Mankin Sees $10 Trillion Economic Loss From Looming El Niño

Mankin预计逼近的厄尔尼诺将造成10万亿美元经济损失 即将到来的厄尔尼诺现象可能永久性拉低全球长期增长率，并通过在全球范围内同时引发的气候混乱，加剧数万亿美元的经济损失。 本期内容探讨了严重厄尔尼诺事件的物理机制及其毁灭性的宏观经济影响。Justin Mankin解释了太平洋信风的转变如何在全球范围内重新分配大量热量，从而同时引发干旱、洪涝和热浪等并发气候灾害。实证数据表明，重大厄尔尼诺事件并非只带来暂时的经济下滑，而是通过同时破坏资本基础设施和扰乱全球供应链，永久性地拉低各国GDP的增长轨迹。预计当前的厄尔尼诺现象将在五年内给全球经济造成10万亿至14万亿美元的损失，讨论着重指出了人类在应对复合气候冲击方面始终缺乏结构性适应能力。 花旗银行、摩根士丹利和美银等主要银行的金融市场研究报告越来越频繁地提及厄尔尼诺现象，原因是对通胀、货币政策转变以及新兴市场货币波动的担忧与日俱增。 (0:00) 厄尔尼诺-南方涛动（ENSO）发生在热带太平洋信风崩溃之时，导致大量温暖表层海水向东晃荡扩散，从根本上改变全球大气天气格局。 (5:00) 包括NOAA预测在内的预报模型表明，当前的厄尔尼诺现象可能达到创纪录的海表温度，超过1982–1983年、1997–1998年和2015–2016年等历史超级厄尔尼诺的基准。 (10:00) 历史和考古证据表明，远在现代仪器出现之前，古代安第斯社区就通过观察遮挡昴星团的高空卷云来预测厄尔尼诺事件，并调整种植时间表。 (15:00) 厄尔尼诺现象发生的时间会直接引发严重的社会经济影响；例如，南亚季风的推迟迫使农民使用柴油灌溉，从而导致燃油价格飙升并影响当地政治稳定。 (25:00)

Dartmouth geographer Justin Mankin argues that severe El Niño events inflict multitrillion-dollar scars on the global economy by permanently depressing national growth trajectories rather than causing temporary, recoverable downturns. Because contemporary El Niño cycles interact with anthropogenic warming and disjointed global supply chains, society remains largely unadapted to their compounding, simultaneous shocks. Oceanic Mechanics and Atmospheric Teleconnections (5:00) El Niño develops when prevailing easterly trade winds across the tropical Pacific Ocean falter, allowing the warm surface waters of the Western Pacific Warm Pool to slosh eastward. Mankin likens neutral climate conditions to a single space heater tucked into a room's corner, whereas an El Niño event acts like wall-to-wall radiators that fundamentally reconfigure global atmospheric circulation. This shifts precipitation belts and forms planetary-scale "teleconnections" that link tropical Pacific sea surface temperatures to weather extremes worldwide, such as the Indian monsoon and rainfall patterns across the Americas. Forecasting models—including the Australian Bureau of Meteorology's Relative Oceanic Niño Index and NOAA's Climate Prediction Center—projected that the mid-2023 event could produce sea surface temperature anomalies exceeding prior benchmark "Super El Niños" recorded in 1982–1983, 1997–1998, and 2015–2016. Depressed Growth Trajectories Versus Level Effects In a 2023 study published in Science, Mankin and co-author Chris Callahan evaluated decades of macroeconomic data by treating El Niño as an exogenous, randomized natural experiment. While conventional economic frameworks assume weather disasters inflict mere "level effects"—temporary dips in economic output followed by swift rebounds—the empirical evidence shows that severe El Niño cycles systematically depress long-term GDP growth rates. Impacted nations do not revert to their pre-shock trends; instead, their growth baseline shifts permanently downward, causing unrealized output losses to accumulate indefinitely. Mankin illustrates this divergence through the 1997–1998 Super El Niño: direct, short-term damage was initially estimated at roughly $36 billion, but empirical tracking revealed approximately $5.7 trillion in cumulative lost global growth over the subsequent five-year period through 2003. Applying a "perfect model framework," the researchers found that current observational data cannot rule out the possibility that these growth reductions are permanent, largely because capital is diverted away from long-term productivity and innovation toward emergency reconstruction and repair. Geographic Simultaneity Strains Global Supply Networks The macroeconomic damage of El Niño is driven by its geographic breadth and physical diversity. Unlike localized weather shocks, which can be mitigated when unaffected regions offset localized losses, El Niño triggers simultaneous, severe hazards across disjointed continents. Floods, heatwaves, wildfires, and droughts strike concurrently, depriving global supply networks of redundant capacity and preventing markets from substituting disrupted commodities. This simultaneity interacts with existing industrial vulnerabilities. In mid-2023, the looming climatic shift coincided with an already strained agricultural backdrop, where an estimated 30% to 40% of global fertilizer supply faced constraints near maritime bottlenecks such as the Strait of Hormuz. When El Niño delays agricultural cycles—such as forcing South Asian farmers to rely on expensive diesel pumps when monsoon rains stall—cascading commodity cost pressures reverberate across international markets. The Adaptation Paradox Under Baseline Warming (43:20) Human awareness of El Niño stretches back centuries, from ancient Andean civilizations observing the Pleiades star cluster to anticipate crop planting schedules to modern satellite observation. Yet Mankin notes that empirical data reveals almost no evidence that modern macro economies have successfully adapted to mitigate its systemic costs. For the active event, Mankin conservatively projects $10 trillion in global economic losses over five years, with extreme tail risks reaching $14 trillion. Critically, only about $10 trillion of these projected losses reflect historical in-sample data. Because baseline anthropogenic global warming has elevated background oceanic and atmospheric heat, the modern event is pushed into unprecedented, out-of-sample territory. Physical adaptations such as reservoirs remain vulnerable—exemplified by record lows at Lake Powell, the water anchor of the American West—while property insurance markets struggle to accurately price escalating systemic risk. While financial risk diversification and localized disaster warnings provide partial insulation, Mankin and hosts emphasize that global markets have historically failed to account for climate variability as an endogenous economic driver. A major unresolved question is whether institutional adaptation and capital allocation can evolve quickly enough to withstand concurrent weather shocks that systematically alter global growth baselines.

