聯(lián)合國(guó)氣候報(bào)告反復(fù)強(qiáng)調(diào)，要把全球升溫幅度控制在1.5攝氏度以內(nèi)。此前《巴黎協(xié)定》提出的目標(biāo)是，要把升幅控制在2攝氏度以內(nèi)，同時(shí)盡力不超過(guò)1.5攝氏度。全球升溫1.5度和2度的區(qū)別到底有多大？

Over and over at the UN climate summit in Glasgow, world leaders have stressed the need to limit global warming to 1.5 degrees Celsius.

在格拉斯哥舉行的聯(lián)合國(guó)氣候變化大會(huì)上，世界各國(guó)領(lǐng)導(dǎo)人反復(fù)強(qiáng)調(diào)，必須把全球變暖幅度控制在1.5攝氏度以內(nèi)。

The 2015 Paris Agreement commits countries to limit the global average temperature rise to well below 2°C above pre-industrial levels, and to aim for 1.5°C.

2015年達(dá)成的《巴黎協(xié)定》中，各國(guó)政府承諾將全球平均溫度控制在比前工業(yè)化水平升溫2攝氏度以內(nèi)，并努力達(dá)到升溫1.5攝氏度以內(nèi)的目標(biāo)。

Scientists have said crossing the 1.5°C threshold risks unleashing far more severe climate change effects on people, wildlife and ecosystems.

科學(xué)家指出，升溫幅度超過(guò)1.5攝氏度意味著人類、野生動(dòng)植物和生態(tài)系統(tǒng)都可能遭受氣候變化帶來(lái)的更嚴(yán)重后果。

Preventing it requires almost halving global CO2 emissions by 2030 from 2010 levels and cutting them to net-zero by 2050.

防止全球升溫超過(guò)1.5攝氏度要求我們?cè)?030年前將全球碳排放量減少為2010年的一半，并在2050年前實(shí)現(xiàn)凈零排放。

But what is the difference between 1.5°C and 2°C of warming?

但是全球升溫1.5攝氏度和升溫2攝氏度有什么不同呢？

Already, the world has heated to around 1.1°C above pre-industrial levels. Each of the last four decades was hotter than any decade since 1850.

當(dāng)前，全球溫度已經(jīng)比前工業(yè)化水平高出約1.1攝氏度。過(guò)去四個(gè)十年的氣溫比1850年以來(lái)的任何一個(gè)十年都更高。

"We never had such a global warming in only a few decades", said climate scientist Daniela Jacob at the Climate Service Center Germany. "Half a degree means much more extreme weather, and it can be more often, more intense, or extended in duration."

德國(guó)氣候服務(wù)中心的氣候科學(xué)家丹妮拉·雅各布說(shuō)：“僅僅數(shù)十年就升溫這么多，這樣的全球變暖是從未發(fā)生過(guò)的。升溫0.5度意味著更極端的天氣會(huì)更頻繁地出現(xiàn)，極端天氣會(huì)更惡劣或持續(xù)更長(zhǎng)時(shí)間。”

Just this year, torrential rains flooded Western Europe, killing hundreds of people. Hundreds more died when temperatures in the Pacific Northwest hit record highs. Greenland saw massive melting events, wildfires ravaged the Mediterranean and Siberia, and record drought hit parts of Brazil.

就在今年，歐洲西部暴雨引發(fā)的洪水令數(shù)百人喪生。太平洋西北地區(qū)的破紀(jì)錄高溫天氣也導(dǎo)致數(shù)百人死亡。格陵蘭島冰川大規(guī)模融化。地中海地區(qū)和西伯利亞野火肆虐。巴西部分地區(qū)遭遇了史上罕見(jiàn)的旱災(zāi)。

"Climate change is already affecting every inhabited region across the globe," said climate scientist Rachel Warren at the University of East Anglia.

東英吉利亞大學(xué)的氣候科學(xué)家瑞秋·沃倫說(shuō)：“氣候變化已經(jīng)影響到了人類居住的每個(gè)角落?！?/p>

More warming to 1.5°C and beyond will worsen such impacts. For example, heatwaves would become both more frequent and more severe.

全球升溫超過(guò)1.5攝氏度將會(huì)加劇氣候變化的影響。比如，高溫將會(huì)更頻繁地來(lái)襲，程度也會(huì)更嚴(yán)重。

A warmer atmosphere can also hold more moisture, resulting in more extreme rainfall that raises flood risks. It also increases evaporation, leading to more intense droughts.

氣溫升高還會(huì)讓大氣變得更濕潤(rùn)，引發(fā)更多強(qiáng)降雨，從而增加洪水風(fēng)險(xiǎn)。蒸發(fā)量增加還會(huì)導(dǎo)致更嚴(yán)重的干旱。

"At 1.5°C, there’s a good chance we can prevent most of the Greenland and west Antarctic ice sheet from collapsing," said climate scientist Michael Mann at Pennsylvania State University.

賓夕法尼亞州立大學(xué)的氣候科學(xué)家邁克爾·曼恩說(shuō)：“如果升溫幅度在1.5攝氏度以內(nèi)，我們還有可能防止格陵蘭島和南極西部的大部分冰蓋融化崩塌?！?/p>

That would help limit sea level rise to a few feet by the end of the century - still a big change that would erode coastlines and inundate some small island states and coastal cities.

