The Amazon rainforest is moving toward a “tipping point” past which trees will start to die off in large numbers， researchers have said.

The study， published in the journal of Natural Climate Change， was conducted by scholars from the University of Exeter， the Potsdam Institute for Climate Impact Research （PIK） and the Technical University of Munich. They used satellite data from 1991 to 2016 to examine trends in deforestation.

They calculated that 75 percent of the rainforest is now at the risk of being unable to recover when experiencing droughts， which are also increasingly more common due to global warming.

“Deforestation and climate change are likely to be the main drivers of this decline，” Niklas Boers of PIK and the Technical University of Munich told the BBC. The study has predicted that it is only a matter of decades until a “significant chunk” of the Amazon is transformed from rainforest into savannah.

What would the world be like without the Amazon rainforest？

研究人員稱，亞馬孫雨林正走向一個(gè)“臨界點(diǎn)”，一旦超過這個(gè)臨界點(diǎn)，樹木將開始大量死亡。

英國?？巳卮髮W(xué)、德國波茨坦氣候影響研究所（PIK）和慕尼黑工業(yè)大學(xué)的學(xué)者合作，利用1991年至2016年的衛(wèi)星數(shù)據(jù)來研究森林砍伐的趨勢(shì)，并最終將成果發(fā)表在《自然氣候變化》雜志上。

據(jù)研究人員計(jì)算，75%的雨林在遭遇干旱時(shí)面臨無法恢復(fù)的風(fēng)險(xiǎn)，而由于全球變暖，干旱現(xiàn)象越來越普遍。

波茨坦氣候影響研究所和慕尼黑工業(yè)大學(xué)的尼克拉斯·伯爾斯在接受英國廣播公司采訪時(shí)表示：“亞馬孫雨林恢復(fù)力下降的主要原因可能是濫伐森林和氣候變化。”這項(xiàng)研究還預(yù)測，只需要幾十年的時(shí)間，“一大片”亞馬孫雨林將從熱帶雨林變?yōu)榇蟛菰?/p>

如果沒有亞馬孫雨林，世界會(huì)是什么樣子？

The destruction of the Amazon rainforest， in some ways caused by global warming， will also speed up this process. “The Amazon stores lots of carbon and all of that would be released into the atmosphere， which would then further contribute to increasing temperatures and have future effects on global mean temperatures，” Professor Boulton of the University of Exeter told the BBC.

This worrying snowball effect means that the destruction of the Amazon will make the much larger battle against global warming more difficult.

The destruction of the Amazon would also have a huge impact on the ecology of the Earth. The Amazon rainforest is home to more than 30，000 species of plants， 2.5 million species of insects， 2，500 fishes， more than 1，500 bird species， 550 reptiles， and 500 mammals， according to the Wildlife Conservation Society. A savannah， a grassland environment that lacks a large variety of plant life， would be unable to host the large and varied ecosystems that currently exist in the rainforest. It is likely that a large number of species would become endangered or even extinct， as they would be unable to adjust to this new ecosystem.

全球變暖某種程度上破壞了亞馬孫雨林，而這又加速了亞馬孫雨林的消失。?？巳卮髮W(xué)的博爾頓教授在接受英國廣播公司采訪時(shí)表示：“亞馬孫雨林儲(chǔ)存了大量的碳，屆時(shí)所有這些碳都將釋放到大氣中，進(jìn)一步導(dǎo)致氣溫上升，并對(duì)未來的全球平均氣溫產(chǎn)生影響。”

這種令人擔(dān)憂的滾雪球效應(yīng)意味著，對(duì)亞馬孫雨林造成破壞將令對(duì)抗全球變暖這場更大的戰(zhàn)役變得更加困難。

破壞亞馬孫雨林也會(huì)對(duì)地球的生態(tài)造成巨大影響。野生動(dòng)物保護(hù)協(xié)會(huì)的數(shù)據(jù)顯示，亞馬孫雨林是許多生物的家園，擁有3萬多種植物、250萬種昆蟲、2500種魚類、1500多種鳥類、550種爬行動(dòng)物和500種哺乳動(dòng)物。而一個(gè)大草原，如果是一個(gè)缺乏多種植物生命的草原環(huán)境，將無法容納目前存在于雨林中的大型且多樣的生態(tài)系統(tǒng)。因?yàn)樯餆o法適應(yīng)新的生態(tài)系統(tǒng)，屆時(shí)很可能會(huì)有大量物種瀕危，甚至滅絕。

Word Bank

tipping point引爆點(diǎn)，臨界點(diǎn)

The tipping point seems to be about 30 percent.

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

ecology /i'k?l?d?i/ n. 生態(tài)；生態(tài)學(xué)

reptile /'repta?l/ n. 爬行動(dòng)物

mammal /'m?ml/ n. 哺乳動(dòng)物