达特茅斯学院学者 Justin Mankin 及其团队研究指出，厄尔尼诺并非仅造成短期经济波动，而是会持久抑制全球潜在经济增长率；叠加长期全球变暖背景，即将到来的强厄尔尼诺事件预计在未来五年内给全球造成 10 万亿至 14 万亿美元的产出损失。 太平洋热机驱动与全球气候遥相关 (5:00) Justin Mankin 阐明，厄尔尼诺南方涛动（ENSO）的根本动力来自热带太平洋与上空大气的耦合作用。在正常或拉尼娜（La Niña）状态下，信风自东向西吹拂，将表层暖水堆积在西太平洋形成“西太平洋暖池”，使亚洲与澳大利亚附近的海平面在物理高度上高于南美沿岸，其效应如同在房间角落放置单一供暖器；当信风减弱或瓦解时，暖水大举东流蔓延至赤道太平洋，相当于在整座房间铺设大面积暖气片，从而从根本上重塑全球大气的能量输送与气候格局。 由于旋转地球上的流体波动具有周期性规律，普林斯顿大学地球物理学家 George Philander 曾将厄尔尼诺比作全球气候变异之树的“树干”。通过测定 Niño 3、Niño 4、Niño 3-4 混合区海温异常以及 E-Index 空间特征，气象学家能够识别不同“风味”的厄尔尼诺，并建立“遥相关”（teleconnections）模型。这一物理桥梁将热带太平洋海温与印度季风或美国西南部降雨等远端天气连接起来，使原本混乱的气象变动转化为具有预测价值的宏观经济参考依据。 宏观经济冲击：增长轨迹的持久压制 在 2023 年发表于《科学》（Science）的一项研究中，Justin Mankin 与合作者 Chris Callahan 分析了数十年的全球宏观数据。传统经济学往往将极端天气视为“水平效应”（level effect），即经济短期受挫后迅速恢复至原定基准线；然而实证数据表明，重大厄尔尼诺事件会系统性削弱受冲击国家的长期 GDP 增长率，使整体经济永久性脱离原有轨迹，损失随时间不断累积。 研究团队指出，以 1997–1998 年的超级厄尔尼诺为例，当时估算的地表直接损失约为 360 亿美元，但随后五年的全球增长轨迹追踪显示，截至 2003 年全球累计产出损失高达约 5.7 万亿美元。计量模型利用厄尔尼诺的外生随机性构建“自然实验”，并通过“完美模型框架”检验发现，统计上无法排除这种经济压制是永久性损害的可能性。基于此模型，Mankin 保守预计本次厄尔尼诺事件将在未来五年给全球带来 10 万亿美元的增长损失，极端尾部风险甚至可达 14 万亿美元。 空间同步性冲击与资本重配成本 厄尔尼诺造成深远宏观伤害的关键，在于其引发极端灾害的“空间同步性”（spatial simultaneity）。一般的局部天气灾害（如美国中西部农业减产被俄罗斯或乌兹别克斯坦的丰收对冲）可以被国际市场调配吸收，但厄尔尼诺会在全球多个大洲同时诱发严重的干旱、洪涝、热浪和野火。这种跨地域的多点并发冲击使全球供应链无法通过常规替代路径规避风险，造成类似新冠疫情期间的连锁供给中断。 当各区域的道路、桥梁和农田水利等基础设施同时遭遇损毁，公共与私人部门的资本必须从生产性扩张和技术创新领域抽调出来，被迫转投于应急救济和灾后重建。这种资本与劳动力配置效率的结构性恶化，使得与厄尔尼诺存在紧密气候联系的国家承受长期的增长拖累。此外，播客主持人提到，当前全球 30% 到 40% 的化肥供应在霍尔木兹海峡等战略航运枢纽附近面临瓶颈，化肥价格高企进一步放大了农业部门在气候冲击下的脆弱性。 历史适应局限与样本外极端暖化叠加 (43:20) 人类观测厄尔尼诺的经验源远流长。古代安第斯山脉的秘鲁农民便曾通过观察昴星团（Pleiades）的清晰度来判断卷云遮挡，进而识别太平洋对流东移并调整作物种植日程。然而 Mankin 强调，尽管人类应对厄尔尼诺已有数百年历史，但实证数据显示现代社会与金融市场尚未形成有效的宏观防御体系。在本次预计的 10 万亿至 14 万亿美元损失中，仅有约 10 万亿美元能被历史样本数据涵盖，其余风险因当代全球经济体量的扩张而充满了未知的样本外不确定性。 更为特殊的是，本次厄尔尼诺是在全球长期人为变暖的背景下发生的。海洋吸收了全球大量过剩热量，随着厄尔尼诺驱动海洋向大气释放热能，当年刷新全球高温记录具有较高概率，而次年出现创纪录高温几乎已被锁定。澳大利亚气象局（RONI）和美国国家海洋和大气管理局（NOAA CPC）等模型均显示，本次事件的海表温度异常可能超越 1982–1983、1997–1998 以及 2015–2016 年的历史极值，对既有金融预测构成了严峻考验。 Mankin 指出，增强韧性需要在微观层面建立精准预警与能够真实定价气候风险的财产保险市场，在宏观层面通过现代投资组合理论分散跨行业供应链风险；但作为美国西部水资源核心的鲍威尔湖（Lake Powell）水位处于历史低位，印证了实体工程的脆弱现状。本次厄尔尼诺不仅是检验全球气候适应能力的试金石，也向市场展现了人为变暖叠加自然变异时，经济系统可能面临的持久结构性冲击。

## Background 本期节目由彭博社（Bloomberg）旗下的知名财经播客《Odd Lots》于2026年8月14日在播客及网络平台发布。节目页面介绍指出，随着气候预报模型显示当前正在酝酿一场可能打破历史纪录的超级厄尔尼诺（El Niño），节目邀请了达特茅斯学院地理学教授贾斯汀·曼金（Justin Mankin），深入探讨厄尔尼诺的底层运作机制、气象预报逻辑及其为何会给全球经济造成长达数年且损失数万亿美元的深远创伤。 ## TL;DR 本期节目深入解析了正在形成的历史性超级厄尔尼诺现象及其对全球宏观经济的系统性颠覆。嘉宾贾斯汀·曼金阐明了厄尔尼诺作为太平洋海气耦合“主热机”的物理本质，并对比了历史上几次重大事件与当下的严峻态势。研究证实，厄尔尼诺造成的冲击绝非短暂的“水平效应”，而是具有全球共时性并会永久击偏经济潜在轨迹的“增长效应”，历史事件在数年内造成的累积损失可达数万亿美元。面对叠加地缘冲突与化肥供应链瓶颈的复杂宏观环境，人类社会在适应机制、金融市场韧性及巨额风险对冲上仍面临严峻考验。 ## Atmosphere & style 对谈在轻松幽默与严谨硬核之间达成了极佳的张力。开场两位主持人以“风寒指数怀疑论”与“天气极客”的日常调侃迅速破冰，随后曼金教授用“整屋铺满暖气片”与“安第斯农民观星种土豆”等生动比喻，将晦涩的地球流体动力学化解得趣味横生。随着话题推进至数万亿美元永久性损失与“全球共时性灾难”的实证剖析，对谈氛围逐渐转入严肃冷峻的危机审视，让听众在财经黑话与气候前沿科学的碰撞中感受到扑面而来的宏观压迫感。 ## Bulletin - `13:02` 最新气候模型预测本轮孕育中的厄尔尼诺事件强度将逼近甚至超越 2015-2016 年的历史峰值，澳大利亚气象局相关预测指数触及前所未有的 3.3 极端阈值。 - `40:00` 达特茅斯学院最新实证研究表明，厄尔尼诺带来的破坏具有长期“增长效应”而非短期“水平效应”；1997-1998 年厄尔尼诺五年内的全球实际经济损失高达 5.7 万亿美元，远超最初估计的 360 亿美元直接损失。 - `45:26` 基于全球经济体量测算，本轮超级厄尔尼诺在未来五年造成的累积经济损失保守估计达 10 万亿美元，极端尾部风险下可能飙升至 14 万亿美元。 - `55:38` 本轮厄尔尼诺正值全球地缘动荡与供应链瓶颈期，约 30% 至 40% 的全球化肥供应受困于霍尔木兹海峡周边，叠加厄尔尼诺导致的南亚季风推迟与农业抽水柴油短缺，全球大宗商品与粮食安全面临多重冲击。 ## Key takeaways - `02:28` 华尔街主要投行（花旗、摩根士丹利、美银等）密集将厄尔尼诺列为宏观经济核心变量，重点警示其推升通胀、扰动央行加息路径及冲击新兴市场货币汇率的风险。 - `05:08` 厄尔尼诺本质上是热带太平洋海气耦合异常：常态下信风将暖水推向西太平洋形成暖池，信风减弱时暖水回流东倾，如同给整个地球系统铺设“暖气片”，彻底重构全球热机运行模式。 - `10:00` 厄尔尼诺通过皮耶克尼斯正反馈（Bjerknes Feedback）自我强化，作为全球气候变异之树的“主干”，通过遥相关机制决定印度季风、美洲降水及澳洲干旱等全球天气格局。 - `20:00` 人类认知厄尔尼诺具有悠久历史，秘鲁古代安第斯原住民早在500年前就通过夜空昂宿星团（Pleiades）的能见度预测厄尔尼诺以指导土豆播种。 - `20:00` 厄尔尼诺具有不同“风味”（如增温中心偏东的 Niño 3 或偏西的 Niño 4），海水的超高比热容使其吸收了全球变暖的大量过剩热量，而厄尔尼诺则是海洋向大气释放热量的爆发期。 - `25:00` 厄尔尼诺通常在春季跨越预测障碍并在北半球冬季达到峰值，由于其热量释放的滞后性，不仅推高当年全球均温，更几乎锁定了次年创下极端高温纪录。 - `30:00` 在经济学识别框架中，厄尔尼诺扮演了极佳的“准自然实验外生冲击”，使学者得以在剥离人为变暖背景下研究内部气候变率对宏观经济的净因果效应。 - `35:00` 厄尔尼诺对宏观经济呈现“增长效应”（Growth effect），全球多地并发灾害导致资本被迫从生产性投资转向被动修复，使受创国家的长期增长轨道被永久性压低。 - `40:00` 基于“完美模型框架”统计检验，科学界目前无法排除厄尔尼诺对全球经济造成的负面影响具有永久性的可能性，潜在财富损失随时间推移无限累加。 - `45:26` 尽管现代气象学提供了宝贵的提前预警时间，但现实数据并未表明人类对自然气候变率形成了实质性适应，本轮极端事件中约 30% 的潜在经济损失属于超出历史经验的样本外未知风险。 - `55:38` 厄尔尼诺与局地天气灾害的根本区别在于“全球共时性”（Global Simultaneity），如同疫情般在多国供应链与生产端同时暴发，使全球金融与大宗商品市场无从分散对冲。 ## Detailed walkthrough ### `02:28` 天气极客与“风寒怀疑论”：华尔街研报里的气候风暴 节目开场，主持人特蕾西·艾洛威（Tracy Alloway）向搭档乔·维森塔尔（Joe Weisenthal）坦白自己其实是个“天气极客”（weather nerd）。她极其迷恋雷暴天气带来的震撼感——当然前提是自己待在室内，而不是坐在颠簸的飞机上；但她也迅速补充了一道免责声明：“我可不喜欢那些会造成经济破坏的恶劣天气。”乔则顺势调侃自己是个不折不扣的“天气真相论者”（weather truther）兼“风寒指数怀疑论者”（wind chill skeptic）。乔质疑气象预报里所谓“气温25度，体感15度”的说法根本无法准确衡量：“你怎么可能知道15度感受起来到底是什么样？”他还拿空气湿度开玩笑，遭到特蕾西的反呛——特蕾西打趣他显然没在夏天去过阿布扎比，乔也承认在经历过纽约和香港湿热窒息的盛夏后，湿度确实真实可感。 ```mermaid flowchart TD accTitle: 厄尔尼诺冲击宏观经济逻辑链路 accDescr: 展示厄尔尼诺现象如何从太平洋气候异动传导至通胀、利率及外汇市场 subgraph MacroShock ["华尔街关注的宏观冲击"] Inflation["通胀上行压力<n花旗：泰国降息路径受阻"] Monetary["央行货币政策扰动<n摩根士丹利：英国央行展望"] FX["新兴市场货币承压<n美银：外汇波动与主权风险"] end subgraph ClimateDriver ["气候系统异动"] ENSO["超强厄尔尼诺<n破数十年纪录预期"] end ClimateDriver --> MacroShock ``` 玩笑过后，话题迅速切入核心：那些足以重创全球经济的极端气候，尤其是正在形成的新一轮厄尔尼诺现象（El Niño）。特蕾西敏锐地发现，过去极少涉及气象专有名词的华尔街卖方研报，近期却密集将厄尔尼诺列为核心变量： - **花旗银行（Citi）**在一份关于泰国经济的研报中探讨利率走势，特别指出厄尔尼诺带来的潜在通胀推升风险； - **摩根士丹利（Morgan Stanley）**在针对英国央行（Bank of England）的前瞻报告中提及厄尔尼诺的负面外溢效应； - **美国银行（Bank of America）**则在外汇展望中警示该现象对新兴市场货币（EM currencies）汇率构成的直接冲击。 乔对此深有感触。他提出一个宏大的历史视角：纵观人类数千年乃至数十万年的漫长历史，真正能从根本上重塑人类社会形态的核心变量其实只有两个——其一是重塑人类思维方式的技术演进与媒介变革，其二便是气候变迁与风暴灾害。历史上的许多关键转折点，往往都系于短暂或持久的天气剧变。眼下，各类气候预测模型纷纷亮起红灯，指出当前正在孕育的可能是一场“数十年未见的破纪录级超强厄尔尼诺”，这对开播多年的《Odd Lots》来说，正是深入探究该议题的关键时刻。 --- ### `05:08` 什么是厄尔尼诺？从热带风向到“暖气片房间”的能量重组 针对乔开玩笑问“是否需要亲自跳进太平洋测水温才能证明厄尔尼诺真实存在”，节目邀请到了达特茅斯学院（Dartmouth College）地理学教授、气候建模与影响研究组（Climate Modeling and Impacts Group）主任贾斯汀·曼金（Justin Mankin）。曼金首先从物理学角度打消了乔对风寒指数的怀疑：风寒并不是凭空捏造的主观感觉，而是空气动力学与潜热（latent heat）释放的真实物理过程——当风吹过皮肤表面，空气流动加速了水分从液态转化为气态的相变吸热，就像人刚洗完澡走出浴室会觉得格外冷一样，风带走热量的速率完全可以被精密测量。 随后，曼金详细解构了厄尔尼诺的底层运作机制。厄尔尼诺是“厄尔尼诺-南方涛动”（ENSO）系统的重要组成部分，本质上是热带太平洋海洋与上空大气之间的耦合互动。在常态或中性状态（Neutral state）下，赤道附近的信风（Trade winds）常年稳定地由东向西吹拂。在热带终年强烈的日照下，表层海水被持续加热，而东风则像推土机一样把这些滚烫的表层水一路向西拖拽，硬生生在西太平洋堆积起一个比东太平洋海平面更高、厚度极深的巨大暖水区，气象学上称之为“西太平洋暖池”（West Pacific warm pool）。 ```mermaid flowchart LR accTitle: ENSO中性状态与厄尔尼诺状态机制对比 accDescr: 对比中性状态下西太平洋暖水堆积与厄尔尼诺状态下暖水东流全球能量重置 subgraph NeutralState ["中性 / 拉尼娜状态"] T1["强劲东风信风<n自东向西吹拂"] --> T2["暖水堆积西太平洋<n形成西太平洋暖池"] T2 --> T3["局域加热<n如同房间角落电暖器"] end subgraph ElNinoState ["厄尔尼诺状态"] E1["东风信风减弱瓦解"] --> E2["深厚暖水东回倾泻<n覆盖广大热带太平洋"] E2 --> E3["全球热机重构<n如同整屋铺满暖气片"] end ``` 然而，当赤道东风信风出现异常减弱甚至瓦解时，原本被束缚在西部的庞大暖水堆便失去阻挡，在重力作用下浩浩荡荡地向东“倾泻回流”（slosh back eastward），重新覆盖整个广袤的热带太平洋。