亞馬孫雨林產(chǎn)生的氧氣占全球氧氣總量的1/10，因此被稱為“地球之肺”。但最新的一項(xiàng)研究表明，“地球之肺”如今可能要保不住了。亞馬孫雨林中大約20%的流域排出的二氧化碳已經(jīng)多于吸收量。

Up to one fifth of the Amazon rainforest is emitting more CO2 than it absorbs， new research suggests.

最新研究表明，多達(dá)五分之一的亞馬孫雨林排放的二氧化碳比吸收的還要多。

Results from a decade-long study of greenhouse gases over the Amazon basin appear to show around 20% of the total area has become a net source of carbon dioxide in the atmosphere.

對(duì)亞馬孫流域溫室氣體的一項(xiàng)長(zhǎng)達(dá)十年的研究結(jié)果顯示，該流域中大約有20%的地區(qū)已成為大氣中二氧化碳的凈來(lái)源地。

One of the main causes is deforestation.

造成這一現(xiàn)象的主要原因之一是森林遭到砍伐。

While trees are growing， they absorb carbon dioxide from the atmosphere; dead trees release it again.

樹木生長(zhǎng)時(shí)，會(huì)從大氣中吸收二氧化碳，而死亡的樹木會(huì)再次釋放二氧化碳。

Millions of trees have been lost to logging and fires in recent years.

近年來(lái)，數(shù)百萬(wàn)棵樹木被砍伐或被火災(zāi)燒毀。

The results of the study， which have not yet been published， have implications for the effort to combat climate change.

這項(xiàng)尚未發(fā)表的研究結(jié)果，會(huì)對(duì)應(yīng)對(duì)氣候變化所做出的努力產(chǎn)生影響。

Gattis research suggests this south-eastern part of the forest， about 20% of the total area， has become a carbon source.

加蒂的研究表明，亞馬孫雨林的東南部，約占總面積的20%，已經(jīng)成為一個(gè)碳源。

“Each year is worse，” she said.

“一年比一年糟糕?！奔拥僬f(shuō)道。

They suggest that the Amazon rainforest—a vital carbon store， or “sink”， that slows the pace of global warming—may be turning into a carbon source faster than previously thought.

研究認(rèn)為，作為至關(guān)重要的碳儲(chǔ)存地（或稱“碳匯”），亞馬孫雨林減緩了全球變暖的步伐，而它轉(zhuǎn)變?yōu)樘寂欧旁吹乃俣瓤赡鼙戎邦A(yù)想的要快。

Every two weeks for the past 10 years， a team of scientists led by Prof Luciana Gatti， a researcher at Brazils National Institute for Space Research （INPE）， has been measuring greenhouse gases by flying aircraft fitted with sensors over different parts of the Amazon basin.

過(guò)去10年里，每隔兩周，由巴西國(guó)家空間研究所研究員盧西亞納·加蒂教授領(lǐng)導(dǎo)的一個(gè)科學(xué)家團(tuán)隊(duì)，就會(huì)在亞馬孫流域的不同區(qū)域，通過(guò)安裝傳感器的飛行器來(lái)測(cè)量溫室氣體。

What the group found was startling： while most of the rainforest still retains its ability to absorb large quantities of carbon dioxide—especially in wetter years—one portion of the forest， which is especially heavily deforested， appears to have lost that capacity.

該小組的發(fā)現(xiàn)令人震驚：雖然大部分雨林仍然保持著吸收大量二氧化碳的能力——尤其是在更濕潤(rùn)的年份，但森林的一部分，尤其是大量被砍伐的森林，似乎已經(jīng)失去了這種能力。

“We observed that this area in the south-east is an important source of carbon. And it doesnt matter whether it is a wet year or a dry year. 2017—2018 was a wet year， but it didnt make any difference.”

“我們觀察到，東南地區(qū)是二氧化碳的重要來(lái)源，而且無(wú)關(guān)年份干燥還是濕潤(rùn)。2017—2018年是濕潤(rùn)的一年，但沒(méi)有什么變化?！?/p>

A forest can become a source of carbon rather than a store， or sink， when trees die and emit carbon into the atmosphere.

