Discuss real solutions for cities to overcome the crisis, through efficient fiscal and environmental actions. In tax terms, an intelligent, sustainable and cyclical taxation, Smart "Tax" City, linked to an environmental taxation, strengthening local taxation, property taxation, technology taxation and technology for taxation. In environmental terms, the analysis and recognition of the concept of One Health, which considers public health as a balance between human health, animal health and the environment. Greenhouse gas emissions during the lockdown significantly decreased, which changed satellite images and raised questions about the measures taken against climate change. Sustainability is now a key factor in productive processes and business practices as the financial market overestimated the so-called green bonds, securities that finance sustainable projects using the raised funds.