科学界正是通过监测“海表温度距平”（Sea surface temperature anomalies）来量化厄尔尼诺的强度，即观察特定区域的海水表层温度比历史平均水平高出多少度。 为了让普通人直观理解这一现象对全球气候的颠覆性影响，曼金给出了一个生动的空间比喻： - **中性或拉尼娜状态（La Niña-like conditions）**：相当于走进一间寒冷的大房间，只有角落里插着一台小巧的局部取暖器（space heater）。它确实在产热，但也仅仅只能烤热它所在的那个角落。 - **厄尔尼诺状态**：相当于整个房间的墙壁四周全部装满了热气腾腾的暖气片（wall-to-wall radiators）。整个房间的热力学状态和人体感受发生彻底转变。 曼金指出，热带海洋是驱动全球天气和气候系统的“主热机”（heat engine）。当浩瀚的赤道暖水向东完全铺展开来时，全球流体大气接收与重新分配太阳能的路径被彻底重组，进而引发连锁性的全球极端气候震荡。 ### `10:00` 气候变异之树的“主干”：为什么厄尔尼诺具有半周期性？ 在解释完厄尔尼诺释放深层海洋热量的物理过程后，主持人感叹自己活了45年终于搞懂了这个机制，并风趣地打比方说，这就像住在漏风的新英格兰老房子里，电暖气只能把房间的某一个角落烤热。随后对话深入到一个核心问题：为什么厄尔尼诺具有半周期性？它为何每隔几年出现一次，而不是一种永久性的恒定状态？ ```mermaid flowchart TD accTitle: 厄尔尼诺与皮耶克尼斯正反馈示意图 accDescr: 展示自东向西信风减弱如何通过皮耶克尼斯正反馈引发暖水东移与全球天气重塑的流程图。 subgraph Trigger["触发诱因（复杂地球流体系统）"] T1["极地海冰面积变化"] T2["赤道与极地温差梯度减弱"] end subgraph PositiveFeedback["皮耶克尼斯反馈循环（Bjerknes Feedback）"] F1["东风信风减弱"] F2["热带太平洋暖水向东倒灌（Sloshing）"] F3["东太平洋海表温度进一步升高"] F1 --> F2 F2 --> F3 F3 -->|放大与自我强化| F1 end subgraph Teleconnection["全球遥相关效应（Teleconnections）"] R1["印度季风系统异常"] R2["美国西南部温湿格局改变"] R3["秘鲁沿岸暴雨 / 澳洲严重干旱"] end Trigger --> F1 PositiveFeedback --> Teleconnection ``` 贾斯汀·曼金（Justin Mankin）指出，最本质的原因在于我们生活在一个不断自转、且拥有海洋与大气这些分层和非分层流体的球体上。在地球物理流体动力学的作用下，能量天然以波动的形式（波峰与波谷）传播。厄尔尼诺便是一种波现象，属于气候科学中所说的“变率模态”（mode of variability）。普林斯顿大学著名的地球物理学家、厄尔尼诺研究泰斗乔治·费兰德（George Philander）曾精辟地将其比作全球气候变异之树的“主干”。由于其具有固定的时空模态，人类得以跳出纯粹的“随机不确定性”（stochastic uncertainty），将其转化为宝贵的“可预测性”（predictability）。 - **遥相关机制（Teleconnections）**：厄尔尼诺现象如同全球天气的物理桥梁，它的发生直接决定了印度季风强弱、美国西南部的降水气温，以及秘鲁和澳大利亚的极端气候。 - **全球气候模态家族**：除厄尔尼诺-南方涛动（ENSO）外，类似的波动模态还包括北大西洋涛动（NAO）、印度洋偶极子（IOD）以及马登-朱利安振荡（MJO，即热带对流的季内振荡）。 - **皮耶克尼斯反馈（Bjerknes Feedback）**：东风信风一旦受到微弱扰动减弱，温暖的海表水便会向东倾斜“倒灌”（slosh eastward），导致东西海温梯度进一步变小，进而反过来使信风更加微弱，形成强烈的自放大正反馈循环。海冰融化或赤道-极地温差变化都可能是点燃这一连锁反应的火星。 --- ### `13:02` 史诗级预报：直逼甚至超越 2015-2016 极强厄尔尼诺 主持人提到，澳大利亚气象局（BOM）等权威机构发布的指标让人十分警惕，其相对海洋尼诺指数（RONI）的预测值甚至触及了前所未见的3.3极端阈值。针对这一轮厄尔尼诺到底有多强，曼金教授回顾了预测技术的发展，并横向对比了人类历史上的几次超强事件。 厄尔尼诺的现代数值预报最早可追溯至20世纪70年代末至80年代初，哥伦比亚大学拉蒙特-多尔蒂地球观测所（Lamont-Doherty Earth Observatory）的马克·凯恩（Mark Cane）与史蒂夫·泽比亚克（Steve Zebiak）构建了人类历史上首个厄尔尼诺物理耦合模型（即著名的 Cane-Zebiak 模型），首次实现了对该现象的科学预测。如今的气象模型既包括基于历史自相关的统计模型，也包括深度模拟海气耦合、风场驱动与气压循环的动力物理模型。 - **历史超强厄尔尼诺对比**： - **1877–1878年**：造成全球大范围极端饥荒的特大事件，已故历史学家麦克·戴维斯（Mike Davis）在2002年的经典著作《维多利亚晚期的大饥荒》（*Late Victorian Holocausts*）中对此进行了深入剖析。 - **1982–1983年**与**1997–1998年**：现代气象观测史上破坏力极强的典型超强厄尔尼诺（97-98年事件曾被赋予极具统治感的称号——"I am the El Niño"）。 - **2015–2016年**：此前大多数官方气象指数中记录到的历史最强事件。 - **当前预报态势**：自6月美国国家海洋和大气管理局（NOAA）气候预测中心发布厄尔尼诺预警以来，目前的综合预测模型普遍显示，正在发展的这一轮厄尔尼诺强度很有可能比2015-2016年的历史极值还要更加偏暖、更为剧烈。 *(注：播客在 至 之间插播了关于 Interactive Brokers 智能投研工具、Minky Couture 限量版毛毯以及伦敦 Bloomberg Tech 科技峰会的商业广告。)* --- ### `17:41` 跨学科考古发现：从秘鲁土豆看人类如何“发现”厄尔尼诺 广告结束后，主持人提出了一个追根溯源的疑问：既然厄尔尼诺并非如钟表般精准按每3到4年准时打卡，古人与科学家究竟是如何将其识别为一种具有规律性的物理现象的？ 曼金教授坦言，从现代仪器观测科学的确立历史来看，细节相当繁复，但他分享了一段更为迷人的科学跨界逸事。当年最早建立厄尔尼诺物理模型的哥伦比亚大学地球物理学家马克·凯恩（Mark Cane），曾与同在拉蒙特-多尔蒂地球观测所的气候学家约翰·奇克（John Chiang）以及哥伦比亚大学著名人类学家本·奥洛夫（Ben Orlove）展开过一项极其亮眼的跨学科合作。 他们在大约20世纪90年代末或2000年代初在《自然》（*Nature*）杂志上发表了一篇里程碑式的论文。该研究通过严谨的考古与人类学证据揭示，生活在安第斯山脉的秘鲁古代原住民早在现代科学诞生数百年前，就通过仰望夜空星象的能见度，建立了一套精准预测厄尔尼诺及指导土豆播种的古老智慧。 ### `20:00` 民间气象学、古老预警与厄尔尼诺的衡量标准 厄尔尼诺现象虽然在现代科学中被精密建模，但人类对其的认知可追溯至数百年前。早在500年前，安第斯山脉的原住民就已经能够成功预测厄尔尼诺的到来。他们的预测手段基于对昂宿星团（Pleiades）能见度的观察。当厄尔尼诺发生时，热带东太平洋的高低云系分布会发生重组，原本发生在澳大拉西亚（Australasia）附近的强对流活动向东移动，进而导致安第斯山脉上空形成大范围的卷云遮蔽层，削弱了星团的能见度。当地农民借此判断气候异动并相应调整播种日期。这种惊人的本土文化知识和民间气象学（folk meteorology），展示了在高度工业化仪器的观测体系之外，人类传统智慧对地球宏观气候系统的敏锐捕捉。主持人打趣指出，古代文明可能往往将厄尔尼诺引发的大旱解读为“君王失去天命”，进而催生政权更迭；这令人想起麦克·戴维斯（Mike Davis）在《维多利亚时代的末日审判：晚期厄尔尼诺饥荒与第三世界的形成》（*Late Victorian Holocausts*）中详述的由厄尔尼诺连锁反应造成的印度、中国北方和巴西东北部的大饥荒。 针对如何衡量所谓“破纪录厄尔尼诺（record El Niño）”的疑问，核心指标实际上是海表温度异常值（Sea Surface Temperature Anomaly）。所谓“异常值”，是指海表温度相对于某一基准或正常预期的偏离程度。由于全球变暖的存在，热带太平洋正在经历长期的长期性增温（secular warming），这使得“正常基准”的界定至关重要，因而产生了诸如相对厄尔尼诺指数（RONI，Relative Oceanic Niño Index）这种采用滚动基准线的方法。 ```mermaid flowchart TD accTitle: 厄尔尼诺现象形成与测量逻辑 accDescr: 展示从海水储热与温室效应不平衡，到区域划分指数与不同风味特征的逻辑链路 subgraph Thermal["地球能量不平衡与海洋储热"] A["温室气体阻碍热量向外太空辐射"] --> B["地球表面 70% 的海洋吸收过剩热量"] B --> C["水的高比热容：成为极佳的巨大能量蓄水池"] end subgraph Measure["区域均温监测与指数体系"] C --> D["热带太平洋特定区域平均海温监测"] D --> E["Niño 3 / Niño 4 / Niño 3.4 核心区海温异常"] D --> F["E-index（空间场降维提取主要模态）"] end subgraph Flavor["空间风味与全球影响"] E & F --> G["不同'风味'的厄尔尼诺（增温中心位置各异）"] G --> H["带来差异化的远程遥相关危害（如大西洋飓风、干旱、洪水）"] end ``` - **海水的超高比热容**：地球表面约70%被水覆盖，水升温所需能量远高于等体积的空气。海洋通过吸收温室气体阻碍地球向外太空辐射能量所造成的“过剩热量”，一直在为人类抵挡剧烈的气候剧变。地球系统为了重建“吸收太阳能量与向外太空辐射能量对等”的辐射平衡，正在持续被迫升温。 - **监测区域与风味（Flavors）**： - **Niño 3 区**：偏向热带中东太平洋； - **Niño 4 区**：偏向热带西太平洋（向东偏移）； - **Niño 3.4 区**：介于两者之间，目前气象界最常用、最典型的基准监测区域； - **E-index**：通过对空间场采用降维技术（dimension reduction technique），提取海温变化的主要主导方向与空间模态； - **风味的多样性**：厄尔尼诺并非千篇一律的单一现象。不同事件中热带太平洋异常增温的具体地理位置各异，其激发的远程遥相关（teleconnections）对美国极端天气、大西洋飓风生成等灾害链条的影响也大相径庭。 --- ### `25:00` 农业窗口期、南亚季风延误与破纪录高温的锁定 由于农作物的耕作与收获高度依附于日历周期，厄尔尼诺爆发的时间点极为敏感。虽然农业界已高度依赖厄尔尼诺预报来调整决策，但当气候冲击与关键农事节点重叠时，仍会引发连锁式的经济与政治震荡。通常情况下，厄尔尼诺往往在经历春季预测障碍（spring prediction barrier）后形成，并在北半球的冬季（12月至次年2月，即南半球夏季）达到强度峰值，随后逐步衰退。 然而，本次厄尔尼诺事件自6月拉响警报起，就已直接撞上了至关重要的“南亚季风爆发期（onset of the South Asian monsoon）”。季风对于南亚次大陆数十亿人口与农耕生计具有决定性影响。由于此次厄尔尼诺导致南亚季风爆发延误，农民为了挽救播种作物，不得不启动地下水灌溉，从而对依靠柴油发电抽水的柴油燃料需求产生剧烈脉冲。这种冲击直接推高了印度国内柴油价格，甚至危及地方市政与基层政客的选举政治生命。 与此同时，此次厄尔尼诺正在将全球平均气温推向历史极值。它不仅使得当年有很大几率刷新人类有记录以来的最高温度，而且由于其热量释放的滞后性与跨年度惯性，几乎直接锁定了随后的2027年创下极端高温纪录。气象历史上最热的年份几乎清一色都是厄尔尼诺年份——当长期的人为全球变暖趋势叠加自然界最强的年际暖异常时，极端异常值便不可避免地集中爆发。虽然其峰值与核心遥相关影响预计要到冬季才会完全显现并持续至2027年春季，但其对实体经济和农业气候的破坏已经在全球多地拉开帷幕。 - **春季预测障碍（Spring Prediction Barrier）**：春季是厄尔尼诺数值预报不确定性最高的时期，越过该窗口后，系统演变路径才逐渐明朗。 - **事件发展时间表**：自6月正式进入“厄尔尼诺警报（El Niño Advisory）”状态，预计在冬季（12月至次年2月）达到强度顶峰，并持续演变至2027年2月至3月左右逐步回落。 - **微观传导链条**：季风推迟 $\rightarrow$ 农作物被迫人工抽水灌溉 $\rightarrow$ 农用柴油需求激增与价格暴涨 $\rightarrow$ 农民陷入债务危机与心理健康问题 $\rightarrow$ 燃料补贴压力冲击地方财政 $\rightarrow$ 基层官员政绩与选举受到直接冲击。 ### `30:00` 走出周期性认知：厄尔尼诺漫长而深远的经济余波 节目在一段轻松的日常与播客插播后，迅速切入核心经济议题。主持人 Joe Weisenthal 坦言，在本次访谈之前，自己对厄尔尼诺的认知大多停留在电视嘉宾胡须微颤、高谈阔论的层面，通常只把它看作一种周期性往复的气候现象——狂风骤雨过去，世界便会自然复原。然而，大量专门探讨厄尔尼诺长期后果的文献却揭示了一个截然不同的现实：严重的厄尔尼诺事件绝非转瞬即逝的短暂插曲，它会拖着一条长长的尾巴，在宏观经济中激起持久而剧烈的连锁涟漪。 达特茅斯学院的 Justin Mankin 教授对此深表赞同，并特别致谢了他的核心合作者、印第安纳大学教授克里斯·卡拉汉（Chris Callahan）。