Seems great, but I see four foreseeable problems.<p>1) These greenhouses are enclosed spaces with reduced airflow compared to outside. We release respiratory droplets when we talk, cough, or sneeze, among other things. These respiratory droplets can remain in the air (if it is stagnant) for 8-14 minutes, according to one study. [1] Another study claims that SARS-CoV-2 was viable in droplets released 3 hours earlier. [2] There could be an unintended consequence here. Asymtompatic people will visit restaurants and could infect people who go inside the greenhouse after the infected person has left droplets carrying SARS-CoV-2 in the greenhouse which the next customers would inhale.<p>2) Many restaurants have limited frontage. Some with narrow pavements would struggle to fit any/very many of these greenhouses, especially in cities.<p>3) How much would these cost to make?<p>4) Have you sat in a greenhouse in the sun before?<p>Please prove me wrong. I'd love to see this work (and eat out again).<p>[1] <a href="https://www.pnas.org/content/early/2020/05/12/2006874117?mod=article_inline" rel="nofollow">https://www.pnas.org/content/early/2020/05/12/2006874117?mod...</a><p>[2] <a href="https://www.nejm.org/doi/10.1056/NEJMc2004973" rel="nofollow">https://www.nejm.org/doi/10.1056/NEJMc2004973</a>