Core Viewpoint - The article discusses the delayed color change of autumn leaves in Beijing, attributed to unfavorable weather conditions and plant diseases, with a notable improvement observed by the end of October [1][5][6]. Group 1: Weather Conditions - The optimal conditions for leaf color change include low temperatures and strong sunlight, which were lacking earlier in the season due to high temperatures and prolonged rainy weather [6][7]. - As of October 31, the weather began to clear, providing favorable conditions for the leaves to change color [6][10]. Group 2: Leaf Color Change Timing - The best viewing period for red leaves in Beijing is projected to be from late October to mid-November, with a one-week delay in color change compared to previous years [5][10]. - The peak viewing period for the iconic Fragrant Hills is from October 25 to November 15, with an expected 80% color change in certain tree species [5][10]. Group 3: Plant Health Issues - Observations indicate that some yellow leaves appear unhealthy, potentially due to two main diseases: powdery mildew and wilt disease, which affect the health and color of the leaves [9][10]. - The wilt disease is caused by a soil-borne fungus that has persisted in the soil for years, affecting the newly planted trees in Beijing [9][10]. Group 4: Diversity of Autumn Foliage - The article highlights that autumn foliage in Beijing is not limited to red leaves; various colors such as yellow, brown, and purple are also present, showcasing a rich diversity of plant species [10][12]. - Parks like the Olympic Forest Park and others feature a variety of colorful leaves, including ginkgo and white wax trees, contributing to the vibrant autumn scenery [12][13].

Core Insights - The value of fallen leaves extends beyond their natural beauty, serving as fertilizers, art pieces, and important ecological indicators [1][8] Group 1: Ecological Significance - Fallen leaves play a crucial role in the forest's material cycle, acting as a "long-lasting slow-release battery" that supports various microorganisms and enhances soil quality [4][6] - The process of leaf decomposition releases essential nutrients like nitrogen, phosphorus, and potassium, which are absorbed by tree roots, thus contributing to the ecosystem's nutrient cycle [4][6] - Research indicates that the timing and color changes of leaves provide valuable data for phenological studies, helping to assess the impact of climate change on ecosystems [6] Group 2: Economic Value - The National Botanical Garden processes approximately 20,000 cubic meters of green waste annually, converting it into about 4,000 cubic meters of high-quality organic matter, which is then used to improve soil fertility [5][6] - This process saves around 1 million yuan in fertilizer procurement and transportation costs, demonstrating a dual enhancement of ecological and economic value [6] Group 3: Cultural and Educational Aspects - Collecting fallen leaves has become a popular activity, allowing individuals to connect with nature and create art, such as bookmarks and collages, thus promoting environmental education [7][8] - The act of picking leaves is seen as a way to respect nature, emphasizing the importance of understanding the ecological roles of fallen leaves in different environments [7][8]

Core Insights - The value of fallen leaves extends beyond their natural beauty, representing a deep connection with nature and ecological wisdom [1][6] Group 1: Ecological Significance - Fallen leaves play a crucial role in the material cycle of forests, acting as a "long-lasting slow-release battery" that supports various organisms and contributes to nutrient cycling [3] - The decomposition of fallen leaves releases essential nutrients like nitrogen, phosphorus, and potassium, which are absorbed by tree roots, enhancing soil structure and promoting carbon storage [3] - The seasonal changes in leaf color and drop provide valuable data for phenological research, aiding in the understanding of climate change impacts on ecosystems [5] Group 2: Economic and Practical Applications - The National Botanical Garden has implemented a system to convert green waste, including fallen leaves, into high-quality organic matter, saving approximately 1 million yuan annually in fertilizer costs [4] - The processing of fallen leaves into organic resources not only promotes ecological sustainability but also enhances economic value through cost savings and resource efficiency [4] Group 3: Educational and Cultural Aspects - Collecting fallen leaves has become a popular activity that fosters a deeper appreciation for nature, leading to creative uses such as bookmarks and art [5] - Fallen leaves serve as excellent educational materials, allowing individuals to engage with the concepts of life cycles and ecological systems in a tangible way [5][6] - The act of collecting leaves should be done respectfully, particularly in protected ecological areas, to maintain the integrity of the ecosystem [6]