Mankin 指出，厄尔尼诺是全球气候年际变率中最为关键的一环，但预测它在2050年或2100年随背景变暖将演变为何种形态，目前仍存在巨大不确定性。因此，其实验室转变了思路：与其猜测遥远的未来，不如转向对既有事实的严格追溯与实证检验。 - 在气候“检测与归因”（Detection and Attribution）科学中，评估迄今为止人类活动导致的气候变化成本，前提是必须剥离出厄尔尼诺等地球系统固有的“内部气候变率”（Internal climate variability）。 - 厄尔尼诺作为一种非人为排放驱动的自然气候现象，在经济学实证框架下扮演了极其理想的“外生冲击”（Exogenous shock）角色，相当于大自然随机施加的准自然实验处理。 --- ### `35:00` 增长效应而非水平效应：2023年《科学》杂志论文的颠覆性发现 为了量化厄尔尼诺的宏观经济代价，研究团队调取了全球各国家在较长时间跨度内的国内生产总值（GDP）数据。与以往仅关注 GDP 绝对水平的研究不同，他们聚焦于经济增长率的年度变化，并引入了“遥相关”（Teleconnection）强度这一关键物理变量——即特定地区的局部天气系统与赤道太平洋厄尔尼诺现象之间的动力耦合紧密程度。 这项发表于2023年《科学》（Science）期刊的研究给出了突破性的结论：厄尔尼诺对经济造成的冲击并不是经济学意义上的“水平效应”（Level effect，即经济产出短期受损后迅速反弹回原有轨迹），而是一种系统性的“增长效应”（Growth effect）。当厄尔尼诺带来道路冲毁、大宗商品中断、极端干旱或洪涝时，受冲击最严重的国家其经济增长轨道被永久性压低，由此引发的产出损失会随着时间推移无限累积。 ```mermaid flowchart TD accTitle: 厄尔尼诺对宏观经济轨迹的冲击机制 accDescr: 对比传统认知的暂时性水平效应与实证发现的长期增长抑制效应 subgraph Traditional["传统假定：水平效应（Level Effect）"] A1["经济常态增长"] --> B1["厄尔尼诺灾害冲击"] B1 --> C1["短期产出骤降"] C1 --> D1["灾后重建与反弹"] D1 --> E1["回归原有增长轨迹"] end subgraph Empirical["实证发现：增长效应（Growth Effect）"] A2["经济常态增长"] --> B2["全球多地并发灾害"] B2 --> C2["资本再投资与供应链受挫"] C2 --> D2["全要素生产率受损"] D2 --> E2["滑向更低的长期增长轨道，损失持续累积"] end ``` 针对主持人提出的疑问——“为何道路被冲毁不能快速修好并恢复原状”，Mankin 深入解释了厄尔尼诺与局地天气灾害的根本区别。局部的小麦减产或棉花歉收往往会被未受灾地区的产量平抑，但厄尔尼诺具有全球尺度的“并发性”（Simultaneity）： - 热浪、旱灾、洪涝、山体滑坡和野火在世界多地同步暴发，没有单一地区能完全免受波及并充当缓冲垫。 - 广泛的物理破坏迫使政府和企业将宝贵资本从前瞻性、生产性投资抽离，转而用于防灾救灾与被动修复。 - 多国生产网络与大宗商品物流的中断在全球市场产生聚合压力，进而系统性地削弱了资本与劳动力协同转化为高生产力的效率。因此，厄尔尼诺成为了观察更广泛全球变暖宏观经济破坏的绝佳微缩样本。 ### `40:00` 增长轨迹被永久击偏：从 360 亿美元到 5.7 万亿美元的真实代价 长期以来，传统经济分析往往将气候灾害视为单一的一次性冲击——造成直接损失后，经济便会迅速反弹并回到原有的增长轨道上。例如，在 1997 至 1998 年超强厄尔尼诺发生后，当时主流估算认为全球直接经济损失约为 360 亿美元。然而，贾斯汀·曼金（Justin Mankin）及其团队的研究推翻了这一假设。实证证据表明，厄尔尼诺不仅带来即时破坏，更会对经济增长产生系统性的长期抑制。截至 2003 年，即该事件结束五年后，全球累积经济损失实际高达约 5.7 万亿美元。 为了验证这种增长滞后是否具有不可逆性，研究团队采用了一种名为“完美模型框架”（perfect model framework）的统计方法。他们设定了一个推论场景：如果我们已知厄尔尼诺的影响在客观上是永久性的，仅凭现有的观测数据记录，能否在统计学上确证其永久性？答案是不能。因为在海量经济噪声中提取微弱信号需要极为庞大的数据量，而现有现实观测记录尚不足以将其从统计上完全剥离。这导出了一个令人震惊的推论：科学上“无法排除厄尔尼诺对全球经济增长造成的负面影响是永久性的可能性”。这意味着，每一次厄尔尼诺发生，整个人类经济都可能被硬生生撞离原有的发展轨道，导致潜在财富损失随着时间推移无限累加。 ```mermaid flowchart TD accTitle: 厄尔尼诺对全球经济的长期与内生性影响机制 accDescr: 展示厄尔尼诺从传统认知的一次性水平冲击，到实际造成的永久性轨道偏移与内生反馈回路。 subgraph Trap["传统视角 vs 现实冲击"] A["传统假设: 360亿美元水平冲击<br/>（灾后迅速回弹归轨）"] B["实证发现: 5年内损失5.7万亿美元<br/>（经济增长率遭系统性压制）"] C["统计检验: 完美模型框架<br/>（无法排除冲击具有永久性）"] A -.->|实证推翻| B B --> C end subgraph Loop["经济与气候内生闭环"] D["经济增长与化石能源消费"] E["温室气体排放增加与全球变暖"] F["极端天气频发 / 超强厄尔尼诺"] G["长期经济增长轨迹受挫"] D --> E E --> F F --> G G -.->|改变经济基础| D end ``` 这种长期损失凸显出气候系统与经济体系之间深刻的“内生性”（endogeneity）。经济增长本身通过排放温室气体改变着地球气候轨道，而气候反过来也在对经济结构与产出“在天平上施加筹码”。理解这种内生双向反馈，对于制定应对气候变率和长期气候变化的经济与产业政策至关重要。 - **传统损失认知与修正**：1997-1998 年厄尔尼诺初期估计损失为 360 亿美元，实际在五年窗口期内核算造成的全球经济增长损失高达 5.7 万亿美元。 - **永久性冲击推论**：在 5 年、8 年乃至 10 年的核算期内，全球经济未能完全弥合缺口，存在长期发展路径永久受损的严峻可能性。 - **内生性机制**：气候不再是外生不可抗力的偶发背景，而是深深嵌入经济活动与资本积累的互动反馈循环中。 --- ### `42:47` 适应性建模难题与预测的科学价值 在面对未来的极端气候情景时，经济学家和决策者常抱有一种乐观预期：随着经济发展和技术升级，人类社会的适应力（adaptation）和韧性（resiliency）理应水涨船高。主持人提出，以秘鲁为例，到 2050 年甚至 2100 年，该国经济体量将更大，基础设施也会大幅改善，道路被洪水冲毁的概率理应大幅降低。那么在气候模型中，该如何量化这种人类预判风险、主动加固资产的适应过程？曼金直言，这在科学建模上极为棘手，因为“对未来的预测在当下是不可证伪的（not falsifiable）”。 适应机制大致可以划分为两类：一类是分散的微观个体采取的“自主适应”（autonomous adaptations），例如历史上秘鲁高地的土豆种植农户会根据夜空昴宿星团（Pleiades）的清晰度来预测降水并调整播种期；另一类则是由政府或跨国机构统筹的“计划适应”（planned adaptations），例如修筑防洪海堤、强化电网系统以及提前进行战略物资储备。无论是哪种适应，其核心前提都在于厄尔尼诺南方涛动（ENSO）预测科学所提供的关键“提前量”（lead time）。 与 1982 至 1983 年那场毫无准备、猝不及防的超强厄尔尼诺相比，当今气象学能够提前数月甚至半年发出预警。这种长视距的预测如同追踪远洋热带气旋，赋予了各国规划供应链冗余、转移危险区域人群以及提前调度财政救灾资源的宝贵窗口。如今，华尔街的金融策略师和全球供应链主管都在将厄尔尼诺预报作为对冲风险的标准依据，这本身就是人类社会构建适应韧性的重要体现。 --- ### `45:26` 面对即将到来的历史性超级厄尔尼诺：人类真的适应了吗？ 尽管现代预测手段日新月异，曼金对人类目前真实的适应能力却给出了相当冷峻的评估。现实证据非常混杂，甚至缺乏足够说服力证明人类已经妥善适应了当前的自然气候变率。人类社会与厄尔尼诺相处了数百年，但每一次极端事件带来的经济创伤依然触目惊心，并未呈现出实质性缩小的趋势。 更令人担忧的是，即将来临的新一轮厄尔尼诺很可能彻底脱离历史常规，成为一个高度“样本外”（out of sample）的未知事件。基于当前全球经济体量和历史响应数据测算： - 在未来五年内，本次厄尔尼诺造成的全球累积经济损失**保守估计在 10 万亿美元左右**； - 若考虑模型尾部极端风险，全球经济损失甚至可能飙升至 **14 万亿美元**； - 在这 14 万亿美元的潜在损失中，**仅有约 70%（即约 10 万亿美元）能够从过往历史数据的“样本内”找到对应支撑**，其余损失则源自超级强度与前所未有的全球暴露度叠加带来的极端不确定性。 这种巨额经济损失表明，全球社会并未形成行之有效、协调一致的防灾减灾闭环。全球变暖的宏观冲击在空间模式上与厄尔尼诺现象具有极高的重合度，而人类应对现有厄尔尼诺尚且步履维艰，更遑论在叠加气候变暖的复合反事实世界（counterfactual world）中全身而退。当被问及理想的成功适应范式应是何种面貌时，曼金指出，真正的适应不仅在于微观层面防止某条道路被冲毁或扑灭澳大利亚致命的丛林大火以控制水涨船高的房屋保险费率，更在于宏观上全面提升全球资本、粮食和航运市场的结构韧性，彻底阻断极端气象冲击向物价、利率及民生福利层面的剧烈传导。 ### `50:00` 保护民生福祉与金融市场韧性的双重挑战 在应对厄尔尼诺带来的冲击时，Justin Mankin 明确区分了两个层面的问题：第一层是直接保障个体与社区基本福祉的近端问题——“面对这些灾害，你还好吗？”；第二层则是如何加固国际金融市场，使其在厄尔尼诺的冲击面前具备足够韧性。这两者性质截然不同，厘清其边界至关重要。公众和市场普遍意识到厄尔尼诺能通过农业减产、矿业停摆或航运交通中断引发连锁冲击，并在全球范围聚合成系统性压力。在资本市场端，投资者根据现代投资组合理论（Modern Portfolio Theory）通过风险分散来锁定收益；但在保护普通人免遭灾害侵袭的问题上，则需要完全不同的工具箱。 这需要建立针对厄尔尼诺地方性灾害特征的精准预警系统，培育深入理解灾害后果的专业技术团队，并重塑保险市场。保险机构必须充分认识到厄尔尼诺独特的地球物理危害及其鲜明的区域依赖性，进而开发出适销对路的保险产品，用来守护普通家庭最核心、也是资本最密集的资产——住房。Mankin 指出，这些举措并非天方夜谭，人类其实一直在做类似的事，比如修建水库以缓解干旱风险；但他话锋一转，打趣道：“先别管鲍威尔湖（Lake Powell）——这座美国西部水资源经济的‘中央银行’——水位正处于历史极低点了”，逗笑了熟悉财经黑话的主持人（“他很懂他的听众”）。总而言之，人类有能力推行这些适应策略，而制定一套连贯的全球厄尔尼诺管理方案，正是检验人类能否抵御更广泛全球变暖的绝佳试验场。 ### `52:45` 反事实分析：将厄尔尼诺视作“准随机自然实验” 主持人提出了一个深刻的经济学反问：研究发现厄尔尼诺并非一次性的周期扰动后经济就能迅速回弹，而是永久性改变了经济增长轨迹；但既然厄尔尼诺自古有之、500多年前南美农民就在试图预测它，我们为何不把它视为一种类似于“寒冬”的自然季节性波动？比如寒冷的12月人们减少出门购物旅游，确实会抑制经济增速，但若因此假设“如果没有12月、世界从不变冷，经济增长率在反事实状态下会更高”，这在逻辑上是荒谬的。厄尔尼诺既然始终与人类相伴，构建一个“没有厄尔尼诺的世界的潜在增长趋势”意义何在？ Mankin 从计量经济学的实证识别策略（Empirical Identification Strategy）给出了正面回应。现实中我们无法在计算机里把人类文明倒带重跑一遍，以此观察没有厄尔尼诺的世界经济会如何演变，因此必须依赖模型构建反事实。厄尔尼诺虽然具有周期性，但其发生时间和强度并不是严格固定的周期震荡，而是具备高度随机性，在统计学上“好比是一次随机分配的干预（Random Treatment）”。这与医学双盲对照试验如出一辙：随机将人群划分为用药组和安慰剂对照组，由于随机化有效消除了个体间的异质性，两组健康状况的差值就纯粹反映了药物的真实疗效。通过比较厄尔尼诺年份（实验组）与非厄尔尼诺年份（对照组）的全球经济生产率差异，研究者得以剥离其他干扰因素，捕捉厄尔尼诺的真实净影响。 ```mermaid flowchart TD accTitle: 厄尔尼诺计量经济学自然实验识别框架 accDescr: 展示将厄尔尼诺视为准随机自然实验的实证分析流程 subgraph Experiment["类比医学对照试验"] A["自然随机波动的气候序列"] --> B["厄尔尼诺发生年 (实验组 / Treatment)"] A --> C["非厄尔尼诺常态年 (对照组 / Control)"] end subgraph Analysis["宏观经济影响测度"] B --> D["遭受外生冲击后的经济产出"] C --> E["常态基准生产率轨迹"] D & E --> F["测算出外生因果效应与持久增长损失"] end ``` - **自然实验有效性**：厄尔尼诺兼具周期性与外生随机扰动特征，使宏观计量能够避开遗漏变量偏误。 - **应对变暖的参照**：与全球变暖这种人类文明从未经历过的“完全超出样本空间（Out of sample）”的气候变动不同，厄尔尼诺是人类反复遭遇的现象；然而即便面对这种应当早已习惯的事件，人类仍未表现出广泛的适应性与韧性。 ### `55:38` 节目尾声：全球共时性与地缘大宗商品风险的双重夹击 访谈结束后，两位主持人 Joe Weisenthal 和 Tracy Alloway 对对话进行了深度复盘与讨论。Joe 坦言自己过去对厄尔尼诺的认知非常模糊，只知道“天气变暖了”，却不明白其运作机理和方向。此次对话中最让他受到震撼的见解，是厄尔尼诺与其他局地极端天气的本质区别在于其“全球共时性（Global Simultaneity）”。