I don't know, are you familiar with carbon capture rates for algae? It's a good point and one to explore: trees/plants vs. algae for carbon capture. If you could make a modular system of tiles (say 10' x 10') comprised of carbon capturing method of choice (algae pools, trees), would it make sense to install these on buildings in cities (or anywhere, but suggest cities because that is certainly where such things do not exist at scale anymore) (then consider fabrication and maintenance costs)? I have no idea what the solution is to the carbon capture problem, but increases opportunities for carbon capture seems like a high level solution.