Collaborative Research: Probing Causal Links Among Volcanism, Dust, and Carbon Burial in the Permian - a Harbinger of the Future?

人类对地球的气候系统进行了一次无意的实验，导致大气中的碳增加到人类从未经历过的水平。气候系统现在正在以明显的方式作出反应，积极反馈的触发将加速变化，对整个生物圈，特别是人类构成巨大风险。对潜在失控效应的日益关注促使人们谈论有意的地球工程，以稳定地球的温度和大冰盖。一个经常讨论的方法是太阳辐射管理（SRM），故意注入大气气溶胶，以模拟由爆发性火山活动自然引起的行星阴影。然而，这种行动的意外后果仍然未知，并可能引发对生物圈更大的破坏。该项目的目标是类似于今天的地球历史间隔-一个大的大陆冰盖和丰富的大气尘埃，然后是“温室”变暖的时间-探索地球的气候和生物圈系统如何应对持续的爆炸性火山活动。 这项研究将测试一系列假设，这些假设的核心思想是，3亿年前赤道盘古超大陆上频繁的爆发性火山活动增加了大气尘埃中微量营养素（如铁）的供应，从而增强了植物的生长和海洋生态系统中广泛缺氧的发展。最近的研究记录了大量积累的尘埃沉积物~300 Mya，这些尘埃的微量营养素含量显着升高，但神秘，以及丰富的爆发性火山活动，特别是在赤道纬度。火山活动、大气尘埃和营养反应的汇合被认为极大地影响了地球的碳循环，从而影响了气候和生物圈。如果社会开始有意的地球工程，那么必须从地球的过去中学习，以了解未来的潜在后果。除了通过出版和传播结果来揭示气候系统的行为外，该项目还将帮助一些学生和早期职业研究人员为STEM劳动力做好准备，提高国家的科学和教育能力。这项工作从两个方面探索气候系统行为的新方面：1.重复的、高频率的爆发性火山活动在直接影响地球气候方面的作用，以及2-将爆发性火山活动与矿物粉尘释放的营养物质以及影响碳循环的生态系统施肥联系起来。为了测试这一点，现场和实验室工作将在一个暴露良好的部分火山岩代表一个巨大的火山活动中心在古赤道泛大陆;火山复发间隔和硫负荷的数据将被收集，并在营养丰富的同时代矿物尘埃。这些数据将能够模拟火山活动如何影响气候，1-直接“遮蔽”地球，2-改变大气酸度，刺激灰尘的微量营养素含量，从而破坏海洋生态系统。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

Humanity has undertaken an unintentional experiment on Earth’s climate system, causing atmospheric carbon to increase to levels never before experienced by humans. The climate system is now responding in palpable ways, and the triggering of positive feedbacks will accelerate changes, posing large risks to the biosphere in general and human populations in particular. Increasing concerns of potential runaway effects have spurred talk of intentional geoengineering to stabilize Earth’s temperatures, and its large ice sheets. A commonly discussed approach is solar radiation management (SRM), the intentional injection of atmospheric aerosols to mimic the planetary shading induced naturally by explosive volcanism. However, the unintended consequences of such action remain unknown, and could initiate even larger disruptions of the biosphere. This project targets an interval of Earth history analogous to today— a time with large continental ice sheets and abundant atmospheric dust followed by “greenhouse” warming— to explore how Earth’s climate and biospheric systems responded to sustained explosive volcanism. This research will test a number of hypotheses centered on the idea that frequent, explosive volcanism over the equatorial Pangean supercontinent ~300 million years ago increased delivery of micronutrients (e.g. iron) from atmospheric dust, leading to enhanced plant growth and development of widespread anoxia in marine ecosystems. Recent research documents large accumulations of dust deposits ~300 Mya, a remarkably elevated but enigmatic micronutrient content of these dusts, and abundant explosive volcanism, especially at equatorial latitudes. The confluence of volcanism, atmospheric dustiness, and nutrient reactivity is posited to have greatly affected Earth’s carbon cycle, and thus climate and biosphere. If society embarks upon intentional geoengineering, it is imperative to learn from Earth’s past to understand potential future consequences. In addition to shedding light on behavior of the climate system through publication and dissemination of results, this project will help prepare several students and early-career researchers for the STEM workforce, enhancing the nation’s capabilities in science and education.This work explores novel aspects of climate-system behavior in two ways: 1— the role of repeated, high-frequency explosive volcanism in affecting Earth’s climate directly, and 2— linkages that tie explosive volcanism to enhanced nutrient release from mineral dusts and consequent ecosystem fertilization that affects the carbon cycle. To test this, field and laboratory work will be done on a well-exposed section of volcanic rocks representative of a vast center of volcanism in paleoequatorial Pangea; data will be collected on volcanic recurrence intervals and sulfur loading, and on the nutrient richness of coeval mineral dusts. These data will enable modeling of how this volcanism affected climate by both 1— direct “shading” of the planet, and 2— altering atmospheric acidity, stimulating micronutrient content of dust and thus fertilizing marine ecosystems. OU Geosciences and Science Education faculty will prepare and deliver long-term professional development for Oklahoma teachers, to increase climate science literacy amongst secondary school students.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.