Core Insights - The World Meteorological Organization (WMO) reports a significant increase in global atmospheric CO2 concentration, reaching a record high of 423.9 ppm in 2024, an increase of 3.5 ppm from 2023 [1] - The report indicates a continuing acceleration in the annual growth rate of atmospheric CO2, which has quadrupled since the 1960s [1] - The last time CO2 levels were similar to current concentrations was 3 to 5 million years ago, before the emergence of humans [1] Group 1 - The three main causes for the sharp increase in CO2 concentration are ongoing fossil fuel emissions, rampant wildfires releasing large amounts of CO2, and a weakened carbon absorption capacity of global land and oceans [1] - Despite international calls for emissions reduction, fossil fuel emissions remain high, highlighting the urgent need to curb fossil fuel use [1] - The 2024 El Niño phenomenon is expected to exacerbate global temperatures and trigger extreme weather events, further impacting carbon absorption capabilities in critical regions like the Amazon [1] Group 2 - The WMO warns that excessive CO2 will continue to contribute to warming effects on Earth for centuries, leading to more frequent extreme weather events [2]

Core Insights - The article highlights the increasing frequency of extreme rainfall events in northern China, leading to significant damage and loss of life, challenging the traditional perception of the region as having low rainfall [1][2][3] Group 1: Extreme Weather Events - Northern regions, including Beijing and Hebei, have experienced unprecedented rainfall, with Beijing recording over 432.7 mm of rain since June 1, which is 75% more than the average for the same period [1] - The rainfall from July 23 to July 29 accounted for nearly 40% of the annual precipitation, indicating a shift in weather patterns [1] Group 2: Climate Change Impact - Meteorological experts attribute the increase in extreme rainfall to global climate change, with the West Pacific subtropical high pressure system becoming stronger and expanding northward [2] - The traditional belief that northern China experiences less rain is becoming outdated, necessitating a reevaluation of flood prevention strategies [2] Group 3: Flood Prevention and Safety Awareness - There is a pressing need to enhance public awareness of flood safety and to update flood prevention measures in response to the new normal of extreme weather [3][4] - Experts emphasize the importance of accurate weather forecasting and the need for communities to adopt a proactive approach to disaster preparedness [3][5] Group 4: Infrastructure and Policy Recommendations - Urban planners and local governments are urged to rethink flood control standards and implement resilient city designs to cope with extreme weather [6] - Recommendations include improving monitoring and early warning systems for localized extreme weather events and enhancing regional collaboration for effective disaster response [6]

Core Viewpoint - The effectiveness of REDD+ projects, aimed at reducing emissions from deforestation and degradation, has been questioned recently, leading to a decline in the value of carbon offsets [2][6]. Group 1: REDD+ Project Analysis - A study published in the journal Science analyzed 52 REDD+ projects across 12 countries in South America, Africa, and Southeast Asia, finding that only 19% of these projects met their self-reported emission reduction targets [3][6]. - The study indicates that while the climate benefits of REDD+ projects are higher than previous assessments, the overall effectiveness remains low, with significant regional variations in project success [6][7]. - The research highlights a concerning issue of "over-crediting," where the number of carbon credits issued exceeds the actual emissions reductions achieved [6][7]. Group 2: Recommendations for Improvement - To enhance the credibility and impact of forest carbon offsets, the study suggests improving baseline setting methods and strengthening verification frameworks [7]. - The findings emphasize that while many REDD+ projects are not as effective as claimed, some have achieved tangible results, particularly in Brazil and Africa [7].

