[런천세미나] SEES COLLOQUIUM(2024.10.30)_김승규 교수(인천대학교 해양학과)

관리자l 2024-10-23l 조회수 96
일시 : 2024-10-30(수) 11:30 ~ 13:00
연사 : 김승규 교수
소속 : 인천대학교 해양학과
문의 : 02-880-6713
장소 : 25-1동 1층 국제회의실
Microplastics and the Earth Environment System: What We Know and What We Don't
 
Our planet, Earth, has evolved over its 4.6 billion years of history as a result of the continuous interactions among the geosphere, hydrosphere, atmosphere, and biosphere, leading to the current environmental conditions. As an integrated system in which each compartment is organically connected, Earth demonstrates that disturbances and changes in one sphere can trigger disruptions in other spheres, potentially causing long-term and irreversible changes. Plastics are recognized as a significant contributor to global systemic disturbances, positioning them as a major environmental issue alongside the pressing challenge of climate change. Consequently, intergovernmental negotiation meetings are underway with the aim of establishing an international treaty to combat plastic pollution by the end of this year. The outcomes of these negotiations are expected to entail comprehensive socio-economic changes in our society.
Plastics, first synthesized artificially in the late 1800s, have experienced exponential growth in production at an annual rate of 8% over the past 70 years, particularly following their commercial success in the 1950s. Despite their known persistence, plastics undergo weathering under typical environmental conditions, fragmenting into smaller particles known as microplastics or nanoplastics. The smaller the size, the easier it is for these particles to be transported and dispersed through ocean currents and wind. Consequently, microplastics have been found in a wide range of environments, from the summit of Mt. Everest to the depths of the Mariana Trench, and from the equatorial regions to the polar areas of the Arctic and Antarctic. When microplastics, with their small size (high specific surface area), exist in large quantities, their particulate nature can increase reactivity in various environmental media (geosphere, hydrosphere, atmosphere, and biosphere), potentially causing significant disturbances. Examples of such disturbances include the substantial release of greenhouse gases during production, processing, and decomposition; changes in microbial communities within soils, sediments, and seawater, leading to alterations in biogeochemical cycling of nutrients and dissolved/particulate organic matter; the disruption of the Earth’s radiative balance through their role as cloud condensation nuclei in the atmosphere; disturbances in air-sea gas exchange; and disruptions in the biological carbon pump in oceans and a decrease of ocean dissolved oxygen. These disturbances are related to changes at the Earth system level, manifesting in the long term and potentially causing irreversible changes. Therefore, the issue of microplastics should not be merely regarded as a pollutant but recognized as a significant factor contributing to global systemic disturbances.
Despite the scientific evidence suggesting that the 70-year history of plastics could disrupt the 4.6 billion-year history of the Earth system, there remains a significant amount of unknowns and uncertainties, leading to the propagation of often distorted truths. This presentation aims to discuss: 1) the history of plastics and humanity's response efforts, 2) the potential for microplastics to act as disruptors within the Earth environmental system, 3) the uncertainties in microplastics research and their underlying causes, 4) the research findings of the Incheon National University team aimed at addressing these uncertainties and future research directions, and 5) the attitudes of scientists learning from microplastics research.