答案，或许就藏在那条看不见的400毫米等降水量线里。 如今的天气不仅越来越热，北方的雨水也悄悄变多了。 以前每到"七下八上"（7月下旬至8月上旬）汛期，咱们都盯着长江、珠江这些南方河流防涝。 可现在，洪涝灾害居然频频出现在过去少见雨的北方。 就在今年夏天，连宁夏同心、青海化隆这些常年难见几滴雨的地方，也接连打破暴雨纪录。 这反常的天气背后，到底藏着什么原因？ 降水北移不是偶然 先介绍下这个"400毫米等降水量线"究竟是怎么回事。 这其实是中国地理上一条至关重要的分界线，大致沿大兴安岭—张家口—兰州—拉萨—喜马拉雅山脉东部延伸，将全国分为东南与西北两大区域。 "400毫米等降水量线"是半湿润区与半干旱区分界线 同时，这条线也是半湿润区与半干旱区的气候分界线，其东南侧降水丰沛，以森林植被和农耕经济为主；西北侧降水较少，通常以草原植被和 畜牧业为主。 更为关键的是，该线与著名的胡焕庸线（中国人口密度分界线）高度重合，其东南侧约38%的国土面积上承载了全国约96%的人口，自古也是农耕文明与 游牧文明的边际线。 百年不变的胡焕庸线 过去近一千年，它基本没怎么动过，哪块地能种粮、哪块地适合放牧，早就被框定好了。 对比19 ...

报告说，今年9月，全球海洋表面平均温度为20.72摄氏度，为有记录以来同月的第三高；北太平洋 大部分海域的海表温度显著高于同期平均水平，部分海域创下历史新高；北极海冰范围较同期平均水平 低12%，南极海冰范围较同期平均水平低5%。 欧洲中期天气预报中心气候战略负责人萨曼莎·伯吉斯说，2025年9月全球气温为有记录以来第三 高，仅比2024年9月低不到0.1摄氏度。"时隔一年，全球气温形势几乎未变，陆地和海洋表面温度依然 持续偏高，反映出温室气体在大气中持续积累所带来的影响。" 新华社布鲁塞尔10月9日电 （记者 丁英华 张馨文）欧盟气候监测机构哥白尼气候变化服务局9日发 布报告说，全球刚刚经历了该机构自1940年有记录以来第三热的9月。 报告显示，今年9月全球平均地表气温为16.11摄氏度，比2023年和2024年同月的全球平均地表气温 分别低0.27摄氏度和0.07摄氏度，但仍较工业化前（1850年至1900年）的平均水平高出1.47摄氏度。 ...

Core Viewpoint - The Iranian President has stated that due to the worsening water crisis, urban expansion, and ground subsidence, Iran has no choice but to relocate its capital from Tehran to the south of the country [3][5]. Group 1: Water Crisis - The Iranian President highlighted that Tehran, Karaj, and Qazvin are currently facing a severe water crisis that is not easily resolvable [5][8]. - Last year's rainfall was only 140mm, which is about 60% lower than the standard rainfall of 260mm, indicating a significant decline in water availability [7][8]. - The cost of transporting water to Tehran could reach up to 4 euros per cubic meter, emphasizing the urgent need for a change in approach to water management [7][8]. Group 2: Urban Expansion and Ground Subsidence - Tehran has developed into a city with over 10 million inhabitants, consuming nearly a quarter of Iran's total water resources [8]. - Ground subsidence is a critical issue, with some areas sinking by 30 centimeters annually, indicating a depletion of underground water resources [7][8]. - The President's remarks suggest that merely accepting the current situation without planning for the future is insufficient [5]. Group 3: Historical Context and Future Planning - There have been long-standing discussions about relocating the capital to the Persian Gulf coast, where water resources are less strained [8]. - The current President is the first to view the relocation as an unavoidable necessity, despite previous criticisms of such proposals [5][8].