這有助于在本世紀(jì)末將海平面上升水平控制在幾英尺以內(nèi)，盡管海平面上升幾英尺仍然會(huì)造成巨變，包括侵蝕海岸線、淹沒(méi)一些小島國(guó)和沿海城市。

But blow past 2°C and the ice sheets could collapse, Mann said, with sea levels rising up to 10 metres - though how quickly that could happen is uncertain.

曼恩說(shuō)，但是如果升溫幅度超過(guò)2攝氏度，冰蓋就會(huì)瓦解，海平面會(huì)上升10米之多。不過(guò)，不確定這一天來(lái)得會(huì)有多快。

Warming of 1.5°C would destroy at least 70% of coral reefs, but at 2°C more than 99% would be lost. That would destroy fish habitats and communities that rely on reefs for their food and livelihoods.

全球升溫1.5攝氏度會(huì)摧毀至少70%的珊瑚礁，但是如果升溫2攝氏度，超過(guò)99%的珊瑚礁都會(huì)死亡。這對(duì)于依賴珊瑚覓食和棲息的魚(yú)群是一個(gè)毀滅性打擊。

Warming of 2°C, versus 1.5°C, would also increase the impact on food production.

全球升溫由1.5攝氏度到2攝氏度還會(huì)加大對(duì)糧食生產(chǎn)的影響。

"If you have crop failures in a couple of the breadbaskets of the world at the same time, then you could see extreme food price spikes and hunger and famine across wide swathes of the world," said climate scientist Simon Lewis at University College London.

倫敦大學(xué)學(xué)院的氣候科學(xué)家西蒙·路易斯說(shuō)：“如果世界上的幾個(gè)糧食主產(chǎn)地同時(shí)發(fā)生農(nóng)作物歉收，大范圍的食品價(jià)格飛漲和饑荒將會(huì)席卷全球?！?/p>

A warmer world could see the mosquitoes that carry diseases such as malaria and dengue fever expand across a wider range. But 2°C would also see a bigger share of insects and animals lose most of their habitat range, compared with 1.5°C, and increase the risk of forest fires - another risk to wildlife.

全球變暖會(huì)導(dǎo)致攜帶瘧疾和登革熱病毒的蚊蟲(chóng)大范圍滋生。相比升溫1.5攝氏度，升溫2攝氏度會(huì)讓更多昆蟲(chóng)和動(dòng)物失去大部分棲息地，還會(huì)增加森林火災(zāi)風(fēng)險(xiǎn)，進(jìn)而危及野生動(dòng)植物的生存。

As the world heats up, the risk increases that the planet will reach "tipping points", where Earth’s systems cross a threshold that triggers irreversible or cascading impacts. Exactly when those points would be reached is uncertain.

隨著全球變暖，地球達(dá)到“臨界點(diǎn)”的風(fēng)險(xiǎn)也會(huì)增加。一旦到達(dá)這個(gè)臨界點(diǎn)，就會(huì)觸發(fā)地球系統(tǒng)不可逆轉(zhuǎn)的連鎖效應(yīng)。但是具體何時(shí)到達(dá)臨界點(diǎn)還不確定。

Droughts, reduced rainfall, and continued destruction of the Amazon through deforestation, for example, could see the rainforest system collapse, releasing CO2 into the atmosphere rather than storing it. Or warming Arctic permafrost could cause long-frozen biomass to decompose, releasing vast amount of carbon emissions.

舉例來(lái)說(shuō)，干旱、降雨減少以及對(duì)亞馬遜雨林持續(xù)性的砍伐，將會(huì)導(dǎo)致雨林系統(tǒng)崩潰，結(jié)果就是將二氧化碳釋放到空氣中而不是將二氧化碳儲(chǔ)存起來(lái)。北極永久凍土的融化會(huì)導(dǎo)致冰封多年的生物遺骸腐爛，從而產(chǎn)生大量的二氧化碳。

Warming of 2.7°C would deliver "unliveable heat" for parts of the year across areas of the tropics and subtropics. Biodiversity would be enormously depleted, food security would drop, and extreme weather would exceed most urban infrastructure's capacity to cope, scientists said.

科學(xué)家指出，全球升溫2.7攝氏度會(huì)導(dǎo)致熱帶和亞熱帶地區(qū)在一年中的部分季節(jié)“因?yàn)檠谉岫鵁o(wú)法居住”。生物多樣性會(huì)遭到極大破壞，糧食安全將受到?jīng)_擊，極端天氣將會(huì)超出多數(shù)城市基建的應(yīng)對(duì)能力。

"If we can keep warming below 3°C we likely remain within our adaptive capacity as a civilization, but at 2.7°C warming we would experience great hardship," said Mann.

曼恩說(shuō)：“如果我們能把全球升溫控制在3攝氏度以內(nèi)，人類文明可能還能夠適應(yīng)氣候變化的影響，但是升溫幅度達(dá)到2.7攝氏度后，我們的日子就會(huì)很難過(guò)?！?/p>

來(lái)源：路透社

翻譯&編輯：丹妮