成果展示
Tingting Jiao , Ellias Yuming Feng , Yongfu Li , Yajun Tian
Macroalgae can bio-sequester atmospheric CO2 into their biomass, thus it has been proposed and debated as a viable carbon dioxide removal strategy to mitigate climate change. We examine the carbon footprints of common macroalgae products through a “cradle-to-grave” life cycle assessment, and find carbon sequestration effect can only be accomplished by some specific macroalgae product types when they are properly stored rather than being used. We identify the product processing and usage stages in macroalgae’s life cycle contribute most carbon emissions, while the net primary production of macroalgae during growth only partially neutralizes its overall CO2 emissions. A sensitivity test for such life cycle model indicates employing clean energy and improving technical efficiency can potentially achieve net-zero for some macroalgae products e.g., biochar. However, even considering macroalgae’s ecological values, our profitability investigation concludes that macroalgae products for carbon sequestration are extremely unattractive to practitioners under current carbon pricing level.
Ellias Y. Feng, Yvonne Sawall, Marlene Wall, Mario Lebrato and Yao Fu
Artificial upwelling (AU) is a novel geoengineering technology that brings seawater from the deep ocean to the surface. Within the context of global warming, AU techniques are proposed to reduce sea surface temperature at times of thermal stress around coral reefs. A computationally fast but coarse 3D Earth System model (3.6° longitude × 1.8° latitude) was used to investigate the environmental impacts of hypothetically implemented AU strategies in the Great Barrier Reef, South China Sea, and Hawaiian regions. While omitting the discussion on sub-grid hydrology, we simulated in our model a water translocation from either 130 or 550 m depth to sea surface at rates of 1 or 50 m3 s–1 as analogs to AU implementation. Under the Representative Concentration Pathway 8.5 emissions scenario from year 2020 on, the model predicted a prevention of coral bleaching until the year 2099 when AU was implemented, except under the least intense AU scenario (water from 130 m depth at 1 m3 s–1). Yet, intense AU implementation (water from 550 m depth at 50 m3 s–1) will likely have adverse effects on coral reefs by overcooling the surface water, altering salinity, decreasing calcium carbonate saturation, and considerably increasing nutrient levels. Our result suggests that if we utilize AU for mitigating coral bleaching during heat stress, AU implementation needs to be carefully designed with respect to AU’s location, depth, intensity and duration so that undesirable environmental effects are minimized. Following a proper installation and management procedure, however, AU has the potential to decelerate destructive bleaching events and buy corals more time to adjust to climate change.
Yvonne Sawall, Moronke Harris, Mario Lebrato, Marlene Wall, Ellias Yuming Feng
Global warming is considered to be the most severe threat to coral reefs globally, which makes it important for scientists to develop novel strategies that mitigate the impact of warming on corals and associated habitats. Artificial upwelling of cooler deep water to the surface layer may be a possible mitigation/management tool. In this study, we investigated the effect of simulated artificial upwelling with deep water off Bermuda collected at 50 m (24°C) and 100 m (20°C) on coral symbiont biology of 3 coral species (Montastrea cavernosa, Porites astreoides, and Pseudodiploria strigosa) in a temperature stress experiment. The following treatments were applied over a period of 3 weeks: (i) control at 28°C (ii) heat at 31°C, (iii) heat at 31°C+ deep water from 50 m depth, and (iv) heat at 31°C+ deep water from 100 m depth. Artificial upwelling was simulated over a period of 25 min on a daily basis resulting in a reduction of temperature for 2 h per day and the following degree-heating-weeks: 5.7°C-weeks for ii, 4.6°C-weeks for iii and 4.2°C-weeks for iv. Comparative analysis of photosynthetic rate, chlorophyll-a concentration and zooxanthellae density revealed a reduction of heat stress responses in artificial upwelling treatments in 2 of the 3 investigated species, and a stronger positive effect of 100-m water than 50-m water. These results indicate that artificial upwelling could be an effective strategy to mitigate coral bleaching during heat stress events allowing corals to adjust to increasing temperatures more gradually. It will still be necessary to further explore the ecological benefits as well as potential ecosystem impacts associated with different artificial upwelling scenarios to carefully implement an effective in situ artificial upwelling strategy in coral reefs.
Ellias Yuming Feng, Bei Su and Andreas Oschlies
Ocean deoxygenation is a threat to marine ecosystems. We evaluated the potential of two ocean intervention technologies, that is, “artificial downwelling (AD)” and “artificial upwelling (AU),” for remedying the expansion of Oxygen Deficient Zones (ODZs). The model-based assessment simulated AD and AU implementations for 80 years along the eastern Pacific ODZ. When AD was simulated by pumping surface seawater to the 178–457 m-depth range of the ODZ, vertically integrated oxygen increased by up to 4.5% in the deployment region. Pumping water from 457 m depth to the surface (i.e., AU), where it can equilibrate with the atmosphere, increased the vertically integrated oxygen by 1.03%. However, both simulated AD and AU increased biological production via enhanced nutrient supply to the sea surface, resulting in enhanced export production and subsequent aerobic remineralization also outside of the actual implementation region, and an ultimate net decline of global oceanic oxygen.