Core Viewpoint - The Iranian President, Pezeshkian, announced the necessity of relocating the capital from Tehran to the southern region of the country due to severe urban expansion, worsening water shortages, and increasing ground subsidence threats [1][3]. Group 1: Urban Expansion and Water Crisis - Pezeshkian emphasized that the current resource crisis in Iran is urgent, necessitating the relocation of the capital, despite previous criticisms of such proposals [3]. - Tehran, Karaj, and Qazvin are currently facing a severe water crisis, which is not easily resolvable [3]. - The region of Hormozgan, located along the Persian Gulf, is seen as a more viable option for relocation due to better access to water resources and trade opportunities [3]. Group 2: Climate and Environmental Challenges - The rainfall in Iran has significantly decreased, with last year's rainfall recorded at 140 mm, compared to a standard of 260 mm, indicating a decline of approximately 50% to 60% [5][6]. - Ground subsidence in Tehran is alarming, with some areas sinking by 30 cm annually, indicating a critical depletion of water resources [6]. - Tehran's population exceeds 10 million, consuming nearly one-quarter of Iran's total water resources, exacerbating the water crisis [6]. Group 3: Historical Context and Future Planning - Iran has been exploring the idea of relocating the capital to the Persian Gulf coast for a long time, as water supply issues are less severe in that region [6]. - Pezeshkian is the first Iranian president to view the relocation of the capital as an unavoidable choice, highlighting the urgency of the situation [6].

Core Viewpoint - Iran's President Pezeshkian announced the necessity of relocating the capital from Tehran to the southern region due to urban expansion, worsening water shortages, and increasing ground subsidence threats [1][3]. Group 1: Urban Expansion and Resource Crisis - The President emphasized that the current resource crisis in Iran is urgent, necessitating a shift in development strategy towards the Persian Gulf region [3]. - Tehran, Karaj, and Qazvin are facing severe water shortages that are not easily resolvable [3]. Group 2: Water Shortage Statistics - Last year's rainfall was recorded at 140 millimeters, significantly below the standard of 260 millimeters, indicating a decrease of approximately 50% to 60% [5][6]. - The cost of transporting water to Tehran could reach up to 4 euros per cubic meter, highlighting the financial burden of the water crisis [6]. Group 3: Ground Subsidence Issues - Ground subsidence in some areas of Tehran is reported to be as severe as 30 centimeters per year, indicating a critical depletion of water resources [6]. - Tehran has developed into a city with over 10 million inhabitants, consuming nearly one-quarter of Iran's total water resources [6]. Group 4: Historical Context and Future Plans - Iran has been exploring the idea of relocating the capital to the Persian Gulf coast for a long time, as water supply issues are less severe in that region [6]. - Pezeshkian is the first Iranian president to view the relocation of the capital as an unavoidable choice, despite previous criticisms of similar proposals [6].

编辑丨王多鱼 排版丨水成文 近日，的 一篇研究文章登上了 登上了 Cell Press 官网头条。 该论文题为 ： Global flux of perfluoroalkyl acids from glaciers in a warming climate （气候变暖背景 下冰川中全氟烷基酸的全球通量 ） ，论文于 2025 年 9 月 19 日在线发表于 Cell 子刊 One Earth 上， 通讯作者为中国科学院 青藏高原研究所 王小萍 研究员、 中国科学院生态环境研究中心 傅建捷 研究员。 该研究评估了气候变暖背景下 全球冰川中的 全氟烷基酸 （PFAA） 通量，确定了包括北极、南亚和中亚在 内的主要的 PFAA 释放热点， 强调了在管理历史遗留污染物和气候缓解方面采取协调行动的紧迫性。 全氟烷基酸 （PFAA） 是一种工业污染物，它们在全球范围内循环，并在包括 冰川 在内的寒冷地区积累 。 PFAA 对生态和人类健康构成重大风险，且具有极强的持久性。 全球气候变暖 正在加速冰川融化，释放出多年来被冰川封存的人造化学物质，其中就包括全氟烷基酸 （PFAA） 。 尽管全球都在努力控制 PFAA 的排放， ...

Core Insights - The article discusses the significant changes observed in the Arctic Ocean, particularly the accelerated melting of sea ice and the expansion of the "ice edge zone" during China's 15th Arctic scientific expedition [1][2]. Group 1: Changes in the Arctic Ocean - The Arctic Ocean is experiencing rapid sea ice melting, with more water ponds observed compared to 15 years ago, indicating faster and more extensive ice loss [1][2]. - The "ice edge zone," defined as areas with 15% to 80% sea ice coverage, has expanded both northward and in high-latitude regions, reflecting rapid changes in the Arctic ecosystem [1][2]. Group 2: Scientific Significance of the Expedition - The expedition, conducted by multiple vessels, marks China's largest Arctic scientific investigation, showcasing the country's enhanced polar research capabilities [2][3]. - The data collected during the expedition provides critical insights into the Arctic ecosystem's response mechanisms to climate change, contributing to a deeper understanding of global warming's impacts [2][3]. Group 3: Technological Innovations and Methodologies - The expedition utilized advanced unmanned survey equipment for comprehensive "air-ice-ocean" observations, significantly improving data collection efficiency [3][4]. - Innovative methodologies included deploying multiple ecological landers and various sampling techniques to gather extensive data on the "ice edge zone," supporting future research on Arctic ecosystem evolution [3][4]. Group 4: Broader Implications - The findings from the expedition are crucial for understanding the implications of Arctic environmental changes on climate security, navigation safety, and sustainable development for China [4][5]. - The expedition's success in utilizing new technologies and collaborative efforts signifies a shift in China's Arctic research from a following role to a more competitive position in the field [4][5].