當(dāng)樹木死亡并向大氣排放二氧化碳時(shí)，森林就會(huì)成為二氧化碳的來(lái)源，而不是二氧化碳的儲(chǔ)存地或森林碳匯。

Areas of deforestation also contribute to the Amazons inability to absorb carbon.

森林被砍伐的區(qū)域也導(dǎo)致了亞馬孫雨林無(wú)法吸收碳。

Carlos Nobre， who co-authored Prof Gattis study， called the observation “very worrying” because “it could be showing the beginnings of a major tipping point”.

加蒂教授研究報(bào)告的合著者卡洛斯·諾布雷稱，這一觀察結(jié)果“非常令人擔(dān)憂”，因?yàn)椤八赡茱@示出一個(gè)重大轉(zhuǎn)折點(diǎn)的開端”。

He believes the new findings suggest that in the next 30 years， more than half of the Amazon could transform from rainforest into savanna.

諾布雷認(rèn)為，新的發(fā)現(xiàn)表明，在未來(lái)30年內(nèi)，超過(guò)一半的亞馬孫雨林可能會(huì)從熱帶雨林變成熱帶草原。

For decades， scientists have warned of an “Amazon tipping-point”： the point at which the forest loses its ability to renew itself and begins to emit more carbon than it absorbs.

幾十年來(lái)，科學(xué)家們一直對(duì)“亞馬孫臨界點(diǎn)”發(fā)出警告。在這個(gè)臨界點(diǎn)上，森林將失去自我更新的能力，釋放的二氧化碳比吸收的更多。

“The Amazon used to be， in the 1980s and 1990s， a very strong carbon sink， perhaps extracting two billion tons of carbon dioxide a year from the atmosphere，” says Prof Nobre， who is also a researcher at the University of Sao Paulos Institute for Advanced Studies and Brazils leading expert on the Amazon.

“亞馬孫雨林在20世紀(jì)八九十年代是一個(gè)非常強(qiáng)大的碳匯，大概每年能從大氣中吸收二十億噸的二氧化碳，”諾布雷教授說(shuō)。他是圣保羅大學(xué)高級(jí)研究所的研究員，也是巴西亞馬孫雨林研究領(lǐng)域領(lǐng)先的專家。

“Today， that strength is reduced perhaps to 1—1.2 billion tons of carbon dioxide a year.”

“如今，這一吸收能力可能已降至每年10至12億噸二氧化碳?！?/p>

Opinions on when this tipping point could occur differs among scientists.

關(guān)于這個(gè)臨界點(diǎn)何時(shí)會(huì)出現(xiàn)，科學(xué)家們的看法各不相同。

“Some people think that it wont be until three-degrees warming—so towards the end of the century， whereas other people think that we could get it with deforestation up above 20% or so and that might happen in the next decade or two. So its really， really uncertain，” explained Simon Lewis， professor of global change science at UCL.

倫敦大學(xué)學(xué)院全球變化科學(xué)教授西蒙·路易斯解釋道：“有些人認(rèn)為，到21世紀(jì)末氣溫上升3攝氏度才會(huì)出現(xiàn)臨界點(diǎn)。而另一些人則認(rèn)為，如果森林砍伐率上升大約20%就會(huì)達(dá)到臨界點(diǎn)，這種情況可能會(huì)在未來(lái)10年或20年內(nèi)出現(xiàn)。所以這是非常不確定的?！?/p>

Word Study

emit /i'm?t/ v. 發(fā)出，射出，散發(fā)（光、熱、聲音、氣等）

absorb /?b's??b/ v. 吸收（液體、氣體等）

The cream is easily absorbed into the skin.

deforestation /di?'f?r?'ste??n/ n. 毀林;濫伐森林;燒林

implication /'?mpl?'ke??n/ n. 可能的影響（或作用、結(jié)果）

extract /?k'str?kt/ v. 提取;提煉

We can extract oil from shale.