Gas stoves leak climate-warming methane even when they're off

搜索

复制

Gas stoves leak climate-warming methane¹ even when they're off

Transcript²

Your natural gas cooking stove may leak climate-warming methane even when it is turned off, warns a new Stanford University study.

That's important because methane is a much more potent³ greenhouse gas than even carbon dioxide, though it doesn't linger in the atmosphere nearly as long.

Stanford scientists measured methane released from gas cooking stoves in 53 California homes. They examined how much methane is leaked each time you turn the knob in that second before the gas lights on fire. They also measured how much unburned methane is released during cooking. And unlike most previous studies, they measured how much methane is released when the stove is off.

In fact, it turned out that's when about 80% of methane emissions⁵ from stoves happen, from loose couplings and fittings between the stove and gas pipes.

"Simply owning a natural gas stove and having natural gas pipes and fittings in your home leads to more emissions over 24 hours than the amount emitted while the burners are on," says Stanford professor of earth sciences Rob Jackson, one of the study's authors.

There are surprisingly very few measurements of this "incomplete combustion⁶ from appliances," says Eric Lebel, lead author of the study, which was published Thursday in the journal Environmental Science & Technology. Lebel conducted the research as a graduate student at Stanford and is now a senior scientist at PSE Healthy Energy.

Lebel's research shows it didn't matter if the stove was old or new or what brand it was — the presence of leaks was consistent. There were 18 brands of stoves and cooktops in the study, and they ranged from three to 30 years old. Stoves using a pilot light instead of an electronic sparker leaked more.

Researchers estimate that up to 1.3% of the gas used in a stove leaks into the atmosphere. Individually, that's a tiny climate impact compared with things like coal-fired power plants. But Jackson says if you add up the more than 40 million gas stoves in the U.S., the amount of leaked methane every year has about the same climate change effect as the carbon dioxide from 500,000 gasoline-powered cars.

There's a battle over gas stoves in the push to rein⁷ in climate change

The U.S. has a goal of zeroing out emissions by 2050 to comply with the Paris climate agreement. And as communities around the country already face climate change impacts from more severe storms, droughts and wildfires, every emission⁴ source is coming under scrutiny⁸.

The stove is special because Americans love "cooking with gas." But the Environmental Protection Agency says buildings account for more than a tenth of the country's greenhouse gas emissions each year.

Climate activists⁹ are trying to convince people to switch to electric stoves as part of a broader campaign to stop using natural gas in buildings. They believe that once Americans switch stoves, they'll be more likely to electrify¹⁰ bigger sources of emissions too, such as the furnace, water heater and clothes dryer¹¹.

Another argument for switching to electric is that the entire natural gas production and supply chain leaks climate-warming methane from start to finish.

The gas utility industry sees the campaign against gas stoves as an existential threat. Utilities and their trade group, the American Gas Association (AGA), are trying to find cleaner replacements¹², such as "renewable natural gas" from agriculture, and using hydrogen produced with renewable energy.

The AGA says it has not had time to fully¹³ review the Stanford study. Still, the trade group says its members are working to reduce emissions across their networks by doing things like replacing older pipes that leak. "Natural gas distribution system emissions have declined 69% since 1990," says Karen Harbert, the AGA's president and CEO.

Utilities also are getting laws passed to preserve their business. According to the Natural Resources Defense¹⁴ Council, 20 states now have laws on the books that prevent cities from banning gas hookups in new buildings. Such bans have become a trend in places like Seattle, Berkeley, Calif., and New York City, as local governments try to meet their increasingly aggressive climate targets.

One defender¹⁵ of natural gas utilities, Frank Maisano, with the energy law and lobbying firm Bracewell, said the methane leakage¹⁶ issue had not emerged in previous testing, which generally focused on indoor air quality. "Certainly, it is new to hear that emissions occur on stoves that are off. That requires further investigation," Maisano said.

There's an easy way to limit methane leaks

Replacing a gas stove with an electric one is not an option for people who can't afford it or for renters. But Jackson says there's still something you can do and all it takes is a wrench¹⁷.

"Pull the stove out from the wall and tighten¹⁸ the connectors to the stove and to the nearby pipes," he says. That should reduce the leaks. The AGA recommends that only licensed¹⁹ professionals do maintenance on gas lines and appliances.

Still, Jackson is among those concluding that the only way to ensure there are no leaks is to switch to an electric stove. He says research has convinced him it's time to do that.

