Air sampling by NOAA over Colorado Finds 4% Methane Leakage, More Than Double Industry Claims

Natural-gas operations could release far more methane into the atmosphere than previously thought. [Source: Nature]

How much methane leaks during the entire lifecycle of unconventional gas has emerged as a key question in the fracking debate.  Natural gas is mostly methane (CH4).  And methane is a far more potent greenhouse gas than (CO2), which is released when any hydrocarbon, like natural gas, is burned.

Even without a high-leakage rate for shale gas, we know that “Absent a Serious Price for Global Warming Pollution, Natural Gas Is A Bridge To Nowhere.”

But the leakage rate does matter.  A major 2011 study by Tom Wigley of the Center for Atmospheric Research (NCAR) concluded:

The most important result, however, in accord with the above authors, is that, unless leakage rates for new methane can be kept below 2%, substituting gas for coal is not an effective means for reducing the magnitude of future climate change.

The industry has tended kept most of the data secret while downplaying the leakage issue.  Yet I know of no independent analysis that finds a rate below 2%, including one by the National Energy Technology Laboratory, the DOE’s premier fossil fuel lab.

Now, as the journal Nature reports, we finally have some actual air sampling measurements, and they appear to confirm the higher estimates put forward by Cornell professor Robert Howarth:

When US government scientists began sampling the air from a tower north of Denver, Colorado, they expected urban smog — but not strong whiffs of what looked like natural gas. They eventually linked the mysterious pollution to a nearby natural-gas field, and their investigation has now produced the first hard evidence that the cleanest-burning fossil fuel might not be much better than coal when it comes to climate change.

Led by researchers at the National Oceanic and Atmospheric Administration (NOAA) and the University of Colorado, Boulder, the study estimates that natural-gas producers in an area known as the Denver-Julesburg Basin are losing about 4% of their gas to the atmosphere — not including additional losses in the pipeline and distribution system. This is more than double the official inventory, but roughly in line with estimates made in 2011 that have been challenged by industry. And because methane is some 25 times more efficient than carbon dioxide at trapping heat in the atmosphere, releases of that magnitude could effectively offset the environmental edge that natural gas is said to enjoy over other fossil fuels.

Methane is 25 times  more efficient than CO2 trapping heat over 100 year — but it is 100 times more efficient than CO2 trapping heat over two decades.

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As the United States has a freakishly warm and calm winter, Europe has been experiencing a frighteningly cold and dangerous season. Hundreds have died in frigid temperatures, snow and ice storms, and floods. This freakish weather in the Northern Hemisphere is connected by unusual behavior in the jet stream, which scientists are attributing to the dramatic changes in the Arctic caused by global warming pollution. In a new paper published in Tellus, scientists at the Alfred Wegener Institute for Polar and Marine Research find that declines in summer Arctic sea ice are a factor in changing the Arctic Oscillation, the circulation pattern that dominates winter weather:

Scientists at the Alfred Wegener Institute for Polar and Marine Research in Potsdam, Germany, say the frigid, snowy European winter has its origins in a warm Arctic summer. The U.S. National Oceanic and Atmospheric Administration reported that July 2011 was the fourth-warmest July on record. A warm summer in the Arctic cuts the amount of sea ice. NOAA reports that sea-ice levels last July were the lowest in three decades.

The effect is twofold, the Wegener scientists report. First, less ice means less solar heat is reflected back into the atmosphere. Rather, it is absorbed into the darker ocean waters. Second, once that heat is in the ocean, the reduced ice cap allows the heat to more easily escape into the air just above the ocean’s surface. Because warmer air tends to rise, the moisture-laden air near the ocean’s surface rises, creating instability in the atmosphere and changing air-pressure patterns, the scientists say.

In an interview with Conducive Chronicle, Dr. Jeff Masters explained why greenhouse pollution should be considered the most likely suspect for unprecedented behavior in the climate system:

The laws of physics demand that the huge amount of heat-trapping gases humans are pumping into the atmosphere must be significantly altering the fundamental large-scale circulation pattern of the atmosphere. Unprecedented behavior like we’ve witnessed in the configuration of the winter jet stream over North America — with the four most extreme years since 1865 occurring since 2006 — could very well be due to human-caused climate change. Something is definitely up with the weather, and it is clear to me that over the past two years, the climate has shifted to a new state capable of delivering rare and unprecedented weather events. Human emissions of heat-trapping gases like carbon dioxide are the most likely cause of such a shift in the climate.

It’s critical to note that the southern hemisphere is also experiencing utterly extreme weather during its summer: Australia is deluged by flood, and heat waves and drought are crippling South America and Africa.

Readers asked what a good extended metaphor was for global warming.  Here’s one, courtesy of the National Center for Atmospheric Research:

AtmosNews takes a lighthearted look at an unexpected analogy, explaining why some people call carbon dioxide (and the other greenhouse gases) the steroids of the climate system. Statistics and extreme behavior are involved, whether we’re talking about baseball or Earth’s atmosphere. NCAR scientist Gerald “Jerry” Meehl explains why.

NCAR has puts it together an very informative website on global warming and extreme weather, which I highly recommend.

Related Post:

• PBS Covers Link Between 2011′s “Mind-Boggling” Extreme Weather and Global Warming: It’s Like “Being on Steroids”