美国国家公共电台 NPR Burning Biomass Is A Complicated Climate Calculation

 

DAVID GREENE, HOST:

World leaders are gathering¹ at a U.N. climate summit in Madrid this week to talk about how to reduce greenhouse emissions². In the search for alternatives to fossil fuel, some countries have now turned to one of the oldest energy sources around - wood. Some are importing it from the United States, calling it clean and renewable. But some environmentalists say this makes no sense. NPR's Dan Charles has the story.

DAN CHARLES, BYLINE³: On a soggy field in eastern North Carolina, Jason Tew and his crew of loggers are cutting trees and sorting the logs into piles depending on their size and what kind of wood they are.

JASON TEW: Poplar, sweetgum, there's an elm right there.

CHARLES: Some piles will go into plywood. Some will become puffy absorbent fiber⁴ in baby diapers. And then there's the least valuable pile, the small limbs and tops of hardwood trees.

TEW: It's basically a trash. We would've normally have hauled that back out in the woods and just left it.

CHARLES: But now there's a new market for that wood - pellet mills. They've expanded across the southeast over the past decade. They'll take this wood, crush it and press it into little pellets ready for burning as fuel.

TEW: The landowner is getting some value. We're getting some production. It's just an all-around good deal.

CHARLES: Most of these pellets, millions of tons each year, will get shipped to Europe where they're burned in power plants because some European governments are offering financial subsidies⁵ to burn these pellets instead of, say, coal. It's supposed to help fight climate change. Here's Seth Ginther, executive director of the industry group that represents wood pellet companies.

SETH GINTHER: The carbon benefits are tremendous.

CHARLES: Burning wood, also called biomass, does release lots of carbon dioxide, the greenhouse gas. But the idea behind the subsidies is you can let forests grow back, and as they do, they'll recapture the carbon dioxide from the air and store it in their branches and roots again. So it's considered renewable, just like wind or solar.

GINTHER: The European Union literally⁶ just passed something known as the Renewable Energy Directive II and biomass - sustainable biomass - was unequivocally included as part of what can meet renewable energy goals.

CHARLES: But environmental groups are challenging that decision in court. They say the idea that large-scale wood burning is carbon neutral is based on bad math. And to explain exactly why, Adam Colette from the environmental group Dogwood Alliance takes me to another patch of land in North Carolina, near the town of Williamston.

ADAM COLETTE: I know it doesn't look like much, but we're going to take a little walk.

CHARLES: It's covered with bushes and little trees maybe 10 feet tall.

COLETTE: In the South, we call it a briar patch. But yet on paper, this is a forest.

CHARLES: Four years ago, it really was a forest with big trees. Then it was logged. Some of it went to make wood pellets. So let's count up the carbon emissions accurately⁷, Colette says. When the big trees were cut, they stopped capturing carbon dioxide from the air. That benefit was lost, at least temporarily, and some of the carbon they'd previously⁸ stored was released into the air when the wood pellets were burned and as tree roots decomposed⁹. But you won't see any of that in the official calculations of greenhouse emissions, he says.

COLETTE: None of it's ever been counted in any of our, like, emissions counting in the U.S. or in Europe.

CHARLES: That's because the forest eventually will grow back and recapture that lost carbon, but it could take a century for that to happen. Now, Seth Ginther from the U.S. Industrial Pellet Association says his industry should not be blamed for those carbon emissions because wood pellets are not the reason forests are cleared.

GINTHER: These are lands that are being harvested for sawtimber, for housing, for paper and for other things. What we're taking is the byproduct of that.

CHARLES: In fact, though, independent forestry¹⁰ experts say that's not completely true. Their data shows that the wood pellet industry is competing for some of the same wood that might go for making paper or diapers. And it's pushing up prices for that wood. Adam Colette from Dogwood Alliance thinks it's persuading some small landowners to harvest their trees.

COLETTE: You have more knocks on those doors, more telephone calls saying, hey, I'll give you X number of dollars for your trees.

CHARLES: What Colette wants is for officials to knock on those doors with a different message, encouraging landowners to maintain forests, expand them.

COLETTE: Our forests are young; they're degraded. And what that means is that the potential to suck carbon out of the atmosphere of forests in the U.S. South is enormous.

CHARLES: Those forests are some of the best climate solutions we have, he says, if they keep growing. Dan Charles, NPR News.

1 gathering   

n.集会，聚会，聚集

参考例句：

• He called on Mr. White to speak at the gathering.他请怀特先生在集会上讲话。
• He is on the wing gathering material for his novels.他正忙于为他的小说收集资料。

2 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。

3 byline   

n.署名；v.署名

参考例句：

• His byline was absent as well.他的署名也不见了。
• We wish to thank the author of this article which carries no byline.我们要感谢这篇文章的那位没有署名的作者。

4 fiber   

n.纤维，纤维质

参考例句：

• The basic structural unit of yarn is the fiber.纤维是纱的基本结构单元。
• The material must be free of fiber clumps.这种材料必须无纤维块。

5 subsidies   

n.补贴，津贴，补助金( subsidy的名词复数 )

参考例句：

• European agriculture ministers failed to break the deadlock over farm subsidies. 欧洲各国农业部长在农业补贴问题上未能打破僵局。
• Agricultural subsidies absorb about half the EU's income. 农业补贴占去了欧盟收入的大约一半。 来自《简明英汉词典》

6 literally   

adv.照字面意义，逐字地；确实

参考例句：

• He translated the passage literally.他逐字逐句地翻译这段文字。
• Sometimes she would not sit down till she was literally faint.有时候，她不走到真正要昏厥了，决不肯坐下来。

7 accurately   

adv.准确地，精确地

参考例句：

• It is hard to hit the ball accurately.准确地击中球很难。
• Now scientists can forecast the weather accurately.现在科学家们能准确地预报天气。

8 previously   

adv.以前，先前（地）

参考例句：

• The bicycle tyre blew out at a previously damaged point.自行车胎在以前损坏过的地方又爆开了。
• Let me digress for a moment and explain what had happened previously.让我岔开一会儿，解释原先发生了什么。

9 decomposed   

已分解的，已腐烂的

参考例句：

• A liquid is decomposed when an electric current passes through it. 当电流通过时，液体就分解。
• Water can be resolved [decomposed] into hydrogen and oxygen. 水可分解为氢和氧。

10 forestry   

n.森林学；林业

参考例句：

• At present, the Chinese forestry is being at a significant transforming period. 当前, 我国的林业正处于一个重大的转折时期。
• Anhua is one of the key forestry counties in Hunan province. 安化县是湖南省重点林区县之一。