普通的局地风暴或洪灾，经济往往能够快速修复并恢复到原本的趋势线上；而厄尔尼诺则如同 COVID-19 疫情一般，在全球范围内几乎同一时间对多个核心区域施加涟漪般的连锁冲击，导致系统性风险无处分散、避无可避，“给人一种上天无路、入地无门的窒息感”。 Tracy 则进一步将气候模型与当下的地缘经济现实联系起来。她联想到播客早先探讨农业化肥供应链的几期节目：眼下这场历史罕见的“超级厄尔尼诺”正在全球背景变暖、化肥价格飙升且供应短缺的大环境下展开；目前全球仍有大约 30% 至 40% 的化肥供应受困于霍尔木兹海峡及周边供应链瓶颈中。在最脆弱的节点遭遇有气象记录以来最猛烈的厄尔尼诺，给全球粮食与大宗商品市场蒙上了巨大阴影。两位主持人最后打趣道，尽管实体世界尚未为迎接厄尔尼诺做好充分准备，但至少通过这期播客，大家在认知上已全副武装，完全能够看懂未来数周乃至数月里各大卖方机构即将发布的连篇研报和宏观新闻了。 - **多重供给冲击叠加**：霍尔木兹海峡受阻导致全球约 30%~40% 的化肥物流受限，加剧了厄尔尼诺可能造成的农业减产危机。 - **无处可逃的共时性**：全球主要产区同时受灾破坏了跨地域的多元化对冲，其连锁冲击远超局地气象灾害。 ## Notable quotes > `02:28` 你怎么可能知道15度感受起来到底是什么样？ — Joe Weisenthal > `02:28` 我可不喜欢那些会造成经济破坏的恶劣天气。 — Tracy Alloway > `05:08` 中性或拉尼娜状态相当于走进一间寒冷的大房间，只有角落里插着一台小巧的局部取暖器。厄尔尼诺状态相当于整个房间的墙壁四周全部装满了热气腾腾的暖气片。 — Justin Mankin > `05:08` 热带海洋是驱动全球天气和气候系统的“主热机”。 — Justin Mankin > `40:00` 科学上无法排除厄尔尼诺对全球经济增长造成的负面影响是永久性的可能性。 — Justin Mankin > `42:47` 对未来的预测在当下是不可证伪的。 — Justin Mankin > `50:00` 面对这些灾害，你还好吗？ — Justin Mankin > `50:00` 先别管鲍威尔湖——这座美国西部水资源经济的‘中央银行’——水位正处于历史极低点了。 — Justin Mankin > `52:45` 在统计学上，好比是一次随机分配的干预。 — Justin Mankin > `55:38` 厄尔尼诺则如同 COVID-19 疫情一般，在全球范围内几乎同一时间对多个核心区域施加涟漪般的连锁冲击，给人一种上天无路、入地无门的窒息感。 — Joe Weisenthal ## Mentioned Tracy Alloway, Joe Weisenthal, Justin Mankin, Chris Callahan, George Philander, Mark Cane, Steve Zebiak, John Chiang, Ben Orlove, Mike Davis, Citi, Morgan Stanley, Bank of America, Bank of England, NOAA, BOM, Dartmouth College, Lamont-Doherty Earth Observatory, Cane-Zebiak 模型, Science, Nature, Late Victorian Holocausts, Interactive Brokers, Minky Couture, Bloomberg Tech, Lake Powell ## Video description <p data-prosemirror-content-type="node" data-prosemirror-node-name="paragraph" data-prosemirror-node-block="true" data-pm-slice="1 1 []">Every few years, weather nerds and agriculture analysts will talk about an upcoming El Ni&ntilde;o, and then they mostly pass by with relatively few headlines. But sometimes El Ni&ntilde;os end up being massively destabilizing -- leading to devastating droughts, flooding, and other catastrophes. And this year's emerging El Ni&ntilde;o could end up being one of the big ones, with forecasters predicting record-breaking intensity. But what exactly is an El Ni&ntilde;o, and what does it mean that this year's could be so big? On this episode, we speak with Justin Mankin, professor of geography at Dartmouth and director of the Climate Modeling and Impacts Group. We discuss the forecasting of El Ni&ntilde;os, and why they can lead to large and long-lasting economic damage.</p> <p data-prosemirror-content-type="node" data-prosemirror-node-name="paragraph" data-prosemirror-node-block="true">Read more:<br data-prosemirror-content-type="node" data-prosemirror-node-name="hardBreak" data-prosemirror-node-inline="true"><a href="https://www.bloomberg.com/news/articles/2026-07-09/super-el-nino-will-give-us-a-glimpse-of-life-in-2035?utm_medium=referral&utm_source=podcast&utm_campaign=odd_lots&utm_content=article" data-prosemirror-content-type="mark" data-prosemirror-mark-name="link">Super El Ni&ntilde;o Will Give Us a Glimpse of Life in 2035</a><br data-prosemirror-content-type="node" data-prosemirror-node-name="hardBreak" data-prosemirror-node-inline="true"><a href="https://www.bloomberg.com/news/articles/2026-08-13/uk-economy-weathers-early-months-of-iran-war-with-0-4-growth?utm_medium=referral&utm_source=podcast&utm_campaign=odd_lots&utm_content=article" data-prosemirror-content-type="mark" data-prosemirror-mark-name="link">Heat Wave and World Cup Hand UK Economy a Surprise Boost</a></p> <p data-prosemirror-content-type="node" data-prosemirror-node-name="paragraph" data-prosemirror-node-block="true">Only <a href="http://Bloomberg.com" data-inline-card="" data-card-data="">http://Bloomberg.com</a> subscribers can get the Odd Lots newsletter in their inbox each week, plus unlimited access to the site and app. Subscribe at&nbsp; <a href="https://www.bloomberg.com/subscriptions/oddlots?in_source=oddlotspodcast" data-prosemirror-content-type="mark" data-prosemirror-mark-name="link">bloomberg.com/subscriptions/oddlots</a></p> <p data-prosemirror-content-type="node" data-prosemirror-node-name="paragraph" data-prosemirror-node-block="true"><a href="http://bloomberg.com/subscriptions/oddlots" data-prosemirror-content-type="mark" data-prosemirror-mark-name="link">Subscribe to the Odd Lots Newsletter</a><br data-prosemirror-content-type="node" data-prosemirror-node-name="hardBreak" data-prosemirror-node-inline="true"><strong data-prosemirror-content-type="mark" data-prosemirror-mark-name="strong">Join the conversation:</strong> <a href="https://discord.gg/oddlots" data-prosemirror-content-type="mark" data-prosemirror-mark-name="link">discord.gg/oddlots</a></p><p>See <a href="https://omnystudio.com/listener">omnystudio.com/listener</a> for privacy information.</p> [Source](https://podtrac.com/pts/redirect.mp3/tracking.swap.fm/track/UVBrz8bN8aM2Xe47PEPu/traffic.omny.fm/d/clips/e73c998e-6e60-432f-8610-ae210140c5b1/8a94442e-5a74-4fa2-8b8d-ae27003a8d6b/906e5071-7abc-4f2c-acb5-b4a5013ff33f/audio.mp3?in_playlist=982f5071-765c-403d-969d-ae27003a8d83)

[2:28] Joe Weisenthal: 你怎么可能知道15度感受起来到底是什么样？ [2:28] Tracy Alloway: 我可不喜欢那些会造成经济破坏的恶劣天气。 [5:08] Justin Mankin: 中性或拉尼娜状态相当于走进一间寒冷的大房间，只有角落里插着一台小巧的局部取暖器。厄尔尼诺状态相当于整个房间的墙壁四周全部装满了热气腾腾的暖气片。 [5:08] Justin Mankin: 热带海洋是驱动全球天气和气候系统的“主热机”。 [40:00] Justin Mankin: 科学上无法排除厄尔尼诺对全球经济增长造成的负面影响是永久性的可能性。 [42:47] Justin Mankin: 对未来的预测在当下是不可证伪的。 [50:00] Justin Mankin: 面对这些灾害，你还好吗？ [50:00] Justin Mankin: 先别管鲍威尔湖——这座美国西部水资源经济的‘中央银行’——水位正处于历史极低点了。 [52:45] Justin Mankin: 在统计学上，好比是一次随机分配的干预。 [55:38] Joe Weisenthal: 厄尔尼诺则如同 COVID-19 疫情一般，在全球范围内几乎同一时间对多个核心区域施加涟漪般的连锁冲击，给人一种上天无路、入地无门的窒息感。

[20:00] Justin Mankin: There's just kind of this remarkable cultural knowledge of being able to grab onto something and be able to make an informed forecast... that we have yet to kind of appreciate and diagnose in the highly industrialized world. [30:00] Justin Mankin: That shock doesn't seem to be what an economist might call a level effect... What we find in this empirical research is that observationally, El Niño seems to systematically change depressed growth... And so those losses just accrue ad infinitum in time.

