Category Archives: Ozone

NEW STUDY: The U.S. oil and gas boom is having global atmospheric consequences

Repost from the Washington Post

The U.S. oil and gas boom is having global atmospheric consequences, scientists suggest

By Chelsea Harvey, April 28, 2016
Advances in hydraulic fracturing and directional drilling have unlocked huge amounts of petroleum in the Badlands of Montana. (AP/Charles Rex Arbogast)

Scientists say they have made a startling discovery about the link between domestic oil and gas development and the world’s levels of atmospheric ethane — a carbon compound that can both damage air quality and contribute to climate change. A new study in the journal Geophysical Research Letters has revealed that the Bakken Shale formation, a region of intensely increasing recent oil production centered in North Dakota and Montana, accounts for about 2 percent of the entire world’s ethane output — and, in fact, may be partly responsible for reversing a decades-long decline in global ethane emissions.

The findings are important for several reasons. First, ethane output can play a big role in local air quality — when it is released into the atmosphere, it interacts with hydrogen and carbon and can cause ozone to form close to the Earth, where it is considered a pollutant that can irritate or damage the lungs.

Ethane is also technically a greenhouse gas, although its lifetime is so short that it is not considered a primary threat to the climate. That said, its presence can help extend the lifespan of methane — a more potent greenhouse gas — in the atmosphere. This, coupled with ethane’s role in the formation of ozone, makes it a significant environmental concern.

From 1987 until about 2009, scientists observed a decreasing trend in global ethane emissions, from 14.3 million metric tons per year to 11.3 million metric tons. But starting in 2009 or 2010, ethane emissions starting rising again — and scientists began to suspect that an increase in shale oil and gas production in the United States was at least partly to blame. The new study’s findings suggest that this may be the case.

The study took place during May 2014. A National Oceanic and Atmospheric Administration (NOAA) aircraft flew over the Bakken Shale and collected data on airborne ethane and methane, as well as ozone, carbon dioxide and other gases.

“We were interested in understanding the atmospheric impacts of some of these oil and gas fields in the U.S. — particularly oil and gas fields that had a lot of expansion of activities in the last decade,” said Eric Kort, the study’s lead author and an atmospheric science professor at the University of Michigan.

The findings were jarring.

“We found that in order to produce the signals we saw on the plane, it would require emissions in the Bakken to be very large for ethane … equivalent to 2 percent of global emissions, which is a very big number for one small region in the U.S.,” Kort said.

Notably, he said, the team’s observations in the Bakken Shale helped shed some light on the mysterious uptick in global ethane emissions observed over the past few years.

“The Bakken on its own cannot explain the complete turn, but it plays a really large role in the change in the global growth rate,” Kort said.

On a regional level, the researchers pointed out that a deeper investigation into the Bakken emissions impact on ozone formation may be warranted — not only for the purpose of analyzing local air quality but also because current models of the atmosphere have not included the jump in ethane output.

Because the researchers were also measuring other gases during the flyovers — including ozone, carbon dioxide and methane — they were able to make another major discovery. They found that the ratio of ethane to methane produced by the Bakken was much higher than what has been observed in many other shale oil and gas fields in the United States — an observation that could have big implications for future methane assessments, which are important for climate scientists.

In many oil and gas fields, methane is often the primary natural gas present — sometimes accounting for up to 90 percent or more of the gas that is released during extraction. Ethane often tends to be present in smaller proportions. In the Bakken, however, the researchers found that ethane accounted for nearly 50 percent of all the natural gas composition, while methane was closer to 20 percent.

This is important because researchers sometimes use trends in global ethane emissions to make assumptions about the amount of methane that’s being released by fossil fuel-related activities. While it’s possible to measure the total methane concentration in the atmosphere, it’s difficult to say exactly where that methane came from, because there are so many possibilities: thawing permafrost in the Arctic, emissions from landfills and agriculture are just a few examples. But because ethane is primarily emitted as a byproduct of fossil fuel development — and because methane and ethane tend to be emitted together in those cases — researchers sometimes use trends in global ethane emissions to make assumptions about how much of the Earth’s methane output can be attributed to oil and gas development.

When global ethane emissions were declining, for instance, many researchers assumed that overall losses of natural gas during fossil fuel extraction were declining, Kort noted. And when ethane emissions began rising again, it was logical to assume that methane emissions — from oil and gas development, specifically — were also likely on the rise. But as the Bakken study points out, this is not necessarily the case. The new study suggests that the Bakken formation has accounted for much of the global increase in ethane emissions while emitting comparatively low levels of methane simultaneously. And the researchers believe that there are other locations in the United States — the Eagle Ford shale in Texas, for example — where conditions are similar.

“They’ve basically shown here that a single shale can account for most of the ethane increase that you’ve seen in the past year,” said Christian Frankenberg, an environmental science and engineering professor at the California Institute of Technology and a researcher at NASA’s Jet Propulsion Laboratory. (Frankenberg was not involved with this study, although he has collaborated with Kort in the past.)

“This is not to say that there’s no enhanced methane in these areas,” he added. But he pointed out that making an incorrect assumption about the ratio of methane escaping compared to ethane “might easily overestimate the methane increases in these areas.”

And making incorrect assumptions about the methane that’s entering the atmosphere alongside ethane can skew climate scientists’ understanding of where the Earth’s methane emissions are coming from and which sources are the biggest priorities when it comes to managing greenhouse gas emissions.

Thus, while the new study contains striking findings about ethane emissions, it perhaps only deepens the already large and contentious mystery over just how much the U.S. oil and gas boom is contributing to emissions of methane, which is widely regarded to be the second most important greenhouse gas after carbon dioxide.