E. Y. Feng, W. Koeve, D. P. Keller and A. Oschlies
The potential of coastal ocean alkalinization (COA), a carbon dioxide removal (CDR) climate engineering strategy that chemically increases ocean carbon uptake and storage, is investigated with an Earth system model of intermediate complexity. The CDR potential and possible environmental side effects are estimated for various COA deployment scenarios, assuming olivine as the alkalinity source in ice-free coastal waters (about 8.6% of the global ocean’s surface area), with dissolution rates being a function of grain size, ambient seawater temperature, and pH. Our results indicate that for a large-enough olivine deployment of small-enough grain sizes (10 μm), atmospheric CO2 could be reduced by more than 800 GtC by the year 2100. However, COA with coarse olivine grains (1000 μm) has little CO2 sequestration potential on this time scale. Ambitious CDR with fine olivine grains would increase coastal aragonite saturation Ω to levels well beyond those that are currently observed. When imposing upper limits for aragonite saturation levels (Ωlim) in the grid boxes subject to COA (Ωlim =3.4 and 9 chosen as examples), COA still has the potential to reduce atmospheric CO2 by 265 GtC (Ωlim =3.4) to 790 GtC (Ωlim =9) and increase ocean carbon storage by 290 Gt (Ωlim =3.4) to 913 Gt (Ωlim =9) by year 2100.
Ellias Y Feng, David P Keller, Wolfgang Koeve and Andreas Oschlies
Artificial ocean alkalinization (AOA) is investigated as a method to mitigate local ocean acidification and protect tropical coral ecosystems during a 21st century high CO2 emission scenario. Employing an Earth system model of intermediate complexity, our implementation of AOA in the Great Barrier Reef, Caribbean Sea and South China Sea regions, shows that alkalinization has the potential to counteract expected 21st century local acidification in regard to both oceanic surface aragonite saturation Ω and surface pCO2. Beyond preventing local acidification, regional AOA, however, results in locally elevated aragonite oversaturation and pCO2 decline. A notable consequence of stopping regional AOA is a rapid shift back to the acidified conditions of the target regions. We conclude that AOA may be a method that could help to keep regional coral ecosystems within saturation states and pCO2 values close to present-day values even in a high-emission scenario and thereby might ‘buy some time’ against the ocean acidification threat, even though regional AOA does not significantly mitigate the warming threat.
冯玉铭, 管长龙, 黄健
波浪破碎诱导生成的海盐粒子是海洋向大气输运无机盐的主要机制,海气界面的无机盐通量对于全球气候变化有重要影响。本文开展了实验室实验模拟海盐粒子生成实验,定量考察了温度和盐度对海盐粒子中离子质量分布的影响,揭示了初生海盐粒子中各离子的富集和亏损现象与温度和盐度的关系。基于实验室观测分析结果和推测假定,提出了1个既包含海面风速、又反映海表温度和海表盐度影响的海-气无机盐通量参数化方案。将此参数化方案应用于估计海盐粒子向大气输运的各种无机盐离子质量通量,并与传统方法估算结果进行了比对分析。
代表性发明专利
Yuming Feng; Vorrichtung zur Zuführung von Tiefenwasser in einen Flachwasserbereich, 2019-11-21, 欧洲发明专利, DE102018111970(A1)
出版著作
[1]素食主义的道德优越感从哪来? 新闻报道 观察者网 2021.12.21 专栏作者
[2]操控环保话语权，渗透气候类NGO，西方给中国设下多少气候陷阱。 新闻报道 环球时报 2021.11.18 专栏作者
[3]西方气候政治咄咄逼人，中国需要高技巧的科学外交。新闻报道 观察者网 2021.11.10 专栏作者
[4]全球变暖如何影响海洋生命？新研究发现——在历史暖期，海洋缺氧区竟曾缩小 新闻报道 科技日报 2022.10.22 采访嘉宾
[5]防范气候议题被泛安全化 新闻报道 环球时报 2022.9.14 专栏作者
[6]又要中国减碳又嫌中国高补贴，到底要怎样？新闻报道 观察者网 2023.3.3 专栏作者
[7]发展中国家应该对“航运排放税”说不 新闻报道 环球时报 2023.7.4 专栏作者
[8]欧洲绿色转型为什么不能少了中国 新闻报道 环球时报 2023.8.26 专栏作者
代表性课题
未来海洋科技基金Future Ocean Exzellenz Grant (德国科学基金会Deutsche Forschungsgemeinschaft ), “Could artificial upwelling prevent and mitigate coral bleaching?”(项目代码：CP1780), 合同额: 20万欧元, 2017.11-2019.10, 主持
联系方式 /You can find us at
电子邮箱/EMAIL
fengyuming@ouc.edu.cn
联系地址/LOCATION
山东省青岛市松岭路238号，中国海洋大学，工程学院 C312