Humans really are weird. Trying to replace a perfectly fine bio-machinery that developed over Thousands of years with their own steel junk. I dont see why anybody would prefer that gadget over a tree.
Can you plant a tree capable of capturing the same amount of CO2 as those algae in that small a space? How about “refilling” the tree if it happens to die?
Society doesn’t have to lock itself to a single solution for countless varied problems. If we’re talking about a long, empty walkway, or a park, then trees are a great solution. If we’re talking about a small space that must be kept free of obstructions, such as a bus stop, then a sack or box of phytoplankton is much better suited.
Your question isn’t entirely a hypothetical - this happened at the dawn of time, when photosynthetic life forms first evolved. First, it won’t ever happen again, no matter how good we get at scooping CO2 from the atmosphere. Second, the result is theoretically catastrophic for aerobic life forms, but it’s also a negative feedback loop, meaning it self corrects.
Catastrophic battery failure isn’t really any less likely than catastrophic power supply failure (conceptually. If you use a brandless grey power supply, results may vary).
While carcinisation does exist as a phenomenon, I believe all examples involve animals of the same order, i.e. it’s even less extreme than comparing a shark and a dolphin.
Right, great idea - let’s all just give up and jump from the top of a cliff headfirst into rocks. No, wait, what I meant is bad idea. Horrible, horrible idea.