The paper below could imply that SRM would help avoid ocean anoxia. I personally believe that anoxia in a high carbon future could pose a serious risk of human extinction. I know of no comparable threat to species survival.
I think some specific modelling in this regard would be very helpful. It's a threshold we can't afford to cross, and therefore seems to offer a strong argument for geoengineering. A www.annualreviews.org/doi/abs/10.1146/annurev.earth.36.031207.124256 Oceanic Euxinia in Earth History: Causes and Consequences Annual Review of Earth and Planetary Sciences DOI: 10.1146/annurev.earth.36.031207.124256 Katja M. Meyer and Lee R. Kump Euxinic ocean conditions accompanied significant events in Earth history, including several Phanerozoic biotic crises. By critically examining modern and ancient euxinic environments and the range of hypotheses for these sulfidic episodes, we elucidate the primary factors that influenced the generation of euxinia. We conclude that periods of global warmth promoted anoxia because of reduced solubility of oxygen, not because of ocean stagnation. Anoxia led to phosphate release from sediments, and continental configurations with expansive nutrient-trapping regions focused nutrient recycling and increased regional nutrient buildup. This great nutrient supply would have fueled high biological productivity and oxygen demand, enhancing oxygen depletion and sulfide buildup via sulfate reduction. As long as warm conditions prevailed, these positive feedbacks sustained euxinic conditions. In rare, extreme cases, euxinia led to biotic crises, a hypothesis best supported by evidence from the end-Permian mass extinction. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