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And I'm Joe Weisenthal. Joe, I don't know if I've ever told you about this, but I'm a little bit of a weather nerd. Okay. Maybe a little, but I know. I just get really excited by weather. I love thunderstorms. I love a good thunderstorm. So great. If I'm inside. I love thunderstorms, except when I'm on an airplane or something like that. I do not like economically damaging weather. I feel like I need to throw that caveat in there. You know what I am? I'm like a weather truther. So, for example, I don't believe that there's any accurate way, for example, to measure wind chill. It's like, oh, it's like 25 degrees out and it feels like 15. It's like, how do you know what 15 feels like? You know what I'm saying? Like, I don't believe in some of these numbers. in the air. Give me a break. There's no water in there. No, that one I believe in. Tell me you've never been to Abu Dhabi in the summer without telling me you've never been to Abu Dhabi in the summer. No, this last week in New York. You were just in Hong Kong. You know what humidity feels like. I know. That one was a joke. I am a windshield skeptic, even though I don't think that's the topic of our conversation today. It is not. The topic of our conversation is actually economically damaging weather. Yes. And specifically the upcoming El Nino, which, by the way, it's not that That often that you see a lot of sell side notes start to mention weather phenomenon. But just in the past few days, I've had a Thailand economics note from Citi talking about interest rates and quoting the potential impact of El Nino, potentially inflationary. I've had a Bank of England outlook from Morgan Stanley that mentioned El Nino and also a Bank of America FX outlook talking about the impact on EM currencies. that people are expecting to have an actual impact both on the global economy and the investment landscape. You know, I will just say, even though I'm not a weather nerd the way you are, I sort of have this thought that if you look at like the really grand sweep of history, like thousands and thousands of years, maybe even hundreds of thousands of years, I sort of think there are two things that matter in human history. One of them, as you know, I'm interested in is like, basically technological evolution, media technology and how it reshapes how we think. And then the other one is sort of climate change, weather and storms. And I think that when we think about history, many things are contingent either on like brief or long periods of weather change, and it can reshape society in permanent, long term, unexpected ways at the time. And have we years of doing this? I don't think we have. But it sounds like this is one that we should cover if it's showing up on all these notes. If we're going to cover one, this should probably be the one because at the moment, well, you have different El Nino forecasts, right? And, you know, there's a range of probabilities involved here, but a lot of the forecasts [5:00] Casting models are currently forecasting that this is going to be a potentially record-breaking El Nino, something we haven't seen in decades. Do you think there are any people who are like, oh, it's interesting you bring up the El Nino? You know, I've always thought La Ninos are the more underrated one. Do you think that's the type of guy? No, I hope not. But are you going to become like an El Nino truther? And you're going to be like, how do you know it's El Nino unless you're standing in the Pacific Ocean measuring the water yourself? Yeah. Oh, good. That'll be a fun transformation for you. OK, well, we do, in fact, have the perfect guest. We're going to be speaking to someone who not only follows the weather, but also tries to measure its economic impact. We have Justin Mankin. He is professor of geography at Dartmouth and director of the Climate Modeling and Impacts Group. So, Justin, thank you so much for coming on All Thoughts. Yeah, happy to be here. Thanks for having me. I feel like maybe the first thing we should do is, can you convince Joe that El Nino is a real thing? No, apparently he needs like a first-person experience of it. What is El Nino? Yeah, what is it? Yeah, light windchill factor. It is in fact real and measurable. And they're both kind of actually aerodynamically related, right? So windchill, the feeling you get on your skin is owing to the fact that the wind is wicking away latent heat from your skin, the heat associated with a phase change of water from a liquid to a vapor. And so that's why when you get out of a shower, you feel cooler than before you get into it, right? So that evaporation off your skin induced by aerodynamic resistance, i.e. the wind, that is the thing that's cooling you down, which is why we can measure it and why we can tell you that cold exposure is a bad thing. It's kind of part of what's called the El Nino Southern Oscillation, which is essentially a relationship between the tropical Pacific and the overlying tropical atmosphere. And it has a tendency to be in what we call a neutral state, which is kind of average conditions where you have these easterly trade winds. So these are winds that are blowing from east to west across the tropics or along the equator. And what they're doing is they're dragging surface water. because it's in the tropics, the sun is just shining there all year round. And so that water heats up and then the winds kind of drag that surface water and create literally a pile such that the sea altitude is higher in the West Pacific than in the East Pacific. And that pile of warm water is something we call the West Pacific warm pool. And so it just sits there weaken and break down. And that pile of warm water that actually penetrates quite deep into the Western tropical Pacific, that pile of warm water just spreads itself out. over the vast expanse that is the tropical Pacific. And so that's actually how we measure El Nino, is we're measuring it as a function of sea surface temperature anomalies. So how much warmer than average are ocean temperatures at the surface? at this time in this location. And there are different ways to kind of calculate what the regional average is, and we can get into that technical nitty gritty. But essentially all this water sloshes back eastward and in doing so reconfigures all of weather which is just energy redistribution from the sun on our our fluid planet right it redistributes all of that energy differently than would have been the case if all that water were piled up in the western pacific i guess like a really simple analogy a listener could maybe grab onto is they've walked into a cold room where there's a little space heater plugged into the corner, right? And that little space heater, yeah, is maybe generating some heat that's warming up the room, but it's really only warming up that corner of the room. Yeah. That is akin to neutral space. or what are called La Nina-like conditions, which is an amplification of the neutral pattern, meaning that those winds are stronger than normal, and the eastern tropical Pacific is cooler than normal. When you slosh all of that water, back across the entire expanse of the tropical Pacific, it's akin to walking into a room that has wall-to-wall radiators instead. The thermodynamics of that room, that's a totally different experience for you than would have been the case if it was just that space heater in the corner. And so when an El Niño occurs, what it is doing, it is essentially the tropics are the heat engine. of global weather and climate. And it's a complete reconfiguration such that so much more of our global atmosphere [10:00] is exposed to that heat energy from the ocean that would have otherwise been buried in the western tropical Pacific. Does that make sense? That was an amazing answer. I understand something that I went 45 years without having any idea of, and now I get it. And as someone who used to live in a drafty New England home, I have a lot of experience with space heaters that only heat up that corner of the room. What are the conditions or what are the drivers such that... these El Ninos are semi-regular? Why do they seem to come every few years? Why are they not a permanent pattern? Why is one year an El Nino year and another year isn't? Yeah, there's a lot of work on kind of the drivers of the breakdown, right? of the winds in the Eastern Tropical Pacific. I think a simple answer is that we live on a sphere that's rotating and has stratified and unstratified fluids in the form of the ocean and the atmosphere. And that essentially means that energy is propagated as wave phenomena, right, with peaks and troughs. And El Nino is akin to a wave phenomena, right? It is kind of a pattern, what we call a mode of variability. George Philander, who is this Princeton geophysicist and major scholar of El Nino, called El Nino the trunk of the variability tree when it comes to climate variation in terms of kind of regulating these our planet. And so, you know, a phenomena like El Nino being modal, meaning it has a canonical pattern temporally and spatially, and then induces physical responses that we can characterize and use as a means of prediction, right? Like we know what we should expect for Peru. We know what we should expect for Australia. And we're able to do that because we've diagnosed this mode of it a name and characterized its length scales and characterized what we call its teleconnections, meaning the kind of physical bridge between El Nino as a phenomenon and what it implies for the Indian monsoon or for the Southwestern United States temperature and precipitation regime for that season. And we've given these things a name and they've become, they've instead of being purely a source of kind of stochastic uncertainty, just kind of random variation in weather and climate, they become a means of predictability. And that's what's really powerful about investigating these type of phenomena and giving them names. Right. We have El Nino or El Nino Southern Oscillation, which is the kind of teleconnection with the overlying atmosphere. We have the North Atlantic Oscillation. We have the Indian Ocean Dipole. We have the Matt and Juliet Oscillation. their kind of manifestation. And in terms of like their underlying drivers, which is, I think, the question you're asking, I think it's just a function mostly of living on a complex planet with geophysical fluid dynamics, such that these wave phenomena just kind of emerge on these characteristic timescales. The precise mechanism of action that kind of leads to the breakdown of of these easterly trade winds, which triggers what's called the Bjorkness feedback, which is this positive feedback loop, so an amplifying feedback that tends to reinforce itself, can come from myriad different places, from changes in ice cover to a weakening of the equator to pole temperature gradient. All kinds of different things have some culpability and potentially causing a breakdown of these winds that allow the sea surface temperatures to slosh eastward again and reconfigure all severe weather on our planet. So talk to us about what the forecast actually is for this particular El Nino, because I read these things like, apparently, the Australian Bureau of Meteorology, which would be interested in this because Australia is particularly affected by El Nino, apparently, the Relative Oceanic Nino Index... or Ronnie for short, apparently has never reached the 3.3 thresholds that they currently project before. So that seems extreme. What are what exactly are we expecting here? So there's a bunch of different ways to forecast El Nino. All of them kind of stem from some of the original innovative work in the late 70s and early 80s by Mark Kane and Steve Ziviak, who built the first kind of physical model of El Nino to explain it as a phenomenon and then actually make predictions of its occurrence, which is pretty remarkable. given kind of autocorrelation in that time series, what it should look like at time T plus one. [15:00] There are others that are physical models that are actually simulating the relationship between oceanic temperatures, winds, the overlying atmosphere, what it does to the kind of pressure and circulation that actually gets air moving in the first place. the 1877-1878 El Nino, which was associated with the Great Famines. And Mike Davis has this amazing book from 2002 about that El Nino event. That one, I think, is kind of indistinguishable in strength from El Nino as we've already had, such as the ones in 1982 and 83, the 97 and 98 El Nino, which of I am the El Nino, right? And the 2015 and 2016 El Nino, which I believe is the one on record depending on your indices. So we've had really strong El Ninos, but this one is looking like it's much bigger potentially. Every forecast right now, I believe, puts the unfolding El Nino because we are in an advisory and we have been since June, Administration's Climate Prediction Center. Essentially, you're looking at every forecast having a warmer El Nino than the 2016 El Nino. What if you could use AI to research your investment portfolio and ask, Find profitable mid-cap energy companies with growing cash flow. Which AI infrastructure stocks appear undervalued? Or rank stock opportunities based on valuation, growth, and risk. With interactive brokers, you can connect ChatGPT or Claude to your investment portfolio to research investments, analyze your holdings, and uncover potential undervalued opportunities. AI accelerates the research. You can make every investment decision. Open and fund an interactive broker's account in minutes at ibkr.com slash invest. Restrictions apply. AI integrations provided by third parties. IBKR does not verify content generated by AI platforms. From red carpets to cozy nights in, Chandler Kinney chose Minky Couture. She lit up Dancing with the Stars, stole scenes in Pretty Little Liars, and now when Chandler designed her dream blanket, she partnered with Minky Couture. Meet the limited edition Chandler Kinney collection at Minky Couture, featuring the aurora with colors that shimmer like the northern lights, and aqua serene, calm and dreamy like morning waves. Each blanket is crafted with Minky Couture's award-winning softness fabric in sizes from infant to grande. This is luxury you can feel, but only for a limited time. Shop the Chandler Kinney Collection now only at Minky Couture at MinkyCouture.com. M-I-N-K-Y Couture.com. AI is entering its most consequential phase where scale, safety, and sovereignty will determine who leads and who lags. Join Bloomberg Tech in London on November the defining trade-offs shaping the future of AI. Thank you to our presenting sponsor, Salesforce, and supporting sponsors, IDA Ireland and Schneider Electric. Learn more at bloomberglive.com slash techlondon. How did we actually discover El Nino as a weather phenomenon? Because it happens with some regularity, but it's not like it happens every three to four years, like right on time at the same intensity as the previous, you know, round. So how did people identify this as an actual measurable phenomenon? Yeah. In terms of the modern instrumental and climate science era, I don't actually know the answer to that. But I do know something that's actually, I'd argue, even more interesting. So the person who first modeled El Nino from a physics perspective, Mark Kane, this amazing geophysicist at Lamont Doherty Earth Observatory at Columbia University, and his colleagues, John Chang, another climate scientist there at the time, and then an anthropologist by the name of Ben Orloff, who is an anthropologist at Columbia, They wrote this incredible paper, I believe in Nature, back in the 90s or early aughts, where they essentially showed that there was really good archaeological evidence that Peruvian potato [20:00] as long as 500 years ago were forecasting El Nino. And they were doing it based on the visibility of the Pleiades, which is a star system you can see from the Andes. And essentially, as El Nino occurs, what it's doing is it's reconfiguring the distribution of high versus low clouds in the Eastern Tropical Pacific. It's essentially taking convection that was happening near Australasia and moving it eastward. And in doing so, you're creating all this, these kind of high cirrus cloud shields over the Andes, and that reduces the visibility of this, this star