亞馬遜雨林可能會開始排放碳而不是吸收碳

亞馬遜雨林可能會開始排放碳而不是吸收碳

The amount of planet-warming carbon dioxide that can be sucked up from the atmosphere and stored by tropical forests is falling as the global climate heats up, researchers said on Wednesday.

研究人員周三表示，隨著全球氣候變暖，從大氣中吸收二氧化碳并儲存在熱帶森林中的數(shù)量正在下降。

They warned in a study that rainforests could tip from absorbing carbon to becoming a source of emissions faster than scientists had previously expected – a switch that could happen in the Amazon as early as the mid-2030s.

他們在一項(xiàng)研究中警告說，熱帶雨林從吸收碳轉(zhuǎn)變?yōu)榕欧旁吹乃俣?，可能比科學(xué)家此前預(yù)期的要快，這種轉(zhuǎn)變最早可能在本世紀(jì)30年代中期就會在亞馬遜地區(qū)發(fā)生。

“The cause of this is climate change impacts – in terms of heat stress and droughts – on these remaining intact forests,” said Simon Lewis, a senior author of the study published in the journal Nature and a professor at Britain’s University of Leeds.

這項(xiàng)研究的資深作者、英國利茲大學(xué)教授西蒙·劉易斯(Simon Lewis)在《自然》雜志上發(fā)表了這項(xiàng)研究，他說：“造成這一現(xiàn)象的原因，是氣候變化對這些保存完好的森林造成的影響——就熱應(yīng)力和干旱而言。”。

The evidence that forests had started the process of turning from a carbon sink into a source was “incredibly worrying”, he told the Thomson Reuters Foundation.

他對湯森路透基金會表示，有證據(jù)顯示森林已經(jīng)開始從碳匯轉(zhuǎn)變?yōu)樘荚?，這一過程“令人難以置信地令人擔(dān)憂”。

“Humanity has been really lucky so far in that these forests have been mopping up our pollution and they might not keep doing that for that much longer,” he added.

他補(bǔ)充道:“到目前為止，人類真的很幸運(yùn)，因?yàn)檫@些森林一直在清理我們的污染，他們可能不會這么做太久了。”

Large swathes of rainforest, including those in Indonesia, Brazil and Democratic Republic of Congo, help regulate rainfall, prevent flooding, protect biodiversity and limit climate change.

包括印度尼西亞、巴西和剛果民主共和國在內(nèi)的大片熱帶雨林有助于調(diào)節(jié)降雨、預(yù)防洪水、保護(hù)生物多樣性和限制氣候變化。

But the 30-year study, led by the University of Leeds and involving almost 100 institutions, showed that the intake of carbon by “intact tropical forests” peaked in the 1990s and had dropped by a third by the 2010s.

但這項(xiàng)由利茲大學(xué)(University of Leeds)牽頭、涉及近100家機(jī)構(gòu)的30年研究顯示，“完整的熱帶森林”的碳攝入量在20世紀(jì)90年代達(dá)到頂峰，到2010年代下降了三分之一。

Intact forests are large areas of continuous forest with no signs of intensive human activity like agriculture or logging. They form part of the world’s roughly 5.5 billion hectares of forest.

完整的森林是大面積的連續(xù)森林，沒有像農(nóng)業(yè)或伐木這樣的人類密集活動的跡象。它們是世界上約55億公頃森林的一部分。

Trees suck carbon dioxide from the air, the main greenhouse gas heating up the Earth’s climate and store carbon, which they release when they are cut down and are burned, or rot.

樹木從空氣中吸收二氧化碳，而二氧化碳是加熱地球氣候的主要溫室氣體，當(dāng)樹木被砍伐、燃燒或腐爛時釋放出來。

Tropical forests are huge reservoirs of carbon, storing 250 billion tonnes in their trees alone – an amount equivalent to 90 years of global fossil-fuel emissions at current levels.

熱帶森林是巨大的碳儲存庫，僅在其樹木中就儲存了2500億噸碳，相當(dāng)于目前水平下全球90年的化石燃料排放量。

Scientific models have typically predicted that the role of tropical forests in storing carbon would continue for decades.

科學(xué)模型通常預(yù)測，熱帶森林在儲存碳方面的作用將會持續(xù)數(shù)十年。

But their ability to offset human emissions is declining faster than thought, Lewis said.

劉易斯說，但它們抵消人類排放的能力下降的速度比想象的要快。

The way to maintain tropical forests as carbon sinks “is to stabilize the climate” by cutting emissions, mainly from fossil-fuel use, to “net zero”, said Lewis.

劉易斯說，保持熱帶森林作為碳匯的方法是通過減少排放(主要來自化石燃料的使用)來穩(wěn)定氣候”，達(dá)到“零排放”。