnes (Mt) of CO₂ based on GWP of 21 that the province uses, and is the current international standard until later this year. That's equivalent to the emissions from operating 3 million cars for one year (Avg: 5.1 ton CO₂/vehicle/year). The province has 2 million licensed passenger vehicles.

Using the climate protection metric of a GWP of 105, then BC's methane leaks are the equivalent of pumping 77.5 Mt of CO₂ into the atmosphere every year, more than doubling the province's carbon footprint.

Emissions for the entire province from all sources, transport, energy, home, industry, etc. was 62 Mt in 2010 (most recent year available). Of that total just 2.2 Mt of CO₂ were attributed to methane emissions from the natural gas industry, according to a senior official at the Ministry of Environment.

The main reason for the huge gap between BC's reported methane emissions of 2.2 Mt vs the more realistic emissions of 15.5 to 77.5 Mt appears to be under-reporting by the industry.

End part one. In part two the gas industry responds, and what fugitive emissions mean for BC's hopes to become an LNG export giant.

© Copyright 2013 Stephen Leahy, All rights Reserved. Written For: StraightGoods.ca