从撒哈拉海到人造火山：巨型“地球工程”的利与弊

Core Viewpoint - Various geoengineering and technological revolutions are ultimately not reliable under the scrutiny of cost accounting [1] Group 1: Climate Change Strategies - According to Nobel laureate William Nordhaus, there are three main strategies to address global climate change: adaptation, geoengineering, and mitigation [2] - Adaptation involves learning to cope with a warming world rather than trying to prevent it, supported by those who oppose high-cost measures [2] - Geoengineering aims to counteract the greenhouse effect by introducing cooling factors, but lacks solid proof and may have dangerous side effects [2] - Mitigation focuses on emission reduction, considered the safest environmental solution but also the most expensive and difficult to implement in the short term [2] Group 2: Solar Radiation Management - A favored geoengineering project is solar radiation management, which aims to reflect sunlight and heat back into space to mitigate warming [3] - The concept is likened to the cooling effect observed after volcanic eruptions, such as the 1991 eruption of Mount Pinatubo, which lowered global temperatures by approximately 0.4°C [3] - Proposals include painting roofs and roads white or launching millions of small reflective particles into the atmosphere to increase planetary albedo [3] - Estimates suggest that reflecting 2% of solar energy could offset warming caused by CO2, with costs for such geoengineering potentially being 1/10 to 1/100 of mitigation measures [3] Group 3: Potential Side Effects of Geoengineering - Nordhaus warns of the potential side effects of geoengineering, noting that current models predict it cannot fully offset the greenhouse effect [4] - Increased atmospheric particles could lead to reduced rainfall and alter monsoon patterns in Asia and Africa [4] - He emphasizes the dual nature of geoengineering, which can be used for both beneficial and malicious purposes, highlighting the risk of "climate warfare" [4] Group 4: Historical Context of Geoengineering - Historical examples of geoengineering concepts, such as the "Sahara Sea Project" proposed in the 19th century, illustrate the long-standing ambition to manipulate climate [5][6] - The project aimed to connect salt lakes with the Mediterranean to create an inland sea, reflecting early concerns about climate change and desertification [6][8] - Although the Sahara Sea Project ultimately failed, it influenced future engineering ideas and highlighted the intersection of technology and colonialism [9] Group 5: Alternative Technological Innovations - Nordhaus points to carbon capture and storage (CCS) as a decentralized technology that could help mitigate climate change without large-scale geoengineering [11] - However, CCS faces challenges such as increased costs and the need for safe storage solutions for captured CO2 [12] - Other innovative ideas, like genetically engineered trees and molecular nanotechnology for solar energy, are discussed but remain uncertain in their feasibility and impact [13] Group 6: Conclusion on Geoengineering - Nordhaus concludes that various geoengineering and technological revolutions are not reliable solutions and should be viewed as emergency measures rather than primary strategies [14] - Effective management of emissions and international cooperation remain the main insurance against climate change [14]