pattern. So they were for and they would alter their, their, their planting dates based on that. So there, there's just kind of this remarkable cultural knowledge of being able to grab onto something and be able to make a forecast and inform forecast. And so I'd argue there's a lot of cultural knowledge about these innate climate phenomena around the world that we have yet to kind of appreciate and diagnosed in the, in the highly industrialized world, instrumentation. Yeah, folk meteorology or folk weather is like extraordinary and like how much they're able to anticipate. I was sort of I was what you know, I imagine that there were probably various civilizations that interpret El Nino as like the king has lost the mandate of heaven. And now, you know, there's a drought. Now we have to have a new political order. Also, this Mike Davis book that you mentioned looks fascinating. It sort of speaks to the point of Making of the Third World, talking about subsequent famines in India, northern China, and northeastern Brazil. Definitely going to have to read that book. When we talk about a, quote, record El Nino, what is the measure? Is it the heat variation? Is it the expected change in rainfall or drought? Like, what are the sort of the gauges that we use to say this is a record El Nino or not, or measuring that? What are the parameters of an El Nino? My understanding is it's all benchmarked to the magnitude of the sea surface temperature anomaly. An anomaly is a departure from expectation or departure from normal. And so what constitutes normal becomes really important there for kind of setting the magnitude of how anomalous something is, right? And that's why, you know, when Tracy was talking about the relative Nino index, right, the Roni, right, that's kind of shifting a kind of a rolling baseline, because we have secular warming in the tropical Pacific owing to global warming that's occurring, right? As you heat up the planet, the largest reservoir of heat storage just happens to be the 70% volume of water that constitutes our planet's surface. And it takes a lot of energy to heat up. a volume of water. It's much more energy intensive to heat up a volume of water than it is an equivalent volume of air. So that specific heat is just much higher. So it's just a great energy reservoir and the ocean has been doing... humanity an incredible solid by absorbing all this excess heat, which is the problem of global warming, right? That we're not allowing our atmosphere to shed heat as efficiently as it otherwise would have been if greenhouse gases were lower in our atmosphere. And in doing so, we're having to heat up to reattain equilibrium such that the energy coming in from the sun is balanced by Earthlight leaving out to space. That is not in balance at the moment. And a lot That's how planetary temperatures increase such that in can equal out again. That's essentially a very simple global warming 101. But the way we're measuring El Nino as a phenomenon is by taking a regional average, so choosing an area in the tropical Pacific that is canonically associated with the manifestation of El Nino. And you can choose different regions and then benchmarking those average temperatures in this month to expectation. what have averages been over time. And so you can choose different regions. So there's a Nino 3 region, which is kind of shifted towards the Central Pacific. There's a Nino 4 region, which is shifted a bit more eastward. There's a Nino 3-4 region, which is kind of the typical region that's now used, which characterizes El Nino over something in between those two regions. Then there's the E-index, which is taking a dimension reduction technique on a spatial field of the dominant directions of variability in that field. And that E-index would kind of represent something differently in the sense that El Nino, while we think of it as a singular phenomenon, it has a geography associated with it. And that geography means that it has [25:00] favors associated with it. And so these flavors mean that different parts of the tropical Pacific warm differently. and look anomalously different. And so not every El Nino is the same. And so its consequences in terms of the hazard it brings for the United States or for hurricane occurrence in the Atlantic Basin or whatever, right, it's not the same for every El Nino event. The spatial pattern of the sea surface temperature anomalies also seems to matter. And so there's been a lot of work to capture some of that. So there are lots of different ways for measuring it, but it's always a sea surface temperature anomaly in degrees Celsius benchmark to some expectation or average of normal. So one of the things that Joe and I have learned in doing various agricultural episodes over the years is that when you have a supply shock, the timing matters, right? So you generally don't want to declare war in the spring planting season when all your soldiers might be off planting stuff instead. Does the timing of this particular El Nino matter? I keep reading that of this El Nino is expected to be in the fall in the Northern Hemisphere? Is that particularly unfortunate timing? There's been a lot of work that looks, the planting and harvest of crops tends to be something that is highly calendar dependent. And there's a bit of flexibility that I think farmers have to be responsive to their expectations for weather variability. And certainly ag forecasts have become important and agriculture at large has become really dependent on El Nino forecasts. in December, January, and February. So this is kind of the boreal, meaning the northern hemisphere winter. And that has implications for the austral summer, right, for the southern hemisphere summer, which is in the opposite season. And also, there's also kind of a time dependency associated with the impact. So let me just concretize this with an example. We've been in an El Nino advisory since June. That's also coincident with the typical onset of the South Asian monsoon, which is a and for billions of people, right? You can link monsoon onset to farmer well-being and farmer suicides. You can link the timing of monsoon onset to diesel prices within India and the political fates of people around diesel subsidies, because if the monsoon onset is delayed, you have a bunch of farmers suddenly needing to irrigate crops where they that rely on diesel fuel. And so you can see price spikes around those types of things and the political fortunes of like municipal and kind of local politicians kind of surviving or not surviving in elections based on those kinds of things. So there's like lots of cascading ways in which an El Nino, even at this early stage in its life cycle, which tends to kind of start after what we call the spring prediction barrier, which is kind of this period in time where it's difficult to make a prediction about whether or not an El Nino is going to occur to next February. So we're looking at kind of a wind down of this event in February, March of 2027. What's interesting about it is that it's going to lock in all sorts of phenomena. has a non-trivial chance of being the warmest year on record, not simply because of global warming, but because of this emerging El Nino. So it is already kind of just increasing. global temperatures over what they would have been in absence of this event. And it's nearly locked in a virtually guaranteed record temperature for 2027, even though we haven't actually had that year unfold yet. It's no coincidence that the hottest years on record have almost always been El Nino years, right? When you take a warming trend and then you impose an anomaly on top of that, you're just going to get these outliers. And so these impacts are arguably already manifesting. So the South Asian monsoon was delayed. That onset was delayed by this El Nino. And so while the kind of major teleconnections and the peak strength associated with this event is anticipated to be in the winter, which is typically the case associated with El Ninos and just kind of the its impacts are manifesting now and will continue to manifest into 2027. [30:00] Music. What does Drew Barrymore reach for at home? A Minky Couture blanket, the ultra soft throw that stops you mid-sentence. Featured on her show and loved in real life, Minky Couture wraps you in premium plush fabric, signature stretch, and award-winning craftsmanship. The blanket that turns every couch into your favorite seat in the house. Drew Barrymore's blanket, only at Minky Couture. Shop now at MinkyCouture.com. That's Minky, M-I-N-K-Y, Couture, C-O-U-T-U-R-E.com. The Bloomberg This Weekend Podcast. News, analysis, and the lighter side of Bloomberg. Including our weekly news quiz. Which edgy American mall staple is being sold to the parent company of Spencer's and Spirit Halloween? I wrote Claire's. That's not edgy. What are you talking about? This is a place David Gurra has never shopped in his life. Hot topic. The Bloomberg This Weekend Podcast. Subscribe today on Apple, Spotify, or wherever you listen. Thank you. Let's talk a little bit about the economic costs that we associate with an El Nino. Like I said, up until your first answer in this interview, I didn't know what an El Nino really was, but that certainly doesn't mean I've never said it or read it before. You know, I used to be on TV, you have a guest, he was like, oh, the upcoming El Nino. Joe is stroking his beard, pontificating about the El Nino. Yes. But it always seems like a sort of cyclical thing. It's like, and then it goes back to normal. But... If there are whole books about the long term consequences of any given El Nino, it sounds like at least in some serious ones, there can be quite a tale, quite a ripple effects. economy paid for it. Yeah, such a good question. I want to call out a key collaborator that I've had in this work, Chris Callahan, who's a professor at Indiana University and just a stellar, stellar scholar. I couldn't have asked for a better PhD student to get to think about these hard things with. that it's such an important part of year to year variation in weather and climate globally. And it's essentially unknowable, right? It's very hard to know what El Nino is going to look like in 2050, what it's going to look like in 2100, and how that picture changes as a function of what your background warming happens to be. One of the things we've been investigating is just, well, we kind of had pivoted from thinking about future to saying, well, we live in a world where global warming has already occurred. We can simply document, what has happened. And so much of what my lab group does here at Dartmouth is investigate retrospectively, kind of build that documentary evidence of here, how's Here are the costs of climate change to date. In thinking about the cost of climate change to date, one of the things you have to do is isolate those costs from the costs that would have happened anyway, such as the cost from El Nino, which is an innate form of climate variability. El Nino occurs in absence of people and their greenhouse gas emissions. And so isolating that cost and kind of partitioning it from the cost accounting of global warming today became a pretty important thing. exercise. So we're always in kind of detection and attribution science, trying to say, well, what is consistent with the world as it has been versus the world as it would have been absent global warming? And that means having a really clear picture of what we call internal climate variability, such as the variability from El Nino. And so we were interested in this cost accounting of El Nino, just to clarify the cost of global warming to date. And when we went back and did techniques. So this is all observationally built, right? We can take data of variation in El Nino, which is essentially a random treatment, right? It is stochastically generated while it has a life cycle against it. Our global economies aren't necessarily shaping sea surface temperature anomaly patterns in places like the tropical Pacific. Right. So it's effectively exogenous. Yeah. To our from our economy. Right. And so that's really crucial in this empirical setting of trying to identify, well, what's the effect of an El Nino on an economy and how [35:00] - That upward aggregate to a macroeconomic toll, What you can do is just take a bunch of data of something like gross domestic product, which is summarizing all economic productivity, goods and services produced by an economy. We have pretty good data on that for at the country scale for a pretty long amount of time. And you can look at differences in that. economic growth. So how did economic growth vary from year to year? So you're not looking at absolute levels of GDP, you're looking at changes in economic growth as embedded in changes in GDP. And then you can look at something like El Nino as a treatment. And then you have another source of variation, which is that not every country is equally linked to El Nino physically. El Nino is in that it generates many different kinds of physical hazards from heat waves to droughts to floods to landslides to wildfires, right? And so in that sense, like its impacts, interestingly, look a lot like the wider impacts from global warming, which is a worthy discussion in and of itself. But we'll put that to the side for a second. relates to the teleconnection, how tightly coupled a location's weather and climate is to El Nino as a phenomenon, and then see what accounts for the variation in economic productivity as measured in changes in GDP. And so that's what we did back in 2023 and published in a paper in Science, where we showed that actually we can detect very sizable deviations in economic growth from El Nino as a phenomenon, and that scales in teleconnection strength, meaning countries that are most influenced climatically and from a meteorological standpoint by the phenomenon of El Nino are most impacted and negatively so. So Peru with road washouts, disrupting commodities That shock doesn't seem to be what an economist might call a level effect, meaning a simple deviation that you then recover from in a subsequent year. What we find in this empirical research is that observationally, El Nino seems to systematically change. depressed growth, meaning your country is growing. at a rate, and then an El Nino occurs, and then you are growing on a different trajectory. And so those losses just accrue ad infinitum in time. And that is a distinct finding than what was previously understood about El Nino. Right. So this is really important. I think most people are used to thinking about weather-related shocks as the sort of short-term thing that, was that there's this longer term impact on essentially output, like growth in the longer term. Why is that? Like, what exactly is happening here? Because again, you would expect like, okay, a road gets washed out. It's probably inconvenient. It's probably expensive to replace, but it does get, you would think it does get replaced relatively quickly. And a lot of these negative effects would a yield loss owing to a heat wave or drought in one part of the upper midwest says nothing about major grain producing regions in russia or cotton prices given growth in the fergana valley in uzbekistan right like these these things are are disparate enough in space that maybe they're not experiencing simultaneous shock. What I think is kind of interesting about El Nino and why El Nino is an interesting analog for the impacts of wider global warming, which is a kind of a universally experienced, you know, there's a high degree of correlation in the impacts of global warming, right? It's not simply a heat wave here. It's a heat wave here, here, here, and here, all at the time, which is one of the reasons why I think it's this simultaneity. of disparate regions experiencing hazards and experiencing losses that then can lead to these up aggregating market forces that systematically depress growth and alter where capital investment can go. You know, the efficiency with which you're able to take labor and capital and mobilize it into productive partnerships. [40:00] to the economy. It is... hard to do that when there are lots of hazards being experienced around the world, right? So it's not one thing disrupting your supply chain. It's maybe a dozen things. And I think that's the was about $36 billion in economic losses estimated at the time