Core Insights - Chinese scientists have discovered a new "chemical switch" that controls global climate through subtle changes in ocean sulfate concentrations, which can alter the consumption of seabed methane [1][4] - The study highlights the potential reactivation of this switch due to rapid warming and freshening of the Arctic Ocean, necessitating close monitoring [1][4] Group 1: Research Findings - Methane is the second-largest greenhouse gas after carbon dioxide, with significant amounts stored as hydrates ("flammable ice") on the seabed [3] - Recent studies indicate that most seabed-released methane dissolves in seawater and is consumed by microorganisms, rather than directly entering the atmosphere [3][4] - The research team reconstructed historical carbon dioxide levels in the Arctic Ocean, revealing that 56 million years ago, the region's CO2 concentration was higher than the global average, indicating a shift from a carbon sink to a carbon source [4] Group 2: Implications - The study suggests that a lack of sulfate in the past led to inefficient methane utilization, resulting in increased carbon dioxide emissions, akin to a power plant operating under fuel shortages [4] - The findings serve as a warning that changes in the Arctic's chemical environment could lead to a similar scenario as 56 million years ago, where methane transitions from efficient use to rapid combustion, exacerbating climate change [4]

这是 2023 年 7 月 25 日从 " 雪龙 2" 号极地科考破冰船拍摄的北极圈内的浮冰。新华社记者 魏弘毅 摄 中国科学家于北京时间25日在国际学术期刊《自然·地球科学》发表的论文显示，海洋硫酸盐浓度 的微妙变化，能够改变海底甲烷的消耗方式，就像一个控制全球气候的"化学开关"。随着现代北极海洋 快速变暖和淡化，类似的开关可能被再次激活，需要密切关注。 研究团队基于北极海洋浮游植物"分子化石"重建的二氧化碳浓度显示，5600万年前北极海洋的二氧 化碳浓度水平比全球平均值高，这说明北极海洋从原本吸收二氧化碳的"海绵"变成了排放二氧化碳 的"烟囱"。 研究人员表示，该研究提醒，当北极海水变淡、化学环境改变时，可能重演5600万年前的故事，即 甲烷从高效利用转向快速燃烧，并加剧气候变化，需要密切关注。 该研究由中国科学院广州地球化学研究所与国际合作团队完成。研究人员表示，在5600万年前的超 级变暖事件中，地球经历了极端的全球变暖和海洋酸化。由于该事件与当前气候变化存在诸多相似，一 直备受科学界关注。然而，其背后的碳循环机制，特别是北极海洋发挥的作用始终是未解之谜。 据介绍，甲烷是仅次于二氧化碳的第二大温室气体 ...

每经记者｜杨弃非 每经编辑｜何小桃 根据现有报道，这条航线仅需18天就能从宁波港到达英国，远低于此前经苏伊士运河的海上运输通道所需的40余天，即便同样从浙江城市出发，经中欧班 列中线抵达欧洲也需20余天。 中欧班列正是上一轮中欧运输变革的"发起者"。从2011年中欧铁路国际贸易大通道首次全线贯通，到去年，中欧班列已形成西、中、东三条国内通道与 北、中、南三线并行境外通道网络多向延伸、海陆互联的格局。不仅有128个城市开通中欧班列，成都、重庆、西安等西部城市也由内陆腹地不断走向开 放前沿。 眼下，北极航道正成为全球发展的焦点，其意义远不止于时空的跨越，从更大的视角来看，还将进一步完善我国对外开放格局，特别是为中欧快捷高效、 安全平稳运输提供新的支撑。 聚焦于此次先行一步的中欧北极快航，其将带来何种影响？又能否再一次改写全国城市开放格局？ 1 北极航道的一举一动，均牵动全球目光。 在中欧北极快航通航的前几天，外交部举行例行记者会上，外媒记者发问：如何评论北方海路对中国的作用？外交部新闻发言人林剑表示，近年来，国际 社会更加关注北极航道的利用前景，北极航道有潜力成为国际贸易的重要路线。 北极航道发展，迎来重要节点。 ...