More broadly, the paper also highlights the immense impact that fossil fuel development in the United States can have on the atmosphere — and how important it is from both an air quality and a climate perspective to closely monitor these activities. As the paper points out, domestic production is already being felt on a global level.

“Ethane globally had been declining from the 80s until about 2009, 2010 … and nobody was really sure why it was increasing in the atmosphere again,” Kort said. “Our measurements showed this one region could explain much of the change in global ethane levels and kind of illustrate the roles these shale plains could play.”

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    EPA proposes new smog standards

    Repost from the EPA
    [Editor: To view the proposal: http://www.epa.gov/glo/.  – RS]

    News Release from Headquarters…

    EPA Proposes Smog Standards to Safeguard Americans from Air Pollution

    Release Date: 11/26/2014
    Contact Information: Enesta Jones, Jones.enesta@epa.gov, 202-564-7873, 202-564-4355; En español: Lina Younes, younes.lina@epa.gov, 202-564-9924, 202-564-4355

    WASHINGTON– Based on extensive recent scientific evidence about the harmful effects of ground-level ozone, or smog, EPA is proposing to strengthen air quality standards to within a range of 65 to 70 parts per billion (ppb) to better protect Americans’ health and the environment, while taking comment on a level as low as 60 ppb. The Clean Air Act requires EPA to review the standards every five years by following a set of open, transparent steps and considering the advice of a panel of independent experts. EPA last updated these standards in 2008, setting them at 75 ppb.

    “Bringing ozone pollution standards in line with the latest science will clean up our air, improve access to crucial air quality information, and protect those most at-risk. It empowers the American people with updated air quality information to protect our loved ones – because whether we work or play outdoors – we deserve to know the air we breathe is safe,” said EPA Administrator Gina McCarthy. “Fulfilling the promise of the Clean Air Act has always been EPA’s responsibility. Our health protections have endured because they’re engineered to evolve, so that’s why we’re using the latest science to update air quality standards – to fulfill the law’s promise, and defend each and every person’s right to clean air.”

    EPA scientists examined numerous scientific studies in its most recent review of the ozone standards, including more than 1,000 new studies published since the last update. Studies indicate that exposure to ozone at levels below 75 ppb — the level of the current standard — can pose serious threats to public health, harm the respiratory system, cause or aggravate asthma and other lung diseases, and is linked to premature death from respiratory and cardiovascular causes. Ground-level ozone forms in the atmosphere when emissions of nitrogen oxides and volatile organic compounds “cook” in the sun from sources like cars, trucks, buses, industries, power plants and certain fumes from fuels, solvents and paints. People most at risk from breathing air containing ozone include people with asthma, children, older adults, and those who are active or work outside. Stronger ozone standards will also provide an added measure of protection for low income and minority families who are more likely to suffer from asthma or to live in communities that are overburdened by pollution. Nationally, 1 in 10 children has been diagnosed with asthma.

    According to EPA’s analysis, strengthening the standard to a range of 65 to 70 ppb will provide significantly better protection for children, preventing from 320,000 to 960,000 asthma attacks and from 330,000 to 1 million missed school days. Strengthening the standard to a range of 70 to 65 ppb would better protect both children and adults by preventing more than 750 to 4,300 premature deaths; 1,400 to 4,300 asthma-related emergency room visits; and 65,000 to 180,000 missed workdays.

    EPA estimates that the benefits of meeting the proposed standards will significantly outweigh the costs. If the standards are finalized, every dollar we invest to meet them will return up to three dollars in health benefits. These large health benefits will be gained from avoiding asthma attacks, heart attacks, missed school days and premature deaths, among other health effects valued at $6.4 to $13 billion annually in 2025 for a standard of 70 ppb, and $19 to $38 billion annually in 2025 for a standard of 65 ppb. Annual costs are estimated at $3.9 billion in 2025 for a standard of 70 ppb, and $15 billion for a standard at 65 ppb.

    A combination of recently finalized or proposed air pollution rules – including “Tier 3” clean vehicle and fuels standards – will significantly cut smog-forming emissions from industry and transportation, helping states meet the proposed standards. EPA’s analysis of federal programs that reduce air pollution from fuels, vehicles and engines of all sizes, power plants and other industries shows that the vast majority of U.S. counties with monitors would meet the more protective standards by 2025 just with the rules and programs now in place or underway. Local communities, states, and the federal government have made substantial progress in reducing ground-level ozone. Nationally, from 1980 to 2013, average ozone levels have fallen 33 percent. EPA projects that this progress will continue.

    The Clean Air Act provides states with time to meet the standards. Depending on the severity of their ozone problem, areas would have between 2020 and 2037 to meet the standards. To ensure that people are alerted when ozone reaches unhealthy levels, EPA is proposing to extend the ozone monitoring season for 33 states. This is particularly important for at-risk groups, including children and people with asthma because it will provide information so families can take steps to protect their health on smoggy days.

    The agency is also proposing to strengthen the “secondary” ozone standard to a level within 65 to 70 ppb to protect plants, trees and ecosystems from damaging levels of ground-level ozone. New studies add to the evidence showing that repeated exposure to ozone stunts the growth of trees, damages plants, and reduces crop yield. The proposed level corresponds to levels of seasonal ozone exposure scientists have determined would be more protective.

    EPA will seek public comment on the proposal for 90 days following publication in the Federal Register, and the agency plans to hold three public hearings. EPA will issue final ozone standards by October 1, 2015.

    To view the proposal: http://www.epa.gov/glo/

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