1 methane   

n.甲烷，沼气

参考例句：

• The blast was caused by pockets of methane gas that ignited.爆炸是由数袋甲烷气体着火引起的。
• Methane may have extraterrestrial significance.甲烷具有星际意义。

2 transcript   

n.抄本，誊本，副本，肄业证书

参考例句：

• A transcript of the tapes was presented as evidence in court.一份录音带的文字本作为证据被呈交法庭。
• They wouldn't let me have a transcript of the interview.他们拒绝给我一份采访的文字整理稿。

3 potent   

adj.强有力的，有权势的；有效力的

参考例句：

• The medicine had a potent effect on your disease.这药物对你的病疗效很大。
• We must account of his potent influence.我们必须考虑他的强有力的影响。

4 emission   

n.发出物，散发物；发出，散发

参考例句：

• Rigorous measures will be taken to reduce the total pollutant emission.采取严格有力措施，降低污染物排放总量。
• Finally,the way to effectively control particulate emission is pointed out.最后，指出有效降低颗粒排放的方向。

5 emissions   

排放物( emission的名词复数 )； 散发物（尤指气体）

参考例句：

• Most scientists accept that climate change is linked to carbon emissions. 大多数科学家都相信气候变化与排放的含碳气体有关。
• Dangerous emissions radiate from plutonium. 危险的辐射物从钚放散出来。

6 combustion   

n.燃烧；氧化；骚动

参考例句：

• We might be tempted to think of combustion.我们也许会联想到氧化。
• The smoke formed by their combustion is negligible.由它燃烧所生成的烟是可忽略的。

7 rein   

n.疆绳，统治，支配；vt.以僵绳控制，统治

参考例句：

• The horse answered to the slightest pull on the rein.只要缰绳轻轻一拉,马就作出反应。
• He never drew rein for a moment till he reached the river.他一刻不停地一直跑到河边。

8 scrutiny   

n.详细检查，仔细观察

参考例句：

• His work looks all right,but it will not bear scrutiny.他的工作似乎很好，但是经不起仔细检查。
• Few wives in their forties can weather such a scrutiny.很少年过四十的妻子经得起这么仔细的观察。

9 activists   

n.（政治活动的）积极分子，活动家( activist的名词复数 )

参考例句：

• His research work was attacked by animal rights activists . 他的研究受到了动物权益维护者的抨击。
• Party activists with lower middle class pedigrees are numerous. 党的激进分子中有很多出身于中产阶级下层。 来自《简明英汉词典》

10 electrify   

v.使充电；使电气化；使触电；使震惊；使兴奋

参考例句：

• The country is now making effort to electrify and informationize manufacture.国家正在致力于制造业的电气化和信息化。
• He needs money to electrify his surface lines.他需要钱把他的地面线路电气化。

11 dryer   

n.干衣机，干燥剂

参考例句：

• He bought a dryer yesterday.他昨天买了一台干燥机。
• There is a washer and a dryer in the basement.地下室里有洗衣机和烘干机。

12 replacements   

n.代替( replacement的名词复数 )；替换的人[物]；替代品；归还

参考例句：

• They infiltrated behind the lines so as to annoy the emery replacements. 他们渗透敌后以便骚扰敌军的调度。 来自辞典例句
• For oil replacements, cheap suddenly looks less of a problem. 对于石油的替代品来说，价格变得无足轻重了。 来自互联网

13 fully   

adv.完全地，全部地，彻底地；充分地

参考例句：

• The doctor asked me to breathe in,then to breathe out fully.医生让我先吸气，然后全部呼出。
• They soon became fully integrated into the local community.他们很快就完全融入了当地人的圈子。

14 defense   

n.防御，保卫；[pl.]防务工事；辩护，答辩

参考例句：

• The accused has the right to defense.被告人有权获得辩护。
• The war has impacted the area with military and defense workers.战争使那个地区挤满了军队和防御工程人员。

15 defender   

n.保卫者，拥护者，辩护人

参考例句：

• He shouldered off a defender and shot at goal.他用肩膀挡开防守队员，然后射门。
• The defender argued down the prosecutor at the court.辩护人在法庭上驳倒了起诉人。

16 leakage   

n.漏，泄漏；泄漏物；漏出量

参考例句：

• Large areas of land have been contaminated by the leakage from the nuclear reactor.大片地区都被核反应堆的泄漏物污染了。
• The continuing leakage is the result of the long crack in the pipe.这根管子上的那一条裂缝致使渗漏不断。

17 wrench   

v.猛拧；挣脱；使扭伤；n.扳手；痛苦，难受

参考例句：

• He gave a wrench to his ankle when he jumped down.他跳下去的时候扭伤了足踝。
• It was a wrench to leave the old home.离开这个老家非常痛苦。

18 tighten   

v.(使)变紧；(使)绷紧

参考例句：

• Turn the screw to the right to tighten it.向右转动螺钉把它拧紧。
• Some countries tighten monetary policy to avoid inflation.一些国家实行紧缩银根的货币政策，以避免通货膨胀。

19 licensed   

adj.得到许可的v.许可，颁发执照(license的过去式和过去分词)

参考例句：

• The new drug has not yet been licensed in the US. 这种新药尚未在美国获得许可。
• Is that gun licensed? 那支枪有持枪执照吗？