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The Best Science Writing Online 2012
Showcasing more than fifty of the most provocative, original, and significant online essays from 2011, The Best Science Writing Online 2012 will change the way...
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The United States is poised to bet its energy future on natural gas as a clean, plentiful fuel that can supplant coal and oil. But new research by the Environmental Protection Agency—and a growing understanding of the pollution associated with the full "life cycle" of gas production—is casting doubt on the assumption that gas offers a quick and easy solution to climate change.
Advocates for natural gas routinely assert that it produces 50 percent less greenhouse gases than coal and is a significant step toward a greener energy future. But those assumptions are based on emissions from the tailpipe or smokestack and don't account for the methane and other pollution emitted when gas is extracted and piped to power plants and other customers.
The EPA's new analysis doubles its previous estimates for the amount of methane gas that leaks from loose pipe fittings and is vented from gas wells, drastically changing the picture of the nation's emissions that the agency painted as recently as April. Calculations for some gas-field emissions jumped by several hundred percent. Methane levels from the hydraulic fracturing of shale gas were 9,000 times higher than previously reported.
When all these emissions are counted, gas may be as little as 25 percent cleaner than coal, or perhaps even less.
Even accounting for the new analysis, natural gas—which also emits less toxic and particulate pollution—offers a significant environmental advantage. But the narrower the margins get, the weaker the political arguments become and the more power utilities flinch at investing billions to switch to a fuel that may someday lose the government's long-term support.
Understanding exactly how much greenhouse gas pollution comes from drilling is especially important, because the Obama administration has signaled that gas production may be an island of common political ground in its never-ending march toward an energy bill. The administration and Congress are seeking not just a steady, independent supply of energy, but a fast and drastic reduction in the greenhouse gases associated with climate change.
Billions of cubic feet of climate-changing greenhouse gases—roughly the equivalent of the annual emissions from 35 million automobiles—seep from loose pipe valves or are vented intentionally from gas production facilities into the atmosphere each year, according to the EPA. Gas drilling emissions alone account for at least one-fifth of human-caused methane in the world's atmosphere, the World Bank estimates, and as more natural gas is drilled, the EPA expects these emissions to increase dramatically.
When scientists evaluate the greenhouse gas emissions of energy sources over their full lifecycle and incorporate the methane emitted during production, the advantage of natural gas holds true only when it is burned in more modern and efficient plants.
But roughly half of the 1,600 gas-fired power plants in the United States operate at the lowest end of the efficiency spectrum. And even before the EPA sharply revised its data, these plants were only 32 percent cleaner than coal, according to a lifecycle analysis by Paulina Jaramillo, an energy expert and associate professor of engineering and public policy at Carnegie Mellon University.
Now that the EPA has doubled its emissions estimates, the advantages are slimmer still. Based on the new numbers, the median gas-powered plant in the United States is just 40 percent cleaner than coal, according to calculations ProPublica made based on Jaramillo's formulas. Those 800 inefficient plants offer only a 25 percent improvement.
Other scientists say the pollution gap between gas and coal could shrink even more. That's in part because the primary pollutant from natural gas, methane, is far more potent than other greenhouse gases, and scientists are still trying to understand its effect on the climate—and because it continues to be difficult to measure exactly how much methane is being emitted.
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12 Comments
Add CommentThe article states:
Reply | Report Abuse | Link to this"The administration and Congress are seeking not just a steady, independent supply of energy, but a fast and drastic reduction in the greenhouse gases associated with climate change."
A lofty goal, but as I understand, after 200 years of accumulation, the current atmospheric co2 levels will not dissipate any time soon, even if humanity eliminated all of its GHG emissions.
The article continues:
"To crunch its numbers, the EPA calculated the average concentration of methane in the atmosphere over a 100-year period and determined that over that period methane is 21 times more potent than carbon dioxide. Using that equation, a ton of methane emissions is the equivalent of 21 tons of carbon dioxide."
That's a nice trick. For example, no matter how much methane was released into the atmosphere during the next ten years, the current 100 year rolling average would be primarily determined by the average during the years of 1920-2010. That works for them!
Finally:
"The EPA now reports that emissions from conventional hydraulic fracturing are 35 times higher than the agency had previously estimated. It also reports that emissions from the type of hydraulic fracturing being used in the nation's bountiful new shale gas reserves, like the Marcellus, are almost 9,000 times higher than it had previously calculated, a figure that begins to correspond with Robert Howarth's research at Cornell."
And that's the good news. The bad news is that it's called 'hydraulic fracturing' because it involves pumping enormous amounts of water and minerals (to protect drill bits, etc.) into a huge area, as I understand often contaminating ground water and potentially even critical fossil aquifers used by many millions for drinking water and agricultural irrigation.