【环球时报特约记者 晨阳】近年来全球极端天气频发，已经引起各国科学界的广泛关注。根据美国国 家航空航天局（NASA）卫星观测数据作出的最新报告显示，在过去20年间，地球反射太阳光的能力明 显下降，也就是通俗所说的"全球变暗"，可能将进一步加剧全球气候变化带来的影响。 美国Discovery杂志网站7日称，20多年来，地球一直在缓慢变暗。研究人员对NASA云和地球辐射能量 系统（CERES）24年间收集到的统计数据进行分析后发现，地球逐渐变暗的原因是地球反射的阳光减 少，其中北半球的变暗更为显著。"尽管地球表面反射的太阳光只发生了微小的变化，却在悄无声息地 改变地球的气候平衡。" 据介绍，早在20世纪90年代，科学家就发现了"全球变暗"的现象。造成这种变化的原因很多，当时更受 关注的因素是太阳辐射的逐年减少。统计显示，从20世纪50年代到90年代，美国地表接收到的太阳能量 下降了10%，苏联地区的降幅则高达30%。2005年，《科学》杂志发表的一篇论文称，从1990年开始， 持续数十年的"全球变暗"过程宣告结束，地球表面日趋明亮。 联合国政府间气候变化专门委员会（IPCC）第四次评估报告（2007）中也表示：" ...

"全球气温形势基本保持不变，陆地和海洋表面温度持续居高不下。" 9日，欧盟气候监测机构哥白尼气候变化服务局表示，刚刚过去的9月是全球有纪录以来第三热的9月，平均地表气温为16.11°C， 比 1991~2020年9月平均气温高出0.66°C。 具体而言，2025年9月比有纪录以来最热的2023年9月低0.27°C，仅比2024年9月低0.07°C。 该机构气候战略负责人伯吉斯（Samantha Burgess）表示："2025年9月的全球气温是有纪录以来第三高的9月，几乎与2024年9月 持平，但比2024年9月低了不到十分之一度。一年过去了，全球气温形势基本保持不变，陆地和海洋表面温度持续居高不下，反 映出温室气体在大气中积累的持续影响。" 只有西欧部分地区的气温低于平均水平，通常比平均水平低不到1°C。 在欧洲以外，加拿大、格陵兰岛部分地区、西伯利亚最西北部及其邻近沿海地区以及南极洲大部分地区的气温高于平均水平。 全球范围内，仅有西伯利亚中北部、澳大利亚西部和南极洲东部部分地区出现明显的负温异常。 9月全球同热 哥白尼气候变化服务局的数据显示，2025年9月的温度比用于定义工业化前水平的1850-1900 ...

Core Insights - The successful completion of China's 15th Arctic scientific expedition marks a significant achievement in enhancing the country's understanding of the rapidly changing Arctic environment and its implications for global climate change [1][3][5] Group 1: Expedition Overview - The expedition involved the "Snow Dragon 2," "Polar," "Deep Sea One," and "Explorer Three" vessels, making it China's largest Arctic scientific investigation to date [5] - The "Deep Sea One" vessel successfully conducted China's first manned deep dive in the Arctic ice zone using the "Jiaolong" manned submersible [5] Group 2: Scientific Contributions - The expedition achieved important progress in multi-disciplinary investigations and collaborative observations in the Arctic, enhancing the capability for synchronous monitoring of the Arctic Ocean [3] - The research revealed significant variations in benthic organism density, biodiversity, and individual size across spatial ranges of tens to hundreds of kilometers, providing insights into the spatial distribution patterns of polar deep-sea organisms and the impact of climate change on deep-sea ecosystems [5]

Core Viewpoint - The article highlights the successful return of the "Xuelong 2" icebreaker from the 15th Arctic scientific expedition, marking China's largest Arctic scientific investigation to date [1] Group 1 - The "Xuelong 2" icebreaker, carrying 100 members of the 15th Arctic scientific expedition team, returned to Shanghai on September 26 [1] - The expedition was organized by the Ministry of Natural Resources and involved four vessels: "Xuelong 2," "Jidi," "Deep Sea One," and "Exploration Three" [1] - This Arctic investigation was part of the national key research and development plan, enhancing China's understanding of the rapidly changing Arctic and its impacts [1] Group 2 - The findings from this expedition provide significant support for understanding and effectively responding to global climate change [1]