The critical Atlantic current system appears significantly more likely to collapse than previously thought after new research found that climate models predicting the biggest slowdown are the most realistic. Scientists called the new finding “very concerning” as a collapse would have catastrophic consequences for Europe, Africa and the Americas.
关键的大西洋洋流系统似乎比之前认为的更有可能崩溃，因为新研究发现预测最大减速的气候模型最为现实。科学家称这一新发现“非常令人担忧”，因为崩溃将对欧洲、非洲和美洲造成灾难性后果。

The Atlantic meridional overturning circulation (Amoc) is a major part of the global climate system and was already known to be at its weakest for 1,600 years as a result of the climate crisis. Scientists spotted warning signs of a tipping point in 2021 and know that the Amoc has collapsed in the Earth’s past.
大西洋子午线翻转环流（Amoc）是全球气候系统的重要组成部分，由于气候危机，已知其在 1600 年来处于最弱状态。科学家们在 2021 年发现了临界点的警示信号 ，并知道阿莫克在地球过去已经坍缩。

Climate scientists use dozens of different computer models to assess the future climate. However, for the complex Amoc system, these produce widely varying results, ranging from some that indicate no further slowdown by 2100 to those suggesting a huge deceleration of about 65%, even when carbon emissions from fossil fuel burning are gradually cut to net zero.
气候科学家使用数十种不同的计算机模型来评估未来气候。然而，对于复杂的 Amoc 系统，这些结果差异很大，有些显示到 2100 年不会再减速，有些则显示即使化石燃料燃烧碳排放逐步降至净零，也将大幅减速约 65%。

The research combined real-world ocean observations with the models to determine the most reliable, and this hugely reduced the spread of uncertainty. They found an estimated slowdown of 42% to 58% in 2100, a level almost certain to end in collapse.
研究结合了真实世界的海洋观测和模型，确定了最可靠的模型，极大地减少了不确定性的扩散。他们发现2100年经济放缓率估计为42%至58%，这一水平几乎必然会崩溃。

The Amoc is a major part of the global climate system and brings sun-warmed tropical water to Europe and the Arctic, where it cools and sinks to form a deep return current. A collapse would shift the tropical rainfall belt on which many millions of people rely to grow their food, plunge western Europe into extreme cold winters and summer droughts, and add 50-100cm to already rising sea levels around the Atlantic.
阿莫克河是全球气候系统的重要组成部分，将阳光加热的热带水带到欧洲和北极，在那里水体冷却和下沉形成深层回流。崩溃将改变数百万人口赖以种植粮食的热带降雨带，使西欧陷入极端寒冷的冬季和夏季干旱，并在大西洋周围本已上升的海平面上增加50-100厘米。

Dr Valentin Portmann, at the Inria Centre de recherche Bordeaux Sud-Ouest in France and who led the new research, said: “We found that the Amoc is going to decline more than expected compared to the average of all climate models. This means we have an Amoc that is closer to a tipping point.”
法国波尔多南部 Inria 研究中心的 Valentin Portmann 博士领导这项新研究表示：“我们发现，与所有气候模型的平均值相比，Amoc 的下降幅度将超出预期。这意味着我们的阿莫克更接近临界点。”

Prof Stefan Rahmstorf, at the Potsdam Institute for Climate Impact Research in Germany, said: “This is an important and very concerning result. It shows that the ‘pessimistic’ models, which show a strong weakening of the Amoc by 2100, are, unfortunately, the realistic ones, in that they agree better with observational data.”
德国波茨坦气候影响研究所的斯特凡·拉姆斯托夫教授表示：“这是一个重要且令人担忧的结果。它显示，那些’悲观’模型，显示到 2100 年 Amoc 会大幅减弱，不幸的是，它们是现实的，因为它们更符合观测数据。”

He added: “I now am increasingly worried that we may well pass that Amoc shutdown tipping point, where it becomes inevitable, in the middle of this century, which is quite close.”
他补充道：“我现在越来越担心，我们很可能会在本世纪中叶度过那个关闭 Amoc 的临界点，届时关闭将不可避免，而这非常接近。”

Rahmstorf, who has studied the Amoc for 35 years, has said a collapse must be avoided “at all costs”. “I argued this when we thought the chance of an Amoc shutdown was maybe 5%, and even then we were saying that risk is too high, given the massive impacts. Now it looks like it’s more than 50%. The most dramatic and drastic climate changes we see in the last 100,000 years of Earth history have been when the Amoc switched to a different state.”
研究阿莫克 35 年的拉姆斯托夫表示， 必须“不惜一切代价”避免崩溃 。“我曾在我们认为 Amoc 关闭概率可能只有 5%时提出过这个观点，即便如此，我们也认为风险太高，考虑到影响巨大。现在看起来已经超过 50%。在过去 10 万年地球历史中，我们所见到的最剧烈、最剧烈的气候变化，是阿莫克转变为另一种状态的时候。”

The Amoc is slowing because air temperatures are rising rapidly in the Arctic because of global heating. That means the ocean cools more slowly there. Warmer water is less dense and therefore sinks into the depths more slowly. This slowing allows more rainfall to accumulate in the salty surface waters, also making it less dense, and further slowing the sinking and forming an Amoc feedback loop.
阿莫克减速是因为全球变暖导致北极的空气温度迅速上升。这意味着那里的海洋降温更慢。温暖的水密度较低，因此沉入深处的速度也更慢。这种减缓使得更多降雨在咸水表层水体中积累，也使其密度降低，进一步减缓下沉并形成阿莫反馈回路。

The Amoc system is highly complex and subject to random natural variations, making precise predictions impossible. However, a major weakening is now expected by scientists and that alone could have serious impacts in the decades to come.
Amoc 系统极其复杂，且容易发生随机自然变化，导致精确预测不可能。然而，科学家们现在预计将出现重大减弱，仅这一点就可能在未来几十年产生严重影响。

The new research, published in the journal Science Advances, explored four different ways of using real-world observations to assess the models. They found a method called ridge regression, which had been little used in climate science before now, provided the best results.
这项发表在《科学进展》期刊上的新研究，探讨了利用真实世界观测数据评估模型的四种不同方法。他们发现一种称为脊回归的方法，此前在气候科学中很少被使用，但取得了最佳结果。

The Amoc is difficult to model because it is governed by subtle differences in water density caused by salinity changes over the entire Atlantic. The reduction in uncertainty in the new analysis results from identifying the models that better reflect surface salinity in the south Atlantic, which scientists already knew was important. This makes the work “very credible”, said Rahmstorf.
阿莫克难以建模，因为它受整个大西洋盐度变化引起的细微水密度差异影响。新分析中不确定性的减少，源于识别出更能反映南大西洋表面盐度的模型，而科学家们早已知道这很重要。拉姆斯托夫说，这使得这部作品“非常可信”。

Rahmstorf said Amoc slowdown in 2100 may be even greater than in the new, pessimistic assessment. This is because the computer models do not include the meltwater from the Greenland ice cap that is also freshening the ocean waters: “That is one additional factor that means the reality is probably still worse.”
拉姆斯托夫表示，2100 年 Amoc 的放缓可能比新的悲观评估更为严重。这是因为计算机模型未包括格陵兰冰盖融水 ，而格陵兰冰盖也在淡化海水：“这是另一个意味着现实可能更糟的因素。”