as a level fact, a shock and then a recovery. What we actually found is that there was empirical evidence for a systematic depression of economic growth. And over a five-year period, that amounts to about $5.7 trillion in global economic losses instead by the year 2003, right? Five years after the 97-98 event. is we played this game where we use what's called a perfect model framework, where we simply ask the question if we know that the impact of El Nino is permanent and of this magnitude, given the observational data we have, could we prove that it's permanent? So these kinds of statistics rely on the ability to pull a signal from noise, which requires a certain amount of data. And that amount of data affects the claims you can make robustly. And so what we were trying to do there is say, even if we had a known effect, can we recover that known effect perfectly given our data record. And what we found is that we couldn't, which means that we cannot rule out the possibility that the economic impacts of El Nino at the global scale are permanent, meaning that every time an El Nino occurs, we're just knocked off our growth trajectory that would have been absent that event, which is kind of remarkable, which implies that these costs kind of accrue ad infinitum in time. In our paper, five and eight and 10 years of growth accounting. But it just says that the economic losses associated with these events are much higher than we understood before, which means, you know, it's just another kind of piece of evidence that shows that weather and climate matter for our economy and our climate system is endogenous. to that economic growth, right? It is greenhouse gas emissions induced by economic growth that is altering our trajectory of climate. And our climate also has a finger on the scale of what constitutes our economy. And so that endogeneity, I think, is something really important to understand and represent, particularly around policies related to climate variability and climate change. That was a fantastic answer. When you think about the impacts of this El Nino or the El Nino in the year 2050 or the El Nino in the year 2100, you know, so obviously, like, one, you Take a country like Peru. It's probably going to be richer in the year 2050, so it'll probably have more economic activity. It may also have better infrastructure in the year 2050, such that road washouts are less likely. How do you model that aspect, both the fact that, OK, there is more economic activity in the sort of temporally connected areas and also presumably governments and companies get better about anticipating the El Ninos and strengthening their infrastructure such that they're not as vulnerable? It turns out it's really hard, right? The predictions of future are not falsifiable. Yeah. And so I hope Peru's wealthier in 2050 and 2100. Yeah. I mean, yeah, we didn't even talk about the fisheries implications. Yeah. One thing that's really I think what you're you're kind of raising is this this question of adaptation and resiliency. And the way I've been thinking about that is evolving right there. There's a story we can tell. That says, OK, if there are market inefficiencies or we're shown to be vulnerable societally in these particular ways, we're going to develop strategies to ensure resilience. Right. Those Peruvian potato farmers noticed they were losing crops, you know, and they altered their sowing dates based on the visibility of the Pleiades overhead. Like that is an adaptation. And you can imagine autonomous adaptations, meaning individual level adaptations. or planned adaptations, such as shoring up kind of resilience. And these things are linked to El Nino forecasts, right? Like one of the things you're seeing, you know, you said at the outset, Tracy, of all these financial benefits. [45:00] planners thinking about the implications of El Nino for markets around the world and supply chains. That is a form of kind of resilience strategy building that that's occurring that is indelibly linked to the science of ENSO forecasting and why El Nino forecasts are so important. Right? The 1982-83 El Nino, we didn't have the benefit of a tremendous amount of lead time and planning for its impacts, right? a tropical cyclone off in the ocean right being able to track it and have sufficient time to get resources injected into the places you need and people out of harm's way right like that requires lead time which is why these types of forecasts are so essential because they allow us to to pursue resilient strategies that we otherwise wouldn't have been able to but this wider question of like Are we well adapted to climate variability we have? And shouldn't we expect that we'll be even better adapted to climate variability in the future. I would say the evidence is pretty mixed. There isn't a whole lot of evidence that we're well adapted to the climate we have. We are finding documenting observationally that the costs of El Nino are astounding. despite the fact that we've been exposed to it for hundreds and hundreds of years, right? This is not something that is novel, right? While the coming El Nino seems to be out of sample, and the costs associated with it are really hard to anticipate because it is so out of sample, right? Like, when I think about the cost of this forthcoming El Nino, I estimate somewhere around $10 trillion of global economic losses conservatively over the next five years, right? Up to $14 trillion of economic losses, if you take some of these tail. But only 70% of that, only about $10 trillion of that is in sample, meaning supported by existing data we have on El Nino's and economic responses. Our global economy is larger. And so these losses are associated not just with the magnitude of the El Nino, but the to be impacted. What that tells me is that we are not optimally adapted to the climate we have. And so there isn't much evidence that we have that we are taking on board the feedback we're getting from the climate system about how things are going and pursuing strategies that really offset or mitigate losses in a coherent way. I think that's pretty telling just given the adapted. I just think that we are not well adapted and there isn't widespread evidence of adaptation to either El Nino as a form of climate variability or wider global warming, since the impacts of global warming look a lot like the impacts of El Nino. And so I think there's like a bunch to kind of disentangle there. But when we're thinking about these future growth impacts from ENSO, would have been. apps in El Nino, but given global warming. And that is a picture of future that I think is really hard to envision. But there are economic tools that people use to create those those those counterfactual worlds. And then you can measure deviations, as could be the case, given what we know to be observationally true about the relationship between El Nino and an economy. I know you just said there aren't a lot of examples of successful adaptations for El Nino, other than perhaps Peruvian potato farmers sowing their crops early. But give us some hope here or some idea of what a successful adaptation could look like in an ideal scenario where this is an have it basically happening all around the world simultaneously. what could we do to try to offset some of the economic impact? Gosh, that's, you know, it's such a great question. One of the ways I think about this is there's improving resiliency in global markets such that these weather and climate shocks don't alter prices and interest rates and all these things that are huge determinants of human well-being. creating a road washout that is a massive disruption to communities there. A wildfire, you know, that rages through the bush in Australia, killing trillions of animals and raising insurance premiums on kind of wildfire protection for homes there, right? There are all these kind of ways you can process trace how El Nino [50:00] you know, hurts an individual or a community. And so I think that protection of human well-being from approximate sense of like, are you okay? given these hazards, that to me is a different question than how you shore up international markets such that they are resilient to the impacts of El Nino. And I think just separating them is really, really valuable. I think the fact that people are aware of El Nino as a phenomenon and that it can induce these cascading shocks through agriculture or through mining or through the transport sector, and that all those things all around the world can up aggregate to a And I don't know enough about how people think about these portfolios, but I know that risk diversification is a strategy to ensure returns. And I imagine that's something that people are embracing given modern portfolio theory or whatever. But I think this question of like, how do you protect people from hazard? That is a different question and requires different sets of warnings about the local manifestation of the hazards associated with El Nino. And to me, teams that are well placed and understand these consequences. That means that we have insurance markets that recognize the hazards, the unique geophysical hazards associated with something like El Nino and its regional dependencies and what it should imply for the types of products those people need to protect the most capital intensive asset they have, which is their home. It's many different kinds of things. And so none of this is out there. of the realm of possibility. There's a lot of these things we do anyway, right? We build reservoirs to mitigate drought risk already. Nevermind the fact that Lake Powell, the central bank of the American West water economy is at a near record low. He knows his audience. Anyway, I guess the point is, is that, you know, I think there are lots of, there's lots of evidence that we, these adaptations are within the realm of possibility, but the constellation and configuration And so I think kind of a coherent global strategy about managing the impacts of El Nino is an interesting test bed for adaptation strategies that would lend itself to wider global warming. And that's something that I'm really intrigued by. So you talk about this idea that what you've discovered through your research is that El Ninos are not these sort of cycles that you bounce back from in and then you resume to trend growth, right, that they change their trajectory. But if El Ninos are something that are very consistent and predictable throughout history, such that we've been, you know, there's evidence of farmers having tried to anticipate them going back over 500 years. Why should we not assume that You know, it's seasonal. Like you could say, for example, that. cold winter months depress economic growth, which they probably do. People don't go out as much and shop and travel as much in the middle of December. And so we could say, oh, if there were no Decembers, if it never got cold, then in the counterfactual, we would have had much higher growth, which is true, but also absurd because the premise of not having a winter is absurd. has always been with us. Why do we even imagine there being a counterfactual trend rate of growth in a world without El Nino's? Yeah, I think, you know, that comes back to the kind of empirical identification strategy. OK, like we don't have the benefit. of re-simulating the world as it has been and kind of the emergence of global society and the global economy absent El Nino. And so we rely on models to create those counterfactuals. We know that El Nino, while being cyclic in nature, it is not perfectly so. It is as good as a random treatment. And so we can separate the experience of the world into those associated with not. And we can examine the differences in economic productivity under those two regimes. So that's essentially what we're doing empirically. It's akin to a medical control trial, right, where you randomize a population into a treatment group that gets a drug and a control group that doesn't, right, or receives a placebo, and you compare medical outcomes, right? There are people that may look different in the treatment and control group. But if you randomized effectively those differences [55:00] among individuals. cancel out. And the kind of efficacy of the drug itself is just the difference between those two groups. El Nino is as good as randomly assigned, despite the fact that it is cyclic in nature. And so you can treat it as this natural experiment, this treatment, and compare it to the control of non-El Nino years. And that's effectively what we're doing here when we're kind of talking about this counterfactual, right? We know what economic productivity looks like. And so you're right to you know, economic productivity looks different in winter than in summer or in spring, right? And it looks different in the face of a tropical cyclone than it does in the face of, you know, a civil conflict or something else, right? Like these, these things have impacts. But what we're doing here is kind of exploiting natural stochastic variation in it, despite its cyclic nature. And impact. that El Niño is not a novel phenomenon. It is not something that we have never experienced before, which global warming is. Global warming is something humanity has never experienced and it is out of sample. And it is arguably making this El Nino that's unfolding, given the background warming, truly out of sample, truly out of sample events. something humanity got it has never experienced before. And I'm saying despite the fact that we should be inured to experiencing El Nino. We have limited evidence of widespread adaptation and resilience. All right, Justin Mankin, thank you so much for coming on Offlogs. Yeah, thanks for having me. Joe, I found that conversation fascinating. Love talking about the weather in all ways. It does come with some regularity. And yet there seems to be some proof that it has this lasting impact, not just on the immediate economy, but on economic growth itself is a very important one when you consider that, like, again, we're about to experience a potentially record-breaking El Nino and with the wider backdrop of climate change, right? that I really, oh, it gets warmer, or something like that. I didn't really know what it was, or why it was, or what direction. I thought it was really interesting, okay, what makes an El Nino different from another random weather event, the global simultaneity of it as being key. Like, okay, other events, you just bounce back from. I mean, everything must have some effect. You never like bounce back from anything that perfectly back to trend. But the simultaneity, of course, we saw that during COVID and the ripple effects from that. And so when you have this weather pattern that is truly global in nature and sort of very, I guess, predictable in the sense that you know what regions they're all going to get hit, it sort of makes sense to think about it in these terms of like, oh, especially if they're intensifying during a trend of global warming. Yeah, nowhere to run, nowhere to hide kind of idea. The other thing I was thinking, of course, back to some of our early agricultural episodes from this year, all of this is happening against a backdrop of higher fertilizer prices and lower supply. Like you still have, I think. 30%, 40%. I can't remember the exact numbers of global fertilizer supply stuck in... the Strait of Hormuz. And that can't be helpful either when you're talking about the biggest El Nino on record. Yeah, no, it's going to be a, well, now we are well-armed. Maybe we're not well-adapted for the El Nino. But we know about it. We are at least well-armed to understand news stories that will be emerging over the weeks and months. And the sell-side analysts. And the sell-side analysts notes in the months ahead. All right, shall we leave it there? Let's leave it there. This has been another episode of the Odd Thoughts Podcast. I'm Tracy Tracy Alloway. And I'm Jill Weisenthal. You can follow me at The Stalwart. Follow our producers, Carmen Rodriguez at Carmen Armand, Dashiell Bennett at Dashbot, Kale Brooks at Kale Brooks, and Kevin Lozano at Kevin Lloyd Lozano. And for more Odd Lots content, go to Bloomberg.com slash Odd Lots for the daily newsletter and all of our episodes. And you can chat about all these topics 24-7 in our Discord, discord.gg slash Odd Lots. 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