If we run out of potable water we may have to use all of our energy desalinating seawater! Potable water is also an extremely critical resource for this, the largest human population that's ever existed, even considering only the U.S.
No matter how much lipstick you put on them, coal, oil, and natural gas still remains very dirty pigs. I know we are concerned about nuclear plants' storage system becoming dirty bombs, leaks at the plant radiating whole communities, and the cost is just mind boggling, but if you do not want to consider Geothermal, which has a 1.5% foot print compared to natural gas at 80%, coal at 90%, and nuclear at an undetermined amount, then nuclear is our only choice. Even though a solar array in Arizona is producing more power than a normal nuclear plant and one river hydro plant in New York is producing enough energy for the whole community of 70,000 and it has even been make friendly to fish...and you don't want to consider electric cars being charged from geothermal, hydro, solar, or wave, then lets go with nuclear and keep our fingers crossed that we don't start glowing green and plunging America into another economic crises from the expense of building nuclear plants.
Reply | Report Abuse | Link to thisEither way, we should/must eliminate all fossil fuel burning plants and transportation.
Since natural gas is now understood to be more equivalent to coal in its "greenhouse effect", we should decide to just burn more coal for power production. It's cheaper and more plentiful. Besides, gas is more suitable for heating homes and businesses and should be reserved for this use.
Reply | Report Abuse | Link to thisThis magazine has long touted the Green point of view rather than a Scientific stance.
Reply | Report Abuse | Link to thisNow in quick succession we have the article on the detrimental effects on forests caused by growing crops for bio fuel followed by a contra report on gas. Wind & solar surely must follow. Eventually we will get to the only Scientific solution. Nuclear.
The old ingrained bias is going to die hard however otherwise why regurgitate the old discredited article from the November 2009 issue A Plan to Power 100 Percent of the Planet with Renewables.
Pathetic.
Methane has no effect on climate. Methane absorbs the same photons that are already totally absorbed by water vapor. Therefore, we cannot blame natural gas for any climate effects.
Reply | Report Abuse | Link to thisNatural gas escapes naturally everywhere. If we do not use the gas it will escape anyway.
We should monitor oxygen instead of CO2 since oxygen also absorbs infrared photons.
In my last comment, I did not supply a reference. Graphs are available at Wikipedia in the article Greenhouse Gas. The graphs show that methane absorbs photons that water vapor totally absorbs already. The graphs also show that oxygen absorbs photons, and so we should measure it. CO2 absorbs all 15-micron photons and so it cannot cause an increased greenhouse effect. This means that burning natural gas or oil or coal will not alter climate. Reduction in oxygen caused by burning fossil fuels will reduce oxygen-caused greenhouse effects and thus cause cooling to counter warming.
Reply | Report Abuse | Link to thisMethane and CO2 will still absorb infrared photons bec. there is almost unlimited supply from the sun. White light when absorbed by earth's surface infrared is radiated. Water vapor is the most abundant greenhouse gas but we don't worry about it bec. it's natural and not man-made. Maybe we should worry. 2% increase in humidity has same radiative forcing as all CO2 emitted since 1750.
Reply | Report Abuse | Link to thisEventually the structure of modern society is going to have to change. Public utilities are going to have to focus on energy storage just as much as energy generation. Fossil fuels are going to slide into decreased production, even with improved extraction methods.
Reply | Report Abuse | Link to thisI almost never agree with JamesDavis or Soccerdad but on this topic I'm in total accord with them. It is long past time to stop messing around and start a real, meaningful effort to eliminate fossil fuels entirely.
The solution to the problem is often said to be CCS. But as CCS will not be applied generally for at least 50 years, we should decarbonise natural gas now using hydrocarbon pyrolysis. This process removes the carbon from methane as coke, leaving clean hydrogen as an energy source. The inert coke can safely go into landfill. The Technology needs to be developped at an industrial scale, but it is cheap and non-polluting.
Reply | Report Abuse | Link to thisThe accident at three mile island although causing damage only to the power station cost far more lives than the Chernobyl incident.
Reply | Report Abuse | Link to thisThe Hysterical over reaction delayed the introduction of clean nuclear power in the USA for at least fourty years leading to the loss of inumerable lives due to polution from coal fired power stations and global warming.
It needs to be remembered that the biomass(corn, fodder beets, etc used to make ethanol, is perfect starch-free feed for cattle, stopping the livestock's methane production, and using the same resources twice! A fact not talked about much by the opponents of ethanol!
Reply | Report Abuse | Link to thisHow long doe it take to screen Comments? I made one regarding ethanol and it seems to have disappeared.
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