Large-scale geoengineering has the potential for unexpected consequences that could seriously damage the environment. This applies to olivine mining and desert

Large-scale geoengineering has the potential for unexpected consequences that could seriously damage the environment. This applies to olivine mining and desert flooding. Personally, I think a good compromise lies in resorting to algal blooms in a controlled setting. Algal blooms have another advantage: there is already hypertrophication around farming regions where water bodies are polluted with fertilizers. So the ideia is to build artificial reservoirs as buffers for algal blooms that not only pollute the water, jam irrigation systems and decrease biodiversity, but also as a means for carbon fixation. The algae would then have to be harvested, processed and buried. A fraction of it could be used to produce biofuels, thus reducing the need for fossil fuels, and for fertilization, which would reduce the usage of artificial, carbon-releasing fertilizers. My only doubt is whether the scalability is interesting enough.